Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

62 files changed, 20553 insertions, 0 deletions

diff --git a/src/common/.gitignore b/src/common/.gitignore
new file mode 100644
index 0000000..ffa3284
--- /dev/null
+++ b/src/common/.gitignore
@@ -0,0 +1 @@
+/kwlist_d.h
diff --git a/src/common/Makefile b/src/common/Makefile
new file mode 100644
index 0000000..880722f
--- /dev/null
+++ b/src/common/Makefile
@@ -0,0 +1,194 @@
+#-------------------------------------------------------------------------
+#
+# Makefile
+#    Makefile for src/common
+#
+# These files are used by the Postgres backend, and also by frontend
+# programs.  These files provide common functionality that isn't directly
+# concerned with portability and thus doesn't belong in src/port.
+#
+# This makefile generates three outputs:
+#
+#	libpgcommon.a - contains object files with FRONTEND defined,
+#		for use by client applications
+#
+#	libpgcommon_shlib.a - contains object files with FRONTEND defined,
+#		built suitably for use in shared libraries; for use
+#		by frontend libraries
+#
+#	libpgcommon_srv.a - contains object files without FRONTEND defined,
+#		for use only by the backend
+#
+# IDENTIFICATION
+#    src/common/Makefile
+#
+#-------------------------------------------------------------------------
+
+subdir = src/common
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+
+# don't include subdirectory-path-dependent -I and -L switches
+STD_CPPFLAGS := $(filter-out -I$(top_srcdir)/src/include -I$(top_builddir)/src/include,$(CPPFLAGS))
+STD_LDFLAGS := $(filter-out -L$(top_builddir)/src/common -L$(top_builddir)/src/port,$(LDFLAGS))
+override CPPFLAGS += -DVAL_CC="\"$(CC)\""
+override CPPFLAGS += -DVAL_CPPFLAGS="\"$(STD_CPPFLAGS)\""
+override CPPFLAGS += -DVAL_CFLAGS="\"$(CFLAGS)\""
+override CPPFLAGS += -DVAL_CFLAGS_SL="\"$(CFLAGS_SL)\""
+override CPPFLAGS += -DVAL_LDFLAGS="\"$(STD_LDFLAGS)\""
+override CPPFLAGS += -DVAL_LDFLAGS_EX="\"$(LDFLAGS_EX)\""
+override CPPFLAGS += -DVAL_LDFLAGS_SL="\"$(LDFLAGS_SL)\""
+override CPPFLAGS += -DVAL_LIBS="\"$(LIBS)\""
+
+override CPPFLAGS := -DFRONTEND -I. -I$(top_srcdir)/src/common $(CPPFLAGS)
+LIBS += $(PTHREAD_LIBS)
+
+# If you add objects here, see also src/tools/msvc/Mkvcbuild.pm
+
+OBJS_COMMON = \
+	archive.o \
+	base64.o \
+	checksum_helper.o \
+	config_info.o \
+	controldata_utils.o \
+	d2s.o \
+	encnames.o \
+	exec.o \
+	f2s.o \
+	file_perm.o \
+	file_utils.o \
+	hashfn.o \
+	ip.o \
+	jsonapi.o \
+	keywords.o \
+	kwlookup.o \
+	link-canary.o \
+	md5_common.o \
+	pg_get_line.o \
+	pg_lzcompress.o \
+	pgfnames.o \
+	psprintf.o \
+	relpath.o \
+	rmtree.o \
+	saslprep.o \
+	scram-common.o \
+	string.o \
+	stringinfo.o \
+	unicode_norm.o \
+	username.o \
+	wait_error.o \
+	wchar.o
+
+ifeq ($(with_ssl),openssl)
+OBJS_COMMON += \
+	protocol_openssl.o \
+	cryptohash_openssl.o \
+	hmac_openssl.o
+else
+OBJS_COMMON += \
+	cryptohash.o \
+	hmac.o \
+	md5.o \
+	sha1.o \
+	sha2.o
+endif
+
+# A few files are currently only built for frontend, not server
+# (Mkvcbuild.pm has a copy of this list, too).  logging.c is excluded
+# from OBJS_FRONTEND_SHLIB (shared library) as a matter of policy,
+# because it is not appropriate for general purpose libraries such
+# as libpq to report errors directly.
+OBJS_FRONTEND_SHLIB = \
+	$(OBJS_COMMON) \
+	fe_memutils.o \
+	restricted_token.o \
+	sprompt.o
+OBJS_FRONTEND = \
+	$(OBJS_FRONTEND_SHLIB) \
+	logging.o
+
+# foo.o, foo_shlib.o, and foo_srv.o are all built from foo.c
+OBJS_SHLIB = $(OBJS_FRONTEND_SHLIB:%.o=%_shlib.o)
+OBJS_SRV = $(OBJS_COMMON:%.o=%_srv.o)
+
+# where to find gen_keywordlist.pl and subsidiary files
+TOOLSDIR = $(top_srcdir)/src/tools
+GEN_KEYWORDLIST = $(PERL) -I $(TOOLSDIR) $(TOOLSDIR)/gen_keywordlist.pl
+GEN_KEYWORDLIST_DEPS = $(TOOLSDIR)/gen_keywordlist.pl $(TOOLSDIR)/PerfectHash.pm
+
+all: libpgcommon.a libpgcommon_shlib.a libpgcommon_srv.a
+
+distprep: kwlist_d.h
+
+# libpgcommon is needed by some contrib
+install: all installdirs
+	$(INSTALL_STLIB) libpgcommon.a '$(DESTDIR)$(libdir)/libpgcommon.a'
+	$(INSTALL_STLIB) libpgcommon_shlib.a '$(DESTDIR)$(libdir)/libpgcommon_shlib.a'
+
+installdirs:
+	$(MKDIR_P) '$(DESTDIR)$(libdir)'
+
+uninstall:
+	rm -f '$(DESTDIR)$(libdir)/libpgcommon.a'
+	rm -f '$(DESTDIR)$(libdir)/libpgcommon_shlib.a'
+
+libpgcommon.a: $(OBJS_FRONTEND)
+	rm -f $@
+	$(AR) $(AROPT) $@ $^
+
+#
+# Shared library versions of object files
+#
+
+libpgcommon_shlib.a: $(OBJS_SHLIB)
+	rm -f $@
+	$(AR) $(AROPT) $@ $^
+
+# Because this uses its own compilation rule, it doesn't use the
+# dependency tracking logic from Makefile.global.  To make sure that
+# dependency tracking works anyway for the *_shlib.o files, depend on
+# their *.o siblings as well, which do have proper dependencies.  It's
+# a hack that might fail someday if there is a *_shlib.o without a
+# corresponding *.o, but there seems little reason for that.
+%_shlib.o: %.c %.o
+	$(CC) $(CFLAGS) $(CFLAGS_SL) $(CPPFLAGS) -c $< -o $@
+
+#
+# Server versions of object files
+#
+
+libpgcommon_srv.a: $(OBJS_SRV)
+	rm -f $@
+	$(AR) $(AROPT) $@ $^
+
+# Because this uses its own compilation rule, it doesn't use the
+# dependency tracking logic from Makefile.global.  To make sure that
+# dependency tracking works anyway for the *_srv.o files, depend on
+# their *.o siblings as well, which do have proper dependencies.  It's
+# a hack that might fail someday if there is a *_srv.o without a
+# corresponding *.o, but it works for now.
+%_srv.o: %.c %.o
+	$(CC) $(CFLAGS) $(subst -DFRONTEND,, $(CPPFLAGS)) -c $< -o $@
+
+# generate SQL keyword lookup table to be included into keywords*.o.
+kwlist_d.h: $(top_srcdir)/src/include/parser/kwlist.h $(GEN_KEYWORDLIST_DEPS)
+	$(GEN_KEYWORDLIST) --extern $<
+
+# Dependencies of keywords*.o need to be managed explicitly to make sure
+# that you don't get broken parsing code, even in a non-enable-depend build.
+keywords.o keywords_shlib.o keywords_srv.o: kwlist_d.h
+
+# The code imported from Ryu gets a pass on declaration-after-statement,
+# in order to keep it more closely aligned with its upstream.
+RYU_FILES = d2s.o f2s.o
+RYU_OBJS = $(RYU_FILES) $(RYU_FILES:%.o=%_shlib.o) $(RYU_FILES:%.o=%_srv.o)
+
+$(RYU_OBJS): CFLAGS += $(PERMIT_DECLARATION_AFTER_STATEMENT)
+
+# kwlist_d.h is in the distribution tarball, so it is not cleaned here.
+clean distclean:
+	rm -f libpgcommon.a libpgcommon_shlib.a libpgcommon_srv.a
+	rm -f $(OBJS_FRONTEND) $(OBJS_SHLIB) $(OBJS_SRV)
+
+maintainer-clean: distclean
+	rm -f kwlist_d.h
diff --git a/src/common/archive.c b/src/common/archive.c
new file mode 100644
index 0000000..d733212
--- /dev/null
+++ b/src/common/archive.c
@@ -0,0 +1,121 @@
+/*-------------------------------------------------------------------------
+ *
+ * archive.c
+ *	  Common WAL archive routines
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/archive.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/archive.h"
+#include "lib/stringinfo.h"
+
+/*
+ * BuildRestoreCommand
+ *
+ * Builds a restore command to retrieve a file from WAL archives, replacing
+ * the supported aliases with values supplied by the caller as defined by
+ * the GUC parameter restore_command: xlogpath for %p, xlogfname for %f and
+ * lastRestartPointFname for %r.
+ *
+ * The result is a palloc'd string for the restore command built.  The
+ * caller is responsible for freeing it.  If any of the required arguments
+ * is NULL and that the corresponding alias is found in the command given
+ * by the caller, then NULL is returned.
+ */
+char *
+BuildRestoreCommand(const char *restoreCommand,
+					const char *xlogpath,
+					const char *xlogfname,
+					const char *lastRestartPointFname)
+{
+	StringInfoData result;
+	const char *sp;
+
+	/*
+	 * Build the command to be executed.
+	 */
+	initStringInfo(&result);
+
+	for (sp = restoreCommand; *sp; sp++)
+	{
+		if (*sp == '%')
+		{
+			switch (sp[1])
+			{
+				case 'p':
+					{
+						char	   *nativePath;
+
+						/* %p: relative path of target file */
+						if (xlogpath == NULL)
+						{
+							pfree(result.data);
+							return NULL;
+						}
+						sp++;
+
+						/*
+						 * This needs to use a placeholder to not modify the
+						 * input with the conversion done via
+						 * make_native_path().
+						 */
+						nativePath = pstrdup(xlogpath);
+						make_native_path(nativePath);
+						appendStringInfoString(&result,
+											   nativePath);
+						pfree(nativePath);
+						break;
+					}
+				case 'f':
+					/* %f: filename of desired file */
+					if (xlogfname == NULL)
+					{
+						pfree(result.data);
+						return NULL;
+					}
+					sp++;
+					appendStringInfoString(&result, xlogfname);
+					break;
+				case 'r':
+					/* %r: filename of last restartpoint */
+					if (lastRestartPointFname == NULL)
+					{
+						pfree(result.data);
+						return NULL;
+					}
+					sp++;
+					appendStringInfoString(&result,
+										   lastRestartPointFname);
+					break;
+				case '%':
+					/* convert %% to a single % */
+					sp++;
+					appendStringInfoChar(&result, *sp);
+					break;
+				default:
+					/* otherwise treat the % as not special */
+					appendStringInfoChar(&result, *sp);
+					break;
+			}
+		}
+		else
+		{
+			appendStringInfoChar(&result, *sp);
+		}
+	}
+
+	return result.data;
+}
diff --git a/src/common/base64.c b/src/common/base64.c
new file mode 100644
index 0000000..b3ade2a
--- /dev/null
+++ b/src/common/base64.c
@@ -0,0 +1,242 @@
+/*-------------------------------------------------------------------------
+ *
+ * base64.c
+ *	  Encoding and decoding routines for base64 without whitespace.
+ *
+ * Copyright (c) 2001-2021, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/base64.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/base64.h"
+
+/*
+ * BASE64
+ */
+
+static const char _base64[] =
+"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static const int8 b64lookup[128] = {
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
+	52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
+	-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
+	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
+	-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
+};
+
+/*
+ * pg_b64_encode
+ *
+ * Encode into base64 the given string.  Returns the length of the encoded
+ * string, and -1 in the event of an error with the result buffer zeroed
+ * for safety.
+ */
+int
+pg_b64_encode(const char *src, int len, char *dst, int dstlen)
+{
+	char	   *p;
+	const char *s,
+			   *end = src + len;
+	int			pos = 2;
+	uint32		buf = 0;
+
+	s = src;
+	p = dst;
+
+	while (s < end)
+	{
+		buf |= (unsigned char) *s << (pos << 3);
+		pos--;
+		s++;
+
+		/* write it out */
+		if (pos < 0)
+		{
+			/*
+			 * Leave if there is an overflow in the area allocated for the
+			 * encoded string.
+			 */
+			if ((p - dst + 4) > dstlen)
+				goto error;
+
+			*p++ = _base64[(buf >> 18) & 0x3f];
+			*p++ = _base64[(buf >> 12) & 0x3f];
+			*p++ = _base64[(buf >> 6) & 0x3f];
+			*p++ = _base64[buf & 0x3f];
+
+			pos = 2;
+			buf = 0;
+		}
+	}
+	if (pos != 2)
+	{
+		/*
+		 * Leave if there is an overflow in the area allocated for the encoded
+		 * string.
+		 */
+		if ((p - dst + 4) > dstlen)
+			goto error;
+
+		*p++ = _base64[(buf >> 18) & 0x3f];
+		*p++ = _base64[(buf >> 12) & 0x3f];
+		*p++ = (pos == 0) ? _base64[(buf >> 6) & 0x3f] : '=';
+		*p++ = '=';
+	}
+
+	Assert((p - dst) <= dstlen);
+	return p - dst;
+
+error:
+	memset(dst, 0, dstlen);
+	return -1;
+}
+
+/*
+ * pg_b64_decode
+ *
+ * Decode the given base64 string.  Returns the length of the decoded
+ * string on success, and -1 in the event of an error with the result
+ * buffer zeroed for safety.
+ */
+int
+pg_b64_decode(const char *src, int len, char *dst, int dstlen)
+{
+	const char *srcend = src + len,
+			   *s = src;
+	char	   *p = dst;
+	char		c;
+	int			b = 0;
+	uint32		buf = 0;
+	int			pos = 0,
+				end = 0;
+
+	while (s < srcend)
+	{
+		c = *s++;
+
+		/* Leave if a whitespace is found */
+		if (c == ' ' || c == '\t' || c == '\n' || c == '\r')
+			goto error;
+
+		if (c == '=')
+		{
+			/* end sequence */
+			if (!end)
+			{
+				if (pos == 2)
+					end = 1;
+				else if (pos == 3)
+					end = 2;
+				else
+				{
+					/*
+					 * Unexpected "=" character found while decoding base64
+					 * sequence.
+					 */
+					goto error;
+				}
+			}
+			b = 0;
+		}
+		else
+		{
+			b = -1;
+			if (c > 0 && c < 127)
+				b = b64lookup[(unsigned char) c];
+			if (b < 0)
+			{
+				/* invalid symbol found */
+				goto error;
+			}
+		}
+		/* add it to buffer */
+		buf = (buf << 6) + b;
+		pos++;
+		if (pos == 4)
+		{
+			/*
+			 * Leave if there is an overflow in the area allocated for the
+			 * decoded string.
+			 */
+			if ((p - dst + 1) > dstlen)
+				goto error;
+			*p++ = (buf >> 16) & 255;
+
+			if (end == 0 || end > 1)
+			{
+				/* overflow check */
+				if ((p - dst + 1) > dstlen)
+					goto error;
+				*p++ = (buf >> 8) & 255;
+			}
+			if (end == 0 || end > 2)
+			{
+				/* overflow check */
+				if ((p - dst + 1) > dstlen)
+					goto error;
+				*p++ = buf & 255;
+			}
+			buf = 0;
+			pos = 0;
+		}
+	}
+
+	if (pos != 0)
+	{
+		/*
+		 * base64 end sequence is invalid.  Input data is missing padding, is
+		 * truncated or is otherwise corrupted.
+		 */
+		goto error;
+	}
+
+	Assert((p - dst) <= dstlen);
+	return p - dst;
+
+error:
+	memset(dst, 0, dstlen);
+	return -1;
+}
+
+/*
+ * pg_b64_enc_len
+ *
+ * Returns to caller the length of the string if it were encoded with
+ * base64 based on the length provided by caller.  This is useful to
+ * estimate how large a buffer allocation needs to be done before doing
+ * the actual encoding.
+ */
+int
+pg_b64_enc_len(int srclen)
+{
+	/* 3 bytes will be converted to 4 */
+	return (srclen + 2) * 4 / 3;
+}
+
+/*
+ * pg_b64_dec_len
+ *
+ * Returns to caller the length of the string if it were to be decoded
+ * with base64, based on the length given by caller.  This is useful to
+ * estimate how large a buffer allocation needs to be done before doing
+ * the actual decoding.
+ */
+int
+pg_b64_dec_len(int srclen)
+{
+	return (srclen * 3) >> 2;
+}
diff --git a/src/common/checksum_helper.c b/src/common/checksum_helper.c
new file mode 100644
index 0000000..431e247
--- /dev/null
+++ b/src/common/checksum_helper.c
@@ -0,0 +1,232 @@
+/*-------------------------------------------------------------------------
+ *
+ * checksum_helper.c
+ *	  Compute a checksum of any of various types using common routines
+ *
+ * Portions Copyright (c) 2016-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		  src/common/checksum_helper.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/checksum_helper.h"
+
+/*
+ * If 'name' is a recognized checksum type, set *type to the corresponding
+ * constant and return true. Otherwise, set *type to CHECKSUM_TYPE_NONE and
+ * return false.
+ */
+bool
+pg_checksum_parse_type(char *name, pg_checksum_type *type)
+{
+	pg_checksum_type result_type = CHECKSUM_TYPE_NONE;
+	bool		result = true;
+
+	if (pg_strcasecmp(name, "none") == 0)
+		result_type = CHECKSUM_TYPE_NONE;
+	else if (pg_strcasecmp(name, "crc32c") == 0)
+		result_type = CHECKSUM_TYPE_CRC32C;
+	else if (pg_strcasecmp(name, "sha224") == 0)
+		result_type = CHECKSUM_TYPE_SHA224;
+	else if (pg_strcasecmp(name, "sha256") == 0)
+		result_type = CHECKSUM_TYPE_SHA256;
+	else if (pg_strcasecmp(name, "sha384") == 0)
+		result_type = CHECKSUM_TYPE_SHA384;
+	else if (pg_strcasecmp(name, "sha512") == 0)
+		result_type = CHECKSUM_TYPE_SHA512;
+	else
+		result = false;
+
+	*type = result_type;
+	return result;
+}
+
+/*
+ * Get the canonical human-readable name corresponding to a checksum type.
+ */
+char *
+pg_checksum_type_name(pg_checksum_type type)
+{
+	switch (type)
+	{
+		case CHECKSUM_TYPE_NONE:
+			return "NONE";
+		case CHECKSUM_TYPE_CRC32C:
+			return "CRC32C";
+		case CHECKSUM_TYPE_SHA224:
+			return "SHA224";
+		case CHECKSUM_TYPE_SHA256:
+			return "SHA256";
+		case CHECKSUM_TYPE_SHA384:
+			return "SHA384";
+		case CHECKSUM_TYPE_SHA512:
+			return "SHA512";
+	}
+
+	Assert(false);
+	return "???";
+}
+
+/*
+ * Initialize a checksum context for checksums of the given type.
+ * Returns 0 for a success, -1 for a failure.
+ */
+int
+pg_checksum_init(pg_checksum_context *context, pg_checksum_type type)
+{
+	context->type = type;
+
+	switch (type)
+	{
+		case CHECKSUM_TYPE_NONE:
+			/* do nothing */
+			break;
+		case CHECKSUM_TYPE_CRC32C:
+			INIT_CRC32C(context->raw_context.c_crc32c);
+			break;
+		case CHECKSUM_TYPE_SHA224:
+			context->raw_context.c_sha2 = pg_cryptohash_create(PG_SHA224);
+			if (context->raw_context.c_sha2 == NULL)
+				return -1;
+			if (pg_cryptohash_init(context->raw_context.c_sha2) < 0)
+			{
+				pg_cryptohash_free(context->raw_context.c_sha2);
+				return -1;
+			}
+			break;
+		case CHECKSUM_TYPE_SHA256:
+			context->raw_context.c_sha2 = pg_cryptohash_create(PG_SHA256);
+			if (context->raw_context.c_sha2 == NULL)
+				return -1;
+			if (pg_cryptohash_init(context->raw_context.c_sha2) < 0)
+			{
+				pg_cryptohash_free(context->raw_context.c_sha2);
+				return -1;
+			}
+			break;
+		case CHECKSUM_TYPE_SHA384:
+			context->raw_context.c_sha2 = pg_cryptohash_create(PG_SHA384);
+			if (context->raw_context.c_sha2 == NULL)
+				return -1;
+			if (pg_cryptohash_init(context->raw_context.c_sha2) < 0)
+			{
+				pg_cryptohash_free(context->raw_context.c_sha2);
+				return -1;
+			}
+			break;
+		case CHECKSUM_TYPE_SHA512:
+			context->raw_context.c_sha2 = pg_cryptohash_create(PG_SHA512);
+			if (context->raw_context.c_sha2 == NULL)
+				return -1;
+			if (pg_cryptohash_init(context->raw_context.c_sha2) < 0)
+			{
+				pg_cryptohash_free(context->raw_context.c_sha2);
+				return -1;
+			}
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * Update a checksum context with new data.
+ * Returns 0 for a success, -1 for a failure.
+ */
+int
+pg_checksum_update(pg_checksum_context *context, const uint8 *input,
+				   size_t len)
+{
+	switch (context->type)
+	{
+		case CHECKSUM_TYPE_NONE:
+			/* do nothing */
+			break;
+		case CHECKSUM_TYPE_CRC32C:
+			COMP_CRC32C(context->raw_context.c_crc32c, input, len);
+			break;
+		case CHECKSUM_TYPE_SHA224:
+		case CHECKSUM_TYPE_SHA256:
+		case CHECKSUM_TYPE_SHA384:
+		case CHECKSUM_TYPE_SHA512:
+			if (pg_cryptohash_update(context->raw_context.c_sha2, input, len) < 0)
+				return -1;
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * Finalize a checksum computation and write the result to an output buffer.
+ *
+ * The caller must ensure that the buffer is at least PG_CHECKSUM_MAX_LENGTH
+ * bytes in length. The return value is the number of bytes actually written,
+ * or -1 for a failure.
+ */
+int
+pg_checksum_final(pg_checksum_context *context, uint8 *output)
+{
+	int			retval = 0;
+
+	StaticAssertStmt(sizeof(pg_crc32c) <= PG_CHECKSUM_MAX_LENGTH,
+					 "CRC-32C digest too big for PG_CHECKSUM_MAX_LENGTH");
+	StaticAssertStmt(PG_SHA224_DIGEST_LENGTH <= PG_CHECKSUM_MAX_LENGTH,
+					 "SHA224 digest too big for PG_CHECKSUM_MAX_LENGTH");
+	StaticAssertStmt(PG_SHA256_DIGEST_LENGTH <= PG_CHECKSUM_MAX_LENGTH,
+					 "SHA256 digest too big for PG_CHECKSUM_MAX_LENGTH");
+	StaticAssertStmt(PG_SHA384_DIGEST_LENGTH <= PG_CHECKSUM_MAX_LENGTH,
+					 "SHA384 digest too big for PG_CHECKSUM_MAX_LENGTH");
+	StaticAssertStmt(PG_SHA512_DIGEST_LENGTH <= PG_CHECKSUM_MAX_LENGTH,
+					 "SHA512 digest too big for PG_CHECKSUM_MAX_LENGTH");
+
+	switch (context->type)
+	{
+		case CHECKSUM_TYPE_NONE:
+			break;
+		case CHECKSUM_TYPE_CRC32C:
+			FIN_CRC32C(context->raw_context.c_crc32c);
+			retval = sizeof(pg_crc32c);
+			memcpy(output, &context->raw_context.c_crc32c, retval);
+			break;
+		case CHECKSUM_TYPE_SHA224:
+			retval = PG_SHA224_DIGEST_LENGTH;
+			if (pg_cryptohash_final(context->raw_context.c_sha2,
+									output, retval) < 0)
+				return -1;
+			pg_cryptohash_free(context->raw_context.c_sha2);
+			break;
+		case CHECKSUM_TYPE_SHA256:
+			retval = PG_SHA256_DIGEST_LENGTH;
+			if (pg_cryptohash_final(context->raw_context.c_sha2,
+									output, retval) < 0)
+				return -1;
+			pg_cryptohash_free(context->raw_context.c_sha2);
+			break;
+		case CHECKSUM_TYPE_SHA384:
+			retval = PG_SHA384_DIGEST_LENGTH;
+			if (pg_cryptohash_final(context->raw_context.c_sha2,
+									output, retval) < 0)
+				return -1;
+			pg_cryptohash_free(context->raw_context.c_sha2);
+			break;
+		case CHECKSUM_TYPE_SHA512:
+			retval = PG_SHA512_DIGEST_LENGTH;
+			if (pg_cryptohash_final(context->raw_context.c_sha2,
+									output, retval) < 0)
+				return -1;
+			pg_cryptohash_free(context->raw_context.c_sha2);
+			break;
+	}
+
+	Assert(retval <= PG_CHECKSUM_MAX_LENGTH);
+	return retval;
+}
diff --git a/src/common/config_info.c b/src/common/config_info.c
new file mode 100644
index 0000000..e72e729
--- /dev/null
+++ b/src/common/config_info.c
@@ -0,0 +1,201 @@
+/*-------------------------------------------------------------------------
+ *
+ * config_info.c
+ *		Common code for pg_config output
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/config_info.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/config_info.h"
+
+
+/*
+ * get_configdata(const char *my_exec_path, size_t *configdata_len)
+ *
+ * Get configure-time constants. The caller is responsible
+ * for pfreeing the result.
+ */
+ConfigData *
+get_configdata(const char *my_exec_path, size_t *configdata_len)
+{
+	ConfigData *configdata;
+	char		path[MAXPGPATH];
+	char	   *lastsep;
+	int			i = 0;
+
+	/* Adjust this to match the number of items filled below */
+	*configdata_len = 23;
+	configdata = (ConfigData *) palloc(*configdata_len * sizeof(ConfigData));
+
+	configdata[i].name = pstrdup("BINDIR");
+	strlcpy(path, my_exec_path, sizeof(path));
+	lastsep = strrchr(path, '/');
+	if (lastsep)
+		*lastsep = '\0';
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("DOCDIR");
+	get_doc_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("HTMLDIR");
+	get_html_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("INCLUDEDIR");
+	get_include_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("PKGINCLUDEDIR");
+	get_pkginclude_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("INCLUDEDIR-SERVER");
+	get_includeserver_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("LIBDIR");
+	get_lib_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("PKGLIBDIR");
+	get_pkglib_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("LOCALEDIR");
+	get_locale_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("MANDIR");
+	get_man_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("SHAREDIR");
+	get_share_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("SYSCONFDIR");
+	get_etc_path(my_exec_path, path);
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("PGXS");
+	get_pkglib_path(my_exec_path, path);
+	strlcat(path, "/pgxs/src/makefiles/pgxs.mk", sizeof(path));
+	cleanup_path(path);
+	configdata[i].setting = pstrdup(path);
+	i++;
+
+	configdata[i].name = pstrdup("CONFIGURE");
+	configdata[i].setting = pstrdup(CONFIGURE_ARGS);
+	i++;
+
+	configdata[i].name = pstrdup("CC");
+#ifdef VAL_CC
+	configdata[i].setting = pstrdup(VAL_CC);
+#else
+	configdata[i].setting = pstrdup(_("not recorded"));
+#endif
+	i++;
+
+	configdata[i].name = pstrdup("CPPFLAGS");
+#ifdef VAL_CPPFLAGS
+	configdata[i].setting = pstrdup(VAL_CPPFLAGS);
+#else
+	configdata[i].setting = pstrdup(_("not recorded"));
+#endif
+	i++;
+
+	configdata[i].name = pstrdup("CFLAGS");
+#ifdef VAL_CFLAGS
+	configdata[i].setting = pstrdup(VAL_CFLAGS);
+#else
+	configdata[i].setting = pstrdup(_("not recorded"));
+#endif
+	i++;
+
+	configdata[i].name = pstrdup("CFLAGS_SL");
+#ifdef VAL_CFLAGS_SL
+	configdata[i].setting = pstrdup(VAL_CFLAGS_SL);
+#else
+	configdata[i].setting = pstrdup(_("not recorded"));
+#endif
+	i++;
+
+	configdata[i].name = pstrdup("LDFLAGS");
+#ifdef VAL_LDFLAGS
+	configdata[i].setting = pstrdup(VAL_LDFLAGS);
+#else
+	configdata[i].setting = pstrdup(_("not recorded"));
+#endif
+	i++;
+
+	configdata[i].name = pstrdup("LDFLAGS_EX");
+#ifdef VAL_LDFLAGS_EX
+	configdata[i].setting = pstrdup(VAL_LDFLAGS_EX);
+#else
+	configdata[i].setting = pstrdup(_("not recorded"));
+#endif
+	i++;
+
+	configdata[i].name = pstrdup("LDFLAGS_SL");
+#ifdef VAL_LDFLAGS_SL
+	configdata[i].setting = pstrdup(VAL_LDFLAGS_SL);
+#else
+	configdata[i].setting = pstrdup(_("not recorded"));
+#endif
+	i++;
+
+	configdata[i].name = pstrdup("LIBS");
+#ifdef VAL_LIBS
+	configdata[i].setting = pstrdup(VAL_LIBS);
+#else
+	configdata[i].setting = pstrdup(_("not recorded"));
+#endif
+	i++;
+
+	configdata[i].name = pstrdup("VERSION");
+	configdata[i].setting = pstrdup("PostgreSQL " PG_VERSION);
+	i++;
+
+	Assert(i == *configdata_len);
+
+	return configdata;
+}
diff --git a/src/common/controldata_utils.c b/src/common/controldata_utils.c
new file mode 100644
index 0000000..7d4af78
--- /dev/null
+++ b/src/common/controldata_utils.c
@@ -0,0 +1,263 @@
+/*-------------------------------------------------------------------------
+ *
+ * controldata_utils.c
+ *		Common code for control data file output.
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/controldata_utils.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <unistd.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "access/xlog_internal.h"
+#include "catalog/pg_control.h"
+#include "common/controldata_utils.h"
+#include "common/file_perm.h"
+#ifdef FRONTEND
+#include "common/logging.h"
+#endif
+#include "port/pg_crc32c.h"
+
+#ifndef FRONTEND
+#include "pgstat.h"
+#include "storage/fd.h"
+#endif
+
+/*
+ * get_controlfile()
+ *
+ * Get controlfile values.  The result is returned as a palloc'd copy of the
+ * control file data.
+ *
+ * crc_ok_p can be used by the caller to see whether the CRC of the control
+ * file data is correct.
+ */
+ControlFileData *
+get_controlfile(const char *DataDir, bool *crc_ok_p)
+{
+	ControlFileData *ControlFile;
+	int			fd;
+	char		ControlFilePath[MAXPGPATH];
+	pg_crc32c	crc;
+	int			r;
+
+	AssertArg(crc_ok_p);
+
+	ControlFile = palloc(sizeof(ControlFileData));
+	snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
+
+#ifndef FRONTEND
+	if ((fd = OpenTransientFile(ControlFilePath, O_RDONLY | PG_BINARY)) == -1)
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not open file \"%s\" for reading: %m",
+						ControlFilePath)));
+#else
+	if ((fd = open(ControlFilePath, O_RDONLY | PG_BINARY, 0)) == -1)
+	{
+		pg_log_fatal("could not open file \"%s\" for reading: %m",
+					 ControlFilePath);
+		exit(EXIT_FAILURE);
+	}
+#endif
+
+	r = read(fd, ControlFile, sizeof(ControlFileData));
+	if (r != sizeof(ControlFileData))
+	{
+		if (r < 0)
+#ifndef FRONTEND
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not read file \"%s\": %m", ControlFilePath)));
+#else
+		{
+			pg_log_fatal("could not read file \"%s\": %m", ControlFilePath);
+			exit(EXIT_FAILURE);
+		}
+#endif
+		else
+#ifndef FRONTEND
+			ereport(ERROR,
+					(errcode(ERRCODE_DATA_CORRUPTED),
+					 errmsg("could not read file \"%s\": read %d of %zu",
+							ControlFilePath, r, sizeof(ControlFileData))));
+#else
+		{
+			pg_log_fatal("could not read file \"%s\": read %d of %zu",
+						 ControlFilePath, r, sizeof(ControlFileData));
+			exit(EXIT_FAILURE);
+		}
+#endif
+	}
+
+#ifndef FRONTEND
+	if (CloseTransientFile(fd) != 0)
+		ereport(ERROR,
+				(errcode_for_file_access(),
+				 errmsg("could not close file \"%s\": %m",
+						ControlFilePath)));
+#else
+	if (close(fd) != 0)
+	{
+		pg_log_fatal("could not close file \"%s\": %m", ControlFilePath);
+		exit(EXIT_FAILURE);
+	}
+#endif
+
+	/* Check the CRC. */
+	INIT_CRC32C(crc);
+	COMP_CRC32C(crc,
+				(char *) ControlFile,
+				offsetof(ControlFileData, crc));
+	FIN_CRC32C(crc);
+
+	*crc_ok_p = EQ_CRC32C(crc, ControlFile->crc);
+
+	/* Make sure the control file is valid byte order. */
+	if (ControlFile->pg_control_version % 65536 == 0 &&
+		ControlFile->pg_control_version / 65536 != 0)
+#ifndef FRONTEND
+		elog(ERROR, _("byte ordering mismatch"));
+#else
+		pg_log_warning("possible byte ordering mismatch\n"
+					   "The byte ordering used to store the pg_control file might not match the one\n"
+					   "used by this program.  In that case the results below would be incorrect, and\n"
+					   "the PostgreSQL installation would be incompatible with this data directory.");
+#endif
+
+	return ControlFile;
+}
+
+/*
+ * update_controlfile()
+ *
+ * Update controlfile values with the contents given by caller.  The
+ * contents to write are included in "ControlFile". "do_sync" can be
+ * optionally used to flush the updated control file.  Note that it is up
+ * to the caller to properly lock ControlFileLock when calling this
+ * routine in the backend.
+ */
+void
+update_controlfile(const char *DataDir,
+				   ControlFileData *ControlFile, bool do_sync)
+{
+	int			fd;
+	char		buffer[PG_CONTROL_FILE_SIZE];
+	char		ControlFilePath[MAXPGPATH];
+
+	/*
+	 * Apply the same static assertions as in backend's WriteControlFile().
+	 */
+	StaticAssertStmt(sizeof(ControlFileData) <= PG_CONTROL_MAX_SAFE_SIZE,
+					 "pg_control is too large for atomic disk writes");
+	StaticAssertStmt(sizeof(ControlFileData) <= PG_CONTROL_FILE_SIZE,
+					 "sizeof(ControlFileData) exceeds PG_CONTROL_FILE_SIZE");
+
+	/* Recalculate CRC of control file */
+	INIT_CRC32C(ControlFile->crc);
+	COMP_CRC32C(ControlFile->crc,
+				(char *) ControlFile,
+				offsetof(ControlFileData, crc));
+	FIN_CRC32C(ControlFile->crc);
+
+	/*
+	 * Write out PG_CONTROL_FILE_SIZE bytes into pg_control by zero-padding
+	 * the excess over sizeof(ControlFileData), to avoid premature EOF related
+	 * errors when reading it.
+	 */
+	memset(buffer, 0, PG_CONTROL_FILE_SIZE);
+	memcpy(buffer, ControlFile, sizeof(ControlFileData));
+
+	snprintf(ControlFilePath, sizeof(ControlFilePath), "%s/%s", DataDir, XLOG_CONTROL_FILE);
+
+#ifndef FRONTEND
+
+	/*
+	 * All errors issue a PANIC, so no need to use OpenTransientFile() and to
+	 * worry about file descriptor leaks.
+	 */
+	if ((fd = BasicOpenFile(ControlFilePath, O_RDWR | PG_BINARY)) < 0)
+		ereport(PANIC,
+				(errcode_for_file_access(),
+				 errmsg("could not open file \"%s\": %m",
+						ControlFilePath)));
+#else
+	if ((fd = open(ControlFilePath, O_WRONLY | PG_BINARY,
+				   pg_file_create_mode)) == -1)
+	{
+		pg_log_fatal("could not open file \"%s\": %m", ControlFilePath);
+		exit(EXIT_FAILURE);
+	}
+#endif
+
+	errno = 0;
+#ifndef FRONTEND
+	pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_WRITE_UPDATE);
+#endif
+	if (write(fd, buffer, PG_CONTROL_FILE_SIZE) != PG_CONTROL_FILE_SIZE)
+	{
+		/* if write didn't set errno, assume problem is no disk space */
+		if (errno == 0)
+			errno = ENOSPC;
+
+#ifndef FRONTEND
+		ereport(PANIC,
+				(errcode_for_file_access(),
+				 errmsg("could not write file \"%s\": %m",
+						ControlFilePath)));
+#else
+		pg_log_fatal("could not write file \"%s\": %m", ControlFilePath);
+		exit(EXIT_FAILURE);
+#endif
+	}
+#ifndef FRONTEND
+	pgstat_report_wait_end();
+#endif
+
+	if (do_sync)
+	{
+#ifndef FRONTEND
+		pgstat_report_wait_start(WAIT_EVENT_CONTROL_FILE_SYNC_UPDATE);
+		if (pg_fsync(fd) != 0)
+			ereport(PANIC,
+					(errcode_for_file_access(),
+					 errmsg("could not fsync file \"%s\": %m",
+							ControlFilePath)));
+		pgstat_report_wait_end();
+#else
+		if (fsync(fd) != 0)
+		{
+			pg_log_fatal("could not fsync file \"%s\": %m", ControlFilePath);
+			exit(EXIT_FAILURE);
+		}
+#endif
+	}
+
+	if (close(fd) != 0)
+	{
+#ifndef FRONTEND
+		ereport(PANIC,
+				(errcode_for_file_access(),
+				 errmsg("could not close file \"%s\": %m",
+						ControlFilePath)));
+#else
+		pg_log_fatal("could not close file \"%s\": %m", ControlFilePath);
+		exit(EXIT_FAILURE);
+#endif
+	}
+}
diff --git a/src/common/cryptohash.c b/src/common/cryptohash.c
new file mode 100644
index 0000000..0dab74a
--- /dev/null
+++ b/src/common/cryptohash.c
@@ -0,0 +1,223 @@
+/*-------------------------------------------------------------------------
+ *
+ * cryptohash.c
+ *	  Fallback implementations for cryptographic hash functions.
+ *
+ * This is the set of in-core functions used when there are no other
+ * alternative options like OpenSSL.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/cryptohash.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <sys/param.h>
+
+#include "common/cryptohash.h"
+#include "md5_int.h"
+#include "sha1_int.h"
+#include "sha2_int.h"
+
+/*
+ * In backend, use palloc/pfree to ease the error handling.  In frontend,
+ * use malloc to be able to return a failure status back to the caller.
+ */
+#ifndef FRONTEND
+#define ALLOC(size) palloc(size)
+#define FREE(ptr) pfree(ptr)
+#else
+#define ALLOC(size) malloc(size)
+#define FREE(ptr) free(ptr)
+#endif
+
+/* Internal pg_cryptohash_ctx structure */
+struct pg_cryptohash_ctx
+{
+	pg_cryptohash_type type;
+
+	union
+	{
+		pg_md5_ctx	md5;
+		pg_sha1_ctx sha1;
+		pg_sha224_ctx sha224;
+		pg_sha256_ctx sha256;
+		pg_sha384_ctx sha384;
+		pg_sha512_ctx sha512;
+	}			data;
+};
+
+/*
+ * pg_cryptohash_create
+ *
+ * Allocate a hash context.  Returns NULL on failure for an OOM.  The
+ * backend issues an error, without returning.
+ */
+pg_cryptohash_ctx *
+pg_cryptohash_create(pg_cryptohash_type type)
+{
+	pg_cryptohash_ctx *ctx;
+
+	/*
+	 * Note that this always allocates enough space for the largest hash. A
+	 * smaller allocation would be enough for md5, sha224 and sha256, but the
+	 * small extra amount of memory does not make it worth complicating this
+	 * code.
+	 */
+	ctx = ALLOC(sizeof(pg_cryptohash_ctx));
+	if (ctx == NULL)
+		return NULL;
+	memset(ctx, 0, sizeof(pg_cryptohash_ctx));
+	ctx->type = type;
+
+	return ctx;
+}
+
+/*
+ * pg_cryptohash_init
+ *
+ * Initialize a hash context.  Note that this implementation is designed
+ * to never fail, so this always returns 0.
+ */
+int
+pg_cryptohash_init(pg_cryptohash_ctx *ctx)
+{
+	if (ctx == NULL)
+		return -1;
+
+	switch (ctx->type)
+	{
+		case PG_MD5:
+			pg_md5_init(&ctx->data.md5);
+			break;
+		case PG_SHA1:
+			pg_sha1_init(&ctx->data.sha1);
+			break;
+		case PG_SHA224:
+			pg_sha224_init(&ctx->data.sha224);
+			break;
+		case PG_SHA256:
+			pg_sha256_init(&ctx->data.sha256);
+			break;
+		case PG_SHA384:
+			pg_sha384_init(&ctx->data.sha384);
+			break;
+		case PG_SHA512:
+			pg_sha512_init(&ctx->data.sha512);
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * pg_cryptohash_update
+ *
+ * Update a hash context.  Note that this implementation is designed
+ * to never fail, so this always returns 0 except if the caller has
+ * given a NULL context.
+ */
+int
+pg_cryptohash_update(pg_cryptohash_ctx *ctx, const uint8 *data, size_t len)
+{
+	if (ctx == NULL)
+		return -1;
+
+	switch (ctx->type)
+	{
+		case PG_MD5:
+			pg_md5_update(&ctx->data.md5, data, len);
+			break;
+		case PG_SHA1:
+			pg_sha1_update(&ctx->data.sha1, data, len);
+			break;
+		case PG_SHA224:
+			pg_sha224_update(&ctx->data.sha224, data, len);
+			break;
+		case PG_SHA256:
+			pg_sha256_update(&ctx->data.sha256, data, len);
+			break;
+		case PG_SHA384:
+			pg_sha384_update(&ctx->data.sha384, data, len);
+			break;
+		case PG_SHA512:
+			pg_sha512_update(&ctx->data.sha512, data, len);
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * pg_cryptohash_final
+ *
+ * Finalize a hash context.  Note that this implementation is designed to
+ * never fail, so this always returns 0 except if the destination buffer
+ * is not large enough.
+ */
+int
+pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
+{
+	if (ctx == NULL)
+		return -1;
+
+	switch (ctx->type)
+	{
+		case PG_MD5:
+			if (len < MD5_DIGEST_LENGTH)
+				return -1;
+			pg_md5_final(&ctx->data.md5, dest);
+			break;
+		case PG_SHA1:
+			if (len < SHA1_DIGEST_LENGTH)
+				return -1;
+			pg_sha1_final(&ctx->data.sha1, dest);
+			break;
+		case PG_SHA224:
+			if (len < PG_SHA224_DIGEST_LENGTH)
+				return -1;
+			pg_sha224_final(&ctx->data.sha224, dest);
+			break;
+		case PG_SHA256:
+			if (len < PG_SHA256_DIGEST_LENGTH)
+				return -1;
+			pg_sha256_final(&ctx->data.sha256, dest);
+			break;
+		case PG_SHA384:
+			if (len < PG_SHA384_DIGEST_LENGTH)
+				return -1;
+			pg_sha384_final(&ctx->data.sha384, dest);
+			break;
+		case PG_SHA512:
+			if (len < PG_SHA512_DIGEST_LENGTH)
+				return -1;
+			pg_sha512_final(&ctx->data.sha512, dest);
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * pg_cryptohash_free
+ *
+ * Free a hash context.
+ */
+void
+pg_cryptohash_free(pg_cryptohash_ctx *ctx)
+{
+	if (ctx == NULL)
+		return;
+
+	explicit_bzero(ctx, sizeof(pg_cryptohash_ctx));
+	FREE(ctx);
+}
diff --git a/src/common/cryptohash_openssl.c b/src/common/cryptohash_openssl.c
new file mode 100644
index 0000000..643cc7a
--- /dev/null
+++ b/src/common/cryptohash_openssl.c
@@ -0,0 +1,250 @@
+/*-------------------------------------------------------------------------
+ *
+ * cryptohash_openssl.c
+ *	  Set of wrapper routines on top of OpenSSL to support cryptographic
+ *	  hash functions.
+ *
+ * This should only be used if code is compiled with OpenSSL support.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *		  src/common/cryptohash_openssl.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <openssl/evp.h>
+
+#include "common/cryptohash.h"
+#include "common/md5.h"
+#include "common/sha1.h"
+#include "common/sha2.h"
+#ifndef FRONTEND
+#include "utils/memutils.h"
+#include "utils/resowner.h"
+#include "utils/resowner_private.h"
+#endif
+
+/*
+ * In the backend, use an allocation in TopMemoryContext to count for
+ * resowner cleanup handling.  In the frontend, use malloc to be able
+ * to return a failure status back to the caller.
+ */
+#ifndef FRONTEND
+#define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
+#define FREE(ptr) pfree(ptr)
+#else
+#define ALLOC(size) malloc(size)
+#define FREE(ptr) free(ptr)
+#endif
+
+/*
+ * Internal pg_cryptohash_ctx structure.
+ *
+ * This tracks the resource owner associated to each EVP context data
+ * for the backend.
+ */
+struct pg_cryptohash_ctx
+{
+	pg_cryptohash_type type;
+
+	EVP_MD_CTX *evpctx;
+
+#ifndef FRONTEND
+	ResourceOwner resowner;
+#endif
+};
+
+/*
+ * pg_cryptohash_create
+ *
+ * Allocate a hash context.  Returns NULL on failure for an OOM.  The
+ * backend issues an error, without returning.
+ */
+pg_cryptohash_ctx *
+pg_cryptohash_create(pg_cryptohash_type type)
+{
+	pg_cryptohash_ctx *ctx;
+
+	/*
+	 * Make sure that the resource owner has space to remember this reference.
+	 * This can error out with "out of memory", so do this before any other
+	 * allocation to avoid leaking.
+	 */
+#ifndef FRONTEND
+	ResourceOwnerEnlargeCryptoHash(CurrentResourceOwner);
+#endif
+
+	ctx = ALLOC(sizeof(pg_cryptohash_ctx));
+	if (ctx == NULL)
+		return NULL;
+	memset(ctx, 0, sizeof(pg_cryptohash_ctx));
+	ctx->type = type;
+
+	/*
+	 * Initialization takes care of assigning the correct type for OpenSSL.
+	 */
+	ctx->evpctx = EVP_MD_CTX_create();
+
+	if (ctx->evpctx == NULL)
+	{
+		explicit_bzero(ctx, sizeof(pg_cryptohash_ctx));
+		FREE(ctx);
+#ifndef FRONTEND
+		ereport(ERROR,
+				(errcode(ERRCODE_OUT_OF_MEMORY),
+				 errmsg("out of memory")));
+#else
+		return NULL;
+#endif
+	}
+
+#ifndef FRONTEND
+	ctx->resowner = CurrentResourceOwner;
+	ResourceOwnerRememberCryptoHash(CurrentResourceOwner,
+									PointerGetDatum(ctx));
+#endif
+
+	return ctx;
+}
+
+/*
+ * pg_cryptohash_init
+ *
+ * Initialize a hash context.  Returns 0 on success, and -1 on failure.
+ */
+int
+pg_cryptohash_init(pg_cryptohash_ctx *ctx)
+{
+	int			status = 0;
+
+	if (ctx == NULL)
+		return -1;
+
+	switch (ctx->type)
+	{
+		case PG_MD5:
+			status = EVP_DigestInit_ex(ctx->evpctx, EVP_md5(), NULL);
+			break;
+		case PG_SHA1:
+			status = EVP_DigestInit_ex(ctx->evpctx, EVP_sha1(), NULL);
+			break;
+		case PG_SHA224:
+			status = EVP_DigestInit_ex(ctx->evpctx, EVP_sha224(), NULL);
+			break;
+		case PG_SHA256:
+			status = EVP_DigestInit_ex(ctx->evpctx, EVP_sha256(), NULL);
+			break;
+		case PG_SHA384:
+			status = EVP_DigestInit_ex(ctx->evpctx, EVP_sha384(), NULL);
+			break;
+		case PG_SHA512:
+			status = EVP_DigestInit_ex(ctx->evpctx, EVP_sha512(), NULL);
+			break;
+	}
+
+	/* OpenSSL internals return 1 on success, 0 on failure */
+	if (status <= 0)
+		return -1;
+	return 0;
+}
+
+/*
+ * pg_cryptohash_update
+ *
+ * Update a hash context.  Returns 0 on success, and -1 on failure.
+ */
+int
+pg_cryptohash_update(pg_cryptohash_ctx *ctx, const uint8 *data, size_t len)
+{
+	int			status = 0;
+
+	if (ctx == NULL)
+		return -1;
+
+	status = EVP_DigestUpdate(ctx->evpctx, data, len);
+
+	/* OpenSSL internals return 1 on success, 0 on failure */
+	if (status <= 0)
+		return -1;
+	return 0;
+}
+
+/*
+ * pg_cryptohash_final
+ *
+ * Finalize a hash context.  Returns 0 on success, and -1 on failure.
+ */
+int
+pg_cryptohash_final(pg_cryptohash_ctx *ctx, uint8 *dest, size_t len)
+{
+	int			status = 0;
+
+	if (ctx == NULL)
+		return -1;
+
+	switch (ctx->type)
+	{
+		case PG_MD5:
+			if (len < MD5_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA1:
+			if (len < SHA1_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA224:
+			if (len < PG_SHA224_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA256:
+			if (len < PG_SHA256_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA384:
+			if (len < PG_SHA384_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA512:
+			if (len < PG_SHA512_DIGEST_LENGTH)
+				return -1;
+			break;
+	}
+
+	status = EVP_DigestFinal_ex(ctx->evpctx, dest, 0);
+
+	/* OpenSSL internals return 1 on success, 0 on failure */
+	if (status <= 0)
+		return -1;
+	return 0;
+}
+
+/*
+ * pg_cryptohash_free
+ *
+ * Free a hash context.
+ */
+void
+pg_cryptohash_free(pg_cryptohash_ctx *ctx)
+{
+	if (ctx == NULL)
+		return;
+
+	EVP_MD_CTX_destroy(ctx->evpctx);
+
+#ifndef FRONTEND
+	ResourceOwnerForgetCryptoHash(ctx->resowner,
+								  PointerGetDatum(ctx));
+#endif
+
+	explicit_bzero(ctx, sizeof(pg_cryptohash_ctx));
+	FREE(ctx);
+}
diff --git a/src/common/d2s.c b/src/common/d2s.c
new file mode 100644
index 0000000..70e3112
--- /dev/null
+++ b/src/common/d2s.c
@@ -0,0 +1,1076 @@
+/*---------------------------------------------------------------------------
+ *
+ * Ryu floating-point output for double precision.
+ *
+ * Portions Copyright (c) 2018-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/d2s.c
+ *
+ * This is a modification of code taken from github.com/ulfjack/ryu under the
+ * terms of the Boost license (not the Apache license). The original copyright
+ * notice follows:
+ *
+ * Copyright 2018 Ulf Adams
+ *
+ * The contents of this file may be used under the terms of the Apache
+ * License, Version 2.0.
+ *
+ *     (See accompanying file LICENSE-Apache or copy at
+ *      http://www.apache.org/licenses/LICENSE-2.0)
+ *
+ * Alternatively, the contents of this file may be used under the terms of the
+ * Boost Software License, Version 1.0.
+ *
+ *     (See accompanying file LICENSE-Boost or copy at
+ *      https://www.boost.org/LICENSE_1_0.txt)
+ *
+ * Unless required by applicable law or agreed to in writing, this software is
+ * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.
+ *
+ *---------------------------------------------------------------------------
+ */
+
+/*
+ *  Runtime compiler options:
+ *
+ *  -DRYU_ONLY_64_BIT_OPS Avoid using uint128 or 64-bit intrinsics. Slower,
+ *      depending on your compiler.
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/shortest_dec.h"
+
+/*
+ * For consistency, we use 128-bit types if and only if the rest of PG also
+ * does, even though we could use them here without worrying about the
+ * alignment concerns that apply elsewhere.
+ */
+#if !defined(HAVE_INT128) && defined(_MSC_VER) \
+	&& !defined(RYU_ONLY_64_BIT_OPS) && defined(_M_X64)
+#define HAS_64_BIT_INTRINSICS
+#endif
+
+#include "ryu_common.h"
+#include "digit_table.h"
+#include "d2s_full_table.h"
+#include "d2s_intrinsics.h"
+
+#define DOUBLE_MANTISSA_BITS 52
+#define DOUBLE_EXPONENT_BITS 11
+#define DOUBLE_BIAS 1023
+
+#define DOUBLE_POW5_INV_BITCOUNT 122
+#define DOUBLE_POW5_BITCOUNT 121
+
+
+static inline uint32
+pow5Factor(uint64 value)
+{
+	uint32		count = 0;
+
+	for (;;)
+	{
+		Assert(value != 0);
+		const uint64 q = div5(value);
+		const uint32 r = (uint32) (value - 5 * q);
+
+		if (r != 0)
+			break;
+
+		value = q;
+		++count;
+	}
+	return count;
+}
+
+/*  Returns true if value is divisible by 5^p. */
+static inline bool
+multipleOfPowerOf5(const uint64 value, const uint32 p)
+{
+	/*
+	 * I tried a case distinction on p, but there was no performance
+	 * difference.
+	 */
+	return pow5Factor(value) >= p;
+}
+
+/*  Returns true if value is divisible by 2^p. */
+static inline bool
+multipleOfPowerOf2(const uint64 value, const uint32 p)
+{
+	/* return __builtin_ctzll(value) >= p; */
+	return (value & ((UINT64CONST(1) << p) - 1)) == 0;
+}
+
+/*
+ * We need a 64x128-bit multiplication and a subsequent 128-bit shift.
+ *
+ * Multiplication:
+ *
+ *    The 64-bit factor is variable and passed in, the 128-bit factor comes
+ *    from a lookup table. We know that the 64-bit factor only has 55
+ *    significant bits (i.e., the 9 topmost bits are zeros). The 128-bit
+ *    factor only has 124 significant bits (i.e., the 4 topmost bits are
+ *    zeros).
+ *
+ * Shift:
+ *
+ *    In principle, the multiplication result requires 55 + 124 = 179 bits to
+ *    represent. However, we then shift this value to the right by j, which is
+ *    at least j >= 115, so the result is guaranteed to fit into 179 - 115 =
+ *    64 bits. This means that we only need the topmost 64 significant bits of
+ *    the 64x128-bit multiplication.
+ *
+ * There are several ways to do this:
+ *
+ *  1. Best case: the compiler exposes a 128-bit type.
+ *     We perform two 64x64-bit multiplications, add the higher 64 bits of the
+ *     lower result to the higher result, and shift by j - 64 bits.
+ *
+ *     We explicitly cast from 64-bit to 128-bit, so the compiler can tell
+ *     that these are only 64-bit inputs, and can map these to the best
+ *     possible sequence of assembly instructions. x86-64 machines happen to
+ *     have matching assembly instructions for 64x64-bit multiplications and
+ *     128-bit shifts.
+ *
+ *  2. Second best case: the compiler exposes intrinsics for the x86-64
+ *     assembly instructions mentioned in 1.
+ *
+ *  3. We only have 64x64 bit instructions that return the lower 64 bits of
+ *     the result, i.e., we have to use plain C.
+ *
+ *     Our inputs are less than the full width, so we have three options:
+ *     a. Ignore this fact and just implement the intrinsics manually.
+ *     b. Split both into 31-bit pieces, which guarantees no internal
+ *        overflow, but requires extra work upfront (unless we change the
+ *        lookup table).
+ *     c. Split only the first factor into 31-bit pieces, which also
+ *        guarantees no internal overflow, but requires extra work since the
+ *        intermediate results are not perfectly aligned.
+ */
+#if defined(HAVE_INT128)
+
+/*  Best case: use 128-bit type. */
+static inline uint64
+mulShift(const uint64 m, const uint64 *const mul, const int32 j)
+{
+	const uint128 b0 = ((uint128) m) * mul[0];
+	const uint128 b2 = ((uint128) m) * mul[1];
+
+	return (uint64) (((b0 >> 64) + b2) >> (j - 64));
+}
+
+static inline uint64
+mulShiftAll(const uint64 m, const uint64 *const mul, const int32 j,
+			uint64 *const vp, uint64 *const vm, const uint32 mmShift)
+{
+	*vp = mulShift(4 * m + 2, mul, j);
+	*vm = mulShift(4 * m - 1 - mmShift, mul, j);
+	return mulShift(4 * m, mul, j);
+}
+
+#elif defined(HAS_64_BIT_INTRINSICS)
+
+static inline uint64
+mulShift(const uint64 m, const uint64 *const mul, const int32 j)
+{
+	/* m is maximum 55 bits */
+	uint64		high1;
+
+	/* 128 */
+	const uint64 low1 = umul128(m, mul[1], &high1);
+
+	/* 64 */
+	uint64		high0;
+	uint64		sum;
+
+	/* 64 */
+	umul128(m, mul[0], &high0);
+	/* 0 */
+	sum = high0 + low1;
+
+	if (sum < high0)
+	{
+		++high1;
+		/* overflow into high1 */
+	}
+	return shiftright128(sum, high1, j - 64);
+}
+
+static inline uint64
+mulShiftAll(const uint64 m, const uint64 *const mul, const int32 j,
+			uint64 *const vp, uint64 *const vm, const uint32 mmShift)
+{
+	*vp = mulShift(4 * m + 2, mul, j);
+	*vm = mulShift(4 * m - 1 - mmShift, mul, j);
+	return mulShift(4 * m, mul, j);
+}
+
+#else							/* // !defined(HAVE_INT128) &&
+								 * !defined(HAS_64_BIT_INTRINSICS) */
+
+static inline uint64
+mulShiftAll(uint64 m, const uint64 *const mul, const int32 j,
+			uint64 *const vp, uint64 *const vm, const uint32 mmShift)
+{
+	m <<= 1;					/* m is maximum 55 bits */
+
+	uint64		tmp;
+	const uint64 lo = umul128(m, mul[0], &tmp);
+	uint64		hi;
+	const uint64 mid = tmp + umul128(m, mul[1], &hi);
+
+	hi += mid < tmp;			/* overflow into hi */
+
+	const uint64 lo2 = lo + mul[0];
+	const uint64 mid2 = mid + mul[1] + (lo2 < lo);
+	const uint64 hi2 = hi + (mid2 < mid);
+
+	*vp = shiftright128(mid2, hi2, j - 64 - 1);
+
+	if (mmShift == 1)
+	{
+		const uint64 lo3 = lo - mul[0];
+		const uint64 mid3 = mid - mul[1] - (lo3 > lo);
+		const uint64 hi3 = hi - (mid3 > mid);
+
+		*vm = shiftright128(mid3, hi3, j - 64 - 1);
+	}
+	else
+	{
+		const uint64 lo3 = lo + lo;
+		const uint64 mid3 = mid + mid + (lo3 < lo);
+		const uint64 hi3 = hi + hi + (mid3 < mid);
+		const uint64 lo4 = lo3 - mul[0];
+		const uint64 mid4 = mid3 - mul[1] - (lo4 > lo3);
+		const uint64 hi4 = hi3 - (mid4 > mid3);
+
+		*vm = shiftright128(mid4, hi4, j - 64);
+	}
+
+	return shiftright128(mid, hi, j - 64 - 1);
+}
+
+#endif							/* // HAS_64_BIT_INTRINSICS */
+
+static inline uint32
+decimalLength(const uint64 v)
+{
+	/* This is slightly faster than a loop. */
+	/* The average output length is 16.38 digits, so we check high-to-low. */
+	/* Function precondition: v is not an 18, 19, or 20-digit number. */
+	/* (17 digits are sufficient for round-tripping.) */
+	Assert(v < 100000000000000000L);
+	if (v >= 10000000000000000L)
+	{
+		return 17;
+	}
+	if (v >= 1000000000000000L)
+	{
+		return 16;
+	}
+	if (v >= 100000000000000L)
+	{
+		return 15;
+	}
+	if (v >= 10000000000000L)
+	{
+		return 14;
+	}
+	if (v >= 1000000000000L)
+	{
+		return 13;
+	}
+	if (v >= 100000000000L)
+	{
+		return 12;
+	}
+	if (v >= 10000000000L)
+	{
+		return 11;
+	}
+	if (v >= 1000000000L)
+	{
+		return 10;
+	}
+	if (v >= 100000000L)
+	{
+		return 9;
+	}
+	if (v >= 10000000L)
+	{
+		return 8;
+	}
+	if (v >= 1000000L)
+	{
+		return 7;
+	}
+	if (v >= 100000L)
+	{
+		return 6;
+	}
+	if (v >= 10000L)
+	{
+		return 5;
+	}
+	if (v >= 1000L)
+	{
+		return 4;
+	}
+	if (v >= 100L)
+	{
+		return 3;
+	}
+	if (v >= 10L)
+	{
+		return 2;
+	}
+	return 1;
+}
+
+/*  A floating decimal representing m * 10^e. */
+typedef struct floating_decimal_64
+{
+	uint64		mantissa;
+	int32		exponent;
+} floating_decimal_64;
+
+static inline floating_decimal_64
+d2d(const uint64 ieeeMantissa, const uint32 ieeeExponent)
+{
+	int32		e2;
+	uint64		m2;
+
+	if (ieeeExponent == 0)
+	{
+		/* We subtract 2 so that the bounds computation has 2 additional bits. */
+		e2 = 1 - DOUBLE_BIAS - DOUBLE_MANTISSA_BITS - 2;
+		m2 = ieeeMantissa;
+	}
+	else
+	{
+		e2 = ieeeExponent - DOUBLE_BIAS - DOUBLE_MANTISSA_BITS - 2;
+		m2 = (UINT64CONST(1) << DOUBLE_MANTISSA_BITS) | ieeeMantissa;
+	}
+
+#if STRICTLY_SHORTEST
+	const bool	even = (m2 & 1) == 0;
+	const bool	acceptBounds = even;
+#else
+	const bool	acceptBounds = false;
+#endif
+
+	/* Step 2: Determine the interval of legal decimal representations. */
+	const uint64 mv = 4 * m2;
+
+	/* Implicit bool -> int conversion. True is 1, false is 0. */
+	const uint32 mmShift = ieeeMantissa != 0 || ieeeExponent <= 1;
+
+	/* We would compute mp and mm like this: */
+	/* uint64 mp = 4 * m2 + 2; */
+	/* uint64 mm = mv - 1 - mmShift; */
+
+	/* Step 3: Convert to a decimal power base using 128-bit arithmetic. */
+	uint64		vr,
+				vp,
+				vm;
+	int32		e10;
+	bool		vmIsTrailingZeros = false;
+	bool		vrIsTrailingZeros = false;
+
+	if (e2 >= 0)
+	{
+		/*
+		 * I tried special-casing q == 0, but there was no effect on
+		 * performance.
+		 *
+		 * This expr is slightly faster than max(0, log10Pow2(e2) - 1).
+		 */
+		const uint32 q = log10Pow2(e2) - (e2 > 3);
+		const int32 k = DOUBLE_POW5_INV_BITCOUNT + pow5bits(q) - 1;
+		const int32 i = -e2 + q + k;
+
+		e10 = q;
+
+		vr = mulShiftAll(m2, DOUBLE_POW5_INV_SPLIT[q], i, &vp, &vm, mmShift);
+
+		if (q <= 21)
+		{
+			/*
+			 * This should use q <= 22, but I think 21 is also safe. Smaller
+			 * values may still be safe, but it's more difficult to reason
+			 * about them.
+			 *
+			 * Only one of mp, mv, and mm can be a multiple of 5, if any.
+			 */
+			const uint32 mvMod5 = (uint32) (mv - 5 * div5(mv));
+
+			if (mvMod5 == 0)
+			{
+				vrIsTrailingZeros = multipleOfPowerOf5(mv, q);
+			}
+			else if (acceptBounds)
+			{
+				/*----
+				 * Same as min(e2 + (~mm & 1), pow5Factor(mm)) >= q
+				 * <=> e2 + (~mm & 1) >= q && pow5Factor(mm) >= q
+				 * <=> true && pow5Factor(mm) >= q, since e2 >= q.
+				 *----
+				 */
+				vmIsTrailingZeros = multipleOfPowerOf5(mv - 1 - mmShift, q);
+			}
+			else
+			{
+				/* Same as min(e2 + 1, pow5Factor(mp)) >= q. */
+				vp -= multipleOfPowerOf5(mv + 2, q);
+			}
+		}
+	}
+	else
+	{
+		/*
+		 * This expression is slightly faster than max(0, log10Pow5(-e2) - 1).
+		 */
+		const uint32 q = log10Pow5(-e2) - (-e2 > 1);
+		const int32 i = -e2 - q;
+		const int32 k = pow5bits(i) - DOUBLE_POW5_BITCOUNT;
+		const int32 j = q - k;
+
+		e10 = q + e2;
+
+		vr = mulShiftAll(m2, DOUBLE_POW5_SPLIT[i], j, &vp, &vm, mmShift);
+
+		if (q <= 1)
+		{
+			/*
+			 * {vr,vp,vm} is trailing zeros if {mv,mp,mm} has at least q
+			 * trailing 0 bits.
+			 */
+			/* mv = 4 * m2, so it always has at least two trailing 0 bits. */
+			vrIsTrailingZeros = true;
+			if (acceptBounds)
+			{
+				/*
+				 * mm = mv - 1 - mmShift, so it has 1 trailing 0 bit iff
+				 * mmShift == 1.
+				 */
+				vmIsTrailingZeros = mmShift == 1;
+			}
+			else
+			{
+				/*
+				 * mp = mv + 2, so it always has at least one trailing 0 bit.
+				 */
+				--vp;
+			}
+		}
+		else if (q < 63)
+		{
+			/* TODO(ulfjack):Use a tighter bound here. */
+			/*
+			 * We need to compute min(ntz(mv), pow5Factor(mv) - e2) >= q - 1
+			 */
+			/* <=> ntz(mv) >= q - 1 && pow5Factor(mv) - e2 >= q - 1 */
+			/* <=> ntz(mv) >= q - 1 (e2 is negative and -e2 >= q) */
+			/* <=> (mv & ((1 << (q - 1)) - 1)) == 0 */
+
+			/*
+			 * We also need to make sure that the left shift does not
+			 * overflow.
+			 */
+			vrIsTrailingZeros = multipleOfPowerOf2(mv, q - 1);
+		}
+	}
+
+	/*
+	 * Step 4: Find the shortest decimal representation in the interval of
+	 * legal representations.
+	 */
+	uint32		removed = 0;
+	uint8		lastRemovedDigit = 0;
+	uint64		output;
+
+	/* On average, we remove ~2 digits. */
+	if (vmIsTrailingZeros || vrIsTrailingZeros)
+	{
+		/* General case, which happens rarely (~0.7%). */
+		for (;;)
+		{
+			const uint64 vpDiv10 = div10(vp);
+			const uint64 vmDiv10 = div10(vm);
+
+			if (vpDiv10 <= vmDiv10)
+				break;
+
+			const uint32 vmMod10 = (uint32) (vm - 10 * vmDiv10);
+			const uint64 vrDiv10 = div10(vr);
+			const uint32 vrMod10 = (uint32) (vr - 10 * vrDiv10);
+
+			vmIsTrailingZeros &= vmMod10 == 0;
+			vrIsTrailingZeros &= lastRemovedDigit == 0;
+			lastRemovedDigit = (uint8) vrMod10;
+			vr = vrDiv10;
+			vp = vpDiv10;
+			vm = vmDiv10;
+			++removed;
+		}
+
+		if (vmIsTrailingZeros)
+		{
+			for (;;)
+			{
+				const uint64 vmDiv10 = div10(vm);
+				const uint32 vmMod10 = (uint32) (vm - 10 * vmDiv10);
+
+				if (vmMod10 != 0)
+					break;
+
+				const uint64 vpDiv10 = div10(vp);
+				const uint64 vrDiv10 = div10(vr);
+				const uint32 vrMod10 = (uint32) (vr - 10 * vrDiv10);
+
+				vrIsTrailingZeros &= lastRemovedDigit == 0;
+				lastRemovedDigit = (uint8) vrMod10;
+				vr = vrDiv10;
+				vp = vpDiv10;
+				vm = vmDiv10;
+				++removed;
+			}
+		}
+
+		if (vrIsTrailingZeros && lastRemovedDigit == 5 && vr % 2 == 0)
+		{
+			/* Round even if the exact number is .....50..0. */
+			lastRemovedDigit = 4;
+		}
+
+		/*
+		 * We need to take vr + 1 if vr is outside bounds or we need to round
+		 * up.
+		 */
+		output = vr + ((vr == vm && (!acceptBounds || !vmIsTrailingZeros)) || lastRemovedDigit >= 5);
+	}
+	else
+	{
+		/*
+		 * Specialized for the common case (~99.3%). Percentages below are
+		 * relative to this.
+		 */
+		bool		roundUp = false;
+		const uint64 vpDiv100 = div100(vp);
+		const uint64 vmDiv100 = div100(vm);
+
+		if (vpDiv100 > vmDiv100)
+		{
+			/* Optimization:remove two digits at a time(~86.2 %). */
+			const uint64 vrDiv100 = div100(vr);
+			const uint32 vrMod100 = (uint32) (vr - 100 * vrDiv100);
+
+			roundUp = vrMod100 >= 50;
+			vr = vrDiv100;
+			vp = vpDiv100;
+			vm = vmDiv100;
+			removed += 2;
+		}
+
+		/*----
+		 * Loop iterations below (approximately), without optimization
+		 * above:
+		 *
+		 * 0: 0.03%, 1: 13.8%, 2: 70.6%, 3: 14.0%, 4: 1.40%, 5: 0.14%,
+		 * 6+: 0.02%
+		 *
+		 * Loop iterations below (approximately), with optimization
+		 * above:
+		 *
+		 * 0: 70.6%, 1: 27.8%, 2: 1.40%, 3: 0.14%, 4+: 0.02%
+		 *----
+		 */
+		for (;;)
+		{
+			const uint64 vpDiv10 = div10(vp);
+			const uint64 vmDiv10 = div10(vm);
+
+			if (vpDiv10 <= vmDiv10)
+				break;
+
+			const uint64 vrDiv10 = div10(vr);
+			const uint32 vrMod10 = (uint32) (vr - 10 * vrDiv10);
+
+			roundUp = vrMod10 >= 5;
+			vr = vrDiv10;
+			vp = vpDiv10;
+			vm = vmDiv10;
+			++removed;
+		}
+
+		/*
+		 * We need to take vr + 1 if vr is outside bounds or we need to round
+		 * up.
+		 */
+		output = vr + (vr == vm || roundUp);
+	}
+
+	const int32 exp = e10 + removed;
+
+	floating_decimal_64 fd;
+
+	fd.exponent = exp;
+	fd.mantissa = output;
+	return fd;
+}
+
+static inline int
+to_chars_df(const floating_decimal_64 v, const uint32 olength, char *const result)
+{
+	/* Step 5: Print the decimal representation. */
+	int			index = 0;
+
+	uint64		output = v.mantissa;
+	int32		exp = v.exponent;
+
+	/*----
+	 * On entry, mantissa * 10^exp is the result to be output.
+	 * Caller has already done the - sign if needed.
+	 *
+	 * We want to insert the point somewhere depending on the output length
+	 * and exponent, which might mean adding zeros:
+	 *
+	 *            exp  | format
+	 *            1+   |  ddddddddd000000
+	 *            0    |  ddddddddd
+	 *  -1 .. -len+1   |  dddddddd.d to d.ddddddddd
+	 *  -len ...       |  0.ddddddddd to 0.000dddddd
+	 */
+	uint32		i = 0;
+	int32		nexp = exp + olength;
+
+	if (nexp <= 0)
+	{
+		/* -nexp is number of 0s to add after '.' */
+		Assert(nexp >= -3);
+		/* 0.000ddddd */
+		index = 2 - nexp;
+		/* won't need more than this many 0s */
+		memcpy(result, "0.000000", 8);
+	}
+	else if (exp < 0)
+	{
+		/*
+		 * dddd.dddd; leave space at the start and move the '.' in after
+		 */
+		index = 1;
+	}
+	else
+	{
+		/*
+		 * We can save some code later by pre-filling with zeros. We know that
+		 * there can be no more than 16 output digits in this form, otherwise
+		 * we would not choose fixed-point output.
+		 */
+		Assert(exp < 16 && exp + olength <= 16);
+		memset(result, '0', 16);
+	}
+
+	/*
+	 * We prefer 32-bit operations, even on 64-bit platforms. We have at most
+	 * 17 digits, and uint32 can store 9 digits. If output doesn't fit into
+	 * uint32, we cut off 8 digits, so the rest will fit into uint32.
+	 */
+	if ((output >> 32) != 0)
+	{
+		/* Expensive 64-bit division. */
+		const uint64 q = div1e8(output);
+		uint32		output2 = (uint32) (output - 100000000 * q);
+		const uint32 c = output2 % 10000;
+
+		output = q;
+		output2 /= 10000;
+
+		const uint32 d = output2 % 10000;
+		const uint32 c0 = (c % 100) << 1;
+		const uint32 c1 = (c / 100) << 1;
+		const uint32 d0 = (d % 100) << 1;
+		const uint32 d1 = (d / 100) << 1;
+
+		memcpy(result + index + olength - i - 2, DIGIT_TABLE + c0, 2);
+		memcpy(result + index + olength - i - 4, DIGIT_TABLE + c1, 2);
+		memcpy(result + index + olength - i - 6, DIGIT_TABLE + d0, 2);
+		memcpy(result + index + olength - i - 8, DIGIT_TABLE + d1, 2);
+		i += 8;
+	}
+
+	uint32		output2 = (uint32) output;
+
+	while (output2 >= 10000)
+	{
+		const uint32 c = output2 - 10000 * (output2 / 10000);
+		const uint32 c0 = (c % 100) << 1;
+		const uint32 c1 = (c / 100) << 1;
+
+		output2 /= 10000;
+		memcpy(result + index + olength - i - 2, DIGIT_TABLE + c0, 2);
+		memcpy(result + index + olength - i - 4, DIGIT_TABLE + c1, 2);
+		i += 4;
+	}
+	if (output2 >= 100)
+	{
+		const uint32 c = (output2 % 100) << 1;
+
+		output2 /= 100;
+		memcpy(result + index + olength - i - 2, DIGIT_TABLE + c, 2);
+		i += 2;
+	}
+	if (output2 >= 10)
+	{
+		const uint32 c = output2 << 1;
+
+		memcpy(result + index + olength - i - 2, DIGIT_TABLE + c, 2);
+	}
+	else
+	{
+		result[index] = (char) ('0' + output2);
+	}
+
+	if (index == 1)
+	{
+		/*
+		 * nexp is 1..15 here, representing the number of digits before the
+		 * point. A value of 16 is not possible because we switch to
+		 * scientific notation when the display exponent reaches 15.
+		 */
+		Assert(nexp < 16);
+		/* gcc only seems to want to optimize memmove for small 2^n */
+		if (nexp & 8)
+		{
+			memmove(result + index - 1, result + index, 8);
+			index += 8;
+		}
+		if (nexp & 4)
+		{
+			memmove(result + index - 1, result + index, 4);
+			index += 4;
+		}
+		if (nexp & 2)
+		{
+			memmove(result + index - 1, result + index, 2);
+			index += 2;
+		}
+		if (nexp & 1)
+		{
+			result[index - 1] = result[index];
+		}
+		result[nexp] = '.';
+		index = olength + 1;
+	}
+	else if (exp >= 0)
+	{
+		/* we supplied the trailing zeros earlier, now just set the length. */
+		index = olength + exp;
+	}
+	else
+	{
+		index = olength + (2 - nexp);
+	}
+
+	return index;
+}
+
+static inline int
+to_chars(floating_decimal_64 v, const bool sign, char *const result)
+{
+	/* Step 5: Print the decimal representation. */
+	int			index = 0;
+
+	uint64		output = v.mantissa;
+	uint32		olength = decimalLength(output);
+	int32		exp = v.exponent + olength - 1;
+
+	if (sign)
+	{
+		result[index++] = '-';
+	}
+
+	/*
+	 * The thresholds for fixed-point output are chosen to match printf
+	 * defaults. Beware that both the code of to_chars_df and the value of
+	 * DOUBLE_SHORTEST_DECIMAL_LEN are sensitive to these thresholds.
+	 */
+	if (exp >= -4 && exp < 15)
+		return to_chars_df(v, olength, result + index) + sign;
+
+	/*
+	 * If v.exponent is exactly 0, we might have reached here via the small
+	 * integer fast path, in which case v.mantissa might contain trailing
+	 * (decimal) zeros. For scientific notation we need to move these zeros
+	 * into the exponent. (For fixed point this doesn't matter, which is why
+	 * we do this here rather than above.)
+	 *
+	 * Since we already calculated the display exponent (exp) above based on
+	 * the old decimal length, that value does not change here. Instead, we
+	 * just reduce the display length for each digit removed.
+	 *
+	 * If we didn't get here via the fast path, the raw exponent will not
+	 * usually be 0, and there will be no trailing zeros, so we pay no more
+	 * than one div10/multiply extra cost. We claw back half of that by
+	 * checking for divisibility by 2 before dividing by 10.
+	 */
+	if (v.exponent == 0)
+	{
+		while ((output & 1) == 0)
+		{
+			const uint64 q = div10(output);
+			const uint32 r = (uint32) (output - 10 * q);
+
+			if (r != 0)
+				break;
+			output = q;
+			--olength;
+		}
+	}
+
+	/*----
+	 * Print the decimal digits.
+	 *
+	 * The following code is equivalent to:
+	 *
+	 * for (uint32 i = 0; i < olength - 1; ++i) {
+	 *   const uint32 c = output % 10; output /= 10;
+	 *   result[index + olength - i] = (char) ('0' + c);
+	 * }
+	 * result[index] = '0' + output % 10;
+	 *----
+	 */
+
+	uint32		i = 0;
+
+	/*
+	 * We prefer 32-bit operations, even on 64-bit platforms. We have at most
+	 * 17 digits, and uint32 can store 9 digits. If output doesn't fit into
+	 * uint32, we cut off 8 digits, so the rest will fit into uint32.
+	 */
+	if ((output >> 32) != 0)
+	{
+		/* Expensive 64-bit division. */
+		const uint64 q = div1e8(output);
+		uint32		output2 = (uint32) (output - 100000000 * q);
+
+		output = q;
+
+		const uint32 c = output2 % 10000;
+
+		output2 /= 10000;
+
+		const uint32 d = output2 % 10000;
+		const uint32 c0 = (c % 100) << 1;
+		const uint32 c1 = (c / 100) << 1;
+		const uint32 d0 = (d % 100) << 1;
+		const uint32 d1 = (d / 100) << 1;
+
+		memcpy(result + index + olength - i - 1, DIGIT_TABLE + c0, 2);
+		memcpy(result + index + olength - i - 3, DIGIT_TABLE + c1, 2);
+		memcpy(result + index + olength - i - 5, DIGIT_TABLE + d0, 2);
+		memcpy(result + index + olength - i - 7, DIGIT_TABLE + d1, 2);
+		i += 8;
+	}
+
+	uint32		output2 = (uint32) output;
+
+	while (output2 >= 10000)
+	{
+		const uint32 c = output2 - 10000 * (output2 / 10000);
+
+		output2 /= 10000;
+
+		const uint32 c0 = (c % 100) << 1;
+		const uint32 c1 = (c / 100) << 1;
+
+		memcpy(result + index + olength - i - 1, DIGIT_TABLE + c0, 2);
+		memcpy(result + index + olength - i - 3, DIGIT_TABLE + c1, 2);
+		i += 4;
+	}
+	if (output2 >= 100)
+	{
+		const uint32 c = (output2 % 100) << 1;
+
+		output2 /= 100;
+		memcpy(result + index + olength - i - 1, DIGIT_TABLE + c, 2);
+		i += 2;
+	}
+	if (output2 >= 10)
+	{
+		const uint32 c = output2 << 1;
+
+		/*
+		 * We can't use memcpy here: the decimal dot goes between these two
+		 * digits.
+		 */
+		result[index + olength - i] = DIGIT_TABLE[c + 1];
+		result[index] = DIGIT_TABLE[c];
+	}
+	else
+	{
+		result[index] = (char) ('0' + output2);
+	}
+
+	/* Print decimal point if needed. */
+	if (olength > 1)
+	{
+		result[index + 1] = '.';
+		index += olength + 1;
+	}
+	else
+	{
+		++index;
+	}
+
+	/* Print the exponent. */
+	result[index++] = 'e';
+	if (exp < 0)
+	{
+		result[index++] = '-';
+		exp = -exp;
+	}
+	else
+		result[index++] = '+';
+
+	if (exp >= 100)
+	{
+		const int32 c = exp % 10;
+
+		memcpy(result + index, DIGIT_TABLE + 2 * (exp / 10), 2);
+		result[index + 2] = (char) ('0' + c);
+		index += 3;
+	}
+	else
+	{
+		memcpy(result + index, DIGIT_TABLE + 2 * exp, 2);
+		index += 2;
+	}
+
+	return index;
+}
+
+static inline bool
+d2d_small_int(const uint64 ieeeMantissa,
+			  const uint32 ieeeExponent,
+			  floating_decimal_64 *v)
+{
+	const int32 e2 = (int32) ieeeExponent - DOUBLE_BIAS - DOUBLE_MANTISSA_BITS;
+
+	/*
+	 * Avoid using multiple "return false;" here since it tends to provoke the
+	 * compiler into inlining multiple copies of d2d, which is undesirable.
+	 */
+
+	if (e2 >= -DOUBLE_MANTISSA_BITS && e2 <= 0)
+	{
+		/*----
+		 * Since 2^52 <= m2 < 2^53 and 0 <= -e2 <= 52:
+		 *   1 <= f = m2 / 2^-e2 < 2^53.
+		 *
+		 * Test if the lower -e2 bits of the significand are 0, i.e. whether
+		 * the fraction is 0. We can use ieeeMantissa here, since the implied
+		 * 1 bit can never be tested by this; the implied 1 can only be part
+		 * of a fraction if e2 < -DOUBLE_MANTISSA_BITS which we already
+		 * checked. (e.g. 0.5 gives ieeeMantissa == 0 and e2 == -53)
+		 */
+		const uint64 mask = (UINT64CONST(1) << -e2) - 1;
+		const uint64 fraction = ieeeMantissa & mask;
+
+		if (fraction == 0)
+		{
+			/*----
+			 * f is an integer in the range [1, 2^53).
+			 * Note: mantissa might contain trailing (decimal) 0's.
+			 * Note: since 2^53 < 10^16, there is no need to adjust
+			 * decimalLength().
+			 */
+			const uint64 m2 = (UINT64CONST(1) << DOUBLE_MANTISSA_BITS) | ieeeMantissa;
+
+			v->mantissa = m2 >> -e2;
+			v->exponent = 0;
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/*
+ * Store the shortest decimal representation of the given double as an
+ * UNTERMINATED string in the caller's supplied buffer (which must be at least
+ * DOUBLE_SHORTEST_DECIMAL_LEN-1 bytes long).
+ *
+ * Returns the number of bytes stored.
+ */
+int
+double_to_shortest_decimal_bufn(double f, char *result)
+{
+	/*
+	 * Step 1: Decode the floating-point number, and unify normalized and
+	 * subnormal cases.
+	 */
+	const uint64 bits = double_to_bits(f);
+
+	/* Decode bits into sign, mantissa, and exponent. */
+	const bool	ieeeSign = ((bits >> (DOUBLE_MANTISSA_BITS + DOUBLE_EXPONENT_BITS)) & 1) != 0;
+	const uint64 ieeeMantissa = bits & ((UINT64CONST(1) << DOUBLE_MANTISSA_BITS) - 1);
+	const uint32 ieeeExponent = (uint32) ((bits >> DOUBLE_MANTISSA_BITS) & ((1u << DOUBLE_EXPONENT_BITS) - 1));
+
+	/* Case distinction; exit early for the easy cases. */
+	if (ieeeExponent == ((1u << DOUBLE_EXPONENT_BITS) - 1u) || (ieeeExponent == 0 && ieeeMantissa == 0))
+	{
+		return copy_special_str(result, ieeeSign, (ieeeExponent != 0), (ieeeMantissa != 0));
+	}
+
+	floating_decimal_64 v;
+	const bool	isSmallInt = d2d_small_int(ieeeMantissa, ieeeExponent, &v);
+
+	if (!isSmallInt)
+	{
+		v = d2d(ieeeMantissa, ieeeExponent);
+	}
+
+	return to_chars(v, ieeeSign, result);
+}
+
+/*
+ * Store the shortest decimal representation of the given double as a
+ * null-terminated string in the caller's supplied buffer (which must be at
+ * least DOUBLE_SHORTEST_DECIMAL_LEN bytes long).
+ *
+ * Returns the string length.
+ */
+int
+double_to_shortest_decimal_buf(double f, char *result)
+{
+	const int	index = double_to_shortest_decimal_bufn(f, result);
+
+	/* Terminate the string. */
+	Assert(index < DOUBLE_SHORTEST_DECIMAL_LEN);
+	result[index] = '\0';
+	return index;
+}
+
+/*
+ * Return the shortest decimal representation as a null-terminated palloc'd
+ * string (outside the backend, uses malloc() instead).
+ *
+ * Caller is responsible for freeing the result.
+ */
+char *
+double_to_shortest_decimal(double f)
+{
+	char	   *const result = (char *) palloc(DOUBLE_SHORTEST_DECIMAL_LEN);
+
+	double_to_shortest_decimal_buf(f, result);
+	return result;
+}
diff --git a/src/common/d2s_full_table.h b/src/common/d2s_full_table.h
new file mode 100644
index 0000000..70b4419
--- /dev/null
+++ b/src/common/d2s_full_table.h
@@ -0,0 +1,358 @@
+/*---------------------------------------------------------------------------
+ *
+ * Ryu floating-point output for double precision.
+ *
+ * Portions Copyright (c) 2018-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/d2s_full_table.h
+ *
+ * This is a modification of code taken from github.com/ulfjack/ryu under the
+ * terms of the Boost license (not the Apache license). The original copyright
+ * notice follows:
+ *
+ * Copyright 2018 Ulf Adams
+ *
+ * The contents of this file may be used under the terms of the Apache
+ * License, Version 2.0.
+ *
+ *     (See accompanying file LICENSE-Apache or copy at
+ *      http://www.apache.org/licenses/LICENSE-2.0)
+ *
+ * Alternatively, the contents of this file may be used under the terms of the
+ * Boost Software License, Version 1.0.
+ *
+ *     (See accompanying file LICENSE-Boost or copy at
+ *      https://www.boost.org/LICENSE_1_0.txt)
+ *
+ * Unless required by applicable law or agreed to in writing, this software is
+ * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.
+ *
+ *---------------------------------------------------------------------------
+ */
+
+#ifndef RYU_D2S_FULL_TABLE_H
+#define RYU_D2S_FULL_TABLE_H
+
+/*
+ * These tables are generated (by the upstream) using PrintDoubleLookupTable
+ * from the upstream sources at github.com/ulfjack/ryu, and then modified (by
+ * us) by adding UINT64CONST.
+ */
+static const uint64 DOUBLE_POW5_INV_SPLIT[292][2] = {
+	{UINT64CONST(1), UINT64CONST(288230376151711744)}, {UINT64CONST(3689348814741910324), UINT64CONST(230584300921369395)},
+	{UINT64CONST(2951479051793528259), UINT64CONST(184467440737095516)}, {UINT64CONST(17118578500402463900), UINT64CONST(147573952589676412)},
+	{UINT64CONST(12632330341676300947), UINT64CONST(236118324143482260)}, {UINT64CONST(10105864273341040758), UINT64CONST(188894659314785808)},
+	{UINT64CONST(15463389048156653253), UINT64CONST(151115727451828646)}, {UINT64CONST(17362724847566824558), UINT64CONST(241785163922925834)},
+	{UINT64CONST(17579528692795369969), UINT64CONST(193428131138340667)}, {UINT64CONST(6684925324752475329), UINT64CONST(154742504910672534)},
+	{UINT64CONST(18074578149087781173), UINT64CONST(247588007857076054)}, {UINT64CONST(18149011334012135262), UINT64CONST(198070406285660843)},
+	{UINT64CONST(3451162622983977240), UINT64CONST(158456325028528675)}, {UINT64CONST(5521860196774363583), UINT64CONST(253530120045645880)},
+	{UINT64CONST(4417488157419490867), UINT64CONST(202824096036516704)}, {UINT64CONST(7223339340677503017), UINT64CONST(162259276829213363)},
+	{UINT64CONST(7867994130342094503), UINT64CONST(259614842926741381)}, {UINT64CONST(2605046489531765280), UINT64CONST(207691874341393105)},
+	{UINT64CONST(2084037191625412224), UINT64CONST(166153499473114484)}, {UINT64CONST(10713157136084480204), UINT64CONST(265845599156983174)},
+	{UINT64CONST(12259874523609494487), UINT64CONST(212676479325586539)}, {UINT64CONST(13497248433629505913), UINT64CONST(170141183460469231)},
+	{UINT64CONST(14216899864323388813), UINT64CONST(272225893536750770)}, {UINT64CONST(11373519891458711051), UINT64CONST(217780714829400616)},
+	{UINT64CONST(5409467098425058518), UINT64CONST(174224571863520493)}, {UINT64CONST(4965798542738183305), UINT64CONST(278759314981632789)},
+	{UINT64CONST(7661987648932456967), UINT64CONST(223007451985306231)}, {UINT64CONST(2440241304404055250), UINT64CONST(178405961588244985)},
+	{UINT64CONST(3904386087046488400), UINT64CONST(285449538541191976)}, {UINT64CONST(17880904128604832013), UINT64CONST(228359630832953580)},
+	{UINT64CONST(14304723302883865611), UINT64CONST(182687704666362864)}, {UINT64CONST(15133127457049002812), UINT64CONST(146150163733090291)},
+	{UINT64CONST(16834306301794583852), UINT64CONST(233840261972944466)}, {UINT64CONST(9778096226693756759), UINT64CONST(187072209578355573)},
+	{UINT64CONST(15201174610838826053), UINT64CONST(149657767662684458)}, {UINT64CONST(2185786488890659746), UINT64CONST(239452428260295134)},
+	{UINT64CONST(5437978005854438120), UINT64CONST(191561942608236107)}, {UINT64CONST(15418428848909281466), UINT64CONST(153249554086588885)},
+	{UINT64CONST(6222742084545298729), UINT64CONST(245199286538542217)}, {UINT64CONST(16046240111861969953), UINT64CONST(196159429230833773)},
+	{UINT64CONST(1768945645263844993), UINT64CONST(156927543384667019)}, {UINT64CONST(10209010661905972635), UINT64CONST(251084069415467230)},
+	{UINT64CONST(8167208529524778108), UINT64CONST(200867255532373784)}, {UINT64CONST(10223115638361732810), UINT64CONST(160693804425899027)},
+	{UINT64CONST(1599589762411131202), UINT64CONST(257110087081438444)}, {UINT64CONST(4969020624670815285), UINT64CONST(205688069665150755)},
+	{UINT64CONST(3975216499736652228), UINT64CONST(164550455732120604)}, {UINT64CONST(13739044029062464211), UINT64CONST(263280729171392966)},
+	{UINT64CONST(7301886408508061046), UINT64CONST(210624583337114373)}, {UINT64CONST(13220206756290269483), UINT64CONST(168499666669691498)},
+	{UINT64CONST(17462981995322520850), UINT64CONST(269599466671506397)}, {UINT64CONST(6591687966774196033), UINT64CONST(215679573337205118)},
+	{UINT64CONST(12652048002903177473), UINT64CONST(172543658669764094)}, {UINT64CONST(9175230360419352987), UINT64CONST(276069853871622551)},
+	{UINT64CONST(3650835473593572067), UINT64CONST(220855883097298041)}, {UINT64CONST(17678063637842498946), UINT64CONST(176684706477838432)},
+	{UINT64CONST(13527506561580357021), UINT64CONST(282695530364541492)}, {UINT64CONST(3443307619780464970), UINT64CONST(226156424291633194)},
+	{UINT64CONST(6443994910566282300), UINT64CONST(180925139433306555)}, {UINT64CONST(5155195928453025840), UINT64CONST(144740111546645244)},
+	{UINT64CONST(15627011115008661990), UINT64CONST(231584178474632390)}, {UINT64CONST(12501608892006929592), UINT64CONST(185267342779705912)},
+	{UINT64CONST(2622589484121723027), UINT64CONST(148213874223764730)}, {UINT64CONST(4196143174594756843), UINT64CONST(237142198758023568)},
+	{UINT64CONST(10735612169159626121), UINT64CONST(189713759006418854)}, {UINT64CONST(12277838550069611220), UINT64CONST(151771007205135083)},
+	{UINT64CONST(15955192865369467629), UINT64CONST(242833611528216133)}, {UINT64CONST(1696107848069843133), UINT64CONST(194266889222572907)},
+	{UINT64CONST(12424932722681605476), UINT64CONST(155413511378058325)}, {UINT64CONST(1433148282581017146), UINT64CONST(248661618204893321)},
+	{UINT64CONST(15903913885032455010), UINT64CONST(198929294563914656)}, {UINT64CONST(9033782293284053685), UINT64CONST(159143435651131725)},
+	{UINT64CONST(14454051669254485895), UINT64CONST(254629497041810760)}, {UINT64CONST(11563241335403588716), UINT64CONST(203703597633448608)},
+	{UINT64CONST(16629290697806691620), UINT64CONST(162962878106758886)}, {UINT64CONST(781423413297334329), UINT64CONST(260740604970814219)},
+	{UINT64CONST(4314487545379777786), UINT64CONST(208592483976651375)}, {UINT64CONST(3451590036303822229), UINT64CONST(166873987181321100)},
+	{UINT64CONST(5522544058086115566), UINT64CONST(266998379490113760)}, {UINT64CONST(4418035246468892453), UINT64CONST(213598703592091008)},
+	{UINT64CONST(10913125826658934609), UINT64CONST(170878962873672806)}, {UINT64CONST(10082303693170474728), UINT64CONST(273406340597876490)},
+	{UINT64CONST(8065842954536379782), UINT64CONST(218725072478301192)}, {UINT64CONST(17520720807854834795), UINT64CONST(174980057982640953)},
+	{UINT64CONST(5897060404116273733), UINT64CONST(279968092772225526)}, {UINT64CONST(1028299508551108663), UINT64CONST(223974474217780421)},
+	{UINT64CONST(15580034865808528224), UINT64CONST(179179579374224336)}, {UINT64CONST(17549358155809824511), UINT64CONST(286687326998758938)},
+	{UINT64CONST(2971440080422128639), UINT64CONST(229349861599007151)}, {UINT64CONST(17134547323305344204), UINT64CONST(183479889279205720)},
+	{UINT64CONST(13707637858644275364), UINT64CONST(146783911423364576)}, {UINT64CONST(14553522944347019935), UINT64CONST(234854258277383322)},
+	{UINT64CONST(4264120725993795302), UINT64CONST(187883406621906658)}, {UINT64CONST(10789994210278856888), UINT64CONST(150306725297525326)},
+	{UINT64CONST(9885293106962350374), UINT64CONST(240490760476040522)}, {UINT64CONST(529536856086059653), UINT64CONST(192392608380832418)},
+	{UINT64CONST(7802327114352668369), UINT64CONST(153914086704665934)}, {UINT64CONST(1415676938738538420), UINT64CONST(246262538727465495)},
+	{UINT64CONST(1132541550990830736), UINT64CONST(197010030981972396)}, {UINT64CONST(15663428499760305882), UINT64CONST(157608024785577916)},
+	{UINT64CONST(17682787970132668764), UINT64CONST(252172839656924666)}, {UINT64CONST(10456881561364224688), UINT64CONST(201738271725539733)},
+	{UINT64CONST(15744202878575200397), UINT64CONST(161390617380431786)}, {UINT64CONST(17812026976236499989), UINT64CONST(258224987808690858)},
+	{UINT64CONST(3181575136763469022), UINT64CONST(206579990246952687)}, {UINT64CONST(13613306553636506187), UINT64CONST(165263992197562149)},
+	{UINT64CONST(10713244041592678929), UINT64CONST(264422387516099439)}, {UINT64CONST(12259944048016053467), UINT64CONST(211537910012879551)},
+	{UINT64CONST(6118606423670932450), UINT64CONST(169230328010303641)}, {UINT64CONST(2411072648389671274), UINT64CONST(270768524816485826)},
+	{UINT64CONST(16686253377679378312), UINT64CONST(216614819853188660)}, {UINT64CONST(13349002702143502650), UINT64CONST(173291855882550928)},
+	{UINT64CONST(17669055508687693916), UINT64CONST(277266969412081485)}, {UINT64CONST(14135244406950155133), UINT64CONST(221813575529665188)},
+	{UINT64CONST(240149081334393137), UINT64CONST(177450860423732151)}, {UINT64CONST(11452284974360759988), UINT64CONST(283921376677971441)},
+	{UINT64CONST(5472479164746697667), UINT64CONST(227137101342377153)}, {UINT64CONST(11756680961281178780), UINT64CONST(181709681073901722)},
+	{UINT64CONST(2026647139541122378), UINT64CONST(145367744859121378)}, {UINT64CONST(18000030682233437097), UINT64CONST(232588391774594204)},
+	{UINT64CONST(18089373360528660001), UINT64CONST(186070713419675363)}, {UINT64CONST(3403452244197197031), UINT64CONST(148856570735740291)},
+	{UINT64CONST(16513570034941246220), UINT64CONST(238170513177184465)}, {UINT64CONST(13210856027952996976), UINT64CONST(190536410541747572)},
+	{UINT64CONST(3189987192878576934), UINT64CONST(152429128433398058)}, {UINT64CONST(1414630693863812771), UINT64CONST(243886605493436893)},
+	{UINT64CONST(8510402184574870864), UINT64CONST(195109284394749514)}, {UINT64CONST(10497670562401807014), UINT64CONST(156087427515799611)},
+	{UINT64CONST(9417575270359070576), UINT64CONST(249739884025279378)}, {UINT64CONST(14912757845771077107), UINT64CONST(199791907220223502)},
+	{UINT64CONST(4551508647133041040), UINT64CONST(159833525776178802)}, {UINT64CONST(10971762650154775986), UINT64CONST(255733641241886083)},
+	{UINT64CONST(16156107749607641435), UINT64CONST(204586912993508866)}, {UINT64CONST(9235537384944202825), UINT64CONST(163669530394807093)},
+	{UINT64CONST(11087511001168814197), UINT64CONST(261871248631691349)}, {UINT64CONST(12559357615676961681), UINT64CONST(209496998905353079)},
+	{UINT64CONST(13736834907283479668), UINT64CONST(167597599124282463)}, {UINT64CONST(18289587036911657145), UINT64CONST(268156158598851941)},
+	{UINT64CONST(10942320814787415393), UINT64CONST(214524926879081553)}, {UINT64CONST(16132554281313752961), UINT64CONST(171619941503265242)},
+	{UINT64CONST(11054691591134363444), UINT64CONST(274591906405224388)}, {UINT64CONST(16222450902391311402), UINT64CONST(219673525124179510)},
+	{UINT64CONST(12977960721913049122), UINT64CONST(175738820099343608)}, {UINT64CONST(17075388340318968271), UINT64CONST(281182112158949773)},
+	{UINT64CONST(2592264228029443648), UINT64CONST(224945689727159819)}, {UINT64CONST(5763160197165465241), UINT64CONST(179956551781727855)},
+	{UINT64CONST(9221056315464744386), UINT64CONST(287930482850764568)}, {UINT64CONST(14755542681855616155), UINT64CONST(230344386280611654)},
+	{UINT64CONST(15493782960226403247), UINT64CONST(184275509024489323)}, {UINT64CONST(1326979923955391628), UINT64CONST(147420407219591459)},
+	{UINT64CONST(9501865507812447252), UINT64CONST(235872651551346334)}, {UINT64CONST(11290841220991868125), UINT64CONST(188698121241077067)},
+	{UINT64CONST(1653975347309673853), UINT64CONST(150958496992861654)}, {UINT64CONST(10025058185179298811), UINT64CONST(241533595188578646)},
+	{UINT64CONST(4330697733401528726), UINT64CONST(193226876150862917)}, {UINT64CONST(14532604630946953951), UINT64CONST(154581500920690333)},
+	{UINT64CONST(1116074521063664381), UINT64CONST(247330401473104534)}, {UINT64CONST(4582208431592841828), UINT64CONST(197864321178483627)},
+	{UINT64CONST(14733813189500004432), UINT64CONST(158291456942786901)}, {UINT64CONST(16195403473716186445), UINT64CONST(253266331108459042)},
+	{UINT64CONST(5577625149489128510), UINT64CONST(202613064886767234)}, {UINT64CONST(8151448934333213131), UINT64CONST(162090451909413787)},
+	{UINT64CONST(16731667109675051333), UINT64CONST(259344723055062059)}, {UINT64CONST(17074682502481951390), UINT64CONST(207475778444049647)},
+	{UINT64CONST(6281048372501740465), UINT64CONST(165980622755239718)}, {UINT64CONST(6360328581260874421), UINT64CONST(265568996408383549)},
+	{UINT64CONST(8777611679750609860), UINT64CONST(212455197126706839)}, {UINT64CONST(10711438158542398211), UINT64CONST(169964157701365471)},
+	{UINT64CONST(9759603424184016492), UINT64CONST(271942652322184754)}, {UINT64CONST(11497031554089123517), UINT64CONST(217554121857747803)},
+	{UINT64CONST(16576322872755119460), UINT64CONST(174043297486198242)}, {UINT64CONST(11764721337440549842), UINT64CONST(278469275977917188)},
+	{UINT64CONST(16790474699436260520), UINT64CONST(222775420782333750)}, {UINT64CONST(13432379759549008416), UINT64CONST(178220336625867000)},
+	{UINT64CONST(3045063541568861850), UINT64CONST(285152538601387201)}, {UINT64CONST(17193446092222730773), UINT64CONST(228122030881109760)},
+	{UINT64CONST(13754756873778184618), UINT64CONST(182497624704887808)}, {UINT64CONST(18382503128506368341), UINT64CONST(145998099763910246)},
+	{UINT64CONST(3586563302416817083), UINT64CONST(233596959622256395)}, {UINT64CONST(2869250641933453667), UINT64CONST(186877567697805116)},
+	{UINT64CONST(17052795772514404226), UINT64CONST(149502054158244092)}, {UINT64CONST(12527077977055405469), UINT64CONST(239203286653190548)},
+	{UINT64CONST(17400360011128145022), UINT64CONST(191362629322552438)}, {UINT64CONST(2852241564676785048), UINT64CONST(153090103458041951)},
+	{UINT64CONST(15631632947708587046), UINT64CONST(244944165532867121)}, {UINT64CONST(8815957543424959314), UINT64CONST(195955332426293697)},
+	{UINT64CONST(18120812478965698421), UINT64CONST(156764265941034957)}, {UINT64CONST(14235904707377476180), UINT64CONST(250822825505655932)},
+	{UINT64CONST(4010026136418160298), UINT64CONST(200658260404524746)}, {UINT64CONST(17965416168102169531), UINT64CONST(160526608323619796)},
+	{UINT64CONST(2919224165770098987), UINT64CONST(256842573317791675)}, {UINT64CONST(2335379332616079190), UINT64CONST(205474058654233340)},
+	{UINT64CONST(1868303466092863352), UINT64CONST(164379246923386672)}, {UINT64CONST(6678634360490491686), UINT64CONST(263006795077418675)},
+	{UINT64CONST(5342907488392393349), UINT64CONST(210405436061934940)}, {UINT64CONST(4274325990713914679), UINT64CONST(168324348849547952)},
+	{UINT64CONST(10528270399884173809), UINT64CONST(269318958159276723)}, {UINT64CONST(15801313949391159694), UINT64CONST(215455166527421378)},
+	{UINT64CONST(1573004715287196786), UINT64CONST(172364133221937103)}, {UINT64CONST(17274202803427156150), UINT64CONST(275782613155099364)},
+	{UINT64CONST(17508711057483635243), UINT64CONST(220626090524079491)}, {UINT64CONST(10317620031244997871), UINT64CONST(176500872419263593)},
+	{UINT64CONST(12818843235250086271), UINT64CONST(282401395870821749)}, {UINT64CONST(13944423402941979340), UINT64CONST(225921116696657399)},
+	{UINT64CONST(14844887537095493795), UINT64CONST(180736893357325919)}, {UINT64CONST(15565258844418305359), UINT64CONST(144589514685860735)},
+	{UINT64CONST(6457670077359736959), UINT64CONST(231343223497377177)}, {UINT64CONST(16234182506113520537), UINT64CONST(185074578797901741)},
+	{UINT64CONST(9297997190148906106), UINT64CONST(148059663038321393)}, {UINT64CONST(11187446689496339446), UINT64CONST(236895460861314229)},
+	{UINT64CONST(12639306166338981880), UINT64CONST(189516368689051383)}, {UINT64CONST(17490142562555006151), UINT64CONST(151613094951241106)},
+	{UINT64CONST(2158786396894637579), UINT64CONST(242580951921985771)}, {UINT64CONST(16484424376483351356), UINT64CONST(194064761537588616)},
+	{UINT64CONST(9498190686444770762), UINT64CONST(155251809230070893)}, {UINT64CONST(11507756283569722895), UINT64CONST(248402894768113429)},
+	{UINT64CONST(12895553841597688639), UINT64CONST(198722315814490743)}, {UINT64CONST(17695140702761971558), UINT64CONST(158977852651592594)},
+	{UINT64CONST(17244178680193423523), UINT64CONST(254364564242548151)}, {UINT64CONST(10105994129412828495), UINT64CONST(203491651394038521)},
+	{UINT64CONST(4395446488788352473), UINT64CONST(162793321115230817)}, {UINT64CONST(10722063196803274280), UINT64CONST(260469313784369307)},
+	{UINT64CONST(1198952927958798777), UINT64CONST(208375451027495446)}, {UINT64CONST(15716557601334680315), UINT64CONST(166700360821996356)},
+	{UINT64CONST(17767794532651667857), UINT64CONST(266720577315194170)}, {UINT64CONST(14214235626121334286), UINT64CONST(213376461852155336)},
+	{UINT64CONST(7682039686155157106), UINT64CONST(170701169481724269)}, {UINT64CONST(1223217053622520399), UINT64CONST(273121871170758831)},
+	{UINT64CONST(15735968901865657612), UINT64CONST(218497496936607064)}, {UINT64CONST(16278123936234436413), UINT64CONST(174797997549285651)},
+	{UINT64CONST(219556594781725998), UINT64CONST(279676796078857043)}, {UINT64CONST(7554342905309201445), UINT64CONST(223741436863085634)},
+	{UINT64CONST(9732823138989271479), UINT64CONST(178993149490468507)}, {UINT64CONST(815121763415193074), UINT64CONST(286389039184749612)},
+	{UINT64CONST(11720143854957885429), UINT64CONST(229111231347799689)}, {UINT64CONST(13065463898708218666), UINT64CONST(183288985078239751)},
+	{UINT64CONST(6763022304224664610), UINT64CONST(146631188062591801)}, {UINT64CONST(3442138057275642729), UINT64CONST(234609900900146882)},
+	{UINT64CONST(13821756890046245153), UINT64CONST(187687920720117505)}, {UINT64CONST(11057405512036996122), UINT64CONST(150150336576094004)},
+	{UINT64CONST(6623802375033462826), UINT64CONST(240240538521750407)}, {UINT64CONST(16367088344252501231), UINT64CONST(192192430817400325)},
+	{UINT64CONST(13093670675402000985), UINT64CONST(153753944653920260)}, {UINT64CONST(2503129006933649959), UINT64CONST(246006311446272417)},
+	{UINT64CONST(13070549649772650937), UINT64CONST(196805049157017933)}, {UINT64CONST(17835137349301941396), UINT64CONST(157444039325614346)},
+	{UINT64CONST(2710778055689733971), UINT64CONST(251910462920982955)}, {UINT64CONST(2168622444551787177), UINT64CONST(201528370336786364)},
+	{UINT64CONST(5424246770383340065), UINT64CONST(161222696269429091)}, {UINT64CONST(1300097203129523457), UINT64CONST(257956314031086546)},
+	{UINT64CONST(15797473021471260058), UINT64CONST(206365051224869236)}, {UINT64CONST(8948629602435097724), UINT64CONST(165092040979895389)},
+	{UINT64CONST(3249760919670425388), UINT64CONST(264147265567832623)}, {UINT64CONST(9978506365220160957), UINT64CONST(211317812454266098)},
+	{UINT64CONST(15361502721659949412), UINT64CONST(169054249963412878)}, {UINT64CONST(2442311466204457120), UINT64CONST(270486799941460606)},
+	{UINT64CONST(16711244431931206989), UINT64CONST(216389439953168484)}, {UINT64CONST(17058344360286875914), UINT64CONST(173111551962534787)},
+	{UINT64CONST(12535955717491360170), UINT64CONST(276978483140055660)}, {UINT64CONST(10028764573993088136), UINT64CONST(221582786512044528)},
+	{UINT64CONST(15401709288678291155), UINT64CONST(177266229209635622)}, {UINT64CONST(9885339602917624555), UINT64CONST(283625966735416996)},
+	{UINT64CONST(4218922867592189321), UINT64CONST(226900773388333597)}, {UINT64CONST(14443184738299482427), UINT64CONST(181520618710666877)},
+	{UINT64CONST(4175850161155765295), UINT64CONST(145216494968533502)}, {UINT64CONST(10370709072591134795), UINT64CONST(232346391949653603)},
+	{UINT64CONST(15675264887556728482), UINT64CONST(185877113559722882)}, {UINT64CONST(5161514280561562140), UINT64CONST(148701690847778306)},
+	{UINT64CONST(879725219414678777), UINT64CONST(237922705356445290)}, {UINT64CONST(703780175531743021), UINT64CONST(190338164285156232)},
+	{UINT64CONST(11631070584651125387), UINT64CONST(152270531428124985)}, {UINT64CONST(162968861732249003), UINT64CONST(243632850284999977)},
+	{UINT64CONST(11198421533611530172), UINT64CONST(194906280227999981)}, {UINT64CONST(5269388412147313814), UINT64CONST(155925024182399985)},
+	{UINT64CONST(8431021459435702103), UINT64CONST(249480038691839976)}, {UINT64CONST(3055468352806651359), UINT64CONST(199584030953471981)},
+	{UINT64CONST(17201769941212962380), UINT64CONST(159667224762777584)}, {UINT64CONST(16454785461715008838), UINT64CONST(255467559620444135)},
+	{UINT64CONST(13163828369372007071), UINT64CONST(204374047696355308)}, {UINT64CONST(17909760324981426303), UINT64CONST(163499238157084246)},
+	{UINT64CONST(2830174816776909822), UINT64CONST(261598781051334795)}, {UINT64CONST(2264139853421527858), UINT64CONST(209279024841067836)},
+	{UINT64CONST(16568707141704863579), UINT64CONST(167423219872854268)}, {UINT64CONST(4373838538276319787), UINT64CONST(267877151796566830)},
+	{UINT64CONST(3499070830621055830), UINT64CONST(214301721437253464)}, {UINT64CONST(6488605479238754987), UINT64CONST(171441377149802771)},
+	{UINT64CONST(3003071137298187333), UINT64CONST(274306203439684434)}, {UINT64CONST(6091805724580460189), UINT64CONST(219444962751747547)},
+	{UINT64CONST(15941491023890099121), UINT64CONST(175555970201398037)}, {UINT64CONST(10748990379256517301), UINT64CONST(280889552322236860)},
+	{UINT64CONST(8599192303405213841), UINT64CONST(224711641857789488)}, {UINT64CONST(14258051472207991719), UINT64CONST(179769313486231590)}
+};
+
+static const uint64 DOUBLE_POW5_SPLIT[326][2] = {
+	{UINT64CONST(0), UINT64CONST(72057594037927936)}, {UINT64CONST(0), UINT64CONST(90071992547409920)},
+	{UINT64CONST(0), UINT64CONST(112589990684262400)}, {UINT64CONST(0), UINT64CONST(140737488355328000)},
+	{UINT64CONST(0), UINT64CONST(87960930222080000)}, {UINT64CONST(0), UINT64CONST(109951162777600000)},
+	{UINT64CONST(0), UINT64CONST(137438953472000000)}, {UINT64CONST(0), UINT64CONST(85899345920000000)},
+	{UINT64CONST(0), UINT64CONST(107374182400000000)}, {UINT64CONST(0), UINT64CONST(134217728000000000)},
+	{UINT64CONST(0), UINT64CONST(83886080000000000)}, {UINT64CONST(0), UINT64CONST(104857600000000000)},
+	{UINT64CONST(0), UINT64CONST(131072000000000000)}, {UINT64CONST(0), UINT64CONST(81920000000000000)},
+	{UINT64CONST(0), UINT64CONST(102400000000000000)}, {UINT64CONST(0), UINT64CONST(128000000000000000)},
+	{UINT64CONST(0), UINT64CONST(80000000000000000)}, {UINT64CONST(0), UINT64CONST(100000000000000000)},
+	{UINT64CONST(0), UINT64CONST(125000000000000000)}, {UINT64CONST(0), UINT64CONST(78125000000000000)},
+	{UINT64CONST(0), UINT64CONST(97656250000000000)}, {UINT64CONST(0), UINT64CONST(122070312500000000)},
+	{UINT64CONST(0), UINT64CONST(76293945312500000)}, {UINT64CONST(0), UINT64CONST(95367431640625000)},
+	{UINT64CONST(0), UINT64CONST(119209289550781250)}, {UINT64CONST(4611686018427387904), UINT64CONST(74505805969238281)},
+	{UINT64CONST(10376293541461622784), UINT64CONST(93132257461547851)}, {UINT64CONST(8358680908399640576), UINT64CONST(116415321826934814)},
+	{UINT64CONST(612489549322387456), UINT64CONST(72759576141834259)}, {UINT64CONST(14600669991935148032), UINT64CONST(90949470177292823)},
+	{UINT64CONST(13639151471491547136), UINT64CONST(113686837721616029)}, {UINT64CONST(3213881284082270208), UINT64CONST(142108547152020037)},
+	{UINT64CONST(4314518811765112832), UINT64CONST(88817841970012523)}, {UINT64CONST(781462496279003136), UINT64CONST(111022302462515654)},
+	{UINT64CONST(10200200157203529728), UINT64CONST(138777878078144567)}, {UINT64CONST(13292654125893287936), UINT64CONST(86736173798840354)},
+	{UINT64CONST(7392445620511834112), UINT64CONST(108420217248550443)}, {UINT64CONST(4628871007212404736), UINT64CONST(135525271560688054)},
+	{UINT64CONST(16728102434789916672), UINT64CONST(84703294725430033)}, {UINT64CONST(7075069988205232128), UINT64CONST(105879118406787542)},
+	{UINT64CONST(18067209522111315968), UINT64CONST(132348898008484427)}, {UINT64CONST(8986162942105878528), UINT64CONST(82718061255302767)},
+	{UINT64CONST(6621017659204960256), UINT64CONST(103397576569128459)}, {UINT64CONST(3664586055578812416), UINT64CONST(129246970711410574)},
+	{UINT64CONST(16125424340018921472), UINT64CONST(80779356694631608)}, {UINT64CONST(1710036351314100224), UINT64CONST(100974195868289511)},
+	{UINT64CONST(15972603494424788992), UINT64CONST(126217744835361888)}, {UINT64CONST(9982877184015493120), UINT64CONST(78886090522101180)},
+	{UINT64CONST(12478596480019366400), UINT64CONST(98607613152626475)}, {UINT64CONST(10986559581596820096), UINT64CONST(123259516440783094)},
+	{UINT64CONST(2254913720070624656), UINT64CONST(77037197775489434)}, {UINT64CONST(12042014186943056628), UINT64CONST(96296497219361792)},
+	{UINT64CONST(15052517733678820785), UINT64CONST(120370621524202240)}, {UINT64CONST(9407823583549262990), UINT64CONST(75231638452626400)},
+	{UINT64CONST(11759779479436578738), UINT64CONST(94039548065783000)}, {UINT64CONST(14699724349295723422), UINT64CONST(117549435082228750)},
+	{UINT64CONST(4575641699882439235), UINT64CONST(73468396926392969)}, {UINT64CONST(10331238143280436948), UINT64CONST(91835496157991211)},
+	{UINT64CONST(8302361660673158281), UINT64CONST(114794370197489014)}, {UINT64CONST(1154580038986672043), UINT64CONST(143492962746861268)},
+	{UINT64CONST(9944984561221445835), UINT64CONST(89683101716788292)}, {UINT64CONST(12431230701526807293), UINT64CONST(112103877145985365)},
+	{UINT64CONST(1703980321626345405), UINT64CONST(140129846432481707)}, {UINT64CONST(17205888765512323542), UINT64CONST(87581154020301066)},
+	{UINT64CONST(12283988920035628619), UINT64CONST(109476442525376333)}, {UINT64CONST(1519928094762372062), UINT64CONST(136845553156720417)},
+	{UINT64CONST(12479170105294952299), UINT64CONST(85528470722950260)}, {UINT64CONST(15598962631618690374), UINT64CONST(106910588403687825)},
+	{UINT64CONST(5663645234241199255), UINT64CONST(133638235504609782)}, {UINT64CONST(17374836326682913246), UINT64CONST(83523897190381113)},
+	{UINT64CONST(7883487353071477846), UINT64CONST(104404871487976392)}, {UINT64CONST(9854359191339347308), UINT64CONST(130506089359970490)},
+	{UINT64CONST(10770660513014479971), UINT64CONST(81566305849981556)}, {UINT64CONST(13463325641268099964), UINT64CONST(101957882312476945)},
+	{UINT64CONST(2994098996302961243), UINT64CONST(127447352890596182)}, {UINT64CONST(15706369927971514489), UINT64CONST(79654595556622613)},
+	{UINT64CONST(5797904354682229399), UINT64CONST(99568244445778267)}, {UINT64CONST(2635694424925398845), UINT64CONST(124460305557222834)},
+	{UINT64CONST(6258995034005762182), UINT64CONST(77787690973264271)}, {UINT64CONST(3212057774079814824), UINT64CONST(97234613716580339)},
+	{UINT64CONST(17850130272881932242), UINT64CONST(121543267145725423)}, {UINT64CONST(18073860448192289507), UINT64CONST(75964541966078389)},
+	{UINT64CONST(8757267504958198172), UINT64CONST(94955677457597987)}, {UINT64CONST(6334898362770359811), UINT64CONST(118694596821997484)},
+	{UINT64CONST(13182683513586250689), UINT64CONST(74184123013748427)}, {UINT64CONST(11866668373555425458), UINT64CONST(92730153767185534)},
+	{UINT64CONST(5609963430089506015), UINT64CONST(115912692208981918)}, {UINT64CONST(17341285199088104971), UINT64CONST(72445432630613698)},
+	{UINT64CONST(12453234462005355406), UINT64CONST(90556790788267123)}, {UINT64CONST(10954857059079306353), UINT64CONST(113195988485333904)},
+	{UINT64CONST(13693571323849132942), UINT64CONST(141494985606667380)}, {UINT64CONST(17781854114260483896), UINT64CONST(88434366004167112)},
+	{UINT64CONST(3780573569116053255), UINT64CONST(110542957505208891)}, {UINT64CONST(114030942967678664), UINT64CONST(138178696881511114)},
+	{UINT64CONST(4682955357782187069), UINT64CONST(86361685550944446)}, {UINT64CONST(15077066234082509644), UINT64CONST(107952106938680557)},
+	{UINT64CONST(5011274737320973344), UINT64CONST(134940133673350697)}, {UINT64CONST(14661261756894078100), UINT64CONST(84337583545844185)},
+	{UINT64CONST(4491519140835433913), UINT64CONST(105421979432305232)}, {UINT64CONST(5614398926044292391), UINT64CONST(131777474290381540)},
+	{UINT64CONST(12732371365632458552), UINT64CONST(82360921431488462)}, {UINT64CONST(6692092170185797382), UINT64CONST(102951151789360578)},
+	{UINT64CONST(17588487249587022536), UINT64CONST(128688939736700722)}, {UINT64CONST(15604490549419276989), UINT64CONST(80430587335437951)},
+	{UINT64CONST(14893927168346708332), UINT64CONST(100538234169297439)}, {UINT64CONST(14005722942005997511), UINT64CONST(125672792711621799)},
+	{UINT64CONST(15671105866394830300), UINT64CONST(78545495444763624)}, {UINT64CONST(1142138259283986260), UINT64CONST(98181869305954531)},
+	{UINT64CONST(15262730879387146537), UINT64CONST(122727336632443163)}, {UINT64CONST(7233363790403272633), UINT64CONST(76704585395276977)},
+	{UINT64CONST(13653390756431478696), UINT64CONST(95880731744096221)}, {UINT64CONST(3231680390257184658), UINT64CONST(119850914680120277)},
+	{UINT64CONST(4325643253124434363), UINT64CONST(74906821675075173)}, {UINT64CONST(10018740084832930858), UINT64CONST(93633527093843966)},
+	{UINT64CONST(3300053069186387764), UINT64CONST(117041908867304958)}, {UINT64CONST(15897591223523656064), UINT64CONST(73151193042065598)},
+	{UINT64CONST(10648616992549794273), UINT64CONST(91438991302581998)}, {UINT64CONST(4087399203832467033), UINT64CONST(114298739128227498)},
+	{UINT64CONST(14332621041645359599), UINT64CONST(142873423910284372)}, {UINT64CONST(18181260187883125557), UINT64CONST(89295889943927732)},
+	{UINT64CONST(4279831161144355331), UINT64CONST(111619862429909666)}, {UINT64CONST(14573160988285219972), UINT64CONST(139524828037387082)},
+	{UINT64CONST(13719911636105650386), UINT64CONST(87203017523366926)}, {UINT64CONST(7926517508277287175), UINT64CONST(109003771904208658)},
+	{UINT64CONST(684774848491833161), UINT64CONST(136254714880260823)}, {UINT64CONST(7345513307948477581), UINT64CONST(85159196800163014)},
+	{UINT64CONST(18405263671790372785), UINT64CONST(106448996000203767)}, {UINT64CONST(18394893571310578077), UINT64CONST(133061245000254709)},
+	{UINT64CONST(13802651491282805250), UINT64CONST(83163278125159193)}, {UINT64CONST(3418256308821342851), UINT64CONST(103954097656448992)},
+	{UINT64CONST(4272820386026678563), UINT64CONST(129942622070561240)}, {UINT64CONST(2670512741266674102), UINT64CONST(81214138794100775)},
+	{UINT64CONST(17173198981865506339), UINT64CONST(101517673492625968)}, {UINT64CONST(3019754653622331308), UINT64CONST(126897091865782461)},
+	{UINT64CONST(4193189667727651020), UINT64CONST(79310682416114038)}, {UINT64CONST(14464859121514339583), UINT64CONST(99138353020142547)},
+	{UINT64CONST(13469387883465536574), UINT64CONST(123922941275178184)}, {UINT64CONST(8418367427165960359), UINT64CONST(77451838296986365)},
+	{UINT64CONST(15134645302384838353), UINT64CONST(96814797871232956)}, {UINT64CONST(471562554271496325), UINT64CONST(121018497339041196)},
+	{UINT64CONST(9518098633274461011), UINT64CONST(75636560836900747)}, {UINT64CONST(7285937273165688360), UINT64CONST(94545701046125934)},
+	{UINT64CONST(18330793628311886258), UINT64CONST(118182126307657417)}, {UINT64CONST(4539216990053847055), UINT64CONST(73863828942285886)},
+	{UINT64CONST(14897393274422084627), UINT64CONST(92329786177857357)}, {UINT64CONST(4786683537745442072), UINT64CONST(115412232722321697)},
+	{UINT64CONST(14520892257159371055), UINT64CONST(72132645451451060)}, {UINT64CONST(18151115321449213818), UINT64CONST(90165806814313825)},
+	{UINT64CONST(8853836096529353561), UINT64CONST(112707258517892282)}, {UINT64CONST(1843923083806916143), UINT64CONST(140884073147365353)},
+	{UINT64CONST(12681666973447792349), UINT64CONST(88052545717103345)}, {UINT64CONST(2017025661527576725), UINT64CONST(110065682146379182)},
+	{UINT64CONST(11744654113764246714), UINT64CONST(137582102682973977)}, {UINT64CONST(422879793461572340), UINT64CONST(85988814176858736)},
+	{UINT64CONST(528599741826965425), UINT64CONST(107486017721073420)}, {UINT64CONST(660749677283706782), UINT64CONST(134357522151341775)},
+	{UINT64CONST(7330497575943398595), UINT64CONST(83973451344588609)}, {UINT64CONST(13774807988356636147), UINT64CONST(104966814180735761)},
+	{UINT64CONST(3383451930163631472), UINT64CONST(131208517725919702)}, {UINT64CONST(15949715511634433382), UINT64CONST(82005323578699813)},
+	{UINT64CONST(6102086334260878016), UINT64CONST(102506654473374767)}, {UINT64CONST(3015921899398709616), UINT64CONST(128133318091718459)},
+	{UINT64CONST(18025852251620051174), UINT64CONST(80083323807324036)}, {UINT64CONST(4085571240815512351), UINT64CONST(100104154759155046)},
+	{UINT64CONST(14330336087874166247), UINT64CONST(125130193448943807)}, {UINT64CONST(15873989082562435760), UINT64CONST(78206370905589879)},
+	{UINT64CONST(15230800334775656796), UINT64CONST(97757963631987349)}, {UINT64CONST(5203442363187407284), UINT64CONST(122197454539984187)},
+	{UINT64CONST(946308467778435600), UINT64CONST(76373409087490117)}, {UINT64CONST(5794571603150432404), UINT64CONST(95466761359362646)},
+	{UINT64CONST(16466586540792816313), UINT64CONST(119333451699203307)}, {UINT64CONST(7985773578781816244), UINT64CONST(74583407312002067)},
+	{UINT64CONST(5370530955049882401), UINT64CONST(93229259140002584)}, {UINT64CONST(6713163693812353001), UINT64CONST(116536573925003230)},
+	{UINT64CONST(18030785363914884337), UINT64CONST(72835358703127018)}, {UINT64CONST(13315109668038829614), UINT64CONST(91044198378908773)},
+	{UINT64CONST(2808829029766373305), UINT64CONST(113805247973635967)}, {UINT64CONST(17346094342490130344), UINT64CONST(142256559967044958)},
+	{UINT64CONST(6229622945628943561), UINT64CONST(88910349979403099)}, {UINT64CONST(3175342663608791547), UINT64CONST(111137937474253874)},
+	{UINT64CONST(13192550366365765242), UINT64CONST(138922421842817342)}, {UINT64CONST(3633657960551215372), UINT64CONST(86826513651760839)},
+	{UINT64CONST(18377130505971182927), UINT64CONST(108533142064701048)}, {UINT64CONST(4524669058754427043), UINT64CONST(135666427580876311)},
+	{UINT64CONST(9745447189362598758), UINT64CONST(84791517238047694)}, {UINT64CONST(2958436949848472639), UINT64CONST(105989396547559618)},
+	{UINT64CONST(12921418224165366607), UINT64CONST(132486745684449522)}, {UINT64CONST(12687572408530742033), UINT64CONST(82804216052780951)},
+	{UINT64CONST(11247779492236039638), UINT64CONST(103505270065976189)}, {UINT64CONST(224666310012885835), UINT64CONST(129381587582470237)},
+	{UINT64CONST(2446259452971747599), UINT64CONST(80863492239043898)}, {UINT64CONST(12281196353069460307), UINT64CONST(101079365298804872)},
+	{UINT64CONST(15351495441336825384), UINT64CONST(126349206623506090)}, {UINT64CONST(14206370669262903769), UINT64CONST(78968254139691306)},
+	{UINT64CONST(8534591299723853903), UINT64CONST(98710317674614133)}, {UINT64CONST(15279925143082205283), UINT64CONST(123387897093267666)},
+	{UINT64CONST(14161639232853766206), UINT64CONST(77117435683292291)}, {UINT64CONST(13090363022639819853), UINT64CONST(96396794604115364)},
+	{UINT64CONST(16362953778299774816), UINT64CONST(120495993255144205)}, {UINT64CONST(12532689120651053212), UINT64CONST(75309995784465128)},
+	{UINT64CONST(15665861400813816515), UINT64CONST(94137494730581410)}, {UINT64CONST(10358954714162494836), UINT64CONST(117671868413226763)},
+	{UINT64CONST(4168503687137865320), UINT64CONST(73544917758266727)}, {UINT64CONST(598943590494943747), UINT64CONST(91931147197833409)},
+	{UINT64CONST(5360365506546067587), UINT64CONST(114913933997291761)}, {UINT64CONST(11312142901609972388), UINT64CONST(143642417496614701)},
+	{UINT64CONST(9375932322719926695), UINT64CONST(89776510935384188)}, {UINT64CONST(11719915403399908368), UINT64CONST(112220638669230235)},
+	{UINT64CONST(10038208235822497557), UINT64CONST(140275798336537794)}, {UINT64CONST(10885566165816448877), UINT64CONST(87672373960336121)},
+	{UINT64CONST(18218643725697949000), UINT64CONST(109590467450420151)}, {UINT64CONST(18161618638695048346), UINT64CONST(136988084313025189)},
+	{UINT64CONST(13656854658398099168), UINT64CONST(85617552695640743)}, {UINT64CONST(12459382304570236056), UINT64CONST(107021940869550929)},
+	{UINT64CONST(1739169825430631358), UINT64CONST(133777426086938662)}, {UINT64CONST(14922039196176308311), UINT64CONST(83610891304336663)},
+	{UINT64CONST(14040862976792997485), UINT64CONST(104513614130420829)}, {UINT64CONST(3716020665709083144), UINT64CONST(130642017663026037)},
+	{UINT64CONST(4628355925281870917), UINT64CONST(81651261039391273)}, {UINT64CONST(10397130925029726550), UINT64CONST(102064076299239091)},
+	{UINT64CONST(8384727637859770284), UINT64CONST(127580095374048864)}, {UINT64CONST(5240454773662356427), UINT64CONST(79737559608780540)},
+	{UINT64CONST(6550568467077945534), UINT64CONST(99671949510975675)}, {UINT64CONST(3576524565420044014), UINT64CONST(124589936888719594)},
+	{UINT64CONST(6847013871814915412), UINT64CONST(77868710555449746)}, {UINT64CONST(17782139376623420074), UINT64CONST(97335888194312182)},
+	{UINT64CONST(13004302183924499284), UINT64CONST(121669860242890228)}, {UINT64CONST(17351060901807587860), UINT64CONST(76043662651806392)},
+	{UINT64CONST(3242082053549933210), UINT64CONST(95054578314757991)}, {UINT64CONST(17887660622219580224), UINT64CONST(118818222893447488)},
+	{UINT64CONST(11179787888887237640), UINT64CONST(74261389308404680)}, {UINT64CONST(13974734861109047050), UINT64CONST(92826736635505850)},
+	{UINT64CONST(8245046539531533005), UINT64CONST(116033420794382313)}, {UINT64CONST(16682369133275677888), UINT64CONST(72520887996488945)},
+	{UINT64CONST(7017903361312433648), UINT64CONST(90651109995611182)}, {UINT64CONST(17995751238495317868), UINT64CONST(113313887494513977)},
+	{UINT64CONST(8659630992836983623), UINT64CONST(141642359368142472)}, {UINT64CONST(5412269370523114764), UINT64CONST(88526474605089045)},
+	{UINT64CONST(11377022731581281359), UINT64CONST(110658093256361306)}, {UINT64CONST(4997906377621825891), UINT64CONST(138322616570451633)},
+	{UINT64CONST(14652906532082110942), UINT64CONST(86451635356532270)}, {UINT64CONST(9092761128247862869), UINT64CONST(108064544195665338)},
+	{UINT64CONST(2142579373455052779), UINT64CONST(135080680244581673)}, {UINT64CONST(12868327154477877747), UINT64CONST(84425425152863545)},
+	{UINT64CONST(2250350887815183471), UINT64CONST(105531781441079432)}, {UINT64CONST(2812938609768979339), UINT64CONST(131914726801349290)},
+	{UINT64CONST(6369772649532999991), UINT64CONST(82446704250843306)}, {UINT64CONST(17185587848771025797), UINT64CONST(103058380313554132)},
+	{UINT64CONST(3035240737254230630), UINT64CONST(128822975391942666)}, {UINT64CONST(6508711479211282048), UINT64CONST(80514359619964166)},
+	{UINT64CONST(17359261385868878368), UINT64CONST(100642949524955207)}, {UINT64CONST(17087390713908710056), UINT64CONST(125803686906194009)},
+	{UINT64CONST(3762090168551861929), UINT64CONST(78627304316371256)}, {UINT64CONST(4702612710689827411), UINT64CONST(98284130395464070)},
+	{UINT64CONST(15101637925217060072), UINT64CONST(122855162994330087)}, {UINT64CONST(16356052730901744401), UINT64CONST(76784476871456304)},
+	{UINT64CONST(1998321839917628885), UINT64CONST(95980596089320381)}, {UINT64CONST(7109588318324424010), UINT64CONST(119975745111650476)},
+	{UINT64CONST(13666864735807540814), UINT64CONST(74984840694781547)}, {UINT64CONST(12471894901332038114), UINT64CONST(93731050868476934)},
+	{UINT64CONST(6366496589810271835), UINT64CONST(117163813585596168)}, {UINT64CONST(3979060368631419896), UINT64CONST(73227383490997605)},
+	{UINT64CONST(9585511479216662775), UINT64CONST(91534229363747006)}, {UINT64CONST(2758517312166052660), UINT64CONST(114417786704683758)},
+	{UINT64CONST(12671518677062341634), UINT64CONST(143022233380854697)}, {UINT64CONST(1002170145522881665), UINT64CONST(89388895863034186)},
+	{UINT64CONST(10476084718758377889), UINT64CONST(111736119828792732)}, {UINT64CONST(13095105898447972362), UINT64CONST(139670149785990915)},
+	{UINT64CONST(5878598177316288774), UINT64CONST(87293843616244322)}, {UINT64CONST(16571619758500136775), UINT64CONST(109117304520305402)},
+	{UINT64CONST(11491152661270395161), UINT64CONST(136396630650381753)}, {UINT64CONST(264441385652915120), UINT64CONST(85247894156488596)},
+	{UINT64CONST(330551732066143900), UINT64CONST(106559867695610745)}, {UINT64CONST(5024875683510067779), UINT64CONST(133199834619513431)},
+	{UINT64CONST(10058076329834874218), UINT64CONST(83249896637195894)}, {UINT64CONST(3349223375438816964), UINT64CONST(104062370796494868)},
+	{UINT64CONST(4186529219298521205), UINT64CONST(130077963495618585)}, {UINT64CONST(14145795808130045513), UINT64CONST(81298727184761615)},
+	{UINT64CONST(13070558741735168987), UINT64CONST(101623408980952019)}, {UINT64CONST(11726512408741573330), UINT64CONST(127029261226190024)},
+	{UINT64CONST(7329070255463483331), UINT64CONST(79393288266368765)}, {UINT64CONST(13773023837756742068), UINT64CONST(99241610332960956)},
+	{UINT64CONST(17216279797195927585), UINT64CONST(124052012916201195)}, {UINT64CONST(8454331864033760789), UINT64CONST(77532508072625747)},
+	{UINT64CONST(5956228811614813082), UINT64CONST(96915635090782184)}, {UINT64CONST(7445286014518516353), UINT64CONST(121144543863477730)},
+	{UINT64CONST(9264989777501460624), UINT64CONST(75715339914673581)}, {UINT64CONST(16192923240304213684), UINT64CONST(94644174893341976)},
+	{UINT64CONST(1794409976670715490), UINT64CONST(118305218616677471)}, {UINT64CONST(8039035263060279037), UINT64CONST(73940761635423419)},
+	{UINT64CONST(5437108060397960892), UINT64CONST(92425952044279274)}, {UINT64CONST(16019757112352226923), UINT64CONST(115532440055349092)},
+	{UINT64CONST(788976158365366019), UINT64CONST(72207775034593183)}, {UINT64CONST(14821278253238871236), UINT64CONST(90259718793241478)},
+	{UINT64CONST(9303225779693813237), UINT64CONST(112824648491551848)}, {UINT64CONST(11629032224617266546), UINT64CONST(141030810614439810)},
+	{UINT64CONST(11879831158813179495), UINT64CONST(88144256634024881)}, {UINT64CONST(1014730893234310657), UINT64CONST(110180320792531102)},
+	{UINT64CONST(10491785653397664129), UINT64CONST(137725400990663877)}, {UINT64CONST(8863209042587234033), UINT64CONST(86078375619164923)},
+	{UINT64CONST(6467325284806654637), UINT64CONST(107597969523956154)}, {UINT64CONST(17307528642863094104), UINT64CONST(134497461904945192)},
+	{UINT64CONST(10817205401789433815), UINT64CONST(84060913690590745)}, {UINT64CONST(18133192770664180173), UINT64CONST(105076142113238431)},
+	{UINT64CONST(18054804944902837312), UINT64CONST(131345177641548039)}, {UINT64CONST(18201782118205355176), UINT64CONST(82090736025967524)},
+	{UINT64CONST(4305483574047142354), UINT64CONST(102613420032459406)}, {UINT64CONST(14605226504413703751), UINT64CONST(128266775040574257)},
+	{UINT64CONST(2210737537617482988), UINT64CONST(80166734400358911)}, {UINT64CONST(16598479977304017447), UINT64CONST(100208418000448638)},
+	{UINT64CONST(11524727934775246001), UINT64CONST(125260522500560798)}, {UINT64CONST(2591268940807140847), UINT64CONST(78287826562850499)},
+	{UINT64CONST(17074144231291089770), UINT64CONST(97859783203563123)}, {UINT64CONST(16730994270686474309), UINT64CONST(122324729004453904)},
+	{UINT64CONST(10456871419179046443), UINT64CONST(76452955627783690)}, {UINT64CONST(3847717237119032246), UINT64CONST(95566194534729613)},
+	{UINT64CONST(9421332564826178211), UINT64CONST(119457743168412016)}, {UINT64CONST(5888332853016361382), UINT64CONST(74661089480257510)},
+	{UINT64CONST(16583788103125227536), UINT64CONST(93326361850321887)}, {UINT64CONST(16118049110479146516), UINT64CONST(116657952312902359)},
+	{UINT64CONST(16991309721690548428), UINT64CONST(72911220195563974)}, {UINT64CONST(12015765115258409727), UINT64CONST(91139025244454968)},
+	{UINT64CONST(15019706394073012159), UINT64CONST(113923781555568710)}, {UINT64CONST(9551260955736489391), UINT64CONST(142404726944460888)},
+	{UINT64CONST(5969538097335305869), UINT64CONST(89002954340288055)}, {UINT64CONST(2850236603241744433), UINT64CONST(111253692925360069)}
+};
+
+#endif							/* RYU_D2S_FULL_TABLE_H */
diff --git a/src/common/d2s_intrinsics.h b/src/common/d2s_intrinsics.h
new file mode 100644
index 0000000..3be2327
--- /dev/null
+++ b/src/common/d2s_intrinsics.h
@@ -0,0 +1,202 @@
+/*---------------------------------------------------------------------------
+ *
+ * Ryu floating-point output for double precision.
+ *
+ * Portions Copyright (c) 2018-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/d2s_intrinsics.h
+ *
+ * This is a modification of code taken from github.com/ulfjack/ryu under the
+ * terms of the Boost license (not the Apache license). The original copyright
+ * notice follows:
+ *
+ * Copyright 2018 Ulf Adams
+ *
+ * The contents of this file may be used under the terms of the Apache
+ * License, Version 2.0.
+ *
+ *     (See accompanying file LICENSE-Apache or copy at
+ *      http://www.apache.org/licenses/LICENSE-2.0)
+ *
+ * Alternatively, the contents of this file may be used under the terms of the
+ * Boost Software License, Version 1.0.
+ *
+ *     (See accompanying file LICENSE-Boost or copy at
+ *      https://www.boost.org/LICENSE_1_0.txt)
+ *
+ * Unless required by applicable law or agreed to in writing, this software is
+ * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.
+ *
+ *---------------------------------------------------------------------------
+ */
+#ifndef RYU_D2S_INTRINSICS_H
+#define RYU_D2S_INTRINSICS_H
+
+#if defined(HAS_64_BIT_INTRINSICS)
+
+#include <intrin.h>
+
+static inline uint64
+umul128(const uint64 a, const uint64 b, uint64 *const productHi)
+{
+	return _umul128(a, b, productHi);
+}
+
+static inline uint64
+shiftright128(const uint64 lo, const uint64 hi, const uint32 dist)
+{
+	/*
+	 * For the __shiftright128 intrinsic, the shift value is always modulo 64.
+	 * In the current implementation of the double-precision version of Ryu,
+	 * the shift value is always < 64. (In the case RYU_OPTIMIZE_SIZE == 0,
+	 * the shift value is in the range [49, 58]. Otherwise in the range [2,
+	 * 59].) Check this here in case a future change requires larger shift
+	 * values. In this case this function needs to be adjusted.
+	 */
+	Assert(dist < 64);
+	return __shiftright128(lo, hi, (unsigned char) dist);
+}
+
+#else							/* defined(HAS_64_BIT_INTRINSICS) */
+
+static inline uint64
+umul128(const uint64 a, const uint64 b, uint64 *const productHi)
+{
+	/*
+	 * The casts here help MSVC to avoid calls to the __allmul library
+	 * function.
+	 */
+	const uint32 aLo = (uint32) a;
+	const uint32 aHi = (uint32) (a >> 32);
+	const uint32 bLo = (uint32) b;
+	const uint32 bHi = (uint32) (b >> 32);
+
+	const uint64 b00 = (uint64) aLo * bLo;
+	const uint64 b01 = (uint64) aLo * bHi;
+	const uint64 b10 = (uint64) aHi * bLo;
+	const uint64 b11 = (uint64) aHi * bHi;
+
+	const uint32 b00Lo = (uint32) b00;
+	const uint32 b00Hi = (uint32) (b00 >> 32);
+
+	const uint64 mid1 = b10 + b00Hi;
+	const uint32 mid1Lo = (uint32) (mid1);
+	const uint32 mid1Hi = (uint32) (mid1 >> 32);
+
+	const uint64 mid2 = b01 + mid1Lo;
+	const uint32 mid2Lo = (uint32) (mid2);
+	const uint32 mid2Hi = (uint32) (mid2 >> 32);
+
+	const uint64 pHi = b11 + mid1Hi + mid2Hi;
+	const uint64 pLo = ((uint64) mid2Lo << 32) + b00Lo;
+
+	*productHi = pHi;
+	return pLo;
+}
+
+static inline uint64
+shiftright128(const uint64 lo, const uint64 hi, const uint32 dist)
+{
+	/* We don't need to handle the case dist >= 64 here (see above). */
+	Assert(dist < 64);
+#if !defined(RYU_32_BIT_PLATFORM)
+	Assert(dist > 0);
+	return (hi << (64 - dist)) | (lo >> dist);
+#else
+	/* Avoid a 64-bit shift by taking advantage of the range of shift values. */
+	Assert(dist >= 32);
+	return (hi << (64 - dist)) | ((uint32) (lo >> 32) >> (dist - 32));
+#endif
+}
+
+#endif							/* // defined(HAS_64_BIT_INTRINSICS) */
+
+#ifdef RYU_32_BIT_PLATFORM
+
+/*  Returns the high 64 bits of the 128-bit product of a and b. */
+static inline uint64
+umulh(const uint64 a, const uint64 b)
+{
+	/*
+	 * Reuse the umul128 implementation. Optimizers will likely eliminate the
+	 * instructions used to compute the low part of the product.
+	 */
+	uint64		hi;
+
+	umul128(a, b, &hi);
+	return hi;
+}
+
+/*----
+ *  On 32-bit platforms, compilers typically generate calls to library
+ *  functions for 64-bit divisions, even if the divisor is a constant.
+ *
+ *  E.g.:
+ *  https://bugs.llvm.org/show_bug.cgi?id=37932
+ *  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=17958
+ *  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=37443
+ *
+ *  The functions here perform division-by-constant using multiplications
+ *  in the same way as 64-bit compilers would do.
+ *
+ *  NB:
+ *  The multipliers and shift values are the ones generated by clang x64
+ *  for expressions like x/5, x/10, etc.
+ *----
+ */
+
+static inline uint64
+div5(const uint64 x)
+{
+	return umulh(x, UINT64CONST(0xCCCCCCCCCCCCCCCD)) >> 2;
+}
+
+static inline uint64
+div10(const uint64 x)
+{
+	return umulh(x, UINT64CONST(0xCCCCCCCCCCCCCCCD)) >> 3;
+}
+
+static inline uint64
+div100(const uint64 x)
+{
+	return umulh(x >> 2, UINT64CONST(0x28F5C28F5C28F5C3)) >> 2;
+}
+
+static inline uint64
+div1e8(const uint64 x)
+{
+	return umulh(x, UINT64CONST(0xABCC77118461CEFD)) >> 26;
+}
+
+#else							/* RYU_32_BIT_PLATFORM */
+
+static inline uint64
+div5(const uint64 x)
+{
+	return x / 5;
+}
+
+static inline uint64
+div10(const uint64 x)
+{
+	return x / 10;
+}
+
+static inline uint64
+div100(const uint64 x)
+{
+	return x / 100;
+}
+
+static inline uint64
+div1e8(const uint64 x)
+{
+	return x / 100000000;
+}
+
+#endif							/* RYU_32_BIT_PLATFORM */
+
+#endif							/* RYU_D2S_INTRINSICS_H */
diff --git a/src/common/digit_table.h b/src/common/digit_table.h
new file mode 100644
index 0000000..483aa17
--- /dev/null
+++ b/src/common/digit_table.h
@@ -0,0 +1,21 @@
+#ifndef RYU_DIGIT_TABLE_H
+#define RYU_DIGIT_TABLE_H
+
+/*
+ * A table of all two-digit numbers. This is used to speed up decimal digit
+ * generation by copying pairs of digits into the final output.
+ */
+static const char DIGIT_TABLE[200] = {
+	'0', '0', '0', '1', '0', '2', '0', '3', '0', '4', '0', '5', '0', '6', '0', '7', '0', '8', '0', '9',
+	'1', '0', '1', '1', '1', '2', '1', '3', '1', '4', '1', '5', '1', '6', '1', '7', '1', '8', '1', '9',
+	'2', '0', '2', '1', '2', '2', '2', '3', '2', '4', '2', '5', '2', '6', '2', '7', '2', '8', '2', '9',
+	'3', '0', '3', '1', '3', '2', '3', '3', '3', '4', '3', '5', '3', '6', '3', '7', '3', '8', '3', '9',
+	'4', '0', '4', '1', '4', '2', '4', '3', '4', '4', '4', '5', '4', '6', '4', '7', '4', '8', '4', '9',
+	'5', '0', '5', '1', '5', '2', '5', '3', '5', '4', '5', '5', '5', '6', '5', '7', '5', '8', '5', '9',
+	'6', '0', '6', '1', '6', '2', '6', '3', '6', '4', '6', '5', '6', '6', '6', '7', '6', '8', '6', '9',
+	'7', '0', '7', '1', '7', '2', '7', '3', '7', '4', '7', '5', '7', '6', '7', '7', '7', '8', '7', '9',
+	'8', '0', '8', '1', '8', '2', '8', '3', '8', '4', '8', '5', '8', '6', '8', '7', '8', '8', '8', '9',
+	'9', '0', '9', '1', '9', '2', '9', '3', '9', '4', '9', '5', '9', '6', '9', '7', '9', '8', '9', '9'
+};
+
+#endif							/* RYU_DIGIT_TABLE_H */
diff --git a/src/common/encnames.c b/src/common/encnames.c
new file mode 100644
index 0000000..f2aaeb4
--- /dev/null
+++ b/src/common/encnames.c
@@ -0,0 +1,598 @@
+/*-------------------------------------------------------------------------
+ *
+ * encnames.c
+ *	  Encoding names and routines for working with them.
+ *
+ * Portions Copyright (c) 2001-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/encnames.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include <ctype.h>
+#include <unistd.h>
+
+#include "mb/pg_wchar.h"
+
+
+/* ----------
+ * All encoding names, sorted:		 *** A L P H A B E T I C ***
+ *
+ * All names must be without irrelevant chars, search routines use
+ * isalnum() chars only. It means ISO-8859-1, iso_8859-1 and Iso8859_1
+ * are always converted to 'iso88591'. All must be lower case.
+ *
+ * The table doesn't contain 'cs' aliases (like csISOLatin1). It's needed?
+ *
+ * Karel Zak, Aug 2001
+ * ----------
+ */
+typedef struct pg_encname
+{
+	const char *name;
+	pg_enc		encoding;
+} pg_encname;
+
+static const pg_encname pg_encname_tbl[] =
+{
+	{
+		"abc", PG_WIN1258
+	},							/* alias for WIN1258 */
+	{
+		"alt", PG_WIN866
+	},							/* IBM866 */
+	{
+		"big5", PG_BIG5
+	},							/* Big5; Chinese for Taiwan multibyte set */
+	{
+		"euccn", PG_EUC_CN
+	},							/* EUC-CN; Extended Unix Code for simplified
+								 * Chinese */
+	{
+		"eucjis2004", PG_EUC_JIS_2004
+	},							/* EUC-JIS-2004; Extended UNIX Code fixed
+								 * Width for Japanese, standard JIS X 0213 */
+	{
+		"eucjp", PG_EUC_JP
+	},							/* EUC-JP; Extended UNIX Code fixed Width for
+								 * Japanese, standard OSF */
+	{
+		"euckr", PG_EUC_KR
+	},							/* EUC-KR; Extended Unix Code for Korean , KS
+								 * X 1001 standard */
+	{
+		"euctw", PG_EUC_TW
+	},							/* EUC-TW; Extended Unix Code for
+								 *
+								 * traditional Chinese */
+	{
+		"gb18030", PG_GB18030
+	},							/* GB18030;GB18030 */
+	{
+		"gbk", PG_GBK
+	},							/* GBK; Chinese Windows CodePage 936
+								 * simplified Chinese */
+	{
+		"iso88591", PG_LATIN1
+	},							/* ISO-8859-1; RFC1345,KXS2 */
+	{
+		"iso885910", PG_LATIN6
+	},							/* ISO-8859-10; RFC1345,KXS2 */
+	{
+		"iso885913", PG_LATIN7
+	},							/* ISO-8859-13; RFC1345,KXS2 */
+	{
+		"iso885914", PG_LATIN8
+	},							/* ISO-8859-14; RFC1345,KXS2 */
+	{
+		"iso885915", PG_LATIN9
+	},							/* ISO-8859-15; RFC1345,KXS2 */
+	{
+		"iso885916", PG_LATIN10
+	},							/* ISO-8859-16; RFC1345,KXS2 */
+	{
+		"iso88592", PG_LATIN2
+	},							/* ISO-8859-2; RFC1345,KXS2 */
+	{
+		"iso88593", PG_LATIN3
+	},							/* ISO-8859-3; RFC1345,KXS2 */
+	{
+		"iso88594", PG_LATIN4
+	},							/* ISO-8859-4; RFC1345,KXS2 */
+	{
+		"iso88595", PG_ISO_8859_5
+	},							/* ISO-8859-5; RFC1345,KXS2 */
+	{
+		"iso88596", PG_ISO_8859_6
+	},							/* ISO-8859-6; RFC1345,KXS2 */
+	{
+		"iso88597", PG_ISO_8859_7
+	},							/* ISO-8859-7; RFC1345,KXS2 */
+	{
+		"iso88598", PG_ISO_8859_8
+	},							/* ISO-8859-8; RFC1345,KXS2 */
+	{
+		"iso88599", PG_LATIN5
+	},							/* ISO-8859-9; RFC1345,KXS2 */
+	{
+		"johab", PG_JOHAB
+	},							/* JOHAB; Extended Unix Code for simplified
+								 * Chinese */
+	{
+		"koi8", PG_KOI8R
+	},							/* _dirty_ alias for KOI8-R (backward
+								 * compatibility) */
+	{
+		"koi8r", PG_KOI8R
+	},							/* KOI8-R; RFC1489 */
+	{
+		"koi8u", PG_KOI8U
+	},							/* KOI8-U; RFC2319 */
+	{
+		"latin1", PG_LATIN1
+	},							/* alias for ISO-8859-1 */
+	{
+		"latin10", PG_LATIN10
+	},							/* alias for ISO-8859-16 */
+	{
+		"latin2", PG_LATIN2
+	},							/* alias for ISO-8859-2 */
+	{
+		"latin3", PG_LATIN3
+	},							/* alias for ISO-8859-3 */
+	{
+		"latin4", PG_LATIN4
+	},							/* alias for ISO-8859-4 */
+	{
+		"latin5", PG_LATIN5
+	},							/* alias for ISO-8859-9 */
+	{
+		"latin6", PG_LATIN6
+	},							/* alias for ISO-8859-10 */
+	{
+		"latin7", PG_LATIN7
+	},							/* alias for ISO-8859-13 */
+	{
+		"latin8", PG_LATIN8
+	},							/* alias for ISO-8859-14 */
+	{
+		"latin9", PG_LATIN9
+	},							/* alias for ISO-8859-15 */
+	{
+		"mskanji", PG_SJIS
+	},							/* alias for Shift_JIS */
+	{
+		"muleinternal", PG_MULE_INTERNAL
+	},
+	{
+		"shiftjis", PG_SJIS
+	},							/* Shift_JIS; JIS X 0202-1991 */
+
+	{
+		"shiftjis2004", PG_SHIFT_JIS_2004
+	},							/* SHIFT-JIS-2004; Shift JIS for Japanese,
+								 * standard JIS X 0213 */
+	{
+		"sjis", PG_SJIS
+	},							/* alias for Shift_JIS */
+	{
+		"sqlascii", PG_SQL_ASCII
+	},
+	{
+		"tcvn", PG_WIN1258
+	},							/* alias for WIN1258 */
+	{
+		"tcvn5712", PG_WIN1258
+	},							/* alias for WIN1258 */
+	{
+		"uhc", PG_UHC
+	},							/* UHC; Korean Windows CodePage 949 */
+	{
+		"unicode", PG_UTF8
+	},							/* alias for UTF8 */
+	{
+		"utf8", PG_UTF8
+	},							/* alias for UTF8 */
+	{
+		"vscii", PG_WIN1258
+	},							/* alias for WIN1258 */
+	{
+		"win", PG_WIN1251
+	},							/* _dirty_ alias for windows-1251 (backward
+								 * compatibility) */
+	{
+		"win1250", PG_WIN1250
+	},							/* alias for Windows-1250 */
+	{
+		"win1251", PG_WIN1251
+	},							/* alias for Windows-1251 */
+	{
+		"win1252", PG_WIN1252
+	},							/* alias for Windows-1252 */
+	{
+		"win1253", PG_WIN1253
+	},							/* alias for Windows-1253 */
+	{
+		"win1254", PG_WIN1254
+	},							/* alias for Windows-1254 */
+	{
+		"win1255", PG_WIN1255
+	},							/* alias for Windows-1255 */
+	{
+		"win1256", PG_WIN1256
+	},							/* alias for Windows-1256 */
+	{
+		"win1257", PG_WIN1257
+	},							/* alias for Windows-1257 */
+	{
+		"win1258", PG_WIN1258
+	},							/* alias for Windows-1258 */
+	{
+		"win866", PG_WIN866
+	},							/* IBM866 */
+	{
+		"win874", PG_WIN874
+	},							/* alias for Windows-874 */
+	{
+		"win932", PG_SJIS
+	},							/* alias for Shift_JIS */
+	{
+		"win936", PG_GBK
+	},							/* alias for GBK */
+	{
+		"win949", PG_UHC
+	},							/* alias for UHC */
+	{
+		"win950", PG_BIG5
+	},							/* alias for BIG5 */
+	{
+		"windows1250", PG_WIN1250
+	},							/* Windows-1251; Microsoft */
+	{
+		"windows1251", PG_WIN1251
+	},							/* Windows-1251; Microsoft */
+	{
+		"windows1252", PG_WIN1252
+	},							/* Windows-1252; Microsoft */
+	{
+		"windows1253", PG_WIN1253
+	},							/* Windows-1253; Microsoft */
+	{
+		"windows1254", PG_WIN1254
+	},							/* Windows-1254; Microsoft */
+	{
+		"windows1255", PG_WIN1255
+	},							/* Windows-1255; Microsoft */
+	{
+		"windows1256", PG_WIN1256
+	},							/* Windows-1256; Microsoft */
+	{
+		"windows1257", PG_WIN1257
+	},							/* Windows-1257; Microsoft */
+	{
+		"windows1258", PG_WIN1258
+	},							/* Windows-1258; Microsoft */
+	{
+		"windows866", PG_WIN866
+	},							/* IBM866 */
+	{
+		"windows874", PG_WIN874
+	},							/* Windows-874; Microsoft */
+	{
+		"windows932", PG_SJIS
+	},							/* alias for Shift_JIS */
+	{
+		"windows936", PG_GBK
+	},							/* alias for GBK */
+	{
+		"windows949", PG_UHC
+	},							/* alias for UHC */
+	{
+		"windows950", PG_BIG5
+	}							/* alias for BIG5 */
+};
+
+/* ----------
+ * These are "official" encoding names.
+ * XXX must be sorted by the same order as enum pg_enc (in mb/pg_wchar.h)
+ * ----------
+ */
+#ifndef WIN32
+#define DEF_ENC2NAME(name, codepage) { #name, PG_##name }
+#else
+#define DEF_ENC2NAME(name, codepage) { #name, PG_##name, codepage }
+#endif
+
+const pg_enc2name pg_enc2name_tbl[] =
+{
+	DEF_ENC2NAME(SQL_ASCII, 0),
+	DEF_ENC2NAME(EUC_JP, 20932),
+	DEF_ENC2NAME(EUC_CN, 20936),
+	DEF_ENC2NAME(EUC_KR, 51949),
+	DEF_ENC2NAME(EUC_TW, 0),
+	DEF_ENC2NAME(EUC_JIS_2004, 20932),
+	DEF_ENC2NAME(UTF8, 65001),
+	DEF_ENC2NAME(MULE_INTERNAL, 0),
+	DEF_ENC2NAME(LATIN1, 28591),
+	DEF_ENC2NAME(LATIN2, 28592),
+	DEF_ENC2NAME(LATIN3, 28593),
+	DEF_ENC2NAME(LATIN4, 28594),
+	DEF_ENC2NAME(LATIN5, 28599),
+	DEF_ENC2NAME(LATIN6, 0),
+	DEF_ENC2NAME(LATIN7, 0),
+	DEF_ENC2NAME(LATIN8, 0),
+	DEF_ENC2NAME(LATIN9, 28605),
+	DEF_ENC2NAME(LATIN10, 0),
+	DEF_ENC2NAME(WIN1256, 1256),
+	DEF_ENC2NAME(WIN1258, 1258),
+	DEF_ENC2NAME(WIN866, 866),
+	DEF_ENC2NAME(WIN874, 874),
+	DEF_ENC2NAME(KOI8R, 20866),
+	DEF_ENC2NAME(WIN1251, 1251),
+	DEF_ENC2NAME(WIN1252, 1252),
+	DEF_ENC2NAME(ISO_8859_5, 28595),
+	DEF_ENC2NAME(ISO_8859_6, 28596),
+	DEF_ENC2NAME(ISO_8859_7, 28597),
+	DEF_ENC2NAME(ISO_8859_8, 28598),
+	DEF_ENC2NAME(WIN1250, 1250),
+	DEF_ENC2NAME(WIN1253, 1253),
+	DEF_ENC2NAME(WIN1254, 1254),
+	DEF_ENC2NAME(WIN1255, 1255),
+	DEF_ENC2NAME(WIN1257, 1257),
+	DEF_ENC2NAME(KOI8U, 21866),
+	DEF_ENC2NAME(SJIS, 932),
+	DEF_ENC2NAME(BIG5, 950),
+	DEF_ENC2NAME(GBK, 936),
+	DEF_ENC2NAME(UHC, 949),
+	DEF_ENC2NAME(GB18030, 54936),
+	DEF_ENC2NAME(JOHAB, 0),
+	DEF_ENC2NAME(SHIFT_JIS_2004, 932)
+};
+
+/* ----------
+ * These are encoding names for gettext.
+ *
+ * This covers all encodings except MULE_INTERNAL, which is alien to gettext.
+ * ----------
+ */
+const pg_enc2gettext pg_enc2gettext_tbl[] =
+{
+	{PG_SQL_ASCII, "US-ASCII"},
+	{PG_UTF8, "UTF-8"},
+	{PG_LATIN1, "LATIN1"},
+	{PG_LATIN2, "LATIN2"},
+	{PG_LATIN3, "LATIN3"},
+	{PG_LATIN4, "LATIN4"},
+	{PG_ISO_8859_5, "ISO-8859-5"},
+	{PG_ISO_8859_6, "ISO_8859-6"},
+	{PG_ISO_8859_7, "ISO-8859-7"},
+	{PG_ISO_8859_8, "ISO-8859-8"},
+	{PG_LATIN5, "LATIN5"},
+	{PG_LATIN6, "LATIN6"},
+	{PG_LATIN7, "LATIN7"},
+	{PG_LATIN8, "LATIN8"},
+	{PG_LATIN9, "LATIN-9"},
+	{PG_LATIN10, "LATIN10"},
+	{PG_KOI8R, "KOI8-R"},
+	{PG_KOI8U, "KOI8-U"},
+	{PG_WIN1250, "CP1250"},
+	{PG_WIN1251, "CP1251"},
+	{PG_WIN1252, "CP1252"},
+	{PG_WIN1253, "CP1253"},
+	{PG_WIN1254, "CP1254"},
+	{PG_WIN1255, "CP1255"},
+	{PG_WIN1256, "CP1256"},
+	{PG_WIN1257, "CP1257"},
+	{PG_WIN1258, "CP1258"},
+	{PG_WIN866, "CP866"},
+	{PG_WIN874, "CP874"},
+	{PG_EUC_CN, "EUC-CN"},
+	{PG_EUC_JP, "EUC-JP"},
+	{PG_EUC_KR, "EUC-KR"},
+	{PG_EUC_TW, "EUC-TW"},
+	{PG_EUC_JIS_2004, "EUC-JP"},
+	{PG_SJIS, "SHIFT-JIS"},
+	{PG_BIG5, "BIG5"},
+	{PG_GBK, "GBK"},
+	{PG_UHC, "UHC"},
+	{PG_GB18030, "GB18030"},
+	{PG_JOHAB, "JOHAB"},
+	{PG_SHIFT_JIS_2004, "SHIFT_JISX0213"},
+	{0, NULL}
+};
+
+
+/*
+ * Table of encoding names for ICU (currently covers backend encodings only)
+ *
+ * Reference: <https://ssl.icu-project.org/icu-bin/convexp>
+ *
+ * NULL entries are not supported by ICU, or their mapping is unclear.
+ */
+static const char *const pg_enc2icu_tbl[] =
+{
+	NULL,						/* PG_SQL_ASCII */
+	"EUC-JP",					/* PG_EUC_JP */
+	"EUC-CN",					/* PG_EUC_CN */
+	"EUC-KR",					/* PG_EUC_KR */
+	"EUC-TW",					/* PG_EUC_TW */
+	NULL,						/* PG_EUC_JIS_2004 */
+	"UTF-8",					/* PG_UTF8 */
+	NULL,						/* PG_MULE_INTERNAL */
+	"ISO-8859-1",				/* PG_LATIN1 */
+	"ISO-8859-2",				/* PG_LATIN2 */
+	"ISO-8859-3",				/* PG_LATIN3 */
+	"ISO-8859-4",				/* PG_LATIN4 */
+	"ISO-8859-9",				/* PG_LATIN5 */
+	"ISO-8859-10",				/* PG_LATIN6 */
+	"ISO-8859-13",				/* PG_LATIN7 */
+	"ISO-8859-14",				/* PG_LATIN8 */
+	"ISO-8859-15",				/* PG_LATIN9 */
+	NULL,						/* PG_LATIN10 */
+	"CP1256",					/* PG_WIN1256 */
+	"CP1258",					/* PG_WIN1258 */
+	"CP866",					/* PG_WIN866 */
+	NULL,						/* PG_WIN874 */
+	"KOI8-R",					/* PG_KOI8R */
+	"CP1251",					/* PG_WIN1251 */
+	"CP1252",					/* PG_WIN1252 */
+	"ISO-8859-5",				/* PG_ISO_8859_5 */
+	"ISO-8859-6",				/* PG_ISO_8859_6 */
+	"ISO-8859-7",				/* PG_ISO_8859_7 */
+	"ISO-8859-8",				/* PG_ISO_8859_8 */
+	"CP1250",					/* PG_WIN1250 */
+	"CP1253",					/* PG_WIN1253 */
+	"CP1254",					/* PG_WIN1254 */
+	"CP1255",					/* PG_WIN1255 */
+	"CP1257",					/* PG_WIN1257 */
+	"KOI8-U",					/* PG_KOI8U */
+};
+
+
+/*
+ * Is this encoding supported by ICU?
+ */
+bool
+is_encoding_supported_by_icu(int encoding)
+{
+	if (!PG_VALID_BE_ENCODING(encoding))
+		return false;
+	return (pg_enc2icu_tbl[encoding] != NULL);
+}
+
+/*
+ * Returns ICU's name for encoding, or NULL if not supported
+ */
+const char *
+get_encoding_name_for_icu(int encoding)
+{
+	StaticAssertStmt(lengthof(pg_enc2icu_tbl) == PG_ENCODING_BE_LAST + 1,
+					 "pg_enc2icu_tbl incomplete");
+
+	if (!PG_VALID_BE_ENCODING(encoding))
+		return NULL;
+	return pg_enc2icu_tbl[encoding];
+}
+
+
+/* ----------
+ * Encoding checks, for error returns -1 else encoding id
+ * ----------
+ */
+int
+pg_valid_client_encoding(const char *name)
+{
+	int			enc;
+
+	if ((enc = pg_char_to_encoding(name)) < 0)
+		return -1;
+
+	if (!PG_VALID_FE_ENCODING(enc))
+		return -1;
+
+	return enc;
+}
+
+int
+pg_valid_server_encoding(const char *name)
+{
+	int			enc;
+
+	if ((enc = pg_char_to_encoding(name)) < 0)
+		return -1;
+
+	if (!PG_VALID_BE_ENCODING(enc))
+		return -1;
+
+	return enc;
+}
+
+int
+pg_valid_server_encoding_id(int encoding)
+{
+	return PG_VALID_BE_ENCODING(encoding);
+}
+
+/*
+ * Remove irrelevant chars from encoding name, store at *newkey
+ *
+ * (Caller's responsibility to provide a large enough buffer)
+ */
+static char *
+clean_encoding_name(const char *key, char *newkey)
+{
+	const char *p;
+	char	   *np;
+
+	for (p = key, np = newkey; *p != '\0'; p++)
+	{
+		if (isalnum((unsigned char) *p))
+		{
+			if (*p >= 'A' && *p <= 'Z')
+				*np++ = *p + 'a' - 'A';
+			else
+				*np++ = *p;
+		}
+	}
+	*np = '\0';
+	return newkey;
+}
+
+/*
+ * Search encoding by encoding name
+ *
+ * Returns encoding ID, or -1 if not recognized
+ */
+int
+pg_char_to_encoding(const char *name)
+{
+	unsigned int nel = lengthof(pg_encname_tbl);
+	const pg_encname *base = pg_encname_tbl,
+			   *last = base + nel - 1,
+			   *position;
+	int			result;
+	char		buff[NAMEDATALEN],
+			   *key;
+
+	if (name == NULL || *name == '\0')
+		return -1;
+
+	if (strlen(name) >= NAMEDATALEN)
+		return -1;				/* it's certainly not in the table */
+
+	key = clean_encoding_name(name, buff);
+
+	while (last >= base)
+	{
+		position = base + ((last - base) >> 1);
+		result = key[0] - position->name[0];
+
+		if (result == 0)
+		{
+			result = strcmp(key, position->name);
+			if (result == 0)
+				return position->encoding;
+		}
+		if (result < 0)
+			last = position - 1;
+		else
+			base = position + 1;
+	}
+	return -1;
+}
+
+const char *
+pg_encoding_to_char(int encoding)
+{
+	if (PG_VALID_ENCODING(encoding))
+	{
+		const pg_enc2name *p = &pg_enc2name_tbl[encoding];
+
+		Assert(encoding == p->encoding);
+		return p->name;
+	}
+	return "";
+}
diff --git a/src/common/exec.c b/src/common/exec.c
new file mode 100644
index 0000000..7dd2f8c
--- /dev/null
+++ b/src/common/exec.c
@@ -0,0 +1,696 @@
+/*-------------------------------------------------------------------------
+ *
+ * exec.c
+ *		Functions for finding and validating executable files
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/exec.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <signal.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+/* Inhibit mingw CRT's auto-globbing of command line arguments */
+#if defined(WIN32) && !defined(_MSC_VER)
+extern int _CRT_glob = 0; /* 0 turns off globbing; 1 turns it on */
+#endif
+
+/*
+ * Hacky solution to allow expressing both frontend and backend error reports
+ * in one macro call.  First argument of log_error is an errcode() call of
+ * some sort (ignored if FRONTEND); the rest are errmsg_internal() arguments,
+ * i.e. message string and any parameters for it.
+ *
+ * Caller must provide the gettext wrapper around the message string, if
+ * appropriate, so that it gets translated in the FRONTEND case; this
+ * motivates using errmsg_internal() not errmsg().  We handle appending a
+ * newline, if needed, inside the macro, so that there's only one translatable
+ * string per call not two.
+ */
+#ifndef FRONTEND
+#define log_error(errcodefn, ...) \
+	ereport(LOG, (errcodefn, errmsg_internal(__VA_ARGS__)))
+#else
+#define log_error(errcodefn, ...) \
+	(fprintf(stderr, __VA_ARGS__), fputc('\n', stderr))
+#endif
+
+#ifdef _MSC_VER
+#define getcwd(cwd,len)  GetCurrentDirectory(len, cwd)
+#endif
+
+static int	resolve_symlinks(char *path);
+
+#ifdef WIN32
+static BOOL GetTokenUser(HANDLE hToken, PTOKEN_USER *ppTokenUser);
+#endif
+
+/*
+ * validate_exec -- validate "path" as an executable file
+ *
+ * returns 0 if the file is found and no error is encountered.
+ *		  -1 if the regular file "path" does not exist or cannot be executed.
+ *		  -2 if the file is otherwise valid but cannot be read.
+ */
+int
+validate_exec(const char *path)
+{
+	struct stat buf;
+	int			is_r;
+	int			is_x;
+
+#ifdef WIN32
+	char		path_exe[MAXPGPATH + sizeof(".exe") - 1];
+
+	/* Win32 requires a .exe suffix for stat() */
+	if (strlen(path) >= strlen(".exe") &&
+		pg_strcasecmp(path + strlen(path) - strlen(".exe"), ".exe") != 0)
+	{
+		strlcpy(path_exe, path, sizeof(path_exe) - 4);
+		strcat(path_exe, ".exe");
+		path = path_exe;
+	}
+#endif
+
+	/*
+	 * Ensure that the file exists and is a regular file.
+	 *
+	 * XXX if you have a broken system where stat() looks at the symlink
+	 * instead of the underlying file, you lose.
+	 */
+	if (stat(path, &buf) < 0)
+		return -1;
+
+	if (!S_ISREG(buf.st_mode))
+		return -1;
+
+	/*
+	 * Ensure that the file is both executable and readable (required for
+	 * dynamic loading).
+	 */
+#ifndef WIN32
+	is_r = (access(path, R_OK) == 0);
+	is_x = (access(path, X_OK) == 0);
+#else
+	is_r = buf.st_mode & S_IRUSR;
+	is_x = buf.st_mode & S_IXUSR;
+#endif
+	return is_x ? (is_r ? 0 : -2) : -1;
+}
+
+
+/*
+ * find_my_exec -- find an absolute path to a valid executable
+ *
+ *	argv0 is the name passed on the command line
+ *	retpath is the output area (must be of size MAXPGPATH)
+ *	Returns 0 if OK, -1 if error.
+ *
+ * The reason we have to work so hard to find an absolute path is that
+ * on some platforms we can't do dynamic loading unless we know the
+ * executable's location.  Also, we need a full path not a relative
+ * path because we will later change working directory.  Finally, we want
+ * a true path not a symlink location, so that we can locate other files
+ * that are part of our installation relative to the executable.
+ */
+int
+find_my_exec(const char *argv0, char *retpath)
+{
+	char		cwd[MAXPGPATH],
+				test_path[MAXPGPATH];
+	char	   *path;
+
+	if (!getcwd(cwd, MAXPGPATH))
+	{
+		log_error(errcode_for_file_access(),
+				  _("could not identify current directory: %m"));
+		return -1;
+	}
+
+	/*
+	 * If argv0 contains a separator, then PATH wasn't used.
+	 */
+	if (first_dir_separator(argv0) != NULL)
+	{
+		if (is_absolute_path(argv0))
+			strlcpy(retpath, argv0, MAXPGPATH);
+		else
+			join_path_components(retpath, cwd, argv0);
+		canonicalize_path(retpath);
+
+		if (validate_exec(retpath) == 0)
+			return resolve_symlinks(retpath);
+
+		log_error(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				  _("invalid binary \"%s\""), retpath);
+		return -1;
+	}
+
+#ifdef WIN32
+	/* Win32 checks the current directory first for names without slashes */
+	join_path_components(retpath, cwd, argv0);
+	if (validate_exec(retpath) == 0)
+		return resolve_symlinks(retpath);
+#endif
+
+	/*
+	 * Since no explicit path was supplied, the user must have been relying on
+	 * PATH.  We'll search the same PATH.
+	 */
+	if ((path = getenv("PATH")) && *path)
+	{
+		char	   *startp = NULL,
+				   *endp = NULL;
+
+		do
+		{
+			if (!startp)
+				startp = path;
+			else
+				startp = endp + 1;
+
+			endp = first_path_var_separator(startp);
+			if (!endp)
+				endp = startp + strlen(startp); /* point to end */
+
+			strlcpy(test_path, startp, Min(endp - startp + 1, MAXPGPATH));
+
+			if (is_absolute_path(test_path))
+				join_path_components(retpath, test_path, argv0);
+			else
+			{
+				join_path_components(retpath, cwd, test_path);
+				join_path_components(retpath, retpath, argv0);
+			}
+			canonicalize_path(retpath);
+
+			switch (validate_exec(retpath))
+			{
+				case 0:			/* found ok */
+					return resolve_symlinks(retpath);
+				case -1:		/* wasn't even a candidate, keep looking */
+					break;
+				case -2:		/* found but disqualified */
+					log_error(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+							  _("could not read binary \"%s\""),
+							  retpath);
+					break;
+			}
+		} while (*endp);
+	}
+
+	log_error(errcode(ERRCODE_UNDEFINED_FILE),
+			  _("could not find a \"%s\" to execute"), argv0);
+	return -1;
+}
+
+
+/*
+ * resolve_symlinks - resolve symlinks to the underlying file
+ *
+ * Replace "path" by the absolute path to the referenced file.
+ *
+ * Returns 0 if OK, -1 if error.
+ *
+ * Note: we are not particularly tense about producing nice error messages
+ * because we are not really expecting error here; we just determined that
+ * the symlink does point to a valid executable.
+ */
+static int
+resolve_symlinks(char *path)
+{
+#ifdef HAVE_READLINK
+	struct stat buf;
+	char		orig_wd[MAXPGPATH],
+				link_buf[MAXPGPATH];
+	char	   *fname;
+
+	/*
+	 * To resolve a symlink properly, we have to chdir into its directory and
+	 * then chdir to where the symlink points; otherwise we may fail to
+	 * resolve relative links correctly (consider cases involving mount
+	 * points, for example).  After following the final symlink, we use
+	 * getcwd() to figure out where the heck we're at.
+	 *
+	 * One might think we could skip all this if path doesn't point to a
+	 * symlink to start with, but that's wrong.  We also want to get rid of
+	 * any directory symlinks that are present in the given path. We expect
+	 * getcwd() to give us an accurate, symlink-free path.
+	 */
+	if (!getcwd(orig_wd, MAXPGPATH))
+	{
+		log_error(errcode_for_file_access(),
+				  _("could not identify current directory: %m"));
+		return -1;
+	}
+
+	for (;;)
+	{
+		char	   *lsep;
+		int			rllen;
+
+		lsep = last_dir_separator(path);
+		if (lsep)
+		{
+			*lsep = '\0';
+			if (chdir(path) == -1)
+			{
+				log_error(errcode_for_file_access(),
+						  _("could not change directory to \"%s\": %m"), path);
+				return -1;
+			}
+			fname = lsep + 1;
+		}
+		else
+			fname = path;
+
+		if (lstat(fname, &buf) < 0 ||
+			!S_ISLNK(buf.st_mode))
+			break;
+
+		errno = 0;
+		rllen = readlink(fname, link_buf, sizeof(link_buf));
+		if (rllen < 0 || rllen >= sizeof(link_buf))
+		{
+			log_error(errcode_for_file_access(),
+					  _("could not read symbolic link \"%s\": %m"), fname);
+			return -1;
+		}
+		link_buf[rllen] = '\0';
+		strcpy(path, link_buf);
+	}
+
+	/* must copy final component out of 'path' temporarily */
+	strlcpy(link_buf, fname, sizeof(link_buf));
+
+	if (!getcwd(path, MAXPGPATH))
+	{
+		log_error(errcode_for_file_access(),
+				  _("could not identify current directory: %m"));
+		return -1;
+	}
+	join_path_components(path, path, link_buf);
+	canonicalize_path(path);
+
+	if (chdir(orig_wd) == -1)
+	{
+		log_error(errcode_for_file_access(),
+				  _("could not change directory to \"%s\": %m"), orig_wd);
+		return -1;
+	}
+#endif							/* HAVE_READLINK */
+
+	return 0;
+}
+
+
+/*
+ * Find another program in our binary's directory,
+ * then make sure it is the proper version.
+ */
+int
+find_other_exec(const char *argv0, const char *target,
+				const char *versionstr, char *retpath)
+{
+	char		cmd[MAXPGPATH];
+	char		line[MAXPGPATH];
+
+	if (find_my_exec(argv0, retpath) < 0)
+		return -1;
+
+	/* Trim off program name and keep just directory */
+	*last_dir_separator(retpath) = '\0';
+	canonicalize_path(retpath);
+
+	/* Now append the other program's name */
+	snprintf(retpath + strlen(retpath), MAXPGPATH - strlen(retpath),
+			 "/%s%s", target, EXE);
+
+	if (validate_exec(retpath) != 0)
+		return -1;
+
+	snprintf(cmd, sizeof(cmd), "\"%s\" -V", retpath);
+
+	if (!pipe_read_line(cmd, line, sizeof(line)))
+		return -1;
+
+	if (strcmp(line, versionstr) != 0)
+		return -2;
+
+	return 0;
+}
+
+
+/*
+ * Execute a command in a pipe and read the first line from it.
+ */
+char *
+pipe_read_line(char *cmd, char *line, int maxsize)
+{
+	FILE	   *pgver;
+
+	/* flush output buffers in case popen does not... */
+	fflush(stdout);
+	fflush(stderr);
+
+	errno = 0;
+	if ((pgver = popen(cmd, "r")) == NULL)
+	{
+		perror("popen failure");
+		return NULL;
+	}
+
+	errno = 0;
+	if (fgets(line, maxsize, pgver) == NULL)
+	{
+		if (feof(pgver))
+			fprintf(stderr, "no data was returned by command \"%s\"\n", cmd);
+		else
+			perror("fgets failure");
+		pclose(pgver);			/* no error checking */
+		return NULL;
+	}
+
+	if (pclose_check(pgver))
+		return NULL;
+
+	return line;
+}
+
+
+/*
+ * pclose() plus useful error reporting
+ */
+int
+pclose_check(FILE *stream)
+{
+	int			exitstatus;
+	char	   *reason;
+
+	exitstatus = pclose(stream);
+
+	if (exitstatus == 0)
+		return 0;				/* all is well */
+
+	if (exitstatus == -1)
+	{
+		/* pclose() itself failed, and hopefully set errno */
+		log_error(errcode(ERRCODE_SYSTEM_ERROR),
+				  _("%s() failed: %m"), "pclose");
+	}
+	else
+	{
+		reason = wait_result_to_str(exitstatus);
+		log_error(errcode(ERRCODE_SYSTEM_ERROR),
+				  "%s", reason);
+		pfree(reason);
+	}
+	return exitstatus;
+}
+
+/*
+ *	set_pglocale_pgservice
+ *
+ *	Set application-specific locale and service directory
+ *
+ *	This function takes the value of argv[0] rather than a full path.
+ *
+ * (You may be wondering why this is in exec.c.  It requires this module's
+ * services and doesn't introduce any new dependencies, so this seems as
+ * good as anyplace.)
+ */
+void
+set_pglocale_pgservice(const char *argv0, const char *app)
+{
+	char		path[MAXPGPATH];
+	char		my_exec_path[MAXPGPATH];
+
+	/* don't set LC_ALL in the backend */
+	if (strcmp(app, PG_TEXTDOMAIN("postgres")) != 0)
+	{
+		setlocale(LC_ALL, "");
+
+		/*
+		 * One could make a case for reproducing here PostmasterMain()'s test
+		 * for whether the process is multithreaded.  Unlike the postmaster,
+		 * no frontend program calls sigprocmask() or otherwise provides for
+		 * mutual exclusion between signal handlers.  While frontends using
+		 * fork(), if multithreaded, are formally exposed to undefined
+		 * behavior, we have not witnessed a concrete bug.  Therefore,
+		 * complaining about multithreading here may be mere pedantry.
+		 */
+	}
+
+	if (find_my_exec(argv0, my_exec_path) < 0)
+		return;
+
+#ifdef ENABLE_NLS
+	get_locale_path(my_exec_path, path);
+	bindtextdomain(app, path);
+	textdomain(app);
+	/* set for libpq to use, but don't override existing setting */
+	setenv("PGLOCALEDIR", path, 0);
+#endif
+
+	if (getenv("PGSYSCONFDIR") == NULL)
+	{
+		get_etc_path(my_exec_path, path);
+		/* set for libpq to use */
+		setenv("PGSYSCONFDIR", path, 0);
+	}
+}
+
+#ifdef WIN32
+
+/*
+ * AddUserToTokenDacl(HANDLE hToken)
+ *
+ * This function adds the current user account to the restricted
+ * token used when we create a restricted process.
+ *
+ * This is required because of some security changes in Windows
+ * that appeared in patches to XP/2K3 and in Vista/2008.
+ *
+ * On these machines, the Administrator account is not included in
+ * the default DACL - you just get Administrators + System. For
+ * regular users you get User + System. Because we strip Administrators
+ * when we create the restricted token, we are left with only System
+ * in the DACL which leads to access denied errors for later CreatePipe()
+ * and CreateProcess() calls when running as Administrator.
+ *
+ * This function fixes this problem by modifying the DACL of the
+ * token the process will use, and explicitly re-adding the current
+ * user account.  This is still secure because the Administrator account
+ * inherits its privileges from the Administrators group - it doesn't
+ * have any of its own.
+ */
+BOOL
+AddUserToTokenDacl(HANDLE hToken)
+{
+	int			i;
+	ACL_SIZE_INFORMATION asi;
+	ACCESS_ALLOWED_ACE *pace;
+	DWORD		dwNewAclSize;
+	DWORD		dwSize = 0;
+	DWORD		dwTokenInfoLength = 0;
+	PACL		pacl = NULL;
+	PTOKEN_USER pTokenUser = NULL;
+	TOKEN_DEFAULT_DACL tddNew;
+	TOKEN_DEFAULT_DACL *ptdd = NULL;
+	TOKEN_INFORMATION_CLASS tic = TokenDefaultDacl;
+	BOOL		ret = FALSE;
+
+	/* Figure out the buffer size for the DACL info */
+	if (!GetTokenInformation(hToken, tic, (LPVOID) NULL, dwTokenInfoLength, &dwSize))
+	{
+		if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+		{
+			ptdd = (TOKEN_DEFAULT_DACL *) LocalAlloc(LPTR, dwSize);
+			if (ptdd == NULL)
+			{
+				log_error(errcode(ERRCODE_OUT_OF_MEMORY),
+						  _("out of memory"));
+				goto cleanup;
+			}
+
+			if (!GetTokenInformation(hToken, tic, (LPVOID) ptdd, dwSize, &dwSize))
+			{
+				log_error(errcode(ERRCODE_SYSTEM_ERROR),
+						  "could not get token information: error code %lu",
+						  GetLastError());
+				goto cleanup;
+			}
+		}
+		else
+		{
+			log_error(errcode(ERRCODE_SYSTEM_ERROR),
+					  "could not get token information buffer size: error code %lu",
+					  GetLastError());
+			goto cleanup;
+		}
+	}
+
+	/* Get the ACL info */
+	if (!GetAclInformation(ptdd->DefaultDacl, (LPVOID) &asi,
+						   (DWORD) sizeof(ACL_SIZE_INFORMATION),
+						   AclSizeInformation))
+	{
+		log_error(errcode(ERRCODE_SYSTEM_ERROR),
+				  "could not get ACL information: error code %lu",
+				  GetLastError());
+		goto cleanup;
+	}
+
+	/* Get the current user SID */
+	if (!GetTokenUser(hToken, &pTokenUser))
+		goto cleanup;			/* callee printed a message */
+
+	/* Figure out the size of the new ACL */
+	dwNewAclSize = asi.AclBytesInUse + sizeof(ACCESS_ALLOWED_ACE) +
+		GetLengthSid(pTokenUser->User.Sid) - sizeof(DWORD);
+
+	/* Allocate the ACL buffer & initialize it */
+	pacl = (PACL) LocalAlloc(LPTR, dwNewAclSize);
+	if (pacl == NULL)
+	{
+		log_error(errcode(ERRCODE_OUT_OF_MEMORY),
+				  _("out of memory"));
+		goto cleanup;
+	}
+
+	if (!InitializeAcl(pacl, dwNewAclSize, ACL_REVISION))
+	{
+		log_error(errcode(ERRCODE_SYSTEM_ERROR),
+				  "could not initialize ACL: error code %lu", GetLastError());
+		goto cleanup;
+	}
+
+	/* Loop through the existing ACEs, and build the new ACL */
+	for (i = 0; i < (int) asi.AceCount; i++)
+	{
+		if (!GetAce(ptdd->DefaultDacl, i, (LPVOID *) &pace))
+		{
+			log_error(errcode(ERRCODE_SYSTEM_ERROR),
+					  "could not get ACE: error code %lu", GetLastError());
+			goto cleanup;
+		}
+
+		if (!AddAce(pacl, ACL_REVISION, MAXDWORD, pace, ((PACE_HEADER) pace)->AceSize))
+		{
+			log_error(errcode(ERRCODE_SYSTEM_ERROR),
+					  "could not add ACE: error code %lu", GetLastError());
+			goto cleanup;
+		}
+	}
+
+	/* Add the new ACE for the current user */
+	if (!AddAccessAllowedAceEx(pacl, ACL_REVISION, OBJECT_INHERIT_ACE, GENERIC_ALL, pTokenUser->User.Sid))
+	{
+		log_error(errcode(ERRCODE_SYSTEM_ERROR),
+				  "could not add access allowed ACE: error code %lu",
+				  GetLastError());
+		goto cleanup;
+	}
+
+	/* Set the new DACL in the token */
+	tddNew.DefaultDacl = pacl;
+
+	if (!SetTokenInformation(hToken, tic, (LPVOID) &tddNew, dwNewAclSize))
+	{
+		log_error(errcode(ERRCODE_SYSTEM_ERROR),
+				  "could not set token information: error code %lu",
+				  GetLastError());
+		goto cleanup;
+	}
+
+	ret = TRUE;
+
+cleanup:
+	if (pTokenUser)
+		LocalFree((HLOCAL) pTokenUser);
+
+	if (pacl)
+		LocalFree((HLOCAL) pacl);
+
+	if (ptdd)
+		LocalFree((HLOCAL) ptdd);
+
+	return ret;
+}
+
+/*
+ * GetTokenUser(HANDLE hToken, PTOKEN_USER *ppTokenUser)
+ *
+ * Get the users token information from a process token.
+ *
+ * The caller of this function is responsible for calling LocalFree() on the
+ * returned TOKEN_USER memory.
+ */
+static BOOL
+GetTokenUser(HANDLE hToken, PTOKEN_USER *ppTokenUser)
+{
+	DWORD		dwLength;
+
+	*ppTokenUser = NULL;
+
+	if (!GetTokenInformation(hToken,
+							 TokenUser,
+							 NULL,
+							 0,
+							 &dwLength))
+	{
+		if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+		{
+			*ppTokenUser = (PTOKEN_USER) LocalAlloc(LPTR, dwLength);
+
+			if (*ppTokenUser == NULL)
+			{
+				log_error(errcode(ERRCODE_OUT_OF_MEMORY),
+						  _("out of memory"));
+				return FALSE;
+			}
+		}
+		else
+		{
+			log_error(errcode(ERRCODE_SYSTEM_ERROR),
+					  "could not get token information buffer size: error code %lu",
+					  GetLastError());
+			return FALSE;
+		}
+	}
+
+	if (!GetTokenInformation(hToken,
+							 TokenUser,
+							 *ppTokenUser,
+							 dwLength,
+							 &dwLength))
+	{
+		LocalFree(*ppTokenUser);
+		*ppTokenUser = NULL;
+
+		log_error(errcode(ERRCODE_SYSTEM_ERROR),
+				  "could not get token information: error code %lu",
+				  GetLastError());
+		return FALSE;
+	}
+
+	/* Memory in *ppTokenUser is LocalFree():d by the caller */
+	return TRUE;
+}
+
+#endif
diff --git a/src/common/f2s.c b/src/common/f2s.c
new file mode 100644
index 0000000..6a9949e
--- /dev/null
+++ b/src/common/f2s.c
@@ -0,0 +1,803 @@
+/*---------------------------------------------------------------------------
+ *
+ * Ryu floating-point output for single precision.
+ *
+ * Portions Copyright (c) 2018-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/f2s.c
+ *
+ * This is a modification of code taken from github.com/ulfjack/ryu under the
+ * terms of the Boost license (not the Apache license). The original copyright
+ * notice follows:
+ *
+ * Copyright 2018 Ulf Adams
+ *
+ * The contents of this file may be used under the terms of the Apache
+ * License, Version 2.0.
+ *
+ *     (See accompanying file LICENSE-Apache or copy at
+ *      http://www.apache.org/licenses/LICENSE-2.0)
+ *
+ * Alternatively, the contents of this file may be used under the terms of the
+ * Boost Software License, Version 1.0.
+ *
+ *     (See accompanying file LICENSE-Boost or copy at
+ *      https://www.boost.org/LICENSE_1_0.txt)
+ *
+ * Unless required by applicable law or agreed to in writing, this software is
+ * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.
+ *
+ *---------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/shortest_dec.h"
+#include "digit_table.h"
+#include "ryu_common.h"
+
+#define FLOAT_MANTISSA_BITS 23
+#define FLOAT_EXPONENT_BITS 8
+#define FLOAT_BIAS 127
+
+/*
+ * This table is generated (by the upstream) by PrintFloatLookupTable,
+ * and modified (by us) to add UINT64CONST.
+ */
+#define FLOAT_POW5_INV_BITCOUNT 59
+static const uint64 FLOAT_POW5_INV_SPLIT[31] = {
+	UINT64CONST(576460752303423489), UINT64CONST(461168601842738791), UINT64CONST(368934881474191033), UINT64CONST(295147905179352826),
+	UINT64CONST(472236648286964522), UINT64CONST(377789318629571618), UINT64CONST(302231454903657294), UINT64CONST(483570327845851670),
+	UINT64CONST(386856262276681336), UINT64CONST(309485009821345069), UINT64CONST(495176015714152110), UINT64CONST(396140812571321688),
+	UINT64CONST(316912650057057351), UINT64CONST(507060240091291761), UINT64CONST(405648192073033409), UINT64CONST(324518553658426727),
+	UINT64CONST(519229685853482763), UINT64CONST(415383748682786211), UINT64CONST(332306998946228969), UINT64CONST(531691198313966350),
+	UINT64CONST(425352958651173080), UINT64CONST(340282366920938464), UINT64CONST(544451787073501542), UINT64CONST(435561429658801234),
+	UINT64CONST(348449143727040987), UINT64CONST(557518629963265579), UINT64CONST(446014903970612463), UINT64CONST(356811923176489971),
+	UINT64CONST(570899077082383953), UINT64CONST(456719261665907162), UINT64CONST(365375409332725730)
+};
+#define FLOAT_POW5_BITCOUNT 61
+static const uint64 FLOAT_POW5_SPLIT[47] = {
+	UINT64CONST(1152921504606846976), UINT64CONST(1441151880758558720), UINT64CONST(1801439850948198400), UINT64CONST(2251799813685248000),
+	UINT64CONST(1407374883553280000), UINT64CONST(1759218604441600000), UINT64CONST(2199023255552000000), UINT64CONST(1374389534720000000),
+	UINT64CONST(1717986918400000000), UINT64CONST(2147483648000000000), UINT64CONST(1342177280000000000), UINT64CONST(1677721600000000000),
+	UINT64CONST(2097152000000000000), UINT64CONST(1310720000000000000), UINT64CONST(1638400000000000000), UINT64CONST(2048000000000000000),
+	UINT64CONST(1280000000000000000), UINT64CONST(1600000000000000000), UINT64CONST(2000000000000000000), UINT64CONST(1250000000000000000),
+	UINT64CONST(1562500000000000000), UINT64CONST(1953125000000000000), UINT64CONST(1220703125000000000), UINT64CONST(1525878906250000000),
+	UINT64CONST(1907348632812500000), UINT64CONST(1192092895507812500), UINT64CONST(1490116119384765625), UINT64CONST(1862645149230957031),
+	UINT64CONST(1164153218269348144), UINT64CONST(1455191522836685180), UINT64CONST(1818989403545856475), UINT64CONST(2273736754432320594),
+	UINT64CONST(1421085471520200371), UINT64CONST(1776356839400250464), UINT64CONST(2220446049250313080), UINT64CONST(1387778780781445675),
+	UINT64CONST(1734723475976807094), UINT64CONST(2168404344971008868), UINT64CONST(1355252715606880542), UINT64CONST(1694065894508600678),
+	UINT64CONST(2117582368135750847), UINT64CONST(1323488980084844279), UINT64CONST(1654361225106055349), UINT64CONST(2067951531382569187),
+	UINT64CONST(1292469707114105741), UINT64CONST(1615587133892632177), UINT64CONST(2019483917365790221)
+};
+
+static inline uint32
+pow5Factor(uint32 value)
+{
+	uint32		count = 0;
+
+	for (;;)
+	{
+		Assert(value != 0);
+		const uint32 q = value / 5;
+		const uint32 r = value % 5;
+
+		if (r != 0)
+			break;
+
+		value = q;
+		++count;
+	}
+	return count;
+}
+
+/*  Returns true if value is divisible by 5^p. */
+static inline bool
+multipleOfPowerOf5(const uint32 value, const uint32 p)
+{
+	return pow5Factor(value) >= p;
+}
+
+/*  Returns true if value is divisible by 2^p. */
+static inline bool
+multipleOfPowerOf2(const uint32 value, const uint32 p)
+{
+	/* return __builtin_ctz(value) >= p; */
+	return (value & ((1u << p) - 1)) == 0;
+}
+
+/*
+ * It seems to be slightly faster to avoid uint128_t here, although the
+ * generated code for uint128_t looks slightly nicer.
+ */
+static inline uint32
+mulShift(const uint32 m, const uint64 factor, const int32 shift)
+{
+	/*
+	 * The casts here help MSVC to avoid calls to the __allmul library
+	 * function.
+	 */
+	const uint32 factorLo = (uint32) (factor);
+	const uint32 factorHi = (uint32) (factor >> 32);
+	const uint64 bits0 = (uint64) m * factorLo;
+	const uint64 bits1 = (uint64) m * factorHi;
+
+	Assert(shift > 32);
+
+#ifdef RYU_32_BIT_PLATFORM
+
+	/*
+	 * On 32-bit platforms we can avoid a 64-bit shift-right since we only
+	 * need the upper 32 bits of the result and the shift value is > 32.
+	 */
+	const uint32 bits0Hi = (uint32) (bits0 >> 32);
+	uint32		bits1Lo = (uint32) (bits1);
+	uint32		bits1Hi = (uint32) (bits1 >> 32);
+
+	bits1Lo += bits0Hi;
+	bits1Hi += (bits1Lo < bits0Hi);
+
+	const int32 s = shift - 32;
+
+	return (bits1Hi << (32 - s)) | (bits1Lo >> s);
+
+#else							/* RYU_32_BIT_PLATFORM */
+
+	const uint64 sum = (bits0 >> 32) + bits1;
+	const uint64 shiftedSum = sum >> (shift - 32);
+
+	Assert(shiftedSum <= PG_UINT32_MAX);
+	return (uint32) shiftedSum;
+
+#endif							/* RYU_32_BIT_PLATFORM */
+}
+
+static inline uint32
+mulPow5InvDivPow2(const uint32 m, const uint32 q, const int32 j)
+{
+	return mulShift(m, FLOAT_POW5_INV_SPLIT[q], j);
+}
+
+static inline uint32
+mulPow5divPow2(const uint32 m, const uint32 i, const int32 j)
+{
+	return mulShift(m, FLOAT_POW5_SPLIT[i], j);
+}
+
+static inline uint32
+decimalLength(const uint32 v)
+{
+	/* Function precondition: v is not a 10-digit number. */
+	/* (9 digits are sufficient for round-tripping.) */
+	Assert(v < 1000000000);
+	if (v >= 100000000)
+	{
+		return 9;
+	}
+	if (v >= 10000000)
+	{
+		return 8;
+	}
+	if (v >= 1000000)
+	{
+		return 7;
+	}
+	if (v >= 100000)
+	{
+		return 6;
+	}
+	if (v >= 10000)
+	{
+		return 5;
+	}
+	if (v >= 1000)
+	{
+		return 4;
+	}
+	if (v >= 100)
+	{
+		return 3;
+	}
+	if (v >= 10)
+	{
+		return 2;
+	}
+	return 1;
+}
+
+/*  A floating decimal representing m * 10^e. */
+typedef struct floating_decimal_32
+{
+	uint32		mantissa;
+	int32		exponent;
+} floating_decimal_32;
+
+static inline floating_decimal_32
+f2d(const uint32 ieeeMantissa, const uint32 ieeeExponent)
+{
+	int32		e2;
+	uint32		m2;
+
+	if (ieeeExponent == 0)
+	{
+		/* We subtract 2 so that the bounds computation has 2 additional bits. */
+		e2 = 1 - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2;
+		m2 = ieeeMantissa;
+	}
+	else
+	{
+		e2 = ieeeExponent - FLOAT_BIAS - FLOAT_MANTISSA_BITS - 2;
+		m2 = (1u << FLOAT_MANTISSA_BITS) | ieeeMantissa;
+	}
+
+#if STRICTLY_SHORTEST
+	const bool	even = (m2 & 1) == 0;
+	const bool	acceptBounds = even;
+#else
+	const bool	acceptBounds = false;
+#endif
+
+	/* Step 2: Determine the interval of legal decimal representations. */
+	const uint32 mv = 4 * m2;
+	const uint32 mp = 4 * m2 + 2;
+
+	/* Implicit bool -> int conversion. True is 1, false is 0. */
+	const uint32 mmShift = ieeeMantissa != 0 || ieeeExponent <= 1;
+	const uint32 mm = 4 * m2 - 1 - mmShift;
+
+	/* Step 3: Convert to a decimal power base using 64-bit arithmetic. */
+	uint32		vr,
+				vp,
+				vm;
+	int32		e10;
+	bool		vmIsTrailingZeros = false;
+	bool		vrIsTrailingZeros = false;
+	uint8		lastRemovedDigit = 0;
+
+	if (e2 >= 0)
+	{
+		const uint32 q = log10Pow2(e2);
+
+		e10 = q;
+
+		const int32 k = FLOAT_POW5_INV_BITCOUNT + pow5bits(q) - 1;
+		const int32 i = -e2 + q + k;
+
+		vr = mulPow5InvDivPow2(mv, q, i);
+		vp = mulPow5InvDivPow2(mp, q, i);
+		vm = mulPow5InvDivPow2(mm, q, i);
+
+		if (q != 0 && (vp - 1) / 10 <= vm / 10)
+		{
+			/*
+			 * We need to know one removed digit even if we are not going to
+			 * loop below. We could use q = X - 1 above, except that would
+			 * require 33 bits for the result, and we've found that 32-bit
+			 * arithmetic is faster even on 64-bit machines.
+			 */
+			const int32 l = FLOAT_POW5_INV_BITCOUNT + pow5bits(q - 1) - 1;
+
+			lastRemovedDigit = (uint8) (mulPow5InvDivPow2(mv, q - 1, -e2 + q - 1 + l) % 10);
+		}
+		if (q <= 9)
+		{
+			/*
+			 * The largest power of 5 that fits in 24 bits is 5^10, but q <= 9
+			 * seems to be safe as well.
+			 *
+			 * Only one of mp, mv, and mm can be a multiple of 5, if any.
+			 */
+			if (mv % 5 == 0)
+			{
+				vrIsTrailingZeros = multipleOfPowerOf5(mv, q);
+			}
+			else if (acceptBounds)
+			{
+				vmIsTrailingZeros = multipleOfPowerOf5(mm, q);
+			}
+			else
+			{
+				vp -= multipleOfPowerOf5(mp, q);
+			}
+		}
+	}
+	else
+	{
+		const uint32 q = log10Pow5(-e2);
+
+		e10 = q + e2;
+
+		const int32 i = -e2 - q;
+		const int32 k = pow5bits(i) - FLOAT_POW5_BITCOUNT;
+		int32		j = q - k;
+
+		vr = mulPow5divPow2(mv, i, j);
+		vp = mulPow5divPow2(mp, i, j);
+		vm = mulPow5divPow2(mm, i, j);
+
+		if (q != 0 && (vp - 1) / 10 <= vm / 10)
+		{
+			j = q - 1 - (pow5bits(i + 1) - FLOAT_POW5_BITCOUNT);
+			lastRemovedDigit = (uint8) (mulPow5divPow2(mv, i + 1, j) % 10);
+		}
+		if (q <= 1)
+		{
+			/*
+			 * {vr,vp,vm} is trailing zeros if {mv,mp,mm} has at least q
+			 * trailing 0 bits.
+			 */
+			/* mv = 4 * m2, so it always has at least two trailing 0 bits. */
+			vrIsTrailingZeros = true;
+			if (acceptBounds)
+			{
+				/*
+				 * mm = mv - 1 - mmShift, so it has 1 trailing 0 bit iff
+				 * mmShift == 1.
+				 */
+				vmIsTrailingZeros = mmShift == 1;
+			}
+			else
+			{
+				/*
+				 * mp = mv + 2, so it always has at least one trailing 0 bit.
+				 */
+				--vp;
+			}
+		}
+		else if (q < 31)
+		{
+			/* TODO(ulfjack):Use a tighter bound here. */
+			vrIsTrailingZeros = multipleOfPowerOf2(mv, q - 1);
+		}
+	}
+
+	/*
+	 * Step 4: Find the shortest decimal representation in the interval of
+	 * legal representations.
+	 */
+	uint32		removed = 0;
+	uint32		output;
+
+	if (vmIsTrailingZeros || vrIsTrailingZeros)
+	{
+		/* General case, which happens rarely (~4.0%). */
+		while (vp / 10 > vm / 10)
+		{
+			vmIsTrailingZeros &= vm - (vm / 10) * 10 == 0;
+			vrIsTrailingZeros &= lastRemovedDigit == 0;
+			lastRemovedDigit = (uint8) (vr % 10);
+			vr /= 10;
+			vp /= 10;
+			vm /= 10;
+			++removed;
+		}
+		if (vmIsTrailingZeros)
+		{
+			while (vm % 10 == 0)
+			{
+				vrIsTrailingZeros &= lastRemovedDigit == 0;
+				lastRemovedDigit = (uint8) (vr % 10);
+				vr /= 10;
+				vp /= 10;
+				vm /= 10;
+				++removed;
+			}
+		}
+
+		if (vrIsTrailingZeros && lastRemovedDigit == 5 && vr % 2 == 0)
+		{
+			/* Round even if the exact number is .....50..0. */
+			lastRemovedDigit = 4;
+		}
+
+		/*
+		 * We need to take vr + 1 if vr is outside bounds or we need to round
+		 * up.
+		 */
+		output = vr + ((vr == vm && (!acceptBounds || !vmIsTrailingZeros)) || lastRemovedDigit >= 5);
+	}
+	else
+	{
+		/*
+		 * Specialized for the common case (~96.0%). Percentages below are
+		 * relative to this.
+		 *
+		 * Loop iterations below (approximately): 0: 13.6%, 1: 70.7%, 2:
+		 * 14.1%, 3: 1.39%, 4: 0.14%, 5+: 0.01%
+		 */
+		while (vp / 10 > vm / 10)
+		{
+			lastRemovedDigit = (uint8) (vr % 10);
+			vr /= 10;
+			vp /= 10;
+			vm /= 10;
+			++removed;
+		}
+
+		/*
+		 * We need to take vr + 1 if vr is outside bounds or we need to round
+		 * up.
+		 */
+		output = vr + (vr == vm || lastRemovedDigit >= 5);
+	}
+
+	const int32 exp = e10 + removed;
+
+	floating_decimal_32 fd;
+
+	fd.exponent = exp;
+	fd.mantissa = output;
+	return fd;
+}
+
+static inline int
+to_chars_f(const floating_decimal_32 v, const uint32 olength, char *const result)
+{
+	/* Step 5: Print the decimal representation. */
+	int			index = 0;
+
+	uint32		output = v.mantissa;
+	int32		exp = v.exponent;
+
+	/*----
+	 * On entry, mantissa * 10^exp is the result to be output.
+	 * Caller has already done the - sign if needed.
+	 *
+	 * We want to insert the point somewhere depending on the output length
+	 * and exponent, which might mean adding zeros:
+	 *
+	 *            exp  | format
+	 *            1+   |  ddddddddd000000
+	 *            0    |  ddddddddd
+	 *  -1 .. -len+1   |  dddddddd.d to d.ddddddddd
+	 *  -len ...       |  0.ddddddddd to 0.000dddddd
+	 */
+	uint32		i = 0;
+	int32		nexp = exp + olength;
+
+	if (nexp <= 0)
+	{
+		/* -nexp is number of 0s to add after '.' */
+		Assert(nexp >= -3);
+		/* 0.000ddddd */
+		index = 2 - nexp;
+		/* copy 8 bytes rather than 5 to let compiler optimize */
+		memcpy(result, "0.000000", 8);
+	}
+	else if (exp < 0)
+	{
+		/*
+		 * dddd.dddd; leave space at the start and move the '.' in after
+		 */
+		index = 1;
+	}
+	else
+	{
+		/*
+		 * We can save some code later by pre-filling with zeros. We know that
+		 * there can be no more than 6 output digits in this form, otherwise
+		 * we would not choose fixed-point output. memset 8 rather than 6
+		 * bytes to let the compiler optimize it.
+		 */
+		Assert(exp < 6 && exp + olength <= 6);
+		memset(result, '0', 8);
+	}
+
+	while (output >= 10000)
+	{
+		const uint32 c = output - 10000 * (output / 10000);
+		const uint32 c0 = (c % 100) << 1;
+		const uint32 c1 = (c / 100) << 1;
+
+		output /= 10000;
+
+		memcpy(result + index + olength - i - 2, DIGIT_TABLE + c0, 2);
+		memcpy(result + index + olength - i - 4, DIGIT_TABLE + c1, 2);
+		i += 4;
+	}
+	if (output >= 100)
+	{
+		const uint32 c = (output % 100) << 1;
+
+		output /= 100;
+		memcpy(result + index + olength - i - 2, DIGIT_TABLE + c, 2);
+		i += 2;
+	}
+	if (output >= 10)
+	{
+		const uint32 c = output << 1;
+
+		memcpy(result + index + olength - i - 2, DIGIT_TABLE + c, 2);
+	}
+	else
+	{
+		result[index] = (char) ('0' + output);
+	}
+
+	if (index == 1)
+	{
+		/*
+		 * nexp is 1..6 here, representing the number of digits before the
+		 * point. A value of 7+ is not possible because we switch to
+		 * scientific notation when the display exponent reaches 6.
+		 */
+		Assert(nexp < 7);
+		/* gcc only seems to want to optimize memmove for small 2^n */
+		if (nexp & 4)
+		{
+			memmove(result + index - 1, result + index, 4);
+			index += 4;
+		}
+		if (nexp & 2)
+		{
+			memmove(result + index - 1, result + index, 2);
+			index += 2;
+		}
+		if (nexp & 1)
+		{
+			result[index - 1] = result[index];
+		}
+		result[nexp] = '.';
+		index = olength + 1;
+	}
+	else if (exp >= 0)
+	{
+		/* we supplied the trailing zeros earlier, now just set the length. */
+		index = olength + exp;
+	}
+	else
+	{
+		index = olength + (2 - nexp);
+	}
+
+	return index;
+}
+
+static inline int
+to_chars(const floating_decimal_32 v, const bool sign, char *const result)
+{
+	/* Step 5: Print the decimal representation. */
+	int			index = 0;
+
+	uint32		output = v.mantissa;
+	uint32		olength = decimalLength(output);
+	int32		exp = v.exponent + olength - 1;
+
+	if (sign)
+		result[index++] = '-';
+
+	/*
+	 * The thresholds for fixed-point output are chosen to match printf
+	 * defaults. Beware that both the code of to_chars_f and the value of
+	 * FLOAT_SHORTEST_DECIMAL_LEN are sensitive to these thresholds.
+	 */
+	if (exp >= -4 && exp < 6)
+		return to_chars_f(v, olength, result + index) + sign;
+
+	/*
+	 * If v.exponent is exactly 0, we might have reached here via the small
+	 * integer fast path, in which case v.mantissa might contain trailing
+	 * (decimal) zeros. For scientific notation we need to move these zeros
+	 * into the exponent. (For fixed point this doesn't matter, which is why
+	 * we do this here rather than above.)
+	 *
+	 * Since we already calculated the display exponent (exp) above based on
+	 * the old decimal length, that value does not change here. Instead, we
+	 * just reduce the display length for each digit removed.
+	 *
+	 * If we didn't get here via the fast path, the raw exponent will not
+	 * usually be 0, and there will be no trailing zeros, so we pay no more
+	 * than one div10/multiply extra cost. We claw back half of that by
+	 * checking for divisibility by 2 before dividing by 10.
+	 */
+	if (v.exponent == 0)
+	{
+		while ((output & 1) == 0)
+		{
+			const uint32 q = output / 10;
+			const uint32 r = output - 10 * q;
+
+			if (r != 0)
+				break;
+			output = q;
+			--olength;
+		}
+	}
+
+	/*----
+	 * Print the decimal digits.
+	 * The following code is equivalent to:
+	 *
+	 * for (uint32 i = 0; i < olength - 1; ++i) {
+	 *   const uint32 c = output % 10; output /= 10;
+	 *   result[index + olength - i] = (char) ('0' + c);
+	 * }
+	 * result[index] = '0' + output % 10;
+	 */
+	uint32		i = 0;
+
+	while (output >= 10000)
+	{
+		const uint32 c = output - 10000 * (output / 10000);
+		const uint32 c0 = (c % 100) << 1;
+		const uint32 c1 = (c / 100) << 1;
+
+		output /= 10000;
+
+		memcpy(result + index + olength - i - 1, DIGIT_TABLE + c0, 2);
+		memcpy(result + index + olength - i - 3, DIGIT_TABLE + c1, 2);
+		i += 4;
+	}
+	if (output >= 100)
+	{
+		const uint32 c = (output % 100) << 1;
+
+		output /= 100;
+		memcpy(result + index + olength - i - 1, DIGIT_TABLE + c, 2);
+		i += 2;
+	}
+	if (output >= 10)
+	{
+		const uint32 c = output << 1;
+
+		/*
+		 * We can't use memcpy here: the decimal dot goes between these two
+		 * digits.
+		 */
+		result[index + olength - i] = DIGIT_TABLE[c + 1];
+		result[index] = DIGIT_TABLE[c];
+	}
+	else
+	{
+		result[index] = (char) ('0' + output);
+	}
+
+	/* Print decimal point if needed. */
+	if (olength > 1)
+	{
+		result[index + 1] = '.';
+		index += olength + 1;
+	}
+	else
+	{
+		++index;
+	}
+
+	/* Print the exponent. */
+	result[index++] = 'e';
+	if (exp < 0)
+	{
+		result[index++] = '-';
+		exp = -exp;
+	}
+	else
+		result[index++] = '+';
+
+	memcpy(result + index, DIGIT_TABLE + 2 * exp, 2);
+	index += 2;
+
+	return index;
+}
+
+static inline bool
+f2d_small_int(const uint32 ieeeMantissa,
+			  const uint32 ieeeExponent,
+			  floating_decimal_32 *v)
+{
+	const int32 e2 = (int32) ieeeExponent - FLOAT_BIAS - FLOAT_MANTISSA_BITS;
+
+	/*
+	 * Avoid using multiple "return false;" here since it tends to provoke the
+	 * compiler into inlining multiple copies of f2d, which is undesirable.
+	 */
+
+	if (e2 >= -FLOAT_MANTISSA_BITS && e2 <= 0)
+	{
+		/*----
+		 * Since 2^23 <= m2 < 2^24 and 0 <= -e2 <= 23:
+		 *   1 <= f = m2 / 2^-e2 < 2^24.
+		 *
+		 * Test if the lower -e2 bits of the significand are 0, i.e. whether
+		 * the fraction is 0. We can use ieeeMantissa here, since the implied
+		 * 1 bit can never be tested by this; the implied 1 can only be part
+		 * of a fraction if e2 < -FLOAT_MANTISSA_BITS which we already
+		 * checked. (e.g. 0.5 gives ieeeMantissa == 0 and e2 == -24)
+		 */
+		const uint32 mask = (1U << -e2) - 1;
+		const uint32 fraction = ieeeMantissa & mask;
+
+		if (fraction == 0)
+		{
+			/*----
+			 * f is an integer in the range [1, 2^24).
+			 * Note: mantissa might contain trailing (decimal) 0's.
+			 * Note: since 2^24 < 10^9, there is no need to adjust
+			 * decimalLength().
+			 */
+			const uint32 m2 = (1U << FLOAT_MANTISSA_BITS) | ieeeMantissa;
+
+			v->mantissa = m2 >> -e2;
+			v->exponent = 0;
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/*
+ * Store the shortest decimal representation of the given float as an
+ * UNTERMINATED string in the caller's supplied buffer (which must be at least
+ * FLOAT_SHORTEST_DECIMAL_LEN-1 bytes long).
+ *
+ * Returns the number of bytes stored.
+ */
+int
+float_to_shortest_decimal_bufn(float f, char *result)
+{
+	/*
+	 * Step 1: Decode the floating-point number, and unify normalized and
+	 * subnormal cases.
+	 */
+	const uint32 bits = float_to_bits(f);
+
+	/* Decode bits into sign, mantissa, and exponent. */
+	const bool	ieeeSign = ((bits >> (FLOAT_MANTISSA_BITS + FLOAT_EXPONENT_BITS)) & 1) != 0;
+	const uint32 ieeeMantissa = bits & ((1u << FLOAT_MANTISSA_BITS) - 1);
+	const uint32 ieeeExponent = (bits >> FLOAT_MANTISSA_BITS) & ((1u << FLOAT_EXPONENT_BITS) - 1);
+
+	/* Case distinction; exit early for the easy cases. */
+	if (ieeeExponent == ((1u << FLOAT_EXPONENT_BITS) - 1u) || (ieeeExponent == 0 && ieeeMantissa == 0))
+	{
+		return copy_special_str(result, ieeeSign, (ieeeExponent != 0), (ieeeMantissa != 0));
+	}
+
+	floating_decimal_32 v;
+	const bool	isSmallInt = f2d_small_int(ieeeMantissa, ieeeExponent, &v);
+
+	if (!isSmallInt)
+	{
+		v = f2d(ieeeMantissa, ieeeExponent);
+	}
+
+	return to_chars(v, ieeeSign, result);
+}
+
+/*
+ * Store the shortest decimal representation of the given float as a
+ * null-terminated string in the caller's supplied buffer (which must be at
+ * least FLOAT_SHORTEST_DECIMAL_LEN bytes long).
+ *
+ * Returns the string length.
+ */
+int
+float_to_shortest_decimal_buf(float f, char *result)
+{
+	const int	index = float_to_shortest_decimal_bufn(f, result);
+
+	/* Terminate the string. */
+	Assert(index < FLOAT_SHORTEST_DECIMAL_LEN);
+	result[index] = '\0';
+	return index;
+}
+
+/*
+ * Return the shortest decimal representation as a null-terminated palloc'd
+ * string (outside the backend, uses malloc() instead).
+ *
+ * Caller is responsible for freeing the result.
+ */
+char *
+float_to_shortest_decimal(float f)
+{
+	char	   *const result = (char *) palloc(FLOAT_SHORTEST_DECIMAL_LEN);
+
+	float_to_shortest_decimal_buf(f, result);
+	return result;
+}
diff --git a/src/common/fe_memutils.c b/src/common/fe_memutils.c
new file mode 100644
index 0000000..ec64172
--- /dev/null
+++ b/src/common/fe_memutils.c
@@ -0,0 +1,176 @@
+/*-------------------------------------------------------------------------
+ *
+ * fe_memutils.c
+ *	  memory management support for frontend code
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/fe_memutils.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#error "This file is not expected to be compiled for backend code"
+#endif
+
+#include "postgres_fe.h"
+
+static inline void *
+pg_malloc_internal(size_t size, int flags)
+{
+	void	   *tmp;
+
+	/* Avoid unportable behavior of malloc(0) */
+	if (size == 0)
+		size = 1;
+	tmp = malloc(size);
+	if (tmp == NULL)
+	{
+		if ((flags & MCXT_ALLOC_NO_OOM) == 0)
+		{
+			fprintf(stderr, _("out of memory\n"));
+			exit(EXIT_FAILURE);
+		}
+		return NULL;
+	}
+
+	if ((flags & MCXT_ALLOC_ZERO) != 0)
+		MemSet(tmp, 0, size);
+	return tmp;
+}
+
+void *
+pg_malloc(size_t size)
+{
+	return pg_malloc_internal(size, 0);
+}
+
+void *
+pg_malloc0(size_t size)
+{
+	return pg_malloc_internal(size, MCXT_ALLOC_ZERO);
+}
+
+void *
+pg_malloc_extended(size_t size, int flags)
+{
+	return pg_malloc_internal(size, flags);
+}
+
+void *
+pg_realloc(void *ptr, size_t size)
+{
+	void	   *tmp;
+
+	/* Avoid unportable behavior of realloc(NULL, 0) */
+	if (ptr == NULL && size == 0)
+		size = 1;
+	tmp = realloc(ptr, size);
+	if (!tmp)
+	{
+		fprintf(stderr, _("out of memory\n"));
+		exit(EXIT_FAILURE);
+	}
+	return tmp;
+}
+
+/*
+ * "Safe" wrapper around strdup().
+ */
+char *
+pg_strdup(const char *in)
+{
+	char	   *tmp;
+
+	if (!in)
+	{
+		fprintf(stderr,
+				_("cannot duplicate null pointer (internal error)\n"));
+		exit(EXIT_FAILURE);
+	}
+	tmp = strdup(in);
+	if (!tmp)
+	{
+		fprintf(stderr, _("out of memory\n"));
+		exit(EXIT_FAILURE);
+	}
+	return tmp;
+}
+
+void
+pg_free(void *ptr)
+{
+	if (ptr != NULL)
+		free(ptr);
+}
+
+/*
+ * Frontend emulation of backend memory management functions.  Useful for
+ * programs that compile backend files.
+ */
+void *
+palloc(Size size)
+{
+	return pg_malloc_internal(size, 0);
+}
+
+void *
+palloc0(Size size)
+{
+	return pg_malloc_internal(size, MCXT_ALLOC_ZERO);
+}
+
+void *
+palloc_extended(Size size, int flags)
+{
+	return pg_malloc_internal(size, flags);
+}
+
+void
+pfree(void *pointer)
+{
+	pg_free(pointer);
+}
+
+char *
+pstrdup(const char *in)
+{
+	return pg_strdup(in);
+}
+
+char *
+pnstrdup(const char *in, Size size)
+{
+	char	   *tmp;
+	int			len;
+
+	if (!in)
+	{
+		fprintf(stderr,
+				_("cannot duplicate null pointer (internal error)\n"));
+		exit(EXIT_FAILURE);
+	}
+
+	len = strnlen(in, size);
+	tmp = malloc(len + 1);
+	if (tmp == NULL)
+	{
+		fprintf(stderr, _("out of memory\n"));
+		exit(EXIT_FAILURE);
+	}
+
+	memcpy(tmp, in, len);
+	tmp[len] = '\0';
+
+	return tmp;
+}
+
+void *
+repalloc(void *pointer, Size size)
+{
+	return pg_realloc(pointer, size);
+}
diff --git a/src/common/file_perm.c b/src/common/file_perm.c
new file mode 100644
index 0000000..ab85765
--- /dev/null
+++ b/src/common/file_perm.c
@@ -0,0 +1,91 @@
+/*-------------------------------------------------------------------------
+ *
+ * File and directory permission routines
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/common/file_perm.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include "common/file_perm.h"
+
+/* Modes for creating directories and files in the data directory */
+int			pg_dir_create_mode = PG_DIR_MODE_OWNER;
+int			pg_file_create_mode = PG_FILE_MODE_OWNER;
+
+/*
+ * Mode mask to pass to umask().  This is more of a preventative measure since
+ * all file/directory creates should be performed using the create modes above.
+ */
+int			pg_mode_mask = PG_MODE_MASK_OWNER;
+
+/*
+ * Set create modes and mask to use when writing to PGDATA based on the data
+ * directory mode passed.  If group read/execute are present in the mode, then
+ * create modes and mask will be relaxed to allow group read/execute on all
+ * newly created files and directories.
+ */
+void
+SetDataDirectoryCreatePerm(int dataDirMode)
+{
+	/* If the data directory mode has group access */
+	if ((PG_DIR_MODE_GROUP & dataDirMode) == PG_DIR_MODE_GROUP)
+	{
+		pg_dir_create_mode = PG_DIR_MODE_GROUP;
+		pg_file_create_mode = PG_FILE_MODE_GROUP;
+		pg_mode_mask = PG_MODE_MASK_GROUP;
+	}
+	/* Else use default permissions */
+	else
+	{
+		pg_dir_create_mode = PG_DIR_MODE_OWNER;
+		pg_file_create_mode = PG_FILE_MODE_OWNER;
+		pg_mode_mask = PG_MODE_MASK_OWNER;
+	}
+}
+
+#ifdef FRONTEND
+
+/*
+ * Get the create modes and mask to use when writing to PGDATA by examining the
+ * mode of the PGDATA directory and calling SetDataDirectoryCreatePerm().
+ *
+ * Errors are not handled here and should be reported by the application when
+ * false is returned.
+ *
+ * Suppress when on Windows, because there may not be proper support for Unix-y
+ * file permissions.
+ */
+bool
+GetDataDirectoryCreatePerm(const char *dataDir)
+{
+#if !defined(WIN32) && !defined(__CYGWIN__)
+	struct stat statBuf;
+
+	/*
+	 * If an error occurs getting the mode then return false.  The caller is
+	 * responsible for generating an error, if appropriate, indicating that we
+	 * were unable to access the data directory.
+	 */
+	if (stat(dataDir, &statBuf) == -1)
+		return false;
+
+	/* Set permissions */
+	SetDataDirectoryCreatePerm(statBuf.st_mode);
+	return true;
+#else							/* !defined(WIN32) && !defined(__CYGWIN__) */
+	/*
+	 * On Windows, we don't have anything to do here since they don't have
+	 * Unix-y permissions.
+	 */
+	return true;
+#endif
+}
+
+
+#endif							/* FRONTEND */
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
new file mode 100644
index 0000000..fd2d113
--- /dev/null
+++ b/src/common/file_utils.c
@@ -0,0 +1,485 @@
+/*-------------------------------------------------------------------------
+ *
+ * File-processing utility routines.
+ *
+ * Assorted utility functions to work on files.
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/common/file_utils.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "common/file_utils.h"
+#ifdef FRONTEND
+#include "common/logging.h"
+#endif
+
+#ifdef FRONTEND
+
+/* Define PG_FLUSH_DATA_WORKS if we have an implementation for pg_flush_data */
+#if defined(HAVE_SYNC_FILE_RANGE)
+#define PG_FLUSH_DATA_WORKS 1
+#elif defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
+#define PG_FLUSH_DATA_WORKS 1
+#endif
+
+/*
+ * pg_xlog has been renamed to pg_wal in version 10.
+ */
+#define MINIMUM_VERSION_FOR_PG_WAL	100000
+
+#ifdef PG_FLUSH_DATA_WORKS
+static int	pre_sync_fname(const char *fname, bool isdir);
+#endif
+static void walkdir(const char *path,
+					int (*action) (const char *fname, bool isdir),
+					bool process_symlinks);
+
+/*
+ * Issue fsync recursively on PGDATA and all its contents.
+ *
+ * We fsync regular files and directories wherever they are, but we follow
+ * symlinks only for pg_wal (or pg_xlog) and immediately under pg_tblspc.
+ * Other symlinks are presumed to point at files we're not responsible for
+ * fsyncing, and might not have privileges to write at all.
+ *
+ * serverVersion indicates the version of the server to be fsync'd.
+ */
+void
+fsync_pgdata(const char *pg_data,
+			 int serverVersion)
+{
+	bool		xlog_is_symlink;
+	char		pg_wal[MAXPGPATH];
+	char		pg_tblspc[MAXPGPATH];
+
+	/* handle renaming of pg_xlog to pg_wal in post-10 clusters */
+	snprintf(pg_wal, MAXPGPATH, "%s/%s", pg_data,
+			 serverVersion < MINIMUM_VERSION_FOR_PG_WAL ? "pg_xlog" : "pg_wal");
+	snprintf(pg_tblspc, MAXPGPATH, "%s/pg_tblspc", pg_data);
+
+	/*
+	 * If pg_wal is a symlink, we'll need to recurse into it separately,
+	 * because the first walkdir below will ignore it.
+	 */
+	xlog_is_symlink = false;
+
+#ifndef WIN32
+	{
+		struct stat st;
+
+		if (lstat(pg_wal, &st) < 0)
+			pg_log_error("could not stat file \"%s\": %m", pg_wal);
+		else if (S_ISLNK(st.st_mode))
+			xlog_is_symlink = true;
+	}
+#else
+	if (pgwin32_is_junction(pg_wal))
+		xlog_is_symlink = true;
+#endif
+
+	/*
+	 * If possible, hint to the kernel that we're soon going to fsync the data
+	 * directory and its contents.
+	 */
+#ifdef PG_FLUSH_DATA_WORKS
+	walkdir(pg_data, pre_sync_fname, false);
+	if (xlog_is_symlink)
+		walkdir(pg_wal, pre_sync_fname, false);
+	walkdir(pg_tblspc, pre_sync_fname, true);
+#endif
+
+	/*
+	 * Now we do the fsync()s in the same order.
+	 *
+	 * The main call ignores symlinks, so in addition to specially processing
+	 * pg_wal if it's a symlink, pg_tblspc has to be visited separately with
+	 * process_symlinks = true.  Note that if there are any plain directories
+	 * in pg_tblspc, they'll get fsync'd twice.  That's not an expected case
+	 * so we don't worry about optimizing it.
+	 */
+	walkdir(pg_data, fsync_fname, false);
+	if (xlog_is_symlink)
+		walkdir(pg_wal, fsync_fname, false);
+	walkdir(pg_tblspc, fsync_fname, true);
+}
+
+/*
+ * Issue fsync recursively on the given directory and all its contents.
+ *
+ * This is a convenient wrapper on top of walkdir().
+ */
+void
+fsync_dir_recurse(const char *dir)
+{
+	/*
+	 * If possible, hint to the kernel that we're soon going to fsync the data
+	 * directory and its contents.
+	 */
+#ifdef PG_FLUSH_DATA_WORKS
+	walkdir(dir, pre_sync_fname, false);
+#endif
+
+	walkdir(dir, fsync_fname, false);
+}
+
+/*
+ * walkdir: recursively walk a directory, applying the action to each
+ * regular file and directory (including the named directory itself).
+ *
+ * If process_symlinks is true, the action and recursion are also applied
+ * to regular files and directories that are pointed to by symlinks in the
+ * given directory; otherwise symlinks are ignored.  Symlinks are always
+ * ignored in subdirectories, ie we intentionally don't pass down the
+ * process_symlinks flag to recursive calls.
+ *
+ * Errors are reported but not considered fatal.
+ *
+ * See also walkdir in fd.c, which is a backend version of this logic.
+ */
+static void
+walkdir(const char *path,
+		int (*action) (const char *fname, bool isdir),
+		bool process_symlinks)
+{
+	DIR		   *dir;
+	struct dirent *de;
+
+	dir = opendir(path);
+	if (dir == NULL)
+	{
+		pg_log_error("could not open directory \"%s\": %m", path);
+		return;
+	}
+
+	while (errno = 0, (de = readdir(dir)) != NULL)
+	{
+		char		subpath[MAXPGPATH * 2];
+
+		if (strcmp(de->d_name, ".") == 0 ||
+			strcmp(de->d_name, "..") == 0)
+			continue;
+
+		snprintf(subpath, sizeof(subpath), "%s/%s", path, de->d_name);
+
+		switch (get_dirent_type(subpath, de, process_symlinks, PG_LOG_ERROR))
+		{
+			case PGFILETYPE_REG:
+				(*action) (subpath, false);
+				break;
+			case PGFILETYPE_DIR:
+				walkdir(subpath, action, false);
+				break;
+			default:
+
+				/*
+				 * Errors are already reported directly by get_dirent_type(),
+				 * and any remaining symlinks and unknown file types are
+				 * ignored.
+				 */
+				break;
+		}
+	}
+
+	if (errno)
+		pg_log_error("could not read directory \"%s\": %m", path);
+
+	(void) closedir(dir);
+
+	/*
+	 * It's important to fsync the destination directory itself as individual
+	 * file fsyncs don't guarantee that the directory entry for the file is
+	 * synced.  Recent versions of ext4 have made the window much wider but
+	 * it's been an issue for ext3 and other filesystems in the past.
+	 */
+	(*action) (path, true);
+}
+
+/*
+ * Hint to the OS that it should get ready to fsync() this file.
+ *
+ * Ignores errors trying to open unreadable files, and reports other errors
+ * non-fatally.
+ */
+#ifdef PG_FLUSH_DATA_WORKS
+
+static int
+pre_sync_fname(const char *fname, bool isdir)
+{
+	int			fd;
+
+	fd = open(fname, O_RDONLY | PG_BINARY, 0);
+
+	if (fd < 0)
+	{
+		if (errno == EACCES || (isdir && errno == EISDIR))
+			return 0;
+		pg_log_error("could not open file \"%s\": %m", fname);
+		return -1;
+	}
+
+	/*
+	 * We do what pg_flush_data() would do in the backend: prefer to use
+	 * sync_file_range, but fall back to posix_fadvise.  We ignore errors
+	 * because this is only a hint.
+	 */
+#if defined(HAVE_SYNC_FILE_RANGE)
+	(void) sync_file_range(fd, 0, 0, SYNC_FILE_RANGE_WRITE);
+#elif defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_DONTNEED)
+	(void) posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED);
+#else
+#error PG_FLUSH_DATA_WORKS should not have been defined
+#endif
+
+	(void) close(fd);
+	return 0;
+}
+
+#endif							/* PG_FLUSH_DATA_WORKS */
+
+/*
+ * fsync_fname -- Try to fsync a file or directory
+ *
+ * Ignores errors trying to open unreadable files, or trying to fsync
+ * directories on systems where that isn't allowed/required.  All other errors
+ * are fatal.
+ */
+int
+fsync_fname(const char *fname, bool isdir)
+{
+	int			fd;
+	int			flags;
+	int			returncode;
+
+	/*
+	 * Some OSs require directories to be opened read-only whereas other
+	 * systems don't allow us to fsync files opened read-only; so we need both
+	 * cases here.  Using O_RDWR will cause us to fail to fsync files that are
+	 * not writable by our userid, but we assume that's OK.
+	 */
+	flags = PG_BINARY;
+	if (!isdir)
+		flags |= O_RDWR;
+	else
+		flags |= O_RDONLY;
+
+	/*
+	 * Open the file, silently ignoring errors about unreadable files (or
+	 * unsupported operations, e.g. opening a directory under Windows), and
+	 * logging others.
+	 */
+	fd = open(fname, flags, 0);
+	if (fd < 0)
+	{
+		if (errno == EACCES || (isdir && errno == EISDIR))
+			return 0;
+		pg_log_error("could not open file \"%s\": %m", fname);
+		return -1;
+	}
+
+	returncode = fsync(fd);
+
+	/*
+	 * Some OSes don't allow us to fsync directories at all, so we can ignore
+	 * those errors. Anything else needs to be reported.
+	 */
+	if (returncode != 0 && !(isdir && (errno == EBADF || errno == EINVAL)))
+	{
+		pg_log_fatal("could not fsync file \"%s\": %m", fname);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+	return 0;
+}
+
+/*
+ * fsync_parent_path -- fsync the parent path of a file or directory
+ *
+ * This is aimed at making file operations persistent on disk in case of
+ * an OS crash or power failure.
+ */
+int
+fsync_parent_path(const char *fname)
+{
+	char		parentpath[MAXPGPATH];
+
+	strlcpy(parentpath, fname, MAXPGPATH);
+	get_parent_directory(parentpath);
+
+	/*
+	 * get_parent_directory() returns an empty string if the input argument is
+	 * just a file name (see comments in path.c), so handle that as being the
+	 * current directory.
+	 */
+	if (strlen(parentpath) == 0)
+		strlcpy(parentpath, ".", MAXPGPATH);
+
+	if (fsync_fname(parentpath, true) != 0)
+		return -1;
+
+	return 0;
+}
+
+/*
+ * durable_rename -- rename(2) wrapper, issuing fsyncs required for durability
+ *
+ * Wrapper around rename, similar to the backend version.
+ */
+int
+durable_rename(const char *oldfile, const char *newfile)
+{
+	int			fd;
+
+	/*
+	 * First fsync the old and target path (if it exists), to ensure that they
+	 * are properly persistent on disk. Syncing the target file is not
+	 * strictly necessary, but it makes it easier to reason about crashes;
+	 * because it's then guaranteed that either source or target file exists
+	 * after a crash.
+	 */
+	if (fsync_fname(oldfile, false) != 0)
+		return -1;
+
+	fd = open(newfile, PG_BINARY | O_RDWR, 0);
+	if (fd < 0)
+	{
+		if (errno != ENOENT)
+		{
+			pg_log_error("could not open file \"%s\": %m", newfile);
+			return -1;
+		}
+	}
+	else
+	{
+		if (fsync(fd) != 0)
+		{
+			pg_log_fatal("could not fsync file \"%s\": %m", newfile);
+			close(fd);
+			exit(EXIT_FAILURE);
+		}
+		close(fd);
+	}
+
+	/* Time to do the real deal... */
+	if (rename(oldfile, newfile) != 0)
+	{
+		pg_log_error("could not rename file \"%s\" to \"%s\": %m",
+					 oldfile, newfile);
+		return -1;
+	}
+
+	/*
+	 * To guarantee renaming the file is persistent, fsync the file with its
+	 * new name, and its containing directory.
+	 */
+	if (fsync_fname(newfile, false) != 0)
+		return -1;
+
+	if (fsync_parent_path(newfile) != 0)
+		return -1;
+
+	return 0;
+}
+
+#endif							/* FRONTEND */
+
+/*
+ * Return the type of a directory entry.
+ *
+ * In frontend code, elevel should be a level from logging.h; in backend code
+ * it should be a level from elog.h.
+ */
+PGFileType
+get_dirent_type(const char *path,
+				const struct dirent *de,
+				bool look_through_symlinks,
+				int elevel)
+{
+	PGFileType	result;
+
+	/*
+	 * Some systems tell us the type directly in the dirent struct, but that's
+	 * a BSD and Linux extension not required by POSIX.  Even when the
+	 * interface is present, sometimes the type is unknown, depending on the
+	 * filesystem.
+	 */
+#if defined(DT_REG) && defined(DT_DIR) && defined(DT_LNK)
+	if (de->d_type == DT_REG)
+		result = PGFILETYPE_REG;
+	else if (de->d_type == DT_DIR)
+		result = PGFILETYPE_DIR;
+	else if (de->d_type == DT_LNK && !look_through_symlinks)
+		result = PGFILETYPE_LNK;
+	else
+		result = PGFILETYPE_UNKNOWN;
+#else
+	result = PGFILETYPE_UNKNOWN;
+#endif
+
+	if (result == PGFILETYPE_UNKNOWN)
+	{
+		struct stat fst;
+		int			sret;
+
+
+		if (look_through_symlinks)
+			sret = stat(path, &fst);
+		else
+			sret = lstat(path, &fst);
+
+		if (sret < 0)
+		{
+			result = PGFILETYPE_ERROR;
+#ifdef FRONTEND
+			pg_log_generic(elevel, "could not stat file \"%s\": %m", path);
+#else
+			ereport(elevel,
+					(errcode_for_file_access(),
+					 errmsg("could not stat file \"%s\": %m", path)));
+#endif
+		}
+		else if (S_ISREG(fst.st_mode))
+			result = PGFILETYPE_REG;
+		else if (S_ISDIR(fst.st_mode))
+			result = PGFILETYPE_DIR;
+#ifdef S_ISLNK
+		else if (S_ISLNK(fst.st_mode))
+			result = PGFILETYPE_LNK;
+#endif
+	}
+
+#if defined(WIN32) && !defined(_MSC_VER)
+
+	/*
+	 * If we're on native Windows (not Cygwin, which has its own POSIX
+	 * symlinks), but not using the MSVC compiler, then we're using a
+	 * readdir() emulation provided by the MinGW runtime that has no d_type.
+	 * Since the lstat() fallback code reports junction points as directories,
+	 * we need an extra system call to check if we should report them as
+	 * symlinks instead, following our convention.
+	 */
+	if (result == PGFILETYPE_DIR &&
+		!look_through_symlinks &&
+		pgwin32_is_junction(path))
+		result = PGFILETYPE_LNK;
+#endif
+
+	return result;
+}
diff --git a/src/common/hashfn.c b/src/common/hashfn.c
new file mode 100644
index 0000000..902a6ad
--- /dev/null
+++ b/src/common/hashfn.c
@@ -0,0 +1,692 @@
+/*-------------------------------------------------------------------------
+ *
+ * hashfn.c
+ *		Generic hashing functions, and hash functions for use in dynahash.c
+ *		hashtables
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/hashfn.c
+ *
+ * NOTES
+ *	  It is expected that every bit of a hash function's 32-bit result is
+ *	  as random as every other; failure to ensure this is likely to lead
+ *	  to poor performance of hash tables.  In most cases a hash
+ *	  function should use hash_bytes() or its variant hash_bytes_uint32(),
+ *	  or the wrappers hash_any() and hash_uint32 defined in hashfn.h.
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "common/hashfn.h"
+
+
+/*
+ * This hash function was written by Bob Jenkins
+ * (bob_jenkins@burtleburtle.net), and superficially adapted
+ * for PostgreSQL by Neil Conway. For more information on this
+ * hash function, see http://burtleburtle.net/bob/hash/doobs.html,
+ * or Bob's article in Dr. Dobb's Journal, Sept. 1997.
+ *
+ * In the current code, we have adopted Bob's 2006 update of his hash
+ * function to fetch the data a word at a time when it is suitably aligned.
+ * This makes for a useful speedup, at the cost of having to maintain
+ * four code paths (aligned vs unaligned, and little-endian vs big-endian).
+ * It also uses two separate mixing functions mix() and final(), instead
+ * of a slower multi-purpose function.
+ */
+
+/* Get a bit mask of the bits set in non-uint32 aligned addresses */
+#define UINT32_ALIGN_MASK (sizeof(uint32) - 1)
+
+/* Rotate a uint32 value left by k bits - note multiple evaluation! */
+#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
+
+/*----------
+ * mix -- mix 3 32-bit values reversibly.
+ *
+ * This is reversible, so any information in (a,b,c) before mix() is
+ * still in (a,b,c) after mix().
+ *
+ * If four pairs of (a,b,c) inputs are run through mix(), or through
+ * mix() in reverse, there are at least 32 bits of the output that
+ * are sometimes the same for one pair and different for another pair.
+ * This was tested for:
+ * * pairs that differed by one bit, by two bits, in any combination
+ *	 of top bits of (a,b,c), or in any combination of bottom bits of
+ *	 (a,b,c).
+ * * "differ" is defined as +, -, ^, or ~^.  For + and -, I transformed
+ *	 the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
+ *	 is commonly produced by subtraction) look like a single 1-bit
+ *	 difference.
+ * * the base values were pseudorandom, all zero but one bit set, or
+ *	 all zero plus a counter that starts at zero.
+ *
+ * This does not achieve avalanche.  There are input bits of (a,b,c)
+ * that fail to affect some output bits of (a,b,c), especially of a.  The
+ * most thoroughly mixed value is c, but it doesn't really even achieve
+ * avalanche in c.
+ *
+ * This allows some parallelism.  Read-after-writes are good at doubling
+ * the number of bits affected, so the goal of mixing pulls in the opposite
+ * direction from the goal of parallelism.  I did what I could.  Rotates
+ * seem to cost as much as shifts on every machine I could lay my hands on,
+ * and rotates are much kinder to the top and bottom bits, so I used rotates.
+ *----------
+ */
+#define mix(a,b,c) \
+{ \
+  a -= c;  a ^= rot(c, 4);	c += b; \
+  b -= a;  b ^= rot(a, 6);	a += c; \
+  c -= b;  c ^= rot(b, 8);	b += a; \
+  a -= c;  a ^= rot(c,16);	c += b; \
+  b -= a;  b ^= rot(a,19);	a += c; \
+  c -= b;  c ^= rot(b, 4);	b += a; \
+}
+
+/*----------
+ * final -- final mixing of 3 32-bit values (a,b,c) into c
+ *
+ * Pairs of (a,b,c) values differing in only a few bits will usually
+ * produce values of c that look totally different.  This was tested for
+ * * pairs that differed by one bit, by two bits, in any combination
+ *	 of top bits of (a,b,c), or in any combination of bottom bits of
+ *	 (a,b,c).
+ * * "differ" is defined as +, -, ^, or ~^.  For + and -, I transformed
+ *	 the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
+ *	 is commonly produced by subtraction) look like a single 1-bit
+ *	 difference.
+ * * the base values were pseudorandom, all zero but one bit set, or
+ *	 all zero plus a counter that starts at zero.
+ *
+ * The use of separate functions for mix() and final() allow for a
+ * substantial performance increase since final() does not need to
+ * do well in reverse, but is does need to affect all output bits.
+ * mix(), on the other hand, does not need to affect all output
+ * bits (affecting 32 bits is enough).  The original hash function had
+ * a single mixing operation that had to satisfy both sets of requirements
+ * and was slower as a result.
+ *----------
+ */
+#define final(a,b,c) \
+{ \
+  c ^= b; c -= rot(b,14); \
+  a ^= c; a -= rot(c,11); \
+  b ^= a; b -= rot(a,25); \
+  c ^= b; c -= rot(b,16); \
+  a ^= c; a -= rot(c, 4); \
+  b ^= a; b -= rot(a,14); \
+  c ^= b; c -= rot(b,24); \
+}
+
+/*
+ * hash_bytes() -- hash a variable-length key into a 32-bit value
+ *		k		: the key (the unaligned variable-length array of bytes)
+ *		len		: the length of the key, counting by bytes
+ *
+ * Returns a uint32 value.  Every bit of the key affects every bit of
+ * the return value.  Every 1-bit and 2-bit delta achieves avalanche.
+ * About 6*len+35 instructions. The best hash table sizes are powers
+ * of 2.  There is no need to do mod a prime (mod is sooo slow!).
+ * If you need less than 32 bits, use a bitmask.
+ *
+ * This procedure must never throw elog(ERROR); the ResourceOwner code
+ * relies on this not to fail.
+ *
+ * Note: we could easily change this function to return a 64-bit hash value
+ * by using the final values of both b and c.  b is perhaps a little less
+ * well mixed than c, however.
+ */
+uint32
+hash_bytes(const unsigned char *k, int keylen)
+{
+	uint32		a,
+				b,
+				c,
+				len;
+
+	/* Set up the internal state */
+	len = keylen;
+	a = b = c = 0x9e3779b9 + len + 3923095;
+
+	/* If the source pointer is word-aligned, we use word-wide fetches */
+	if (((uintptr_t) k & UINT32_ALIGN_MASK) == 0)
+	{
+		/* Code path for aligned source data */
+		const uint32 *ka = (const uint32 *) k;
+
+		/* handle most of the key */
+		while (len >= 12)
+		{
+			a += ka[0];
+			b += ka[1];
+			c += ka[2];
+			mix(a, b, c);
+			ka += 3;
+			len -= 12;
+		}
+
+		/* handle the last 11 bytes */
+		k = (const unsigned char *) ka;
+#ifdef WORDS_BIGENDIAN
+		switch (len)
+		{
+			case 11:
+				c += ((uint32) k[10] << 8);
+				/* fall through */
+			case 10:
+				c += ((uint32) k[9] << 16);
+				/* fall through */
+			case 9:
+				c += ((uint32) k[8] << 24);
+				/* fall through */
+			case 8:
+				/* the lowest byte of c is reserved for the length */
+				b += ka[1];
+				a += ka[0];
+				break;
+			case 7:
+				b += ((uint32) k[6] << 8);
+				/* fall through */
+			case 6:
+				b += ((uint32) k[5] << 16);
+				/* fall through */
+			case 5:
+				b += ((uint32) k[4] << 24);
+				/* fall through */
+			case 4:
+				a += ka[0];
+				break;
+			case 3:
+				a += ((uint32) k[2] << 8);
+				/* fall through */
+			case 2:
+				a += ((uint32) k[1] << 16);
+				/* fall through */
+			case 1:
+				a += ((uint32) k[0] << 24);
+				/* case 0: nothing left to add */
+		}
+#else							/* !WORDS_BIGENDIAN */
+		switch (len)
+		{
+			case 11:
+				c += ((uint32) k[10] << 24);
+				/* fall through */
+			case 10:
+				c += ((uint32) k[9] << 16);
+				/* fall through */
+			case 9:
+				c += ((uint32) k[8] << 8);
+				/* fall through */
+			case 8:
+				/* the lowest byte of c is reserved for the length */
+				b += ka[1];
+				a += ka[0];
+				break;
+			case 7:
+				b += ((uint32) k[6] << 16);
+				/* fall through */
+			case 6:
+				b += ((uint32) k[5] << 8);
+				/* fall through */
+			case 5:
+				b += k[4];
+				/* fall through */
+			case 4:
+				a += ka[0];
+				break;
+			case 3:
+				a += ((uint32) k[2] << 16);
+				/* fall through */
+			case 2:
+				a += ((uint32) k[1] << 8);
+				/* fall through */
+			case 1:
+				a += k[0];
+				/* case 0: nothing left to add */
+		}
+#endif							/* WORDS_BIGENDIAN */
+	}
+	else
+	{
+		/* Code path for non-aligned source data */
+
+		/* handle most of the key */
+		while (len >= 12)
+		{
+#ifdef WORDS_BIGENDIAN
+			a += (k[3] + ((uint32) k[2] << 8) + ((uint32) k[1] << 16) + ((uint32) k[0] << 24));
+			b += (k[7] + ((uint32) k[6] << 8) + ((uint32) k[5] << 16) + ((uint32) k[4] << 24));
+			c += (k[11] + ((uint32) k[10] << 8) + ((uint32) k[9] << 16) + ((uint32) k[8] << 24));
+#else							/* !WORDS_BIGENDIAN */
+			a += (k[0] + ((uint32) k[1] << 8) + ((uint32) k[2] << 16) + ((uint32) k[3] << 24));
+			b += (k[4] + ((uint32) k[5] << 8) + ((uint32) k[6] << 16) + ((uint32) k[7] << 24));
+			c += (k[8] + ((uint32) k[9] << 8) + ((uint32) k[10] << 16) + ((uint32) k[11] << 24));
+#endif							/* WORDS_BIGENDIAN */
+			mix(a, b, c);
+			k += 12;
+			len -= 12;
+		}
+
+		/* handle the last 11 bytes */
+#ifdef WORDS_BIGENDIAN
+		switch (len)
+		{
+			case 11:
+				c += ((uint32) k[10] << 8);
+				/* fall through */
+			case 10:
+				c += ((uint32) k[9] << 16);
+				/* fall through */
+			case 9:
+				c += ((uint32) k[8] << 24);
+				/* fall through */
+			case 8:
+				/* the lowest byte of c is reserved for the length */
+				b += k[7];
+				/* fall through */
+			case 7:
+				b += ((uint32) k[6] << 8);
+				/* fall through */
+			case 6:
+				b += ((uint32) k[5] << 16);
+				/* fall through */
+			case 5:
+				b += ((uint32) k[4] << 24);
+				/* fall through */
+			case 4:
+				a += k[3];
+				/* fall through */
+			case 3:
+				a += ((uint32) k[2] << 8);
+				/* fall through */
+			case 2:
+				a += ((uint32) k[1] << 16);
+				/* fall through */
+			case 1:
+				a += ((uint32) k[0] << 24);
+				/* case 0: nothing left to add */
+		}
+#else							/* !WORDS_BIGENDIAN */
+		switch (len)
+		{
+			case 11:
+				c += ((uint32) k[10] << 24);
+				/* fall through */
+			case 10:
+				c += ((uint32) k[9] << 16);
+				/* fall through */
+			case 9:
+				c += ((uint32) k[8] << 8);
+				/* fall through */
+			case 8:
+				/* the lowest byte of c is reserved for the length */
+				b += ((uint32) k[7] << 24);
+				/* fall through */
+			case 7:
+				b += ((uint32) k[6] << 16);
+				/* fall through */
+			case 6:
+				b += ((uint32) k[5] << 8);
+				/* fall through */
+			case 5:
+				b += k[4];
+				/* fall through */
+			case 4:
+				a += ((uint32) k[3] << 24);
+				/* fall through */
+			case 3:
+				a += ((uint32) k[2] << 16);
+				/* fall through */
+			case 2:
+				a += ((uint32) k[1] << 8);
+				/* fall through */
+			case 1:
+				a += k[0];
+				/* case 0: nothing left to add */
+		}
+#endif							/* WORDS_BIGENDIAN */
+	}
+
+	final(a, b, c);
+
+	/* report the result */
+	return c;
+}
+
+/*
+ * hash_bytes_extended() -- hash into a 64-bit value, using an optional seed
+ *		k		: the key (the unaligned variable-length array of bytes)
+ *		len		: the length of the key, counting by bytes
+ *		seed	: a 64-bit seed (0 means no seed)
+ *
+ * Returns a uint64 value.  Otherwise similar to hash_bytes.
+ */
+uint64
+hash_bytes_extended(const unsigned char *k, int keylen, uint64 seed)
+{
+	uint32		a,
+				b,
+				c,
+				len;
+
+	/* Set up the internal state */
+	len = keylen;
+	a = b = c = 0x9e3779b9 + len + 3923095;
+
+	/* If the seed is non-zero, use it to perturb the internal state. */
+	if (seed != 0)
+	{
+		/*
+		 * In essence, the seed is treated as part of the data being hashed,
+		 * but for simplicity, we pretend that it's padded with four bytes of
+		 * zeroes so that the seed constitutes a 12-byte chunk.
+		 */
+		a += (uint32) (seed >> 32);
+		b += (uint32) seed;
+		mix(a, b, c);
+	}
+
+	/* If the source pointer is word-aligned, we use word-wide fetches */
+	if (((uintptr_t) k & UINT32_ALIGN_MASK) == 0)
+	{
+		/* Code path for aligned source data */
+		const uint32 *ka = (const uint32 *) k;
+
+		/* handle most of the key */
+		while (len >= 12)
+		{
+			a += ka[0];
+			b += ka[1];
+			c += ka[2];
+			mix(a, b, c);
+			ka += 3;
+			len -= 12;
+		}
+
+		/* handle the last 11 bytes */
+		k = (const unsigned char *) ka;
+#ifdef WORDS_BIGENDIAN
+		switch (len)
+		{
+			case 11:
+				c += ((uint32) k[10] << 8);
+				/* fall through */
+			case 10:
+				c += ((uint32) k[9] << 16);
+				/* fall through */
+			case 9:
+				c += ((uint32) k[8] << 24);
+				/* fall through */
+			case 8:
+				/* the lowest byte of c is reserved for the length */
+				b += ka[1];
+				a += ka[0];
+				break;
+			case 7:
+				b += ((uint32) k[6] << 8);
+				/* fall through */
+			case 6:
+				b += ((uint32) k[5] << 16);
+				/* fall through */
+			case 5:
+				b += ((uint32) k[4] << 24);
+				/* fall through */
+			case 4:
+				a += ka[0];
+				break;
+			case 3:
+				a += ((uint32) k[2] << 8);
+				/* fall through */
+			case 2:
+				a += ((uint32) k[1] << 16);
+				/* fall through */
+			case 1:
+				a += ((uint32) k[0] << 24);
+				/* case 0: nothing left to add */
+		}
+#else							/* !WORDS_BIGENDIAN */
+		switch (len)
+		{
+			case 11:
+				c += ((uint32) k[10] << 24);
+				/* fall through */
+			case 10:
+				c += ((uint32) k[9] << 16);
+				/* fall through */
+			case 9:
+				c += ((uint32) k[8] << 8);
+				/* fall through */
+			case 8:
+				/* the lowest byte of c is reserved for the length */
+				b += ka[1];
+				a += ka[0];
+				break;
+			case 7:
+				b += ((uint32) k[6] << 16);
+				/* fall through */
+			case 6:
+				b += ((uint32) k[5] << 8);
+				/* fall through */
+			case 5:
+				b += k[4];
+				/* fall through */
+			case 4:
+				a += ka[0];
+				break;
+			case 3:
+				a += ((uint32) k[2] << 16);
+				/* fall through */
+			case 2:
+				a += ((uint32) k[1] << 8);
+				/* fall through */
+			case 1:
+				a += k[0];
+				/* case 0: nothing left to add */
+		}
+#endif							/* WORDS_BIGENDIAN */
+	}
+	else
+	{
+		/* Code path for non-aligned source data */
+
+		/* handle most of the key */
+		while (len >= 12)
+		{
+#ifdef WORDS_BIGENDIAN
+			a += (k[3] + ((uint32) k[2] << 8) + ((uint32) k[1] << 16) + ((uint32) k[0] << 24));
+			b += (k[7] + ((uint32) k[6] << 8) + ((uint32) k[5] << 16) + ((uint32) k[4] << 24));
+			c += (k[11] + ((uint32) k[10] << 8) + ((uint32) k[9] << 16) + ((uint32) k[8] << 24));
+#else							/* !WORDS_BIGENDIAN */
+			a += (k[0] + ((uint32) k[1] << 8) + ((uint32) k[2] << 16) + ((uint32) k[3] << 24));
+			b += (k[4] + ((uint32) k[5] << 8) + ((uint32) k[6] << 16) + ((uint32) k[7] << 24));
+			c += (k[8] + ((uint32) k[9] << 8) + ((uint32) k[10] << 16) + ((uint32) k[11] << 24));
+#endif							/* WORDS_BIGENDIAN */
+			mix(a, b, c);
+			k += 12;
+			len -= 12;
+		}
+
+		/* handle the last 11 bytes */
+#ifdef WORDS_BIGENDIAN
+		switch (len)
+		{
+			case 11:
+				c += ((uint32) k[10] << 8);
+				/* fall through */
+			case 10:
+				c += ((uint32) k[9] << 16);
+				/* fall through */
+			case 9:
+				c += ((uint32) k[8] << 24);
+				/* fall through */
+			case 8:
+				/* the lowest byte of c is reserved for the length */
+				b += k[7];
+				/* fall through */
+			case 7:
+				b += ((uint32) k[6] << 8);
+				/* fall through */
+			case 6:
+				b += ((uint32) k[5] << 16);
+				/* fall through */
+			case 5:
+				b += ((uint32) k[4] << 24);
+				/* fall through */
+			case 4:
+				a += k[3];
+				/* fall through */
+			case 3:
+				a += ((uint32) k[2] << 8);
+				/* fall through */
+			case 2:
+				a += ((uint32) k[1] << 16);
+				/* fall through */
+			case 1:
+				a += ((uint32) k[0] << 24);
+				/* case 0: nothing left to add */
+		}
+#else							/* !WORDS_BIGENDIAN */
+		switch (len)
+		{
+			case 11:
+				c += ((uint32) k[10] << 24);
+				/* fall through */
+			case 10:
+				c += ((uint32) k[9] << 16);
+				/* fall through */
+			case 9:
+				c += ((uint32) k[8] << 8);
+				/* fall through */
+			case 8:
+				/* the lowest byte of c is reserved for the length */
+				b += ((uint32) k[7] << 24);
+				/* fall through */
+			case 7:
+				b += ((uint32) k[6] << 16);
+				/* fall through */
+			case 6:
+				b += ((uint32) k[5] << 8);
+				/* fall through */
+			case 5:
+				b += k[4];
+				/* fall through */
+			case 4:
+				a += ((uint32) k[3] << 24);
+				/* fall through */
+			case 3:
+				a += ((uint32) k[2] << 16);
+				/* fall through */
+			case 2:
+				a += ((uint32) k[1] << 8);
+				/* fall through */
+			case 1:
+				a += k[0];
+				/* case 0: nothing left to add */
+		}
+#endif							/* WORDS_BIGENDIAN */
+	}
+
+	final(a, b, c);
+
+	/* report the result */
+	return ((uint64) b << 32) | c;
+}
+
+/*
+ * hash_bytes_uint32() -- hash a 32-bit value to a 32-bit value
+ *
+ * This has the same result as
+ *		hash_bytes(&k, sizeof(uint32))
+ * but is faster and doesn't force the caller to store k into memory.
+ */
+uint32
+hash_bytes_uint32(uint32 k)
+{
+	uint32		a,
+				b,
+				c;
+
+	a = b = c = 0x9e3779b9 + (uint32) sizeof(uint32) + 3923095;
+	a += k;
+
+	final(a, b, c);
+
+	/* report the result */
+	return c;
+}
+
+/*
+ * hash_bytes_uint32_extended() -- hash 32-bit value to 64-bit value, with seed
+ *
+ * Like hash_bytes_uint32, this is a convenience function.
+ */
+uint64
+hash_bytes_uint32_extended(uint32 k, uint64 seed)
+{
+	uint32		a,
+				b,
+				c;
+
+	a = b = c = 0x9e3779b9 + (uint32) sizeof(uint32) + 3923095;
+
+	if (seed != 0)
+	{
+		a += (uint32) (seed >> 32);
+		b += (uint32) seed;
+		mix(a, b, c);
+	}
+
+	a += k;
+
+	final(a, b, c);
+
+	/* report the result */
+	return ((uint64) b << 32) | c;
+}
+
+/*
+ * string_hash: hash function for keys that are NUL-terminated strings.
+ *
+ * NOTE: this is the default hash function if none is specified.
+ */
+uint32
+string_hash(const void *key, Size keysize)
+{
+	/*
+	 * If the string exceeds keysize-1 bytes, we want to hash only that many,
+	 * because when it is copied into the hash table it will be truncated at
+	 * that length.
+	 */
+	Size		s_len = strlen((const char *) key);
+
+	s_len = Min(s_len, keysize - 1);
+	return hash_bytes((const unsigned char *) key, (int) s_len);
+}
+
+/*
+ * tag_hash: hash function for fixed-size tag values
+ */
+uint32
+tag_hash(const void *key, Size keysize)
+{
+	return hash_bytes((const unsigned char *) key, (int) keysize);
+}
+
+/*
+ * uint32_hash: hash function for keys that are uint32 or int32
+ *
+ * (tag_hash works for this case too, but is slower)
+ */
+uint32
+uint32_hash(const void *key, Size keysize)
+{
+	Assert(keysize == sizeof(uint32));
+	return hash_bytes_uint32(*((const uint32 *) key));
+}
diff --git a/src/common/hmac.c b/src/common/hmac.c
new file mode 100644
index 0000000..1af7276
--- /dev/null
+++ b/src/common/hmac.c
@@ -0,0 +1,266 @@
+/*-------------------------------------------------------------------------
+ *
+ * hmac.c
+ *	  Implements Keyed-Hashing for Message Authentication (HMAC)
+ *
+ * Fallback implementation of HMAC, as specified in RFC 2104.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/hmac.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/cryptohash.h"
+#include "common/hmac.h"
+#include "common/md5.h"
+#include "common/sha1.h"
+#include "common/sha2.h"
+
+/*
+ * In backend, use palloc/pfree to ease the error handling.  In frontend,
+ * use malloc to be able to return a failure status back to the caller.
+ */
+#ifndef FRONTEND
+#define ALLOC(size) palloc(size)
+#define FREE(ptr) pfree(ptr)
+#else
+#define ALLOC(size) malloc(size)
+#define FREE(ptr) free(ptr)
+#endif
+
+/* Internal pg_hmac_ctx structure */
+struct pg_hmac_ctx
+{
+	pg_cryptohash_ctx *hash;
+	pg_cryptohash_type type;
+	int			block_size;
+	int			digest_size;
+
+	/*
+	 * Use the largest block size among supported options.  This wastes some
+	 * memory but simplifies the allocation logic.
+	 */
+	uint8		k_ipad[PG_SHA512_BLOCK_LENGTH];
+	uint8		k_opad[PG_SHA512_BLOCK_LENGTH];
+};
+
+#define HMAC_IPAD 0x36
+#define HMAC_OPAD 0x5C
+
+/*
+ * pg_hmac_create
+ *
+ * Allocate a hash context.  Returns NULL on failure for an OOM.  The
+ * backend issues an error, without returning.
+ */
+pg_hmac_ctx *
+pg_hmac_create(pg_cryptohash_type type)
+{
+	pg_hmac_ctx *ctx;
+
+	ctx = ALLOC(sizeof(pg_hmac_ctx));
+	if (ctx == NULL)
+		return NULL;
+	memset(ctx, 0, sizeof(pg_hmac_ctx));
+	ctx->type = type;
+
+	/*
+	 * Initialize the context data.  This requires to know the digest and
+	 * block lengths, that depend on the type of hash used.
+	 */
+	switch (type)
+	{
+		case PG_MD5:
+			ctx->digest_size = MD5_DIGEST_LENGTH;
+			ctx->block_size = MD5_BLOCK_SIZE;
+			break;
+		case PG_SHA1:
+			ctx->digest_size = SHA1_DIGEST_LENGTH;
+			ctx->block_size = SHA1_BLOCK_SIZE;
+			break;
+		case PG_SHA224:
+			ctx->digest_size = PG_SHA224_DIGEST_LENGTH;
+			ctx->block_size = PG_SHA224_BLOCK_LENGTH;
+			break;
+		case PG_SHA256:
+			ctx->digest_size = PG_SHA256_DIGEST_LENGTH;
+			ctx->block_size = PG_SHA256_BLOCK_LENGTH;
+			break;
+		case PG_SHA384:
+			ctx->digest_size = PG_SHA384_DIGEST_LENGTH;
+			ctx->block_size = PG_SHA384_BLOCK_LENGTH;
+			break;
+		case PG_SHA512:
+			ctx->digest_size = PG_SHA512_DIGEST_LENGTH;
+			ctx->block_size = PG_SHA512_BLOCK_LENGTH;
+			break;
+	}
+
+	ctx->hash = pg_cryptohash_create(type);
+	if (ctx->hash == NULL)
+	{
+		explicit_bzero(ctx, sizeof(pg_hmac_ctx));
+		FREE(ctx);
+		return NULL;
+	}
+
+	return ctx;
+}
+
+/*
+ * pg_hmac_init
+ *
+ * Initialize a HMAC context.  Returns 0 on success, -1 on failure.
+ */
+int
+pg_hmac_init(pg_hmac_ctx *ctx, const uint8 *key, size_t len)
+{
+	int			i;
+	int			digest_size;
+	int			block_size;
+	uint8	   *shrinkbuf = NULL;
+
+	if (ctx == NULL)
+		return -1;
+
+	digest_size = ctx->digest_size;
+	block_size = ctx->block_size;
+
+	memset(ctx->k_opad, HMAC_OPAD, ctx->block_size);
+	memset(ctx->k_ipad, HMAC_IPAD, ctx->block_size);
+
+	/*
+	 * If the key is longer than the block size, pass it through the hash once
+	 * to shrink it down.
+	 */
+	if (len > block_size)
+	{
+		pg_cryptohash_ctx *hash_ctx;
+
+		/* temporary buffer for one-time shrink */
+		shrinkbuf = ALLOC(digest_size);
+		if (shrinkbuf == NULL)
+			return -1;
+		memset(shrinkbuf, 0, digest_size);
+
+		hash_ctx = pg_cryptohash_create(ctx->type);
+		if (hash_ctx == NULL)
+		{
+			FREE(shrinkbuf);
+			return -1;
+		}
+
+		if (pg_cryptohash_init(hash_ctx) < 0 ||
+			pg_cryptohash_update(hash_ctx, key, len) < 0 ||
+			pg_cryptohash_final(hash_ctx, shrinkbuf, digest_size) < 0)
+		{
+			pg_cryptohash_free(hash_ctx);
+			FREE(shrinkbuf);
+			return -1;
+		}
+
+		key = shrinkbuf;
+		len = digest_size;
+		pg_cryptohash_free(hash_ctx);
+	}
+
+	for (i = 0; i < len; i++)
+	{
+		ctx->k_ipad[i] ^= key[i];
+		ctx->k_opad[i] ^= key[i];
+	}
+
+	/* tmp = H(K XOR ipad, text) */
+	if (pg_cryptohash_init(ctx->hash) < 0 ||
+		pg_cryptohash_update(ctx->hash, ctx->k_ipad, ctx->block_size) < 0)
+	{
+		if (shrinkbuf)
+			FREE(shrinkbuf);
+		return -1;
+	}
+
+	if (shrinkbuf)
+		FREE(shrinkbuf);
+	return 0;
+}
+
+/*
+ * pg_hmac_update
+ *
+ * Update a HMAC context.  Returns 0 on success, -1 on failure.
+ */
+int
+pg_hmac_update(pg_hmac_ctx *ctx, const uint8 *data, size_t len)
+{
+	if (ctx == NULL)
+		return -1;
+
+	if (pg_cryptohash_update(ctx->hash, data, len) < 0)
+		return -1;
+
+	return 0;
+}
+
+/*
+ * pg_hmac_final
+ *
+ * Finalize a HMAC context.  Returns 0 on success, -1 on failure.
+ */
+int
+pg_hmac_final(pg_hmac_ctx *ctx, uint8 *dest, size_t len)
+{
+	uint8	   *h;
+
+	if (ctx == NULL)
+		return -1;
+
+	h = ALLOC(ctx->digest_size);
+	if (h == NULL)
+		return -1;
+	memset(h, 0, ctx->digest_size);
+
+	if (pg_cryptohash_final(ctx->hash, h, ctx->digest_size) < 0)
+	{
+		FREE(h);
+		return -1;
+	}
+
+	/* H(K XOR opad, tmp) */
+	if (pg_cryptohash_init(ctx->hash) < 0 ||
+		pg_cryptohash_update(ctx->hash, ctx->k_opad, ctx->block_size) < 0 ||
+		pg_cryptohash_update(ctx->hash, h, ctx->digest_size) < 0 ||
+		pg_cryptohash_final(ctx->hash, dest, len) < 0)
+	{
+		FREE(h);
+		return -1;
+	}
+
+	FREE(h);
+	return 0;
+}
+
+/*
+ * pg_hmac_free
+ *
+ * Free a HMAC context.
+ */
+void
+pg_hmac_free(pg_hmac_ctx *ctx)
+{
+	if (ctx == NULL)
+		return;
+
+	pg_cryptohash_free(ctx->hash);
+	explicit_bzero(ctx, sizeof(pg_hmac_ctx));
+	FREE(ctx);
+}
diff --git a/src/common/hmac_openssl.c b/src/common/hmac_openssl.c
new file mode 100644
index 0000000..95b4944
--- /dev/null
+++ b/src/common/hmac_openssl.c
@@ -0,0 +1,254 @@
+/*-------------------------------------------------------------------------
+ *
+ * hmac_openssl.c
+ *	  Implementation of HMAC with OpenSSL.
+ *
+ * This should only be used if code is compiled with OpenSSL support.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/hmac_openssl.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <openssl/hmac.h>
+
+#include "common/hmac.h"
+#include "common/md5.h"
+#include "common/sha1.h"
+#include "common/sha2.h"
+#ifndef FRONTEND
+#include "utils/memutils.h"
+#include "utils/resowner.h"
+#include "utils/resowner_private.h"
+#endif
+
+/*
+ * In backend, use an allocation in TopMemoryContext to count for resowner
+ * cleanup handling if necessary.  For versions of OpenSSL where HMAC_CTX is
+ * known, just use palloc().  In frontend, use malloc to be able to return
+ * a failure status back to the caller.
+ */
+#ifndef FRONTEND
+#ifdef HAVE_HMAC_CTX_NEW
+#define ALLOC(size) MemoryContextAlloc(TopMemoryContext, size)
+#else
+#define ALLOC(size) palloc(size)
+#endif
+#define FREE(ptr) pfree(ptr)
+#else							/* FRONTEND */
+#define ALLOC(size) malloc(size)
+#define FREE(ptr) free(ptr)
+#endif							/* FRONTEND */
+
+/* Internal pg_hmac_ctx structure */
+struct pg_hmac_ctx
+{
+	HMAC_CTX   *hmacctx;
+	pg_cryptohash_type type;
+
+#ifndef FRONTEND
+	ResourceOwner resowner;
+#endif
+};
+
+/*
+ * pg_hmac_create
+ *
+ * Allocate a hash context.  Returns NULL on failure for an OOM.  The
+ * backend issues an error, without returning.
+ */
+pg_hmac_ctx *
+pg_hmac_create(pg_cryptohash_type type)
+{
+	pg_hmac_ctx *ctx;
+
+	ctx = ALLOC(sizeof(pg_hmac_ctx));
+	if (ctx == NULL)
+		return NULL;
+	memset(ctx, 0, sizeof(pg_hmac_ctx));
+
+	ctx->type = type;
+
+	/*
+	 * Initialization takes care of assigning the correct type for OpenSSL.
+	 */
+#ifdef HAVE_HMAC_CTX_NEW
+#ifndef FRONTEND
+	ResourceOwnerEnlargeHMAC(CurrentResourceOwner);
+#endif
+	ctx->hmacctx = HMAC_CTX_new();
+#else
+	ctx->hmacctx = ALLOC(sizeof(HMAC_CTX));
+#endif
+
+	if (ctx->hmacctx == NULL)
+	{
+		explicit_bzero(ctx, sizeof(pg_hmac_ctx));
+		FREE(ctx);
+#ifndef FRONTEND
+		ereport(ERROR,
+				(errcode(ERRCODE_OUT_OF_MEMORY),
+				 errmsg("out of memory")));
+#endif
+		return NULL;
+	}
+
+#ifdef HAVE_HMAC_CTX_NEW
+#ifndef FRONTEND
+	ctx->resowner = CurrentResourceOwner;
+	ResourceOwnerRememberHMAC(CurrentResourceOwner, PointerGetDatum(ctx));
+#endif
+#else
+	memset(ctx->hmacctx, 0, sizeof(HMAC_CTX));
+#endif							/* HAVE_HMAC_CTX_NEW */
+
+	return ctx;
+}
+
+/*
+ * pg_hmac_init
+ *
+ * Initialize a HMAC context.  Returns 0 on success, -1 on failure.
+ */
+int
+pg_hmac_init(pg_hmac_ctx *ctx, const uint8 *key, size_t len)
+{
+	int			status = 0;
+
+	if (ctx == NULL)
+		return -1;
+
+	switch (ctx->type)
+	{
+		case PG_MD5:
+			status = HMAC_Init_ex(ctx->hmacctx, key, len, EVP_md5(), NULL);
+			break;
+		case PG_SHA1:
+			status = HMAC_Init_ex(ctx->hmacctx, key, len, EVP_sha1(), NULL);
+			break;
+		case PG_SHA224:
+			status = HMAC_Init_ex(ctx->hmacctx, key, len, EVP_sha224(), NULL);
+			break;
+		case PG_SHA256:
+			status = HMAC_Init_ex(ctx->hmacctx, key, len, EVP_sha256(), NULL);
+			break;
+		case PG_SHA384:
+			status = HMAC_Init_ex(ctx->hmacctx, key, len, EVP_sha384(), NULL);
+			break;
+		case PG_SHA512:
+			status = HMAC_Init_ex(ctx->hmacctx, key, len, EVP_sha512(), NULL);
+			break;
+	}
+
+	/* OpenSSL internals return 1 on success, 0 on failure */
+	if (status <= 0)
+		return -1;
+
+	return 0;
+}
+
+/*
+ * pg_hmac_update
+ *
+ * Update a HMAC context.  Returns 0 on success, -1 on failure.
+ */
+int
+pg_hmac_update(pg_hmac_ctx *ctx, const uint8 *data, size_t len)
+{
+	int			status = 0;
+
+	if (ctx == NULL)
+		return -1;
+
+	status = HMAC_Update(ctx->hmacctx, data, len);
+
+	/* OpenSSL internals return 1 on success, 0 on failure */
+	if (status <= 0)
+		return -1;
+	return 0;
+}
+
+/*
+ * pg_hmac_final
+ *
+ * Finalize a HMAC context.  Returns 0 on success, -1 on failure.
+ */
+int
+pg_hmac_final(pg_hmac_ctx *ctx, uint8 *dest, size_t len)
+{
+	int			status = 0;
+	uint32		outlen;
+
+	if (ctx == NULL)
+		return -1;
+
+	switch (ctx->type)
+	{
+		case PG_MD5:
+			if (len < MD5_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA1:
+			if (len < SHA1_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA224:
+			if (len < PG_SHA224_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA256:
+			if (len < PG_SHA256_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA384:
+			if (len < PG_SHA384_DIGEST_LENGTH)
+				return -1;
+			break;
+		case PG_SHA512:
+			if (len < PG_SHA512_DIGEST_LENGTH)
+				return -1;
+			break;
+	}
+
+	status = HMAC_Final(ctx->hmacctx, dest, &outlen);
+
+	/* OpenSSL internals return 1 on success, 0 on failure */
+	if (status <= 0)
+		return -1;
+	return 0;
+}
+
+/*
+ * pg_hmac_free
+ *
+ * Free a HMAC context.
+ */
+void
+pg_hmac_free(pg_hmac_ctx *ctx)
+{
+	if (ctx == NULL)
+		return;
+
+#ifdef HAVE_HMAC_CTX_FREE
+	HMAC_CTX_free(ctx->hmacctx);
+#ifndef FRONTEND
+	ResourceOwnerForgetHMAC(ctx->resowner, PointerGetDatum(ctx));
+#endif
+#else
+	explicit_bzero(ctx->hmacctx, sizeof(HMAC_CTX));
+	FREE(ctx->hmacctx);
+#endif
+
+	explicit_bzero(ctx, sizeof(pg_hmac_ctx));
+	FREE(ctx);
+}
diff --git a/src/common/ip.c b/src/common/ip.c
new file mode 100644
index 0000000..9b611d8
--- /dev/null
+++ b/src/common/ip.c
@@ -0,0 +1,281 @@
+/*-------------------------------------------------------------------------
+ *
+ * ip.c
+ *	  IPv6-aware network access.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/ip.c
+ *
+ * This file and the IPV6 implementation were initially provided by
+ * Nigel Kukard <nkukard@lbsd.net>, Linux Based Systems Design
+ * http://www.lbsd.net.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#ifdef HAVE_NETINET_TCP_H
+#include <netinet/tcp.h>
+#endif
+#include <arpa/inet.h>
+#include <sys/file.h>
+
+#include "common/ip.h"
+
+
+
+#ifdef	HAVE_UNIX_SOCKETS
+static int	getaddrinfo_unix(const char *path,
+							 const struct addrinfo *hintsp,
+							 struct addrinfo **result);
+
+static int	getnameinfo_unix(const struct sockaddr_un *sa, int salen,
+							 char *node, int nodelen,
+							 char *service, int servicelen,
+							 int flags);
+#endif
+
+
+/*
+ *	pg_getaddrinfo_all - get address info for Unix, IPv4 and IPv6 sockets
+ */
+int
+pg_getaddrinfo_all(const char *hostname, const char *servname,
+				   const struct addrinfo *hintp, struct addrinfo **result)
+{
+	int			rc;
+
+	/* not all versions of getaddrinfo() zero *result on failure */
+	*result = NULL;
+
+#ifdef HAVE_UNIX_SOCKETS
+	if (hintp->ai_family == AF_UNIX)
+		return getaddrinfo_unix(servname, hintp, result);
+#endif
+
+	/* NULL has special meaning to getaddrinfo(). */
+	rc = getaddrinfo((!hostname || hostname[0] == '\0') ? NULL : hostname,
+					 servname, hintp, result);
+
+	return rc;
+}
+
+
+/*
+ *	pg_freeaddrinfo_all - free addrinfo structures for IPv4, IPv6, or Unix
+ *
+ * Note: the ai_family field of the original hint structure must be passed
+ * so that we can tell whether the addrinfo struct was built by the system's
+ * getaddrinfo() routine or our own getaddrinfo_unix() routine.  Some versions
+ * of getaddrinfo() might be willing to return AF_UNIX addresses, so it's
+ * not safe to look at ai_family in the addrinfo itself.
+ */
+void
+pg_freeaddrinfo_all(int hint_ai_family, struct addrinfo *ai)
+{
+#ifdef HAVE_UNIX_SOCKETS
+	if (hint_ai_family == AF_UNIX)
+	{
+		/* struct was built by getaddrinfo_unix (see pg_getaddrinfo_all) */
+		while (ai != NULL)
+		{
+			struct addrinfo *p = ai;
+
+			ai = ai->ai_next;
+			free(p->ai_addr);
+			free(p);
+		}
+	}
+	else
+#endif							/* HAVE_UNIX_SOCKETS */
+	{
+		/* struct was built by getaddrinfo() */
+		if (ai != NULL)
+			freeaddrinfo(ai);
+	}
+}
+
+
+/*
+ *	pg_getnameinfo_all - get name info for Unix, IPv4 and IPv6 sockets
+ *
+ * The API of this routine differs from the standard getnameinfo() definition
+ * in two ways: first, the addr parameter is declared as sockaddr_storage
+ * rather than struct sockaddr, and second, the node and service fields are
+ * guaranteed to be filled with something even on failure return.
+ */
+int
+pg_getnameinfo_all(const struct sockaddr_storage *addr, int salen,
+				   char *node, int nodelen,
+				   char *service, int servicelen,
+				   int flags)
+{
+	int			rc;
+
+#ifdef HAVE_UNIX_SOCKETS
+	if (addr && addr->ss_family == AF_UNIX)
+		rc = getnameinfo_unix((const struct sockaddr_un *) addr, salen,
+							  node, nodelen,
+							  service, servicelen,
+							  flags);
+	else
+#endif
+		rc = getnameinfo((const struct sockaddr *) addr, salen,
+						 node, nodelen,
+						 service, servicelen,
+						 flags);
+
+	if (rc != 0)
+	{
+		if (node)
+			strlcpy(node, "???", nodelen);
+		if (service)
+			strlcpy(service, "???", servicelen);
+	}
+
+	return rc;
+}
+
+
+#if defined(HAVE_UNIX_SOCKETS)
+
+/* -------
+ *	getaddrinfo_unix - get unix socket info using IPv6-compatible API
+ *
+ *	Bugs: only one addrinfo is set even though hintsp is NULL or
+ *		  ai_socktype is 0
+ *		  AI_CANONNAME is not supported.
+ * -------
+ */
+static int
+getaddrinfo_unix(const char *path, const struct addrinfo *hintsp,
+				 struct addrinfo **result)
+{
+	struct addrinfo hints;
+	struct addrinfo *aip;
+	struct sockaddr_un *unp;
+
+	*result = NULL;
+
+	MemSet(&hints, 0, sizeof(hints));
+
+	if (strlen(path) >= sizeof(unp->sun_path))
+		return EAI_FAIL;
+
+	if (hintsp == NULL)
+	{
+		hints.ai_family = AF_UNIX;
+		hints.ai_socktype = SOCK_STREAM;
+	}
+	else
+		memcpy(&hints, hintsp, sizeof(hints));
+
+	if (hints.ai_socktype == 0)
+		hints.ai_socktype = SOCK_STREAM;
+
+	if (hints.ai_family != AF_UNIX)
+	{
+		/* shouldn't have been called */
+		return EAI_FAIL;
+	}
+
+	aip = calloc(1, sizeof(struct addrinfo));
+	if (aip == NULL)
+		return EAI_MEMORY;
+
+	unp = calloc(1, sizeof(struct sockaddr_un));
+	if (unp == NULL)
+	{
+		free(aip);
+		return EAI_MEMORY;
+	}
+
+	aip->ai_family = AF_UNIX;
+	aip->ai_socktype = hints.ai_socktype;
+	aip->ai_protocol = hints.ai_protocol;
+	aip->ai_next = NULL;
+	aip->ai_canonname = NULL;
+	*result = aip;
+
+	unp->sun_family = AF_UNIX;
+	aip->ai_addr = (struct sockaddr *) unp;
+	aip->ai_addrlen = sizeof(struct sockaddr_un);
+
+	strcpy(unp->sun_path, path);
+
+	/*
+	 * If the supplied path starts with @, replace that with a zero byte for
+	 * the internal representation.  In that mode, the entire sun_path is the
+	 * address, including trailing zero bytes.  But we set the address length
+	 * to only include the length of the original string.  That way the
+	 * trailing zero bytes won't show up in any network or socket lists of the
+	 * operating system.  This is just a convention, also followed by other
+	 * packages.
+	 */
+	if (path[0] == '@')
+	{
+		unp->sun_path[0] = '\0';
+		aip->ai_addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(path);
+	}
+
+#ifdef HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN
+	unp->sun_len = sizeof(struct sockaddr_un);
+#endif
+
+	return 0;
+}
+
+/*
+ * Convert an address to a hostname.
+ */
+static int
+getnameinfo_unix(const struct sockaddr_un *sa, int salen,
+				 char *node, int nodelen,
+				 char *service, int servicelen,
+				 int flags)
+{
+	int			ret;
+
+	/* Invalid arguments. */
+	if (sa == NULL || sa->sun_family != AF_UNIX ||
+		(node == NULL && service == NULL))
+		return EAI_FAIL;
+
+	if (node)
+	{
+		ret = snprintf(node, nodelen, "%s", "[local]");
+		if (ret < 0 || ret >= nodelen)
+			return EAI_MEMORY;
+	}
+
+	if (service)
+	{
+		/*
+		 * Check whether it looks like an abstract socket, but it could also
+		 * just be an empty string.
+		 */
+		if (sa->sun_path[0] == '\0' && sa->sun_path[1] != '\0')
+			ret = snprintf(service, servicelen, "@%s", sa->sun_path + 1);
+		else
+			ret = snprintf(service, servicelen, "%s", sa->sun_path);
+		if (ret < 0 || ret >= servicelen)
+			return EAI_MEMORY;
+	}
+
+	return 0;
+}
+#endif							/* HAVE_UNIX_SOCKETS */
diff --git a/src/common/jsonapi.c b/src/common/jsonapi.c
new file mode 100644
index 0000000..d376ab1
--- /dev/null
+++ b/src/common/jsonapi.c
@@ -0,0 +1,1134 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonapi.c
+ *		JSON parser and lexer interfaces
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/jsonapi.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/jsonapi.h"
+#include "mb/pg_wchar.h"
+
+#ifdef FRONTEND
+#include "common/logging.h"
+#else
+#include "miscadmin.h"
+#endif
+
+#ifdef FRONTEND
+#define check_stack_depth()
+#define json_log_and_abort(...) \
+	do { pg_log_fatal(__VA_ARGS__); exit(1); } while(0)
+#else
+#define json_log_and_abort(...) elog(ERROR, __VA_ARGS__)
+#endif
+
+/*
+ * The context of the parser is maintained by the recursive descent
+ * mechanism, but is passed explicitly to the error reporting routine
+ * for better diagnostics.
+ */
+typedef enum					/* contexts of JSON parser */
+{
+	JSON_PARSE_VALUE,			/* expecting a value */
+	JSON_PARSE_STRING,			/* expecting a string (for a field name) */
+	JSON_PARSE_ARRAY_START,		/* saw '[', expecting value or ']' */
+	JSON_PARSE_ARRAY_NEXT,		/* saw array element, expecting ',' or ']' */
+	JSON_PARSE_OBJECT_START,	/* saw '{', expecting label or '}' */
+	JSON_PARSE_OBJECT_LABEL,	/* saw object label, expecting ':' */
+	JSON_PARSE_OBJECT_NEXT,		/* saw object value, expecting ',' or '}' */
+	JSON_PARSE_OBJECT_COMMA,	/* saw object ',', expecting next label */
+	JSON_PARSE_END				/* saw the end of a document, expect nothing */
+} JsonParseContext;
+
+static inline JsonParseErrorType json_lex_string(JsonLexContext *lex);
+static inline JsonParseErrorType json_lex_number(JsonLexContext *lex, char *s,
+												 bool *num_err, int *total_len);
+static inline JsonParseErrorType parse_scalar(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType parse_object_field(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType parse_object(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType parse_array_element(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType parse_array(JsonLexContext *lex, JsonSemAction *sem);
+static JsonParseErrorType report_parse_error(JsonParseContext ctx, JsonLexContext *lex);
+static char *extract_token(JsonLexContext *lex);
+
+/* the null action object used for pure validation */
+JsonSemAction nullSemAction =
+{
+	NULL, NULL, NULL, NULL, NULL,
+	NULL, NULL, NULL, NULL, NULL
+};
+
+/* Recursive Descent parser support routines */
+
+/*
+ * lex_peek
+ *
+ * what is the current look_ahead token?
+*/
+static inline JsonTokenType
+lex_peek(JsonLexContext *lex)
+{
+	return lex->token_type;
+}
+
+/*
+ * lex_expect
+ *
+ * move the lexer to the next token if the current look_ahead token matches
+ * the parameter token. Otherwise, report an error.
+ */
+static inline JsonParseErrorType
+lex_expect(JsonParseContext ctx, JsonLexContext *lex, JsonTokenType token)
+{
+	if (lex_peek(lex) == token)
+		return json_lex(lex);
+	else
+		return report_parse_error(ctx, lex);
+}
+
+/* chars to consider as part of an alphanumeric token */
+#define JSON_ALPHANUMERIC_CHAR(c)  \
+	(((c) >= 'a' && (c) <= 'z') || \
+	 ((c) >= 'A' && (c) <= 'Z') || \
+	 ((c) >= '0' && (c) <= '9') || \
+	 (c) == '_' || \
+	 IS_HIGHBIT_SET(c))
+
+/*
+ * Utility function to check if a string is a valid JSON number.
+ *
+ * str is of length len, and need not be null-terminated.
+ */
+bool
+IsValidJsonNumber(const char *str, int len)
+{
+	bool		numeric_error;
+	int			total_len;
+	JsonLexContext dummy_lex;
+
+	if (len <= 0)
+		return false;
+
+	/*
+	 * json_lex_number expects a leading  '-' to have been eaten already.
+	 *
+	 * having to cast away the constness of str is ugly, but there's not much
+	 * easy alternative.
+	 */
+	if (*str == '-')
+	{
+		dummy_lex.input = unconstify(char *, str) + 1;
+		dummy_lex.input_length = len - 1;
+	}
+	else
+	{
+		dummy_lex.input = unconstify(char *, str);
+		dummy_lex.input_length = len;
+	}
+
+	json_lex_number(&dummy_lex, dummy_lex.input, &numeric_error, &total_len);
+
+	return (!numeric_error) && (total_len == dummy_lex.input_length);
+}
+
+/*
+ * makeJsonLexContextCstringLen
+ *
+ * lex constructor, with or without StringInfo object for de-escaped lexemes.
+ *
+ * Without is better as it makes the processing faster, so only make one
+ * if really required.
+ */
+JsonLexContext *
+makeJsonLexContextCstringLen(char *json, int len, int encoding, bool need_escapes)
+{
+	JsonLexContext *lex = palloc0(sizeof(JsonLexContext));
+
+	lex->input = lex->token_terminator = lex->line_start = json;
+	lex->line_number = 1;
+	lex->input_length = len;
+	lex->input_encoding = encoding;
+	if (need_escapes)
+		lex->strval = makeStringInfo();
+	return lex;
+}
+
+/*
+ * pg_parse_json
+ *
+ * Publicly visible entry point for the JSON parser.
+ *
+ * lex is a lexing context, set up for the json to be processed by calling
+ * makeJsonLexContext(). sem is a structure of function pointers to semantic
+ * action routines to be called at appropriate spots during parsing, and a
+ * pointer to a state object to be passed to those routines.
+ */
+JsonParseErrorType
+pg_parse_json(JsonLexContext *lex, JsonSemAction *sem)
+{
+	JsonTokenType tok;
+	JsonParseErrorType result;
+
+	/* get the initial token */
+	result = json_lex(lex);
+	if (result != JSON_SUCCESS)
+		return result;
+
+	tok = lex_peek(lex);
+
+	/* parse by recursive descent */
+	switch (tok)
+	{
+		case JSON_TOKEN_OBJECT_START:
+			result = parse_object(lex, sem);
+			break;
+		case JSON_TOKEN_ARRAY_START:
+			result = parse_array(lex, sem);
+			break;
+		default:
+			result = parse_scalar(lex, sem);	/* json can be a bare scalar */
+	}
+
+	if (result == JSON_SUCCESS)
+		result = lex_expect(JSON_PARSE_END, lex, JSON_TOKEN_END);
+
+	return result;
+}
+
+/*
+ * json_count_array_elements
+ *
+ * Returns number of array elements in lex context at start of array token
+ * until end of array token at same nesting level.
+ *
+ * Designed to be called from array_start routines.
+ */
+JsonParseErrorType
+json_count_array_elements(JsonLexContext *lex, int *elements)
+{
+	JsonLexContext copylex;
+	int			count;
+	JsonParseErrorType result;
+
+	/*
+	 * It's safe to do this with a shallow copy because the lexical routines
+	 * don't scribble on the input. They do scribble on the other pointers
+	 * etc, so doing this with a copy makes that safe.
+	 */
+	memcpy(&copylex, lex, sizeof(JsonLexContext));
+	copylex.strval = NULL;		/* not interested in values here */
+	copylex.lex_level++;
+
+	count = 0;
+	result = lex_expect(JSON_PARSE_ARRAY_START, &copylex,
+						JSON_TOKEN_ARRAY_START);
+	if (result != JSON_SUCCESS)
+		return result;
+	if (lex_peek(&copylex) != JSON_TOKEN_ARRAY_END)
+	{
+		while (1)
+		{
+			count++;
+			result = parse_array_element(&copylex, &nullSemAction);
+			if (result != JSON_SUCCESS)
+				return result;
+			if (copylex.token_type != JSON_TOKEN_COMMA)
+				break;
+			result = json_lex(&copylex);
+			if (result != JSON_SUCCESS)
+				return result;
+		}
+	}
+	result = lex_expect(JSON_PARSE_ARRAY_NEXT, &copylex,
+						JSON_TOKEN_ARRAY_END);
+	if (result != JSON_SUCCESS)
+		return result;
+
+	*elements = count;
+	return JSON_SUCCESS;
+}
+
+/*
+ *	Recursive Descent parse routines. There is one for each structural
+ *	element in a json document:
+ *	  - scalar (string, number, true, false, null)
+ *	  - array  ( [ ] )
+ *	  - array element
+ *	  - object ( { } )
+ *	  - object field
+ */
+static inline JsonParseErrorType
+parse_scalar(JsonLexContext *lex, JsonSemAction *sem)
+{
+	char	   *val = NULL;
+	json_scalar_action sfunc = sem->scalar;
+	JsonTokenType tok = lex_peek(lex);
+	JsonParseErrorType result;
+
+	/* a scalar must be a string, a number, true, false, or null */
+	if (tok != JSON_TOKEN_STRING && tok != JSON_TOKEN_NUMBER &&
+		tok != JSON_TOKEN_TRUE && tok != JSON_TOKEN_FALSE &&
+		tok != JSON_TOKEN_NULL)
+		return report_parse_error(JSON_PARSE_VALUE, lex);
+
+	/* if no semantic function, just consume the token */
+	if (sfunc == NULL)
+		return json_lex(lex);
+
+	/* extract the de-escaped string value, or the raw lexeme */
+	if (lex_peek(lex) == JSON_TOKEN_STRING)
+	{
+		if (lex->strval != NULL)
+			val = pstrdup(lex->strval->data);
+	}
+	else
+	{
+		int			len = (lex->token_terminator - lex->token_start);
+
+		val = palloc(len + 1);
+		memcpy(val, lex->token_start, len);
+		val[len] = '\0';
+	}
+
+	/* consume the token */
+	result = json_lex(lex);
+	if (result != JSON_SUCCESS)
+		return result;
+
+	/* invoke the callback */
+	(*sfunc) (sem->semstate, val, tok);
+
+	return JSON_SUCCESS;
+}
+
+static JsonParseErrorType
+parse_object_field(JsonLexContext *lex, JsonSemAction *sem)
+{
+	/*
+	 * An object field is "fieldname" : value where value can be a scalar,
+	 * object or array.  Note: in user-facing docs and error messages, we
+	 * generally call a field name a "key".
+	 */
+
+	char	   *fname = NULL;	/* keep compiler quiet */
+	json_ofield_action ostart = sem->object_field_start;
+	json_ofield_action oend = sem->object_field_end;
+	bool		isnull;
+	JsonTokenType tok;
+	JsonParseErrorType result;
+
+	if (lex_peek(lex) != JSON_TOKEN_STRING)
+		return report_parse_error(JSON_PARSE_STRING, lex);
+	if ((ostart != NULL || oend != NULL) && lex->strval != NULL)
+		fname = pstrdup(lex->strval->data);
+	result = json_lex(lex);
+	if (result != JSON_SUCCESS)
+		return result;
+
+	result = lex_expect(JSON_PARSE_OBJECT_LABEL, lex, JSON_TOKEN_COLON);
+	if (result != JSON_SUCCESS)
+		return result;
+
+	tok = lex_peek(lex);
+	isnull = tok == JSON_TOKEN_NULL;
+
+	if (ostart != NULL)
+		(*ostart) (sem->semstate, fname, isnull);
+
+	switch (tok)
+	{
+		case JSON_TOKEN_OBJECT_START:
+			result = parse_object(lex, sem);
+			break;
+		case JSON_TOKEN_ARRAY_START:
+			result = parse_array(lex, sem);
+			break;
+		default:
+			result = parse_scalar(lex, sem);
+	}
+	if (result != JSON_SUCCESS)
+		return result;
+
+	if (oend != NULL)
+		(*oend) (sem->semstate, fname, isnull);
+	return JSON_SUCCESS;
+}
+
+static JsonParseErrorType
+parse_object(JsonLexContext *lex, JsonSemAction *sem)
+{
+	/*
+	 * an object is a possibly empty sequence of object fields, separated by
+	 * commas and surrounded by curly braces.
+	 */
+	json_struct_action ostart = sem->object_start;
+	json_struct_action oend = sem->object_end;
+	JsonTokenType tok;
+	JsonParseErrorType result;
+
+	check_stack_depth();
+
+	if (ostart != NULL)
+		(*ostart) (sem->semstate);
+
+	/*
+	 * Data inside an object is at a higher nesting level than the object
+	 * itself. Note that we increment this after we call the semantic routine
+	 * for the object start and restore it before we call the routine for the
+	 * object end.
+	 */
+	lex->lex_level++;
+
+	Assert(lex_peek(lex) == JSON_TOKEN_OBJECT_START);
+	result = json_lex(lex);
+	if (result != JSON_SUCCESS)
+		return result;
+
+	tok = lex_peek(lex);
+	switch (tok)
+	{
+		case JSON_TOKEN_STRING:
+			result = parse_object_field(lex, sem);
+			while (result == JSON_SUCCESS && lex_peek(lex) == JSON_TOKEN_COMMA)
+			{
+				result = json_lex(lex);
+				if (result != JSON_SUCCESS)
+					break;
+				result = parse_object_field(lex, sem);
+			}
+			break;
+		case JSON_TOKEN_OBJECT_END:
+			break;
+		default:
+			/* case of an invalid initial token inside the object */
+			result = report_parse_error(JSON_PARSE_OBJECT_START, lex);
+	}
+	if (result != JSON_SUCCESS)
+		return result;
+
+	result = lex_expect(JSON_PARSE_OBJECT_NEXT, lex, JSON_TOKEN_OBJECT_END);
+	if (result != JSON_SUCCESS)
+		return result;
+
+	lex->lex_level--;
+
+	if (oend != NULL)
+		(*oend) (sem->semstate);
+
+	return JSON_SUCCESS;
+}
+
+static JsonParseErrorType
+parse_array_element(JsonLexContext *lex, JsonSemAction *sem)
+{
+	json_aelem_action astart = sem->array_element_start;
+	json_aelem_action aend = sem->array_element_end;
+	JsonTokenType tok = lex_peek(lex);
+	JsonParseErrorType result;
+
+	bool		isnull;
+
+	isnull = tok == JSON_TOKEN_NULL;
+
+	if (astart != NULL)
+		(*astart) (sem->semstate, isnull);
+
+	/* an array element is any object, array or scalar */
+	switch (tok)
+	{
+		case JSON_TOKEN_OBJECT_START:
+			result = parse_object(lex, sem);
+			break;
+		case JSON_TOKEN_ARRAY_START:
+			result = parse_array(lex, sem);
+			break;
+		default:
+			result = parse_scalar(lex, sem);
+	}
+
+	if (result != JSON_SUCCESS)
+		return result;
+
+	if (aend != NULL)
+		(*aend) (sem->semstate, isnull);
+
+	return JSON_SUCCESS;
+}
+
+static JsonParseErrorType
+parse_array(JsonLexContext *lex, JsonSemAction *sem)
+{
+	/*
+	 * an array is a possibly empty sequence of array elements, separated by
+	 * commas and surrounded by square brackets.
+	 */
+	json_struct_action astart = sem->array_start;
+	json_struct_action aend = sem->array_end;
+	JsonParseErrorType result;
+
+	check_stack_depth();
+
+	if (astart != NULL)
+		(*astart) (sem->semstate);
+
+	/*
+	 * Data inside an array is at a higher nesting level than the array
+	 * itself. Note that we increment this after we call the semantic routine
+	 * for the array start and restore it before we call the routine for the
+	 * array end.
+	 */
+	lex->lex_level++;
+
+	result = lex_expect(JSON_PARSE_ARRAY_START, lex, JSON_TOKEN_ARRAY_START);
+	if (result == JSON_SUCCESS && lex_peek(lex) != JSON_TOKEN_ARRAY_END)
+	{
+		result = parse_array_element(lex, sem);
+
+		while (result == JSON_SUCCESS && lex_peek(lex) == JSON_TOKEN_COMMA)
+		{
+			result = json_lex(lex);
+			if (result != JSON_SUCCESS)
+				break;
+			result = parse_array_element(lex, sem);
+		}
+	}
+	if (result != JSON_SUCCESS)
+		return result;
+
+	result = lex_expect(JSON_PARSE_ARRAY_NEXT, lex, JSON_TOKEN_ARRAY_END);
+	if (result != JSON_SUCCESS)
+		return result;
+
+	lex->lex_level--;
+
+	if (aend != NULL)
+		(*aend) (sem->semstate);
+
+	return JSON_SUCCESS;
+}
+
+/*
+ * Lex one token from the input stream.
+ */
+JsonParseErrorType
+json_lex(JsonLexContext *lex)
+{
+	char	   *s;
+	int			len;
+	JsonParseErrorType result;
+
+	/* Skip leading whitespace. */
+	s = lex->token_terminator;
+	len = s - lex->input;
+	while (len < lex->input_length &&
+		   (*s == ' ' || *s == '\t' || *s == '\n' || *s == '\r'))
+	{
+		if (*s++ == '\n')
+		{
+			++lex->line_number;
+			lex->line_start = s;
+		}
+		len++;
+	}
+	lex->token_start = s;
+
+	/* Determine token type. */
+	if (len >= lex->input_length)
+	{
+		lex->token_start = NULL;
+		lex->prev_token_terminator = lex->token_terminator;
+		lex->token_terminator = s;
+		lex->token_type = JSON_TOKEN_END;
+	}
+	else
+	{
+		switch (*s)
+		{
+				/* Single-character token, some kind of punctuation mark. */
+			case '{':
+				lex->prev_token_terminator = lex->token_terminator;
+				lex->token_terminator = s + 1;
+				lex->token_type = JSON_TOKEN_OBJECT_START;
+				break;
+			case '}':
+				lex->prev_token_terminator = lex->token_terminator;
+				lex->token_terminator = s + 1;
+				lex->token_type = JSON_TOKEN_OBJECT_END;
+				break;
+			case '[':
+				lex->prev_token_terminator = lex->token_terminator;
+				lex->token_terminator = s + 1;
+				lex->token_type = JSON_TOKEN_ARRAY_START;
+				break;
+			case ']':
+				lex->prev_token_terminator = lex->token_terminator;
+				lex->token_terminator = s + 1;
+				lex->token_type = JSON_TOKEN_ARRAY_END;
+				break;
+			case ',':
+				lex->prev_token_terminator = lex->token_terminator;
+				lex->token_terminator = s + 1;
+				lex->token_type = JSON_TOKEN_COMMA;
+				break;
+			case ':':
+				lex->prev_token_terminator = lex->token_terminator;
+				lex->token_terminator = s + 1;
+				lex->token_type = JSON_TOKEN_COLON;
+				break;
+			case '"':
+				/* string */
+				result = json_lex_string(lex);
+				if (result != JSON_SUCCESS)
+					return result;
+				lex->token_type = JSON_TOKEN_STRING;
+				break;
+			case '-':
+				/* Negative number. */
+				result = json_lex_number(lex, s + 1, NULL, NULL);
+				if (result != JSON_SUCCESS)
+					return result;
+				lex->token_type = JSON_TOKEN_NUMBER;
+				break;
+			case '0':
+			case '1':
+			case '2':
+			case '3':
+			case '4':
+			case '5':
+			case '6':
+			case '7':
+			case '8':
+			case '9':
+				/* Positive number. */
+				result = json_lex_number(lex, s, NULL, NULL);
+				if (result != JSON_SUCCESS)
+					return result;
+				lex->token_type = JSON_TOKEN_NUMBER;
+				break;
+			default:
+				{
+					char	   *p;
+
+					/*
+					 * We're not dealing with a string, number, legal
+					 * punctuation mark, or end of string.  The only legal
+					 * tokens we might find here are true, false, and null,
+					 * but for error reporting purposes we scan until we see a
+					 * non-alphanumeric character.  That way, we can report
+					 * the whole word as an unexpected token, rather than just
+					 * some unintuitive prefix thereof.
+					 */
+					for (p = s; p - s < lex->input_length - len && JSON_ALPHANUMERIC_CHAR(*p); p++)
+						 /* skip */ ;
+
+					/*
+					 * We got some sort of unexpected punctuation or an
+					 * otherwise unexpected character, so just complain about
+					 * that one character.
+					 */
+					if (p == s)
+					{
+						lex->prev_token_terminator = lex->token_terminator;
+						lex->token_terminator = s + 1;
+						return JSON_INVALID_TOKEN;
+					}
+
+					/*
+					 * We've got a real alphanumeric token here.  If it
+					 * happens to be true, false, or null, all is well.  If
+					 * not, error out.
+					 */
+					lex->prev_token_terminator = lex->token_terminator;
+					lex->token_terminator = p;
+					if (p - s == 4)
+					{
+						if (memcmp(s, "true", 4) == 0)
+							lex->token_type = JSON_TOKEN_TRUE;
+						else if (memcmp(s, "null", 4) == 0)
+							lex->token_type = JSON_TOKEN_NULL;
+						else
+							return JSON_INVALID_TOKEN;
+					}
+					else if (p - s == 5 && memcmp(s, "false", 5) == 0)
+						lex->token_type = JSON_TOKEN_FALSE;
+					else
+						return JSON_INVALID_TOKEN;
+
+				}
+		}						/* end of switch */
+	}
+
+	return JSON_SUCCESS;
+}
+
+/*
+ * The next token in the input stream is known to be a string; lex it.
+ */
+static inline JsonParseErrorType
+json_lex_string(JsonLexContext *lex)
+{
+	char	   *s;
+	int			len;
+	int			hi_surrogate = -1;
+
+	if (lex->strval != NULL)
+		resetStringInfo(lex->strval);
+
+	Assert(lex->input_length > 0);
+	s = lex->token_start;
+	len = lex->token_start - lex->input;
+	for (;;)
+	{
+		s++;
+		len++;
+		/* Premature end of the string. */
+		if (len >= lex->input_length)
+		{
+			lex->token_terminator = s;
+			return JSON_INVALID_TOKEN;
+		}
+		else if (*s == '"')
+			break;
+		else if ((unsigned char) *s < 32)
+		{
+			/* Per RFC4627, these characters MUST be escaped. */
+			/* Since *s isn't printable, exclude it from the context string */
+			lex->token_terminator = s;
+			return JSON_ESCAPING_REQUIRED;
+		}
+		else if (*s == '\\')
+		{
+			/* OK, we have an escape character. */
+			s++;
+			len++;
+			if (len >= lex->input_length)
+			{
+				lex->token_terminator = s;
+				return JSON_INVALID_TOKEN;
+			}
+			else if (*s == 'u')
+			{
+				int			i;
+				int			ch = 0;
+
+				for (i = 1; i <= 4; i++)
+				{
+					s++;
+					len++;
+					if (len >= lex->input_length)
+					{
+						lex->token_terminator = s;
+						return JSON_INVALID_TOKEN;
+					}
+					else if (*s >= '0' && *s <= '9')
+						ch = (ch * 16) + (*s - '0');
+					else if (*s >= 'a' && *s <= 'f')
+						ch = (ch * 16) + (*s - 'a') + 10;
+					else if (*s >= 'A' && *s <= 'F')
+						ch = (ch * 16) + (*s - 'A') + 10;
+					else
+					{
+						lex->token_terminator = s + pg_encoding_mblen_bounded(lex->input_encoding, s);
+						return JSON_UNICODE_ESCAPE_FORMAT;
+					}
+				}
+				if (lex->strval != NULL)
+				{
+					/*
+					 * Combine surrogate pairs.
+					 */
+					if (is_utf16_surrogate_first(ch))
+					{
+						if (hi_surrogate != -1)
+							return JSON_UNICODE_HIGH_SURROGATE;
+						hi_surrogate = ch;
+						continue;
+					}
+					else if (is_utf16_surrogate_second(ch))
+					{
+						if (hi_surrogate == -1)
+							return JSON_UNICODE_LOW_SURROGATE;
+						ch = surrogate_pair_to_codepoint(hi_surrogate, ch);
+						hi_surrogate = -1;
+					}
+
+					if (hi_surrogate != -1)
+						return JSON_UNICODE_LOW_SURROGATE;
+
+					/*
+					 * Reject invalid cases.  We can't have a value above
+					 * 0xFFFF here (since we only accepted 4 hex digits
+					 * above), so no need to test for out-of-range chars.
+					 */
+					if (ch == 0)
+					{
+						/* We can't allow this, since our TEXT type doesn't */
+						return JSON_UNICODE_CODE_POINT_ZERO;
+					}
+
+					/*
+					 * Add the represented character to lex->strval.  In the
+					 * backend, we can let pg_unicode_to_server() handle any
+					 * required character set conversion; in frontend, we can
+					 * only deal with trivial conversions.
+					 *
+					 * Note: pg_unicode_to_server() will throw an error for a
+					 * conversion failure, rather than returning a failure
+					 * indication.  That seems OK.
+					 */
+#ifndef FRONTEND
+					{
+						char		cbuf[MAX_UNICODE_EQUIVALENT_STRING + 1];
+
+						pg_unicode_to_server(ch, (unsigned char *) cbuf);
+						appendStringInfoString(lex->strval, cbuf);
+					}
+#else
+					if (lex->input_encoding == PG_UTF8)
+					{
+						/* OK, we can map the code point to UTF8 easily */
+						char		utf8str[5];
+						int			utf8len;
+
+						unicode_to_utf8(ch, (unsigned char *) utf8str);
+						utf8len = pg_utf_mblen((unsigned char *) utf8str);
+						appendBinaryStringInfo(lex->strval, utf8str, utf8len);
+					}
+					else if (ch <= 0x007f)
+					{
+						/* The ASCII range is the same in all encodings */
+						appendStringInfoChar(lex->strval, (char) ch);
+					}
+					else
+						return JSON_UNICODE_HIGH_ESCAPE;
+#endif							/* FRONTEND */
+				}
+			}
+			else if (lex->strval != NULL)
+			{
+				if (hi_surrogate != -1)
+					return JSON_UNICODE_LOW_SURROGATE;
+
+				switch (*s)
+				{
+					case '"':
+					case '\\':
+					case '/':
+						appendStringInfoChar(lex->strval, *s);
+						break;
+					case 'b':
+						appendStringInfoChar(lex->strval, '\b');
+						break;
+					case 'f':
+						appendStringInfoChar(lex->strval, '\f');
+						break;
+					case 'n':
+						appendStringInfoChar(lex->strval, '\n');
+						break;
+					case 'r':
+						appendStringInfoChar(lex->strval, '\r');
+						break;
+					case 't':
+						appendStringInfoChar(lex->strval, '\t');
+						break;
+					default:
+						/* Not a valid string escape, so signal error. */
+						lex->token_start = s;
+						lex->token_terminator = s + pg_encoding_mblen_bounded(lex->input_encoding, s);
+						return JSON_ESCAPING_INVALID;
+				}
+			}
+			else if (strchr("\"\\/bfnrt", *s) == NULL)
+			{
+				/*
+				 * Simpler processing if we're not bothered about de-escaping
+				 *
+				 * It's very tempting to remove the strchr() call here and
+				 * replace it with a switch statement, but testing so far has
+				 * shown it's not a performance win.
+				 */
+				lex->token_start = s;
+				lex->token_terminator = s + pg_encoding_mblen_bounded(lex->input_encoding, s);
+				return JSON_ESCAPING_INVALID;
+			}
+
+		}
+		else if (lex->strval != NULL)
+		{
+			if (hi_surrogate != -1)
+				return JSON_UNICODE_LOW_SURROGATE;
+
+			appendStringInfoChar(lex->strval, *s);
+		}
+
+	}
+
+	if (hi_surrogate != -1)
+		return JSON_UNICODE_LOW_SURROGATE;
+
+	/* Hooray, we found the end of the string! */
+	lex->prev_token_terminator = lex->token_terminator;
+	lex->token_terminator = s + 1;
+	return JSON_SUCCESS;
+}
+
+/*
+ * The next token in the input stream is known to be a number; lex it.
+ *
+ * In JSON, a number consists of four parts:
+ *
+ * (1) An optional minus sign ('-').
+ *
+ * (2) Either a single '0', or a string of one or more digits that does not
+ *	   begin with a '0'.
+ *
+ * (3) An optional decimal part, consisting of a period ('.') followed by
+ *	   one or more digits.  (Note: While this part can be omitted
+ *	   completely, it's not OK to have only the decimal point without
+ *	   any digits afterwards.)
+ *
+ * (4) An optional exponent part, consisting of 'e' or 'E', optionally
+ *	   followed by '+' or '-', followed by one or more digits.  (Note:
+ *	   As with the decimal part, if 'e' or 'E' is present, it must be
+ *	   followed by at least one digit.)
+ *
+ * The 's' argument to this function points to the ostensible beginning
+ * of part 2 - i.e. the character after any optional minus sign, or the
+ * first character of the string if there is none.
+ *
+ * If num_err is not NULL, we return an error flag to *num_err rather than
+ * raising an error for a badly-formed number.  Also, if total_len is not NULL
+ * the distance from lex->input to the token end+1 is returned to *total_len.
+ */
+static inline JsonParseErrorType
+json_lex_number(JsonLexContext *lex, char *s,
+				bool *num_err, int *total_len)
+{
+	bool		error = false;
+	int			len = s - lex->input;
+
+	/* Part (1): leading sign indicator. */
+	/* Caller already did this for us; so do nothing. */
+
+	/* Part (2): parse main digit string. */
+	if (len < lex->input_length && *s == '0')
+	{
+		s++;
+		len++;
+	}
+	else if (len < lex->input_length && *s >= '1' && *s <= '9')
+	{
+		do
+		{
+			s++;
+			len++;
+		} while (len < lex->input_length && *s >= '0' && *s <= '9');
+	}
+	else
+		error = true;
+
+	/* Part (3): parse optional decimal portion. */
+	if (len < lex->input_length && *s == '.')
+	{
+		s++;
+		len++;
+		if (len == lex->input_length || *s < '0' || *s > '9')
+			error = true;
+		else
+		{
+			do
+			{
+				s++;
+				len++;
+			} while (len < lex->input_length && *s >= '0' && *s <= '9');
+		}
+	}
+
+	/* Part (4): parse optional exponent. */
+	if (len < lex->input_length && (*s == 'e' || *s == 'E'))
+	{
+		s++;
+		len++;
+		if (len < lex->input_length && (*s == '+' || *s == '-'))
+		{
+			s++;
+			len++;
+		}
+		if (len == lex->input_length || *s < '0' || *s > '9')
+			error = true;
+		else
+		{
+			do
+			{
+				s++;
+				len++;
+			} while (len < lex->input_length && *s >= '0' && *s <= '9');
+		}
+	}
+
+	/*
+	 * Check for trailing garbage.  As in json_lex(), any alphanumeric stuff
+	 * here should be considered part of the token for error-reporting
+	 * purposes.
+	 */
+	for (; len < lex->input_length && JSON_ALPHANUMERIC_CHAR(*s); s++, len++)
+		error = true;
+
+	if (total_len != NULL)
+		*total_len = len;
+
+	if (num_err != NULL)
+	{
+		/* let the caller handle any error */
+		*num_err = error;
+	}
+	else
+	{
+		/* return token endpoint */
+		lex->prev_token_terminator = lex->token_terminator;
+		lex->token_terminator = s;
+		/* handle error if any */
+		if (error)
+			return JSON_INVALID_TOKEN;
+	}
+
+	return JSON_SUCCESS;
+}
+
+/*
+ * Report a parse error.
+ *
+ * lex->token_start and lex->token_terminator must identify the current token.
+ */
+static JsonParseErrorType
+report_parse_error(JsonParseContext ctx, JsonLexContext *lex)
+{
+	/* Handle case where the input ended prematurely. */
+	if (lex->token_start == NULL || lex->token_type == JSON_TOKEN_END)
+		return JSON_EXPECTED_MORE;
+
+	/* Otherwise choose the error type based on the parsing context. */
+	switch (ctx)
+	{
+		case JSON_PARSE_END:
+			return JSON_EXPECTED_END;
+		case JSON_PARSE_VALUE:
+			return JSON_EXPECTED_JSON;
+		case JSON_PARSE_STRING:
+			return JSON_EXPECTED_STRING;
+		case JSON_PARSE_ARRAY_START:
+			return JSON_EXPECTED_ARRAY_FIRST;
+		case JSON_PARSE_ARRAY_NEXT:
+			return JSON_EXPECTED_ARRAY_NEXT;
+		case JSON_PARSE_OBJECT_START:
+			return JSON_EXPECTED_OBJECT_FIRST;
+		case JSON_PARSE_OBJECT_LABEL:
+			return JSON_EXPECTED_COLON;
+		case JSON_PARSE_OBJECT_NEXT:
+			return JSON_EXPECTED_OBJECT_NEXT;
+		case JSON_PARSE_OBJECT_COMMA:
+			return JSON_EXPECTED_STRING;
+	}
+
+	/*
+	 * We don't use a default: case, so that the compiler will warn about
+	 * unhandled enum values.  But this needs to be here anyway to cover the
+	 * possibility of an incorrect input.
+	 */
+	json_log_and_abort("unexpected json parse state: %d", (int) ctx);
+	return JSON_SUCCESS;		/* silence stupider compilers */
+}
+
+/*
+ * Construct a detail message for a JSON error.
+ */
+char *
+json_errdetail(JsonParseErrorType error, JsonLexContext *lex)
+{
+	switch (error)
+	{
+		case JSON_SUCCESS:
+			/* fall through to the error code after switch */
+			break;
+		case JSON_ESCAPING_INVALID:
+			return psprintf(_("Escape sequence \"\\%s\" is invalid."),
+							extract_token(lex));
+		case JSON_ESCAPING_REQUIRED:
+			return psprintf(_("Character with value 0x%02x must be escaped."),
+							(unsigned char) *(lex->token_terminator));
+		case JSON_EXPECTED_END:
+			return psprintf(_("Expected end of input, but found \"%s\"."),
+							extract_token(lex));
+		case JSON_EXPECTED_ARRAY_FIRST:
+			return psprintf(_("Expected array element or \"]\", but found \"%s\"."),
+							extract_token(lex));
+		case JSON_EXPECTED_ARRAY_NEXT:
+			return psprintf(_("Expected \",\" or \"]\", but found \"%s\"."),
+							extract_token(lex));
+		case JSON_EXPECTED_COLON:
+			return psprintf(_("Expected \":\", but found \"%s\"."),
+							extract_token(lex));
+		case JSON_EXPECTED_JSON:
+			return psprintf(_("Expected JSON value, but found \"%s\"."),
+							extract_token(lex));
+		case JSON_EXPECTED_MORE:
+			return _("The input string ended unexpectedly.");
+		case JSON_EXPECTED_OBJECT_FIRST:
+			return psprintf(_("Expected string or \"}\", but found \"%s\"."),
+							extract_token(lex));
+		case JSON_EXPECTED_OBJECT_NEXT:
+			return psprintf(_("Expected \",\" or \"}\", but found \"%s\"."),
+							extract_token(lex));
+		case JSON_EXPECTED_STRING:
+			return psprintf(_("Expected string, but found \"%s\"."),
+							extract_token(lex));
+		case JSON_INVALID_TOKEN:
+			return psprintf(_("Token \"%s\" is invalid."),
+							extract_token(lex));
+		case JSON_UNICODE_CODE_POINT_ZERO:
+			return _("\\u0000 cannot be converted to text.");
+		case JSON_UNICODE_ESCAPE_FORMAT:
+			return _("\"\\u\" must be followed by four hexadecimal digits.");
+		case JSON_UNICODE_HIGH_ESCAPE:
+			/* note: this case is only reachable in frontend not backend */
+			return _("Unicode escape values cannot be used for code point values above 007F when the encoding is not UTF8.");
+		case JSON_UNICODE_HIGH_SURROGATE:
+			return _("Unicode high surrogate must not follow a high surrogate.");
+		case JSON_UNICODE_LOW_SURROGATE:
+			return _("Unicode low surrogate must follow a high surrogate.");
+	}
+
+	/*
+	 * We don't use a default: case, so that the compiler will warn about
+	 * unhandled enum values.  But this needs to be here anyway to cover the
+	 * possibility of an incorrect input.
+	 */
+	json_log_and_abort("unexpected json parse error type: %d", (int) error);
+	return NULL;				/* silence stupider compilers */
+}
+
+/*
+ * Extract the current token from a lexing context, for error reporting.
+ */
+static char *
+extract_token(JsonLexContext *lex)
+{
+	int			toklen = lex->token_terminator - lex->token_start;
+	char	   *token = palloc(toklen + 1);
+
+	memcpy(token, lex->token_start, toklen);
+	token[toklen] = '\0';
+	return token;
+}
diff --git a/src/common/keywords.c b/src/common/keywords.c
new file mode 100644
index 0000000..d8497f7
--- /dev/null
+++ b/src/common/keywords.c
@@ -0,0 +1,48 @@
+/*-------------------------------------------------------------------------
+ *
+ * keywords.c
+ *	  PostgreSQL's list of SQL keywords
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/keywords.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include "common/keywords.h"
+
+
+/* ScanKeywordList lookup data for SQL keywords */
+
+#include "kwlist_d.h"
+
+/* Keyword categories for SQL keywords */
+
+#define PG_KEYWORD(kwname, value, category, collabel) category,
+
+const uint8 ScanKeywordCategories[SCANKEYWORDS_NUM_KEYWORDS] = {
+#include "parser/kwlist.h"
+};
+
+#undef PG_KEYWORD
+
+/* Keyword can-be-bare-label flags for SQL keywords */
+
+#define PG_KEYWORD(kwname, value, category, collabel) collabel,
+
+#define BARE_LABEL true
+#define AS_LABEL false
+
+const bool	ScanKeywordBareLabel[SCANKEYWORDS_NUM_KEYWORDS] = {
+#include "parser/kwlist.h"
+};
+
+#undef PG_KEYWORD
+#undef BARE_LABEL
+#undef AS_LABEL
diff --git a/src/common/kwlist_d.h b/src/common/kwlist_d.h
new file mode 100644
index 0000000..3190723
--- /dev/null
+++ b/src/common/kwlist_d.h
@@ -0,0 +1,1088 @@
+/*-------------------------------------------------------------------------
+ *
+ * kwlist_d.h
+ *    List of keywords represented as a ScanKeywordList.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * NOTES
+ *  ******************************
+ *  *** DO NOT EDIT THIS FILE! ***
+ *  ******************************
+ *
+ *  It has been GENERATED by src/tools/gen_keywordlist.pl
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef KWLIST_D_H
+#define KWLIST_D_H
+
+#include "common/kwlookup.h"
+
+static const char ScanKeywords_kw_string[] =
+	"abort\0"
+	"absolute\0"
+	"access\0"
+	"action\0"
+	"add\0"
+	"admin\0"
+	"after\0"
+	"aggregate\0"
+	"all\0"
+	"also\0"
+	"alter\0"
+	"always\0"
+	"analyse\0"
+	"analyze\0"
+	"and\0"
+	"any\0"
+	"array\0"
+	"as\0"
+	"asc\0"
+	"asensitive\0"
+	"assertion\0"
+	"assignment\0"
+	"asymmetric\0"
+	"at\0"
+	"atomic\0"
+	"attach\0"
+	"attribute\0"
+	"authorization\0"
+	"backward\0"
+	"before\0"
+	"begin\0"
+	"between\0"
+	"bigint\0"
+	"binary\0"
+	"bit\0"
+	"boolean\0"
+	"both\0"
+	"breadth\0"
+	"by\0"
+	"cache\0"
+	"call\0"
+	"called\0"
+	"cascade\0"
+	"cascaded\0"
+	"case\0"
+	"cast\0"
+	"catalog\0"
+	"chain\0"
+	"char\0"
+	"character\0"
+	"characteristics\0"
+	"check\0"
+	"checkpoint\0"
+	"class\0"
+	"close\0"
+	"cluster\0"
+	"coalesce\0"
+	"collate\0"
+	"collation\0"
+	"column\0"
+	"columns\0"
+	"comment\0"
+	"comments\0"
+	"commit\0"
+	"committed\0"
+	"compression\0"
+	"concurrently\0"
+	"configuration\0"
+	"conflict\0"
+	"connection\0"
+	"constraint\0"
+	"constraints\0"
+	"content\0"
+	"continue\0"
+	"conversion\0"
+	"copy\0"
+	"cost\0"
+	"create\0"
+	"cross\0"
+	"csv\0"
+	"cube\0"
+	"current\0"
+	"current_catalog\0"
+	"current_date\0"
+	"current_role\0"
+	"current_schema\0"
+	"current_time\0"
+	"current_timestamp\0"
+	"current_user\0"
+	"cursor\0"
+	"cycle\0"
+	"data\0"
+	"database\0"
+	"day\0"
+	"deallocate\0"
+	"dec\0"
+	"decimal\0"
+	"declare\0"
+	"default\0"
+	"defaults\0"
+	"deferrable\0"
+	"deferred\0"
+	"definer\0"
+	"delete\0"
+	"delimiter\0"
+	"delimiters\0"
+	"depends\0"
+	"depth\0"
+	"desc\0"
+	"detach\0"
+	"dictionary\0"
+	"disable\0"
+	"discard\0"
+	"distinct\0"
+	"do\0"
+	"document\0"
+	"domain\0"
+	"double\0"
+	"drop\0"
+	"each\0"
+	"else\0"
+	"enable\0"
+	"encoding\0"
+	"encrypted\0"
+	"end\0"
+	"enum\0"
+	"escape\0"
+	"event\0"
+	"except\0"
+	"exclude\0"
+	"excluding\0"
+	"exclusive\0"
+	"execute\0"
+	"exists\0"
+	"explain\0"
+	"expression\0"
+	"extension\0"
+	"external\0"
+	"extract\0"
+	"false\0"
+	"family\0"
+	"fetch\0"
+	"filter\0"
+	"finalize\0"
+	"first\0"
+	"float\0"
+	"following\0"
+	"for\0"
+	"force\0"
+	"foreign\0"
+	"forward\0"
+	"freeze\0"
+	"from\0"
+	"full\0"
+	"function\0"
+	"functions\0"
+	"generated\0"
+	"global\0"
+	"grant\0"
+	"granted\0"
+	"greatest\0"
+	"group\0"
+	"grouping\0"
+	"groups\0"
+	"handler\0"
+	"having\0"
+	"header\0"
+	"hold\0"
+	"hour\0"
+	"identity\0"
+	"if\0"
+	"ilike\0"
+	"immediate\0"
+	"immutable\0"
+	"implicit\0"
+	"import\0"
+	"in\0"
+	"include\0"
+	"including\0"
+	"increment\0"
+	"index\0"
+	"indexes\0"
+	"inherit\0"
+	"inherits\0"
+	"initially\0"
+	"inline\0"
+	"inner\0"
+	"inout\0"
+	"input\0"
+	"insensitive\0"
+	"insert\0"
+	"instead\0"
+	"int\0"
+	"integer\0"
+	"intersect\0"
+	"interval\0"
+	"into\0"
+	"invoker\0"
+	"is\0"
+	"isnull\0"
+	"isolation\0"
+	"join\0"
+	"key\0"
+	"label\0"
+	"language\0"
+	"large\0"
+	"last\0"
+	"lateral\0"
+	"leading\0"
+	"leakproof\0"
+	"least\0"
+	"left\0"
+	"level\0"
+	"like\0"
+	"limit\0"
+	"listen\0"
+	"load\0"
+	"local\0"
+	"localtime\0"
+	"localtimestamp\0"
+	"location\0"
+	"lock\0"
+	"locked\0"
+	"logged\0"
+	"mapping\0"
+	"match\0"
+	"materialized\0"
+	"maxvalue\0"
+	"method\0"
+	"minute\0"
+	"minvalue\0"
+	"mode\0"
+	"month\0"
+	"move\0"
+	"name\0"
+	"names\0"
+	"national\0"
+	"natural\0"
+	"nchar\0"
+	"new\0"
+	"next\0"
+	"nfc\0"
+	"nfd\0"
+	"nfkc\0"
+	"nfkd\0"
+	"no\0"
+	"none\0"
+	"normalize\0"
+	"normalized\0"
+	"not\0"
+	"nothing\0"
+	"notify\0"
+	"notnull\0"
+	"nowait\0"
+	"null\0"
+	"nullif\0"
+	"nulls\0"
+	"numeric\0"
+	"object\0"
+	"of\0"
+	"off\0"
+	"offset\0"
+	"oids\0"
+	"old\0"
+	"on\0"
+	"only\0"
+	"operator\0"
+	"option\0"
+	"options\0"
+	"or\0"
+	"order\0"
+	"ordinality\0"
+	"others\0"
+	"out\0"
+	"outer\0"
+	"over\0"
+	"overlaps\0"
+	"overlay\0"
+	"overriding\0"
+	"owned\0"
+	"owner\0"
+	"parallel\0"
+	"parser\0"
+	"partial\0"
+	"partition\0"
+	"passing\0"
+	"password\0"
+	"placing\0"
+	"plans\0"
+	"policy\0"
+	"position\0"
+	"preceding\0"
+	"precision\0"
+	"prepare\0"
+	"prepared\0"
+	"preserve\0"
+	"primary\0"
+	"prior\0"
+	"privileges\0"
+	"procedural\0"
+	"procedure\0"
+	"procedures\0"
+	"program\0"
+	"publication\0"
+	"quote\0"
+	"range\0"
+	"read\0"
+	"real\0"
+	"reassign\0"
+	"recheck\0"
+	"recursive\0"
+	"ref\0"
+	"references\0"
+	"referencing\0"
+	"refresh\0"
+	"reindex\0"
+	"relative\0"
+	"release\0"
+	"rename\0"
+	"repeatable\0"
+	"replace\0"
+	"replica\0"
+	"reset\0"
+	"restart\0"
+	"restrict\0"
+	"return\0"
+	"returning\0"
+	"returns\0"
+	"revoke\0"
+	"right\0"
+	"role\0"
+	"rollback\0"
+	"rollup\0"
+	"routine\0"
+	"routines\0"
+	"row\0"
+	"rows\0"
+	"rule\0"
+	"savepoint\0"
+	"schema\0"
+	"schemas\0"
+	"scroll\0"
+	"search\0"
+	"second\0"
+	"security\0"
+	"select\0"
+	"sequence\0"
+	"sequences\0"
+	"serializable\0"
+	"server\0"
+	"session\0"
+	"session_user\0"
+	"set\0"
+	"setof\0"
+	"sets\0"
+	"share\0"
+	"show\0"
+	"similar\0"
+	"simple\0"
+	"skip\0"
+	"smallint\0"
+	"snapshot\0"
+	"some\0"
+	"sql\0"
+	"stable\0"
+	"standalone\0"
+	"start\0"
+	"statement\0"
+	"statistics\0"
+	"stdin\0"
+	"stdout\0"
+	"storage\0"
+	"stored\0"
+	"strict\0"
+	"strip\0"
+	"subscription\0"
+	"substring\0"
+	"support\0"
+	"symmetric\0"
+	"sysid\0"
+	"system\0"
+	"table\0"
+	"tables\0"
+	"tablesample\0"
+	"tablespace\0"
+	"temp\0"
+	"template\0"
+	"temporary\0"
+	"text\0"
+	"then\0"
+	"ties\0"
+	"time\0"
+	"timestamp\0"
+	"to\0"
+	"trailing\0"
+	"transaction\0"
+	"transform\0"
+	"treat\0"
+	"trigger\0"
+	"trim\0"
+	"true\0"
+	"truncate\0"
+	"trusted\0"
+	"type\0"
+	"types\0"
+	"uescape\0"
+	"unbounded\0"
+	"uncommitted\0"
+	"unencrypted\0"
+	"union\0"
+	"unique\0"
+	"unknown\0"
+	"unlisten\0"
+	"unlogged\0"
+	"until\0"
+	"update\0"
+	"user\0"
+	"using\0"
+	"vacuum\0"
+	"valid\0"
+	"validate\0"
+	"validator\0"
+	"value\0"
+	"values\0"
+	"varchar\0"
+	"variadic\0"
+	"varying\0"
+	"verbose\0"
+	"version\0"
+	"view\0"
+	"views\0"
+	"volatile\0"
+	"when\0"
+	"where\0"
+	"whitespace\0"
+	"window\0"
+	"with\0"
+	"within\0"
+	"without\0"
+	"work\0"
+	"wrapper\0"
+	"write\0"
+	"xml\0"
+	"xmlattributes\0"
+	"xmlconcat\0"
+	"xmlelement\0"
+	"xmlexists\0"
+	"xmlforest\0"
+	"xmlnamespaces\0"
+	"xmlparse\0"
+	"xmlpi\0"
+	"xmlroot\0"
+	"xmlserialize\0"
+	"xmltable\0"
+	"year\0"
+	"yes\0"
+	"zone";
+
+static const uint16 ScanKeywords_kw_offsets[] = {
+	0,
+	6,
+	15,
+	22,
+	29,
+	33,
+	39,
+	45,
+	55,
+	59,
+	64,
+	70,
+	77,
+	85,
+	93,
+	97,
+	101,
+	107,
+	110,
+	114,
+	125,
+	135,
+	146,
+	157,
+	160,
+	167,
+	174,
+	184,
+	198,
+	207,
+	214,
+	220,
+	228,
+	235,
+	242,
+	246,
+	254,
+	259,
+	267,
+	270,
+	276,
+	281,
+	288,
+	296,
+	305,
+	310,
+	315,
+	323,
+	329,
+	334,
+	344,
+	360,
+	366,
+	377,
+	383,
+	389,
+	397,
+	406,
+	414,
+	424,
+	431,
+	439,
+	447,
+	456,
+	463,
+	473,
+	485,
+	498,
+	512,
+	521,
+	532,
+	543,
+	555,
+	563,
+	572,
+	583,
+	588,
+	593,
+	600,
+	606,
+	610,
+	615,
+	623,
+	639,
+	652,
+	665,
+	680,
+	693,
+	711,
+	724,
+	731,
+	737,
+	742,
+	751,
+	755,
+	766,
+	770,
+	778,
+	786,
+	794,
+	803,
+	814,
+	823,
+	831,
+	838,
+	848,
+	859,
+	867,
+	873,
+	878,
+	885,
+	896,
+	904,
+	912,
+	921,
+	924,
+	933,
+	940,
+	947,
+	952,
+	957,
+	962,
+	969,
+	978,
+	988,
+	992,
+	997,
+	1004,
+	1010,
+	1017,
+	1025,
+	1035,
+	1045,
+	1053,
+	1060,
+	1068,
+	1079,
+	1089,
+	1098,
+	1106,
+	1112,
+	1119,
+	1125,
+	1132,
+	1141,
+	1147,
+	1153,
+	1163,
+	1167,
+	1173,
+	1181,
+	1189,
+	1196,
+	1201,
+	1206,
+	1215,
+	1225,
+	1235,
+	1242,
+	1248,
+	1256,
+	1265,
+	1271,
+	1280,
+	1287,
+	1295,
+	1302,
+	1309,
+	1314,
+	1319,
+	1328,
+	1331,
+	1337,
+	1347,
+	1357,
+	1366,
+	1373,
+	1376,
+	1384,
+	1394,
+	1404,
+	1410,
+	1418,
+	1426,
+	1435,
+	1445,
+	1452,
+	1458,
+	1464,
+	1470,
+	1482,
+	1489,
+	1497,
+	1501,
+	1509,
+	1519,
+	1528,
+	1533,
+	1541,
+	1544,
+	1551,
+	1561,
+	1566,
+	1570,
+	1576,
+	1585,
+	1591,
+	1596,
+	1604,
+	1612,
+	1622,
+	1628,
+	1633,
+	1639,
+	1644,
+	1650,
+	1657,
+	1662,
+	1668,
+	1678,
+	1693,
+	1702,
+	1707,
+	1714,
+	1721,
+	1729,
+	1735,
+	1748,
+	1757,
+	1764,
+	1771,
+	1780,
+	1785,
+	1791,
+	1796,
+	1801,
+	1807,
+	1816,
+	1824,
+	1830,
+	1834,
+	1839,
+	1843,
+	1847,
+	1852,
+	1857,
+	1860,
+	1865,
+	1875,
+	1886,
+	1890,
+	1898,
+	1905,
+	1913,
+	1920,
+	1925,
+	1932,
+	1938,
+	1946,
+	1953,
+	1956,
+	1960,
+	1967,
+	1972,
+	1976,
+	1979,
+	1984,
+	1993,
+	2000,
+	2008,
+	2011,
+	2017,
+	2028,
+	2035,
+	2039,
+	2045,
+	2050,
+	2059,
+	2067,
+	2078,
+	2084,
+	2090,
+	2099,
+	2106,
+	2114,
+	2124,
+	2132,
+	2141,
+	2149,
+	2155,
+	2162,
+	2171,
+	2181,
+	2191,
+	2199,
+	2208,
+	2217,
+	2225,
+	2231,
+	2242,
+	2253,
+	2263,
+	2274,
+	2282,
+	2294,
+	2300,
+	2306,
+	2311,
+	2316,
+	2325,
+	2333,
+	2343,
+	2347,
+	2358,
+	2370,
+	2378,
+	2386,
+	2395,
+	2403,
+	2410,
+	2421,
+	2429,
+	2437,
+	2443,
+	2451,
+	2460,
+	2467,
+	2477,
+	2485,
+	2492,
+	2498,
+	2503,
+	2512,
+	2519,
+	2527,
+	2536,
+	2540,
+	2545,
+	2550,
+	2560,
+	2567,
+	2575,
+	2582,
+	2589,
+	2596,
+	2605,
+	2612,
+	2621,
+	2631,
+	2644,
+	2651,
+	2659,
+	2672,
+	2676,
+	2682,
+	2687,
+	2693,
+	2698,
+	2706,
+	2713,
+	2718,
+	2727,
+	2736,
+	2741,
+	2745,
+	2752,
+	2763,
+	2769,
+	2779,
+	2790,
+	2796,
+	2803,
+	2811,
+	2818,
+	2825,
+	2831,
+	2844,
+	2854,
+	2862,
+	2872,
+	2878,
+	2885,
+	2891,
+	2898,
+	2910,
+	2921,
+	2926,
+	2935,
+	2945,
+	2950,
+	2955,
+	2960,
+	2965,
+	2975,
+	2978,
+	2987,
+	2999,
+	3009,
+	3015,
+	3023,
+	3028,
+	3033,
+	3042,
+	3050,
+	3055,
+	3061,
+	3069,
+	3079,
+	3091,
+	3103,
+	3109,
+	3116,
+	3124,
+	3133,
+	3142,
+	3148,
+	3155,
+	3160,
+	3166,
+	3173,
+	3179,
+	3188,
+	3198,
+	3204,
+	3211,
+	3219,
+	3228,
+	3236,
+	3244,
+	3252,
+	3257,
+	3263,
+	3272,
+	3277,
+	3283,
+	3294,
+	3301,
+	3306,
+	3313,
+	3321,
+	3326,
+	3334,
+	3340,
+	3344,
+	3358,
+	3368,
+	3379,
+	3389,
+	3399,
+	3413,
+	3422,
+	3428,
+	3436,
+	3449,
+	3458,
+	3463,
+	3467,
+};
+
+#define SCANKEYWORDS_NUM_KEYWORDS 457
+
+static int
+ScanKeywords_hash_func(const void *key, size_t keylen)
+{
+	static const int16 h[915] = {
+		32767, 32767, 32767, 32767, 32767, -208,  338,   32767,
+		378,   612,   289,   640,   0,     32767, 184,   32767,
+		882,   32767, 362,   -196,  -25,   250,   32767, 179,
+		-65,   32767, -70,   32767, 244,   32767, -55,   32767,
+		-547,  0,     36,    0,     32767, 32767, 313,   32767,
+		32767, 32767, -25,   32767, 100,   7,     32767, 32767,
+		32767, 32767, 3,     32767, 32767, 0,     32767, 127,
+		0,     279,   69,    243,   -245,  132,   63,    0,
+		72,    32767, 32767, 32767, 0,     -311,  32767, -474,
+		-53,   119,   32767, 178,   32767, 32767, 32767, 352,
+		-169,  32767, 0,     32767, 32767, -234,  172,   234,
+		89,    363,   32767, 32767, 74,    81,    827,   53,
+		603,   0,     448,   32767, 183,   417,   550,   -170,
+		32767, -179,  32767, 32767, 433,   -657,  271,   32767,
+		32767, 32767, -149,  32767, 181,   32767, 32767, 32767,
+		0,     0,     0,     -193,  -371,  32767, -45,   582,
+		32767, 49,    30,    32767, 138,   32767, 36,    390,
+		-126,  -24,   0,     996,   32767, 354,   296,   -765,
+		-20,   598,   -404,  -577,  32767, 32767, 53,    -52,
+		189,   32767, 43,    482,   70,    32767, 0,     539,
+		287,   -249,  -20,   32767, 0,     32767, 94,    -387,
+		32767, 32767, 32767, 427,   32767, 32767, -206,  32767,
+		273,   101,   218,   32767, 2,     32767, 106,   32767,
+		32767, 215,   32767, -427,  389,   -159,  -101,  809,
+		41,    0,     0,     32767, 719,   32767, -215,  32767,
+		651,   167,   32767, -380,  32767, 32767, 328,   -26,
+		32767, 32767, 32767, 114,   0,     -290,  -182,  -192,
+		32767, -809,  -476,  833,   67,    247,   119,   32767,
+		32767, 200,   32767, 394,   -176,  98,    32767, 447,
+		32767, 596,   438,   32767, -750,  32767, 0,     32767,
+		0,     555,   -109,  83,    -34,   82,    32767, 32767,
+		330,   32767, 0,     -17,   0,     21,    545,   286,
+		32767, 32767, 124,   32767, 0,     32767, 137,   0,
+		-354,  183,   351,   885,   0,     190,   -319,  224,
+		-292,  0,     32767, 32767, 792,   32767, 37,    200,
+		342,   671,   356,   0,     -163,  -511,  43,    32767,
+		32767, 163,   0,     32767, 32767, 32767, -81,   -100,
+		50,    18,    -525,  452,   32767, 32767, 32767, 543,
+		332,   406,   32767, 32767, 197,   32767, 32767, 32767,
+		32767, -236,  32767, 32767, 243,   244,   32767, 194,
+		32767, 32767, 32767, 32767, 32767, 32767, 32767, 32767,
+		-122,  684,   217,   32767, 360,   32767, 1085,  -155,
+		0,     8,     350,   202,   635,   32767, 325,   398,
+		336,   32767, 32767, 900,   32767, 417,   200,   32767,
+		-44,   32767, 0,     32767, 32767, -361,  32767, 204,
+		0,     0,     32767, 32767, 32767, 32767, -172,  32767,
+		178,   32767, 93,    0,     151,   37,    32767, 32767,
+		32767, 32767, 32767, 32767, 0,     98,    205,   32767,
+		32767, 32767, -178,  -781,  0,     70,    32767, 219,
+		301,   291,   0,     32767, 327,   -295,  32767, 32767,
+		120,   291,   32767, -10,   32767, 32767, 32767, 317,
+		32767, 32767, 453,   208,   32767, 174,   0,     32767,
+		0,     0,     215,   32767, 370,   32767, 416,   0,
+		32767, 32767, 32767, 130,   366,   -80,   32767, 32767,
+		80,    212,   0,     267,   32767, 32767, 32767, 52,
+		32767, 356,   0,     -43,   170,   -40,   369,   32767,
+		252,   432,   62,    32767, 32767, 32767, 282,   19,
+		26,    -244,  32767, 32767, 32767, 32767, 0,     0,
+		-185,  -612,  271,   -14,   -182,  -122,  32767, 32767,
+		-296,  0,     423,   32767, 32767, 32767, 32767, 26,
+		0,     32767, 0,     262,   412,   118,   -138,  -385,
+		32767, 134,   311,   -338,  309,   105,   754,   32767,
+		762,   32767, 32767, 0,     32767, 32767, -509,  0,
+		525,   803,   32767, -372,  32767, 524,   32767, -695,
+		32767, 32767, 0,     253,   -202,  32767, 32767, 32767,
+		489,   32767, 32767, 0,     -157,  130,   456,   200,
+		32767, 32767, 26,    32767, -563,  32767, 392,   0,
+		379,   373,   89,    70,    32767, 32767, 167,   241,
+		553,   32767, 0,     -49,   32767, 0,     230,   -12,
+		-102,  0,     -123,  32767, 32767, 0,     32767, 20,
+		-664,  -249,  32767, 32767, 352,   53,    32767, 32767,
+		249,   0,     -144,  -772,  0,     32767, 32767, 32767,
+		268,   0,     101,   0,     32767, 44,    32767, 0,
+		-765,  32767, 32767, 272,   32767, 32767, 680,   0,
+		32767, 367,   9,     840,   -353,  677,   32767, 32767,
+		145,   32767, 423,   65,    0,     0,     324,   32767,
+		32767, 426,   332,   0,     32767, 32767, 189,   32767,
+		-534,  32767, 32767, 40,    33,    0,     32767, 0,
+		289,   -238,  182,   25,    0,     32767, 0,     140,
+		206,   32767, 32767, 32767, 32767, 176,   -132,  229,
+		127,   -578,  204,   393,   32767, 265,   32767, 189,
+		32767, 0,     855,   32767, 0,     206,   -338,  224,
+		32767, 235,   34,    330,   386,   419,   407,   32767,
+		-28,   32767, -91,   0,     32767, 0,     32767, 32767,
+		67,    352,   326,   290,   -78,   87,    54,    9,
+		223,   -637,  133,   388,   32767, -123,  123,   32767,
+		436,   613,   -260,  32767, 31,    32767, 32767, -126,
+		32767, 556,   32767, 0,     94,    -523,  232,   -58,
+		32767, -456,  32767, 172,   918,   32767, 415,   0,
+		32767, 0,     167,   658,   32767, -158,  32767, -265,
+		-1,    32767, 32767, 0,     32767, 0,     32767, 27,
+		32767, 867,   189,   0,     155,   0,     386,   32767,
+		32767, 0,     0,     32767, 246,   567,   32767, 32767,
+		-214,  31,    239,   -474,  32767, 0,     159,   107,
+		32767, 0,     49,    32767, -82,   -31,   330,   174,
+		74,    32767, 32767, 109,   311,   32767, 32767, -478,
+		151,   32767, 0,     323,   0,     32767, 32767, 248,
+		32767, 32767, 32767, 0,     32767, 0,     452,   0,
+		321,   0,     0,     0,     -12,   103,   32767, 103,
+		32767, -261,  0,     32767, 398,   96,    32767, 32767,
+		32767, -290,  566,   0,     32767, 0,     32767, 408,
+		32767, 32767, 32767, 685,   32767, 42,    32767, 0,
+		136,   0,     32767, 32767, 32767, 306,   32767, -180,
+		124,   32767, 361,   32767, 0,     0,     0,     203,
+		138,   321,   32767, 260,   32767, 32767, 32767, 766,
+		32767, 0,     0,     14,    -232,  598,   32767, 32767,
+		924,   0,     32767, 0,     32767, 295,   32767, 32767,
+		32767, 32767, 32767, 32767, 57,    80,    0,     221,
+		15,    288,   -3,    136,   426,   0,     32767, 32767,
+		413,   32767, 32767, -771,  217,   801,   32767, 365,
+		46,    32767, 32767, 0,     52,    405,   32767, 119,
+		0,     32767, 308,   32767, 0,     10,    0,     32767,
+		188,   32767, 0,     32767, 207,   32767, 146,   32767,
+		308,   50,    305,   0,     32767, 32767, 425,   293,
+		402,   375,   32767
+	};
+
+	const unsigned char *k = (const unsigned char *) key;
+	uint32		a = 0;
+	uint32		b = 5;
+
+	while (keylen--)
+	{
+		unsigned char c = *k++ | 0x20;
+
+		a = a * 257 + c;
+		b = b * 17 + c;
+	}
+	return h[a % 915] + h[b % 915];
+}
+
+const ScanKeywordList ScanKeywords = {
+	ScanKeywords_kw_string,
+	ScanKeywords_kw_offsets,
+	ScanKeywords_hash_func,
+	SCANKEYWORDS_NUM_KEYWORDS,
+	17
+};
+
+#endif							/* KWLIST_D_H */
diff --git a/src/common/kwlookup.c b/src/common/kwlookup.c
new file mode 100644
index 0000000..19a4f52
--- /dev/null
+++ b/src/common/kwlookup.c
@@ -0,0 +1,85 @@
+/*-------------------------------------------------------------------------
+ *
+ * kwlookup.c
+ *	  Key word lookup for PostgreSQL
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/kwlookup.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include "common/kwlookup.h"
+
+
+/*
+ * ScanKeywordLookup - see if a given word is a keyword
+ *
+ * The list of keywords to be matched against is passed as a ScanKeywordList.
+ *
+ * Returns the keyword number (0..N-1) of the keyword, or -1 if no match.
+ * Callers typically use the keyword number to index into information
+ * arrays, but that is no concern of this code.
+ *
+ * The match is done case-insensitively.  Note that we deliberately use a
+ * dumbed-down case conversion that will only translate 'A'-'Z' into 'a'-'z',
+ * even if we are in a locale where tolower() would produce more or different
+ * translations.  This is to conform to the SQL99 spec, which says that
+ * keywords are to be matched in this way even though non-keyword identifiers
+ * receive a different case-normalization mapping.
+ */
+int
+ScanKeywordLookup(const char *str,
+				  const ScanKeywordList *keywords)
+{
+	size_t		len;
+	int			h;
+	const char *kw;
+
+	/*
+	 * Reject immediately if too long to be any keyword.  This saves useless
+	 * hashing and downcasing work on long strings.
+	 */
+	len = strlen(str);
+	if (len > keywords->max_kw_len)
+		return -1;
+
+	/*
+	 * Compute the hash function.  We assume it was generated to produce
+	 * case-insensitive results.  Since it's a perfect hash, we need only
+	 * match to the specific keyword it identifies.
+	 */
+	h = keywords->hash(str, len);
+
+	/* An out-of-range result implies no match */
+	if (h < 0 || h >= keywords->num_keywords)
+		return -1;
+
+	/*
+	 * Compare character-by-character to see if we have a match, applying an
+	 * ASCII-only downcasing to the input characters.  We must not use
+	 * tolower() since it may produce the wrong translation in some locales
+	 * (eg, Turkish).
+	 */
+	kw = GetScanKeyword(h, keywords);
+	while (*str != '\0')
+	{
+		char		ch = *str++;
+
+		if (ch >= 'A' && ch <= 'Z')
+			ch += 'a' - 'A';
+		if (ch != *kw++)
+			return -1;
+	}
+	if (*kw != '\0')
+		return -1;
+
+	/* Success! */
+	return h;
+}
diff --git a/src/common/link-canary.c b/src/common/link-canary.c
new file mode 100644
index 0000000..5933b8e
--- /dev/null
+++ b/src/common/link-canary.c
@@ -0,0 +1,36 @@
+/*-------------------------------------------------------------------------
+ * link-canary.c
+ *	  Detect whether src/common functions came from frontend or backend.
+ *
+ * Copyright (c) 2018-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/link-canary.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include "common/link-canary.h"
+
+/*
+ * This function just reports whether this file was compiled for frontend
+ * or backend environment.  We need this because in some systems, mainly
+ * ELF-based platforms, it is possible for a shlib (such as libpq) loaded
+ * into the backend to call a backend function named XYZ in preference to
+ * the shlib's own function XYZ.  That's bad if the two functions don't
+ * act identically.  This exact situation comes up for many functions in
+ * src/common and src/port, where the same function names exist in both
+ * libpq and the backend but they don't act quite identically.  To verify
+ * that appropriate measures have been taken to prevent incorrect symbol
+ * resolution, libpq should test that this function returns true.
+ */
+bool
+pg_link_canary_is_frontend(void)
+{
+#ifdef FRONTEND
+	return true;
+#else
+	return false;
+#endif
+}
diff --git a/src/common/logging.c b/src/common/logging.c
new file mode 100644
index 0000000..fb1a9b1
--- /dev/null
+++ b/src/common/logging.c
@@ -0,0 +1,308 @@
+/*-------------------------------------------------------------------------
+ * Logging framework for frontend programs
+ *
+ * Copyright (c) 2018-2021, PostgreSQL Global Development Group
+ *
+ * src/common/logging.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#error "This file is not expected to be compiled for backend code"
+#endif
+
+#include "postgres_fe.h"
+
+#include <unistd.h>
+
+#include "common/logging.h"
+
+enum pg_log_level __pg_log_level;
+
+static const char *progname;
+static int	log_flags;
+
+static void (*log_pre_callback) (void);
+static void (*log_locus_callback) (const char **, uint64 *);
+
+static const char *sgr_error = NULL;
+static const char *sgr_warning = NULL;
+static const char *sgr_locus = NULL;
+
+#define SGR_ERROR_DEFAULT "01;31"
+#define SGR_WARNING_DEFAULT "01;35"
+#define SGR_LOCUS_DEFAULT "01"
+
+#define ANSI_ESCAPE_FMT "\x1b[%sm"
+#define ANSI_ESCAPE_RESET "\x1b[0m"
+
+#ifdef WIN32
+
+#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
+#define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
+#endif
+
+/*
+ * Attempt to enable VT100 sequence processing for colorization on Windows.
+ * If current environment is not VT100-compatible or if this mode could not
+ * be enabled, return false.
+ */
+static bool
+enable_vt_processing(void)
+{
+	/* Check stderr */
+	HANDLE		hOut = GetStdHandle(STD_ERROR_HANDLE);
+	DWORD		dwMode = 0;
+
+	if (hOut == INVALID_HANDLE_VALUE)
+		return false;
+
+	/*
+	 * Look for the current console settings and check if VT100 is already
+	 * enabled.
+	 */
+	if (!GetConsoleMode(hOut, &dwMode))
+		return false;
+	if ((dwMode & ENABLE_VIRTUAL_TERMINAL_PROCESSING) != 0)
+		return true;
+
+	dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
+	if (!SetConsoleMode(hOut, dwMode))
+		return false;
+	return true;
+}
+#endif							/* WIN32 */
+
+/*
+ * This should be called before any output happens.
+ */
+void
+pg_logging_init(const char *argv0)
+{
+	const char *pg_color_env = getenv("PG_COLOR");
+	bool		log_color = false;
+	bool		color_terminal = isatty(fileno(stderr));
+
+#ifdef WIN32
+
+	/*
+	 * On Windows, check if environment is VT100-compatible if using a
+	 * terminal.
+	 */
+	if (color_terminal)
+		color_terminal = enable_vt_processing();
+#endif
+
+	/* usually the default, but not on Windows */
+	setvbuf(stderr, NULL, _IONBF, 0);
+
+	progname = get_progname(argv0);
+	__pg_log_level = PG_LOG_INFO;
+
+	if (pg_color_env)
+	{
+		if (strcmp(pg_color_env, "always") == 0 ||
+			(strcmp(pg_color_env, "auto") == 0 && color_terminal))
+			log_color = true;
+	}
+
+	if (log_color)
+	{
+		const char *pg_colors_env = getenv("PG_COLORS");
+
+		if (pg_colors_env)
+		{
+			char	   *colors = strdup(pg_colors_env);
+
+			if (colors)
+			{
+				for (char *token = strtok(colors, ":"); token; token = strtok(NULL, ":"))
+				{
+					char	   *e = strchr(token, '=');
+
+					if (e)
+					{
+						char	   *name;
+						char	   *value;
+
+						*e = '\0';
+						name = token;
+						value = e + 1;
+
+						if (strcmp(name, "error") == 0)
+							sgr_error = strdup(value);
+						if (strcmp(name, "warning") == 0)
+							sgr_warning = strdup(value);
+						if (strcmp(name, "locus") == 0)
+							sgr_locus = strdup(value);
+					}
+				}
+
+				free(colors);
+			}
+		}
+		else
+		{
+			sgr_error = SGR_ERROR_DEFAULT;
+			sgr_warning = SGR_WARNING_DEFAULT;
+			sgr_locus = SGR_LOCUS_DEFAULT;
+		}
+	}
+}
+
+void
+pg_logging_config(int new_flags)
+{
+	log_flags = new_flags;
+}
+
+/*
+ * pg_logging_init sets the default log level to INFO.  Programs that prefer
+ * a different default should use this to set it, immediately afterward.
+ */
+void
+pg_logging_set_level(enum pg_log_level new_level)
+{
+	__pg_log_level = new_level;
+}
+
+/*
+ * Command line switches such as --verbose should invoke this.
+ */
+void
+pg_logging_increase_verbosity(void)
+{
+	/*
+	 * The enum values are chosen such that we have to decrease __pg_log_level
+	 * in order to become more verbose.
+	 */
+	if (__pg_log_level > PG_LOG_NOTSET + 1)
+		__pg_log_level--;
+}
+
+void
+pg_logging_set_pre_callback(void (*cb) (void))
+{
+	log_pre_callback = cb;
+}
+
+void
+pg_logging_set_locus_callback(void (*cb) (const char **filename, uint64 *lineno))
+{
+	log_locus_callback = cb;
+}
+
+void
+pg_log_generic(enum pg_log_level level, const char *pg_restrict fmt,...)
+{
+	va_list		ap;
+
+	va_start(ap, fmt);
+	pg_log_generic_v(level, fmt, ap);
+	va_end(ap);
+}
+
+void
+pg_log_generic_v(enum pg_log_level level, const char *pg_restrict fmt, va_list ap)
+{
+	int			save_errno = errno;
+	const char *filename = NULL;
+	uint64		lineno = 0;
+	va_list		ap2;
+	size_t		required_len;
+	char	   *buf;
+
+	Assert(progname);
+	Assert(level);
+	Assert(fmt);
+	Assert(fmt[strlen(fmt) - 1] != '\n');
+
+	/*
+	 * Flush stdout before output to stderr, to ensure sync even when stdout
+	 * is buffered.
+	 */
+	fflush(stdout);
+
+	if (log_pre_callback)
+		log_pre_callback();
+
+	if (log_locus_callback)
+		log_locus_callback(&filename, &lineno);
+
+	fmt = _(fmt);
+
+	if (!(log_flags & PG_LOG_FLAG_TERSE) || filename)
+	{
+		if (sgr_locus)
+			fprintf(stderr, ANSI_ESCAPE_FMT, sgr_locus);
+		if (!(log_flags & PG_LOG_FLAG_TERSE))
+			fprintf(stderr, "%s:", progname);
+		if (filename)
+		{
+			fprintf(stderr, "%s:", filename);
+			if (lineno > 0)
+				fprintf(stderr, UINT64_FORMAT ":", lineno);
+		}
+		fprintf(stderr, " ");
+		if (sgr_locus)
+			fprintf(stderr, ANSI_ESCAPE_RESET);
+	}
+
+	if (!(log_flags & PG_LOG_FLAG_TERSE))
+	{
+		switch (level)
+		{
+			case PG_LOG_FATAL:
+				if (sgr_error)
+					fprintf(stderr, ANSI_ESCAPE_FMT, sgr_error);
+				fprintf(stderr, _("fatal: "));
+				if (sgr_error)
+					fprintf(stderr, ANSI_ESCAPE_RESET);
+				break;
+			case PG_LOG_ERROR:
+				if (sgr_error)
+					fprintf(stderr, ANSI_ESCAPE_FMT, sgr_error);
+				fprintf(stderr, _("error: "));
+				if (sgr_error)
+					fprintf(stderr, ANSI_ESCAPE_RESET);
+				break;
+			case PG_LOG_WARNING:
+				if (sgr_warning)
+					fprintf(stderr, ANSI_ESCAPE_FMT, sgr_warning);
+				fprintf(stderr, _("warning: "));
+				if (sgr_warning)
+					fprintf(stderr, ANSI_ESCAPE_RESET);
+				break;
+			default:
+				break;
+		}
+	}
+
+	errno = save_errno;
+
+	va_copy(ap2, ap);
+	required_len = vsnprintf(NULL, 0, fmt, ap2) + 1;
+	va_end(ap2);
+
+	buf = pg_malloc_extended(required_len, MCXT_ALLOC_NO_OOM);
+
+	errno = save_errno;			/* malloc might change errno */
+
+	if (!buf)
+	{
+		/* memory trouble, just print what we can and get out of here */
+		vfprintf(stderr, fmt, ap);
+		return;
+	}
+
+	vsnprintf(buf, required_len, fmt, ap);
+
+	/* strip one newline, for PQerrorMessage() */
+	if (required_len >= 2 && buf[required_len - 2] == '\n')
+		buf[required_len - 2] = '\0';
+
+	fprintf(stderr, "%s\n", buf);
+
+	free(buf);
+}
diff --git a/src/common/md5.c b/src/common/md5.c
new file mode 100644
index 0000000..7d3b639
--- /dev/null
+++ b/src/common/md5.c
@@ -0,0 +1,439 @@
+/*-------------------------------------------------------------------------
+ *
+ *	md5.c
+ *	  Implements the MD5 Message-Digest Algorithm
+ *
+ * Fallback implementation of MD5, as specified in RFC 1321.  This
+ * implementation is a simple one, in that it needs every input byte
+ * to be buffered before doing any calculations.
+ *
+ *	Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ *	Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/md5.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*    $KAME: md5.c,v 1.3 2000/02/22 14:01:17 itojun Exp $     */
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "md5_int.h"
+
+#define SHIFT(X, s) (((X) << (s)) | ((X) >> (32 - (s))))
+
+#define F(X, Y, Z) (((X) & (Y)) | ((~X) & (Z)))
+#define G(X, Y, Z) (((X) & (Z)) | ((Y) & (~Z)))
+#define H(X, Y, Z) ((X) ^ (Y) ^ (Z))
+#define I(X, Y, Z) ((Y) ^ ((X) | (~Z)))
+
+#define ROUND1(a, b, c, d, k, s, i) \
+do { \
+	(a) = (a) + F((b), (c), (d)) + X[(k)] + T[(i)]; \
+	(a) = SHIFT((a), (s)); \
+	(a) = (b) + (a); \
+} while (0)
+
+#define ROUND2(a, b, c, d, k, s, i) \
+do { \
+	(a) = (a) + G((b), (c), (d)) + X[(k)] + T[(i)]; \
+	(a) = SHIFT((a), (s)); \
+	(a) = (b) + (a); \
+} while (0)
+
+#define ROUND3(a, b, c, d, k, s, i) \
+do { \
+	(a) = (a) + H((b), (c), (d)) + X[(k)] + T[(i)]; \
+	(a) = SHIFT((a), (s)); \
+	(a) = (b) + (a); \
+} while (0)
+
+#define ROUND4(a, b, c, d, k, s, i) \
+do { \
+	(a) = (a) + I((b), (c), (d)) + X[(k)] + T[(i)]; \
+	(a) = SHIFT((a), (s)); \
+	(a) = (b) + (a); \
+} while (0)
+
+#define Sa	 7
+#define Sb	12
+#define Sc	17
+#define Sd	22
+
+#define Se	 5
+#define Sf	 9
+#define Sg	14
+#define Sh	20
+
+#define Si	 4
+#define Sj	11
+#define Sk	16
+#define Sl	23
+
+#define Sm	 6
+#define Sn	10
+#define So	15
+#define Sp	21
+
+#define MD5_A0	0x67452301
+#define MD5_B0	0xefcdab89
+#define MD5_C0	0x98badcfe
+#define MD5_D0	0x10325476
+
+/* Integer part of 4294967296 times abs(sin(i)), where i is in radians. */
+static const uint32 T[65] = {
+	0,
+	0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
+	0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
+	0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
+	0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
+
+	0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
+	0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8,
+	0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
+	0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
+
+	0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
+	0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
+	0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
+	0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
+
+	0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
+	0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
+	0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
+	0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
+};
+
+static const uint8 md5_paddat[MD5_BUFLEN] = {
+	0x80, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0,
+};
+
+#ifdef WORDS_BIGENDIAN
+static uint32 X[16];
+#endif
+
+static void
+md5_calc(const uint8 *b64, pg_md5_ctx *ctx)
+{
+	uint32		A = ctx->md5_sta;
+	uint32		B = ctx->md5_stb;
+	uint32		C = ctx->md5_stc;
+	uint32		D = ctx->md5_std;
+
+#ifndef WORDS_BIGENDIAN
+	const uint32 *X = (const uint32 *) b64;
+#else
+	/* 4 byte words */
+	/* what a brute force but fast! */
+	uint8	   *y = (uint8 *) X;
+
+	y[0] = b64[3];
+	y[1] = b64[2];
+	y[2] = b64[1];
+	y[3] = b64[0];
+	y[4] = b64[7];
+	y[5] = b64[6];
+	y[6] = b64[5];
+	y[7] = b64[4];
+	y[8] = b64[11];
+	y[9] = b64[10];
+	y[10] = b64[9];
+	y[11] = b64[8];
+	y[12] = b64[15];
+	y[13] = b64[14];
+	y[14] = b64[13];
+	y[15] = b64[12];
+	y[16] = b64[19];
+	y[17] = b64[18];
+	y[18] = b64[17];
+	y[19] = b64[16];
+	y[20] = b64[23];
+	y[21] = b64[22];
+	y[22] = b64[21];
+	y[23] = b64[20];
+	y[24] = b64[27];
+	y[25] = b64[26];
+	y[26] = b64[25];
+	y[27] = b64[24];
+	y[28] = b64[31];
+	y[29] = b64[30];
+	y[30] = b64[29];
+	y[31] = b64[28];
+	y[32] = b64[35];
+	y[33] = b64[34];
+	y[34] = b64[33];
+	y[35] = b64[32];
+	y[36] = b64[39];
+	y[37] = b64[38];
+	y[38] = b64[37];
+	y[39] = b64[36];
+	y[40] = b64[43];
+	y[41] = b64[42];
+	y[42] = b64[41];
+	y[43] = b64[40];
+	y[44] = b64[47];
+	y[45] = b64[46];
+	y[46] = b64[45];
+	y[47] = b64[44];
+	y[48] = b64[51];
+	y[49] = b64[50];
+	y[50] = b64[49];
+	y[51] = b64[48];
+	y[52] = b64[55];
+	y[53] = b64[54];
+	y[54] = b64[53];
+	y[55] = b64[52];
+	y[56] = b64[59];
+	y[57] = b64[58];
+	y[58] = b64[57];
+	y[59] = b64[56];
+	y[60] = b64[63];
+	y[61] = b64[62];
+	y[62] = b64[61];
+	y[63] = b64[60];
+#endif
+
+	ROUND1(A, B, C, D, 0, Sa, 1);
+	ROUND1(D, A, B, C, 1, Sb, 2);
+	ROUND1(C, D, A, B, 2, Sc, 3);
+	ROUND1(B, C, D, A, 3, Sd, 4);
+	ROUND1(A, B, C, D, 4, Sa, 5);
+	ROUND1(D, A, B, C, 5, Sb, 6);
+	ROUND1(C, D, A, B, 6, Sc, 7);
+	ROUND1(B, C, D, A, 7, Sd, 8);
+	ROUND1(A, B, C, D, 8, Sa, 9);
+	ROUND1(D, A, B, C, 9, Sb, 10);
+	ROUND1(C, D, A, B, 10, Sc, 11);
+	ROUND1(B, C, D, A, 11, Sd, 12);
+	ROUND1(A, B, C, D, 12, Sa, 13);
+	ROUND1(D, A, B, C, 13, Sb, 14);
+	ROUND1(C, D, A, B, 14, Sc, 15);
+	ROUND1(B, C, D, A, 15, Sd, 16);
+
+	ROUND2(A, B, C, D, 1, Se, 17);
+	ROUND2(D, A, B, C, 6, Sf, 18);
+	ROUND2(C, D, A, B, 11, Sg, 19);
+	ROUND2(B, C, D, A, 0, Sh, 20);
+	ROUND2(A, B, C, D, 5, Se, 21);
+	ROUND2(D, A, B, C, 10, Sf, 22);
+	ROUND2(C, D, A, B, 15, Sg, 23);
+	ROUND2(B, C, D, A, 4, Sh, 24);
+	ROUND2(A, B, C, D, 9, Se, 25);
+	ROUND2(D, A, B, C, 14, Sf, 26);
+	ROUND2(C, D, A, B, 3, Sg, 27);
+	ROUND2(B, C, D, A, 8, Sh, 28);
+	ROUND2(A, B, C, D, 13, Se, 29);
+	ROUND2(D, A, B, C, 2, Sf, 30);
+	ROUND2(C, D, A, B, 7, Sg, 31);
+	ROUND2(B, C, D, A, 12, Sh, 32);
+
+	ROUND3(A, B, C, D, 5, Si, 33);
+	ROUND3(D, A, B, C, 8, Sj, 34);
+	ROUND3(C, D, A, B, 11, Sk, 35);
+	ROUND3(B, C, D, A, 14, Sl, 36);
+	ROUND3(A, B, C, D, 1, Si, 37);
+	ROUND3(D, A, B, C, 4, Sj, 38);
+	ROUND3(C, D, A, B, 7, Sk, 39);
+	ROUND3(B, C, D, A, 10, Sl, 40);
+	ROUND3(A, B, C, D, 13, Si, 41);
+	ROUND3(D, A, B, C, 0, Sj, 42);
+	ROUND3(C, D, A, B, 3, Sk, 43);
+	ROUND3(B, C, D, A, 6, Sl, 44);
+	ROUND3(A, B, C, D, 9, Si, 45);
+	ROUND3(D, A, B, C, 12, Sj, 46);
+	ROUND3(C, D, A, B, 15, Sk, 47);
+	ROUND3(B, C, D, A, 2, Sl, 48);
+
+	ROUND4(A, B, C, D, 0, Sm, 49);
+	ROUND4(D, A, B, C, 7, Sn, 50);
+	ROUND4(C, D, A, B, 14, So, 51);
+	ROUND4(B, C, D, A, 5, Sp, 52);
+	ROUND4(A, B, C, D, 12, Sm, 53);
+	ROUND4(D, A, B, C, 3, Sn, 54);
+	ROUND4(C, D, A, B, 10, So, 55);
+	ROUND4(B, C, D, A, 1, Sp, 56);
+	ROUND4(A, B, C, D, 8, Sm, 57);
+	ROUND4(D, A, B, C, 15, Sn, 58);
+	ROUND4(C, D, A, B, 6, So, 59);
+	ROUND4(B, C, D, A, 13, Sp, 60);
+	ROUND4(A, B, C, D, 4, Sm, 61);
+	ROUND4(D, A, B, C, 11, Sn, 62);
+	ROUND4(C, D, A, B, 2, So, 63);
+	ROUND4(B, C, D, A, 9, Sp, 64);
+
+	ctx->md5_sta += A;
+	ctx->md5_stb += B;
+	ctx->md5_stc += C;
+	ctx->md5_std += D;
+}
+
+static void
+md5_pad(pg_md5_ctx *ctx)
+{
+	unsigned int gap;
+
+	/* Don't count up padding. Keep md5_n. */
+	gap = MD5_BUFLEN - ctx->md5_i;
+	if (gap > 8)
+	{
+		memmove(ctx->md5_buf + ctx->md5_i, md5_paddat,
+				gap - sizeof(ctx->md5_n));
+	}
+	else
+	{
+		/* including gap == 8 */
+		memmove(ctx->md5_buf + ctx->md5_i, md5_paddat, gap);
+		md5_calc(ctx->md5_buf, ctx);
+		memmove(ctx->md5_buf, md5_paddat + gap,
+				MD5_BUFLEN - sizeof(ctx->md5_n));
+	}
+
+	/* 8 byte word */
+#ifndef WORDS_BIGENDIAN
+	memmove(&ctx->md5_buf[56], &ctx->md5_n8[0], 8);
+#else
+	ctx->md5_buf[56] = ctx->md5_n8[7];
+	ctx->md5_buf[57] = ctx->md5_n8[6];
+	ctx->md5_buf[58] = ctx->md5_n8[5];
+	ctx->md5_buf[59] = ctx->md5_n8[4];
+	ctx->md5_buf[60] = ctx->md5_n8[3];
+	ctx->md5_buf[61] = ctx->md5_n8[2];
+	ctx->md5_buf[62] = ctx->md5_n8[1];
+	ctx->md5_buf[63] = ctx->md5_n8[0];
+#endif
+
+	md5_calc(ctx->md5_buf, ctx);
+}
+
+static void
+md5_result(uint8 *digest, pg_md5_ctx *ctx)
+{
+	/* 4 byte words */
+#ifndef WORDS_BIGENDIAN
+	memmove(digest, &ctx->md5_st8[0], 16);
+#else
+	digest[0] = ctx->md5_st8[3];
+	digest[1] = ctx->md5_st8[2];
+	digest[2] = ctx->md5_st8[1];
+	digest[3] = ctx->md5_st8[0];
+	digest[4] = ctx->md5_st8[7];
+	digest[5] = ctx->md5_st8[6];
+	digest[6] = ctx->md5_st8[5];
+	digest[7] = ctx->md5_st8[4];
+	digest[8] = ctx->md5_st8[11];
+	digest[9] = ctx->md5_st8[10];
+	digest[10] = ctx->md5_st8[9];
+	digest[11] = ctx->md5_st8[8];
+	digest[12] = ctx->md5_st8[15];
+	digest[13] = ctx->md5_st8[14];
+	digest[14] = ctx->md5_st8[13];
+	digest[15] = ctx->md5_st8[12];
+#endif
+}
+
+
+/* External routines for this MD5 implementation */
+
+/*
+ * pg_md5_init
+ *
+ * Initialize a MD5 context.
+ */
+void
+pg_md5_init(pg_md5_ctx *ctx)
+{
+	ctx->md5_n = 0;
+	ctx->md5_i = 0;
+	ctx->md5_sta = MD5_A0;
+	ctx->md5_stb = MD5_B0;
+	ctx->md5_stc = MD5_C0;
+	ctx->md5_std = MD5_D0;
+	memset(ctx->md5_buf, 0, sizeof(ctx->md5_buf));
+}
+
+
+/*
+ * pg_md5_update
+ *
+ * Update a MD5 context.
+ */
+void
+pg_md5_update(pg_md5_ctx *ctx, const uint8 *data, size_t len)
+{
+	unsigned int gap,
+				i;
+
+	ctx->md5_n += len * 8;		/* byte to bit */
+	gap = MD5_BUFLEN - ctx->md5_i;
+
+	if (len >= gap)
+	{
+		memmove(ctx->md5_buf + ctx->md5_i, data, gap);
+		md5_calc(ctx->md5_buf, ctx);
+
+		for (i = gap; i + MD5_BUFLEN <= len; i += MD5_BUFLEN)
+			md5_calc(data + i, ctx);
+
+		ctx->md5_i = len - i;
+		memmove(ctx->md5_buf, data + i, ctx->md5_i);
+	}
+	else
+	{
+		memmove(ctx->md5_buf + ctx->md5_i, data, len);
+		ctx->md5_i += len;
+	}
+}
+
+/*
+ * pg_md5_final
+ *
+ * Finalize a MD5 context.
+ */
+void
+pg_md5_final(pg_md5_ctx *ctx, uint8 *dest)
+{
+	md5_pad(ctx);
+	md5_result(dest, ctx);
+}
diff --git a/src/common/md5_common.c b/src/common/md5_common.c
new file mode 100644
index 0000000..2114890
--- /dev/null
+++ b/src/common/md5_common.c
@@ -0,0 +1,149 @@
+/*-------------------------------------------------------------------------
+ *
+ * md5_common.c
+ *	  Routines shared between all MD5 implementations used for encrypted
+ *	  passwords.
+ *
+ * Sverre H. Huseby <sverrehu@online.no>
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/md5_common.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/cryptohash.h"
+#include "common/md5.h"
+
+static void
+bytesToHex(uint8 b[16], char *s)
+{
+	static const char *hex = "0123456789abcdef";
+	int			q,
+				w;
+
+	for (q = 0, w = 0; q < 16; q++)
+	{
+		s[w++] = hex[(b[q] >> 4) & 0x0F];
+		s[w++] = hex[b[q] & 0x0F];
+	}
+	s[w] = '\0';
+}
+
+/*
+ *	pg_md5_hash
+ *
+ *	Calculates the MD5 sum of the bytes in a buffer.
+ *
+ *	SYNOPSIS	  #include "md5.h"
+ *				  int pg_md5_hash(const void *buff, size_t len, char *hexsum)
+ *
+ *	INPUT		  buff	  the buffer containing the bytes that you want
+ *						  the MD5 sum of.
+ *				  len	  number of bytes in the buffer.
+ *
+ *	OUTPUT		  hexsum  the MD5 sum as a '\0'-terminated string of
+ *						  hexadecimal digits.  an MD5 sum is 16 bytes long.
+ *						  each byte is represented by two hexadecimal
+ *						  characters.  you thus need to provide an array
+ *						  of 33 characters, including the trailing '\0'.
+ *
+ *	RETURNS		  false on failure (out of memory for internal buffers
+ *				  or MD5 computation failure) or true on success.
+ *
+ *	STANDARDS	  MD5 is described in RFC 1321.
+ *
+ *	AUTHOR		  Sverre H. Huseby <sverrehu@online.no>
+ *
+ */
+
+bool
+pg_md5_hash(const void *buff, size_t len, char *hexsum)
+{
+	uint8		sum[MD5_DIGEST_LENGTH];
+	pg_cryptohash_ctx *ctx;
+
+	ctx = pg_cryptohash_create(PG_MD5);
+	if (ctx == NULL)
+		return false;
+
+	if (pg_cryptohash_init(ctx) < 0 ||
+		pg_cryptohash_update(ctx, buff, len) < 0 ||
+		pg_cryptohash_final(ctx, sum, sizeof(sum)) < 0)
+	{
+		pg_cryptohash_free(ctx);
+		return false;
+	}
+
+	bytesToHex(sum, hexsum);
+	pg_cryptohash_free(ctx);
+	return true;
+}
+
+bool
+pg_md5_binary(const void *buff, size_t len, void *outbuf)
+{
+	pg_cryptohash_ctx *ctx;
+
+	ctx = pg_cryptohash_create(PG_MD5);
+	if (ctx == NULL)
+		return false;
+
+	if (pg_cryptohash_init(ctx) < 0 ||
+		pg_cryptohash_update(ctx, buff, len) < 0 ||
+		pg_cryptohash_final(ctx, outbuf, MD5_DIGEST_LENGTH) < 0)
+	{
+		pg_cryptohash_free(ctx);
+		return false;
+	}
+
+	pg_cryptohash_free(ctx);
+	return true;
+}
+
+
+/*
+ * Computes MD5 checksum of "passwd" (a null-terminated string) followed
+ * by "salt" (which need not be null-terminated).
+ *
+ * Output format is "md5" followed by a 32-hex-digit MD5 checksum.
+ * Hence, the output buffer "buf" must be at least 36 bytes long.
+ *
+ * Returns true if okay, false on error (out of memory).
+ */
+bool
+pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
+			   char *buf)
+{
+	size_t		passwd_len = strlen(passwd);
+
+	/* +1 here is just to avoid risk of unportable malloc(0) */
+	char	   *crypt_buf = malloc(passwd_len + salt_len + 1);
+	bool		ret;
+
+	if (!crypt_buf)
+		return false;
+
+	/*
+	 * Place salt at the end because it may be known by users trying to crack
+	 * the MD5 output.
+	 */
+	memcpy(crypt_buf, passwd, passwd_len);
+	memcpy(crypt_buf + passwd_len, salt, salt_len);
+
+	strcpy(buf, "md5");
+	ret = pg_md5_hash(crypt_buf, passwd_len + salt_len, buf + 3);
+
+	free(crypt_buf);
+
+	return ret;
+}
diff --git a/src/common/md5_int.h b/src/common/md5_int.h
new file mode 100644
index 0000000..4ce7f7d
--- /dev/null
+++ b/src/common/md5_int.h
@@ -0,0 +1,85 @@
+/*-------------------------------------------------------------------------
+ *
+ * md5_int.h
+ *	  Internal headers for fallback implementation of MD5
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *		  src/common/md5_int.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*	   $KAME: md5.h,v 1.3 2000/02/22 14:01:18 itojun Exp $	   */
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *	  notice, this list of conditions and the following disclaimer in the
+ *	  documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *	  may be used to endorse or promote products derived from this software
+ *	  without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef PG_MD5_INT_H
+#define PG_MD5_INT_H
+
+#include "common/md5.h"
+
+#define MD5_BUFLEN 64
+
+/* Context data for MD5 */
+typedef struct
+{
+	union
+	{
+		uint32		md5_state32[4];
+		uint8		md5_state8[16];
+	}			md5_st;
+
+#define md5_sta     md5_st.md5_state32[0]
+#define md5_stb     md5_st.md5_state32[1]
+#define md5_stc     md5_st.md5_state32[2]
+#define md5_std     md5_st.md5_state32[3]
+#define md5_st8     md5_st.md5_state8
+
+	union
+	{
+		uint64		md5_count64;
+		uint8		md5_count8[8];
+	}			md5_count;
+#define md5_n   md5_count.md5_count64
+#define md5_n8  md5_count.md5_count8
+
+	unsigned int md5_i;
+	uint8		md5_buf[MD5_BUFLEN];
+} pg_md5_ctx;
+
+/* Interface routines for MD5 */
+extern void pg_md5_init(pg_md5_ctx *ctx);
+extern void pg_md5_update(pg_md5_ctx *ctx, const uint8 *data, size_t len);
+extern void pg_md5_final(pg_md5_ctx *ctx, uint8 *dest);
+
+#endif							/* PG_MD5_INT_H */
diff --git a/src/common/pg_get_line.c b/src/common/pg_get_line.c
new file mode 100644
index 0000000..a80d196
--- /dev/null
+++ b/src/common/pg_get_line.c
@@ -0,0 +1,140 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_get_line.c
+ *	  fgets() with an expansible result buffer
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/pg_get_line.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/string.h"
+#include "lib/stringinfo.h"
+
+
+/*
+ * pg_get_line()
+ *
+ * This is meant to be equivalent to fgets(), except that instead of
+ * reading into a caller-supplied, fixed-size buffer, it reads into
+ * a palloc'd (in frontend, really malloc'd) string, which is resized
+ * as needed to handle indefinitely long input lines.  The caller is
+ * responsible for pfree'ing the result string when appropriate.
+ *
+ * As with fgets(), returns NULL if there is a read error or if no
+ * characters are available before EOF.  The caller can distinguish
+ * these cases by checking ferror(stream).
+ *
+ * Since this is meant to be equivalent to fgets(), the trailing newline
+ * (if any) is not stripped.  Callers may wish to apply pg_strip_crlf().
+ *
+ * Note that while I/O errors are reflected back to the caller to be
+ * dealt with, an OOM condition for the palloc'd buffer will not be;
+ * there'll be an ereport(ERROR) or exit(1) inside stringinfo.c.
+ *
+ * Also note that the palloc'd buffer is usually a lot longer than
+ * strictly necessary, so it may be inadvisable to use this function
+ * to collect lots of long-lived data.  A less memory-hungry option
+ * is to use pg_get_line_buf() or pg_get_line_append() in a loop,
+ * then pstrdup() each line.
+ */
+char *
+pg_get_line(FILE *stream)
+{
+	StringInfoData buf;
+
+	initStringInfo(&buf);
+
+	if (!pg_get_line_append(stream, &buf))
+	{
+		/* ensure that free() doesn't mess up errno */
+		int			save_errno = errno;
+
+		pfree(buf.data);
+		errno = save_errno;
+		return NULL;
+	}
+
+	return buf.data;
+}
+
+/*
+ * pg_get_line_buf()
+ *
+ * This has similar behavior to pg_get_line(), and thence to fgets(),
+ * except that the collected data is returned in a caller-supplied
+ * StringInfo buffer.  This is a convenient API for code that just
+ * wants to read and process one line at a time, without any artificial
+ * limit on line length.
+ *
+ * Returns true if a line was successfully collected (including the
+ * case of a non-newline-terminated line at EOF).  Returns false if
+ * there was an I/O error or no data was available before EOF.
+ * (Check ferror(stream) to distinguish these cases.)
+ *
+ * In the false-result case, buf is reset to empty.
+ */
+bool
+pg_get_line_buf(FILE *stream, StringInfo buf)
+{
+	/* We just need to drop any data from the previous call */
+	resetStringInfo(buf);
+	return pg_get_line_append(stream, buf);
+}
+
+/*
+ * pg_get_line_append()
+ *
+ * This has similar behavior to pg_get_line(), and thence to fgets(),
+ * except that the collected data is appended to whatever is in *buf.
+ * This is useful in preference to pg_get_line_buf() if the caller wants
+ * to merge some lines together, e.g. to implement backslash continuation.
+ *
+ * Returns true if a line was successfully collected (including the
+ * case of a non-newline-terminated line at EOF).  Returns false if
+ * there was an I/O error or no data was available before EOF.
+ * (Check ferror(stream) to distinguish these cases.)
+ *
+ * In the false-result case, the contents of *buf are logically unmodified,
+ * though it's possible that the buffer has been resized.
+ */
+bool
+pg_get_line_append(FILE *stream, StringInfo buf)
+{
+	int			orig_len = buf->len;
+
+	/* Read some data, appending it to whatever we already have */
+	while (fgets(buf->data + buf->len, buf->maxlen - buf->len, stream) != NULL)
+	{
+		buf->len += strlen(buf->data + buf->len);
+
+		/* Done if we have collected a newline */
+		if (buf->len > orig_len && buf->data[buf->len - 1] == '\n')
+			return true;
+
+		/* Make some more room in the buffer, and loop to read more data */
+		enlargeStringInfo(buf, 128);
+	}
+
+	/* Check for I/O errors and EOF */
+	if (ferror(stream) || buf->len == orig_len)
+	{
+		/* Discard any data we collected before detecting error */
+		buf->len = orig_len;
+		buf->data[orig_len] = '\0';
+		return false;
+	}
+
+	/* No newline at EOF, but we did collect some data */
+	return true;
+}
diff --git a/src/common/pg_lzcompress.c b/src/common/pg_lzcompress.c
new file mode 100644
index 0000000..a30a2c2
--- /dev/null
+++ b/src/common/pg_lzcompress.c
@@ -0,0 +1,872 @@
+/* ----------
+ * pg_lzcompress.c -
+ *
+ *		This is an implementation of LZ compression for PostgreSQL.
+ *		It uses a simple history table and generates 2-3 byte tags
+ *		capable of backward copy information for 3-273 bytes with
+ *		a max offset of 4095.
+ *
+ *		Entry routines:
+ *
+ *			int32
+ *			pglz_compress(const char *source, int32 slen, char *dest,
+ *						  const PGLZ_Strategy *strategy);
+ *
+ *				source is the input data to be compressed.
+ *
+ *				slen is the length of the input data.
+ *
+ *				dest is the output area for the compressed result.
+ *					It must be at least as big as PGLZ_MAX_OUTPUT(slen).
+ *
+ *				strategy is a pointer to some information controlling
+ *					the compression algorithm. If NULL, the compiled
+ *					in default strategy is used.
+ *
+ *				The return value is the number of bytes written in the
+ *				buffer dest, or -1 if compression fails; in the latter
+ *				case the contents of dest are undefined.
+ *
+ *			int32
+ *			pglz_decompress(const char *source, int32 slen, char *dest,
+ *							int32 rawsize, bool check_complete)
+ *
+ *				source is the compressed input.
+ *
+ *				slen is the length of the compressed input.
+ *
+ *				dest is the area where the uncompressed data will be
+ *					written to. It is the callers responsibility to
+ *					provide enough space.
+ *
+ *					The data is written to buff exactly as it was handed
+ *					to pglz_compress(). No terminating zero byte is added.
+ *
+ *				rawsize is the length of the uncompressed data.
+ *
+ *				check_complete is a flag to let us know if -1 should be
+ *					returned in cases where we don't reach the end of the
+ *					source or dest buffers, or not.  This should be false
+ *					if the caller is asking for only a partial result and
+ *					true otherwise.
+ *
+ *				The return value is the number of bytes written in the
+ *				buffer dest, or -1 if decompression fails.
+ *
+ *		The decompression algorithm and internal data format:
+ *
+ *			It is made with the compressed data itself.
+ *
+ *			The data representation is easiest explained by describing
+ *			the process of decompression.
+ *
+ *			If compressed_size == rawsize, then the data
+ *			is stored uncompressed as plain bytes. Thus, the decompressor
+ *			simply copies rawsize bytes to the destination.
+ *
+ *			Otherwise the first byte tells what to do the next 8 times.
+ *			We call this the control byte.
+ *
+ *			An unset bit in the control byte means, that one uncompressed
+ *			byte follows, which is copied from input to output.
+ *
+ *			A set bit in the control byte means, that a tag of 2-3 bytes
+ *			follows. A tag contains information to copy some bytes, that
+ *			are already in the output buffer, to the current location in
+ *			the output. Let's call the three tag bytes T1, T2 and T3. The
+ *			position of the data to copy is coded as an offset from the
+ *			actual output position.
+ *
+ *			The offset is in the upper nibble of T1 and in T2.
+ *			The length is in the lower nibble of T1.
+ *
+ *			So the 16 bits of a 2 byte tag are coded as
+ *
+ *				7---T1--0  7---T2--0
+ *				OOOO LLLL  OOOO OOOO
+ *
+ *			This limits the offset to 1-4095 (12 bits) and the length
+ *			to 3-18 (4 bits) because 3 is always added to it. To emit
+ *			a tag of 2 bytes with a length of 2 only saves one control
+ *			bit. But we lose one byte in the possible length of a tag.
+ *
+ *			In the actual implementation, the 2 byte tag's length is
+ *			limited to 3-17, because the value 0xF in the length nibble
+ *			has special meaning. It means, that the next following
+ *			byte (T3) has to be added to the length value of 18. That
+ *			makes total limits of 1-4095 for offset and 3-273 for length.
+ *
+ *			Now that we have successfully decoded a tag. We simply copy
+ *			the output that occurred <offset> bytes back to the current
+ *			output location in the specified <length>. Thus, a
+ *			sequence of 200 spaces (think about bpchar fields) could be
+ *			coded in 4 bytes. One literal space and a three byte tag to
+ *			copy 199 bytes with a -1 offset. Whow - that's a compression
+ *			rate of 98%! Well, the implementation needs to save the
+ *			original data size too, so we need another 4 bytes for it
+ *			and end up with a total compression rate of 96%, what's still
+ *			worth a Whow.
+ *
+ *		The compression algorithm
+ *
+ *			The following uses numbers used in the default strategy.
+ *
+ *			The compressor works best for attributes of a size between
+ *			1K and 1M. For smaller items there's not that much chance of
+ *			redundancy in the character sequence (except for large areas
+ *			of identical bytes like trailing spaces) and for bigger ones
+ *			our 4K maximum look-back distance is too small.
+ *
+ *			The compressor creates a table for lists of positions.
+ *			For each input position (except the last 3), a hash key is
+ *			built from the 4 next input bytes and the position remembered
+ *			in the appropriate list. Thus, the table points to linked
+ *			lists of likely to be at least in the first 4 characters
+ *			matching strings. This is done on the fly while the input
+ *			is compressed into the output area.  Table entries are only
+ *			kept for the last 4096 input positions, since we cannot use
+ *			back-pointers larger than that anyway.  The size of the hash
+ *			table is chosen based on the size of the input - a larger table
+ *			has a larger startup cost, as it needs to be initialized to
+ *			zero, but reduces the number of hash collisions on long inputs.
+ *
+ *			For each byte in the input, its hash key (built from this
+ *			byte and the next 3) is used to find the appropriate list
+ *			in the table. The lists remember the positions of all bytes
+ *			that had the same hash key in the past in increasing backward
+ *			offset order. Now for all entries in the used lists, the
+ *			match length is computed by comparing the characters from the
+ *			entries position with the characters from the actual input
+ *			position.
+ *
+ *			The compressor starts with a so called "good_match" of 128.
+ *			It is a "prefer speed against compression ratio" optimizer.
+ *			So if the first entry looked at already has 128 or more
+ *			matching characters, the lookup stops and that position is
+ *			used for the next tag in the output.
+ *
+ *			For each subsequent entry in the history list, the "good_match"
+ *			is lowered by 10%. So the compressor will be more happy with
+ *			short matches the further it has to go back in the history.
+ *			Another "speed against ratio" preference characteristic of
+ *			the algorithm.
+ *
+ *			Thus there are 3 stop conditions for the lookup of matches:
+ *
+ *				- a match >= good_match is found
+ *				- there are no more history entries to look at
+ *				- the next history entry is already too far back
+ *				  to be coded into a tag.
+ *
+ *			Finally the match algorithm checks that at least a match
+ *			of 3 or more bytes has been found, because that is the smallest
+ *			amount of copy information to code into a tag. If so, a tag
+ *			is omitted and all the input bytes covered by that are just
+ *			scanned for the history add's, otherwise a literal character
+ *			is omitted and only his history entry added.
+ *
+ *		Acknowledgments:
+ *
+ *			Many thanks to Adisak Pochanayon, who's article about SLZ
+ *			inspired me to write the PostgreSQL compression this way.
+ *
+ *			Jan Wieck
+ *
+ * Copyright (c) 1999-2021, PostgreSQL Global Development Group
+ *
+ * src/common/pg_lzcompress.c
+ * ----------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <limits.h>
+
+#include "common/pg_lzcompress.h"
+
+
+/* ----------
+ * Local definitions
+ * ----------
+ */
+#define PGLZ_MAX_HISTORY_LISTS	8192	/* must be power of 2 */
+#define PGLZ_HISTORY_SIZE		4096
+#define PGLZ_MAX_MATCH			273
+
+
+/* ----------
+ * PGLZ_HistEntry -
+ *
+ *		Linked list for the backward history lookup
+ *
+ * All the entries sharing a hash key are linked in a doubly linked list.
+ * This makes it easy to remove an entry when it's time to recycle it
+ * (because it's more than 4K positions old).
+ * ----------
+ */
+typedef struct PGLZ_HistEntry
+{
+	struct PGLZ_HistEntry *next;	/* links for my hash key's list */
+	struct PGLZ_HistEntry *prev;
+	int			hindex;			/* my current hash key */
+	const char *pos;			/* my input position */
+} PGLZ_HistEntry;
+
+
+/* ----------
+ * The provided standard strategies
+ * ----------
+ */
+static const PGLZ_Strategy strategy_default_data = {
+	32,							/* Data chunks less than 32 bytes are not
+								 * compressed */
+	INT_MAX,					/* No upper limit on what we'll try to
+								 * compress */
+	25,							/* Require 25% compression rate, or not worth
+								 * it */
+	1024,						/* Give up if no compression in the first 1KB */
+	128,						/* Stop history lookup if a match of 128 bytes
+								 * is found */
+	10							/* Lower good match size by 10% at every loop
+								 * iteration */
+};
+const PGLZ_Strategy *const PGLZ_strategy_default = &strategy_default_data;
+
+
+static const PGLZ_Strategy strategy_always_data = {
+	0,							/* Chunks of any size are compressed */
+	INT_MAX,
+	0,							/* It's enough to save one single byte */
+	INT_MAX,					/* Never give up early */
+	128,						/* Stop history lookup if a match of 128 bytes
+								 * is found */
+	6							/* Look harder for a good match */
+};
+const PGLZ_Strategy *const PGLZ_strategy_always = &strategy_always_data;
+
+
+/* ----------
+ * Statically allocated work arrays for history
+ * ----------
+ */
+static int16 hist_start[PGLZ_MAX_HISTORY_LISTS];
+static PGLZ_HistEntry hist_entries[PGLZ_HISTORY_SIZE + 1];
+
+/*
+ * Element 0 in hist_entries is unused, and means 'invalid'. Likewise,
+ * INVALID_ENTRY_PTR in next/prev pointers mean 'invalid'.
+ */
+#define INVALID_ENTRY			0
+#define INVALID_ENTRY_PTR		(&hist_entries[INVALID_ENTRY])
+
+/* ----------
+ * pglz_hist_idx -
+ *
+ *		Computes the history table slot for the lookup by the next 4
+ *		characters in the input.
+ *
+ * NB: because we use the next 4 characters, we are not guaranteed to
+ * find 3-character matches; they very possibly will be in the wrong
+ * hash list.  This seems an acceptable tradeoff for spreading out the
+ * hash keys more.
+ * ----------
+ */
+#define pglz_hist_idx(_s,_e, _mask) (										\
+			((((_e) - (_s)) < 4) ? (int) (_s)[0] :							\
+			 (((_s)[0] << 6) ^ ((_s)[1] << 4) ^								\
+			  ((_s)[2] << 2) ^ (_s)[3])) & (_mask)				\
+		)
+
+
+/* ----------
+ * pglz_hist_add -
+ *
+ *		Adds a new entry to the history table.
+ *
+ * If _recycle is true, then we are recycling a previously used entry,
+ * and must first delink it from its old hashcode's linked list.
+ *
+ * NOTE: beware of multiple evaluations of macro's arguments, and note that
+ * _hn and _recycle are modified in the macro.
+ * ----------
+ */
+#define pglz_hist_add(_hs,_he,_hn,_recycle,_s,_e, _mask)	\
+do {									\
+			int __hindex = pglz_hist_idx((_s),(_e), (_mask));				\
+			int16 *__myhsp = &(_hs)[__hindex];								\
+			PGLZ_HistEntry *__myhe = &(_he)[_hn];							\
+			if (_recycle) {													\
+				if (__myhe->prev == NULL)									\
+					(_hs)[__myhe->hindex] = __myhe->next - (_he);			\
+				else														\
+					__myhe->prev->next = __myhe->next;						\
+				if (__myhe->next != NULL)									\
+					__myhe->next->prev = __myhe->prev;						\
+			}																\
+			__myhe->next = &(_he)[*__myhsp];								\
+			__myhe->prev = NULL;											\
+			__myhe->hindex = __hindex;										\
+			__myhe->pos  = (_s);											\
+			/* If there was an existing entry in this hash slot, link */	\
+			/* this new entry to it. However, the 0th entry in the */		\
+			/* entries table is unused, so we can freely scribble on it. */ \
+			/* So don't bother checking if the slot was used - we'll */		\
+			/* scribble on the unused entry if it was not, but that's */	\
+			/* harmless. Avoiding the branch in this critical path */		\
+			/* speeds this up a little bit. */								\
+			/* if (*__myhsp != INVALID_ENTRY) */							\
+				(_he)[(*__myhsp)].prev = __myhe;							\
+			*__myhsp = _hn;													\
+			if (++(_hn) >= PGLZ_HISTORY_SIZE + 1) {							\
+				(_hn) = 1;													\
+				(_recycle) = true;											\
+			}																\
+} while (0)
+
+
+/* ----------
+ * pglz_out_ctrl -
+ *
+ *		Outputs the last and allocates a new control byte if needed.
+ * ----------
+ */
+#define pglz_out_ctrl(__ctrlp,__ctrlb,__ctrl,__buf) \
+do { \
+	if ((__ctrl & 0xff) == 0)												\
+	{																		\
+		*(__ctrlp) = __ctrlb;												\
+		__ctrlp = (__buf)++;												\
+		__ctrlb = 0;														\
+		__ctrl = 1;															\
+	}																		\
+} while (0)
+
+
+/* ----------
+ * pglz_out_literal -
+ *
+ *		Outputs a literal byte to the destination buffer including the
+ *		appropriate control bit.
+ * ----------
+ */
+#define pglz_out_literal(_ctrlp,_ctrlb,_ctrl,_buf,_byte) \
+do { \
+	pglz_out_ctrl(_ctrlp,_ctrlb,_ctrl,_buf);								\
+	*(_buf)++ = (unsigned char)(_byte);										\
+	_ctrl <<= 1;															\
+} while (0)
+
+
+/* ----------
+ * pglz_out_tag -
+ *
+ *		Outputs a backward reference tag of 2-4 bytes (depending on
+ *		offset and length) to the destination buffer including the
+ *		appropriate control bit.
+ * ----------
+ */
+#define pglz_out_tag(_ctrlp,_ctrlb,_ctrl,_buf,_len,_off) \
+do { \
+	pglz_out_ctrl(_ctrlp,_ctrlb,_ctrl,_buf);								\
+	_ctrlb |= _ctrl;														\
+	_ctrl <<= 1;															\
+	if (_len > 17)															\
+	{																		\
+		(_buf)[0] = (unsigned char)((((_off) & 0xf00) >> 4) | 0x0f);		\
+		(_buf)[1] = (unsigned char)(((_off) & 0xff));						\
+		(_buf)[2] = (unsigned char)((_len) - 18);							\
+		(_buf) += 3;														\
+	} else {																\
+		(_buf)[0] = (unsigned char)((((_off) & 0xf00) >> 4) | ((_len) - 3)); \
+		(_buf)[1] = (unsigned char)((_off) & 0xff);							\
+		(_buf) += 2;														\
+	}																		\
+} while (0)
+
+
+/* ----------
+ * pglz_find_match -
+ *
+ *		Lookup the history table if the actual input stream matches
+ *		another sequence of characters, starting somewhere earlier
+ *		in the input buffer.
+ * ----------
+ */
+static inline int
+pglz_find_match(int16 *hstart, const char *input, const char *end,
+				int *lenp, int *offp, int good_match, int good_drop, int mask)
+{
+	PGLZ_HistEntry *hent;
+	int16		hentno;
+	int32		len = 0;
+	int32		off = 0;
+
+	/*
+	 * Traverse the linked history list until a good enough match is found.
+	 */
+	hentno = hstart[pglz_hist_idx(input, end, mask)];
+	hent = &hist_entries[hentno];
+	while (hent != INVALID_ENTRY_PTR)
+	{
+		const char *ip = input;
+		const char *hp = hent->pos;
+		int32		thisoff;
+		int32		thislen;
+
+		/*
+		 * Stop if the offset does not fit into our tag anymore.
+		 */
+		thisoff = ip - hp;
+		if (thisoff >= 0x0fff)
+			break;
+
+		/*
+		 * Determine length of match. A better match must be larger than the
+		 * best so far. And if we already have a match of 16 or more bytes,
+		 * it's worth the call overhead to use memcmp() to check if this match
+		 * is equal for the same size. After that we must fallback to
+		 * character by character comparison to know the exact position where
+		 * the diff occurred.
+		 */
+		thislen = 0;
+		if (len >= 16)
+		{
+			if (memcmp(ip, hp, len) == 0)
+			{
+				thislen = len;
+				ip += len;
+				hp += len;
+				while (ip < end && *ip == *hp && thislen < PGLZ_MAX_MATCH)
+				{
+					thislen++;
+					ip++;
+					hp++;
+				}
+			}
+		}
+		else
+		{
+			while (ip < end && *ip == *hp && thislen < PGLZ_MAX_MATCH)
+			{
+				thislen++;
+				ip++;
+				hp++;
+			}
+		}
+
+		/*
+		 * Remember this match as the best (if it is)
+		 */
+		if (thislen > len)
+		{
+			len = thislen;
+			off = thisoff;
+		}
+
+		/*
+		 * Advance to the next history entry
+		 */
+		hent = hent->next;
+
+		/*
+		 * Be happy with lesser good matches the more entries we visited. But
+		 * no point in doing calculation if we're at end of list.
+		 */
+		if (hent != INVALID_ENTRY_PTR)
+		{
+			if (len >= good_match)
+				break;
+			good_match -= (good_match * good_drop) / 100;
+		}
+	}
+
+	/*
+	 * Return match information only if it results at least in one byte
+	 * reduction.
+	 */
+	if (len > 2)
+	{
+		*lenp = len;
+		*offp = off;
+		return 1;
+	}
+
+	return 0;
+}
+
+
+/* ----------
+ * pglz_compress -
+ *
+ *		Compresses source into dest using strategy. Returns the number of
+ *		bytes written in buffer dest, or -1 if compression fails.
+ * ----------
+ */
+int32
+pglz_compress(const char *source, int32 slen, char *dest,
+			  const PGLZ_Strategy *strategy)
+{
+	unsigned char *bp = (unsigned char *) dest;
+	unsigned char *bstart = bp;
+	int			hist_next = 1;
+	bool		hist_recycle = false;
+	const char *dp = source;
+	const char *dend = source + slen;
+	unsigned char ctrl_dummy = 0;
+	unsigned char *ctrlp = &ctrl_dummy;
+	unsigned char ctrlb = 0;
+	unsigned char ctrl = 0;
+	bool		found_match = false;
+	int32		match_len;
+	int32		match_off;
+	int32		good_match;
+	int32		good_drop;
+	int32		result_size;
+	int32		result_max;
+	int32		need_rate;
+	int			hashsz;
+	int			mask;
+
+	/*
+	 * Our fallback strategy is the default.
+	 */
+	if (strategy == NULL)
+		strategy = PGLZ_strategy_default;
+
+	/*
+	 * If the strategy forbids compression (at all or if source chunk size out
+	 * of range), fail.
+	 */
+	if (strategy->match_size_good <= 0 ||
+		slen < strategy->min_input_size ||
+		slen > strategy->max_input_size)
+		return -1;
+
+	/*
+	 * Limit the match parameters to the supported range.
+	 */
+	good_match = strategy->match_size_good;
+	if (good_match > PGLZ_MAX_MATCH)
+		good_match = PGLZ_MAX_MATCH;
+	else if (good_match < 17)
+		good_match = 17;
+
+	good_drop = strategy->match_size_drop;
+	if (good_drop < 0)
+		good_drop = 0;
+	else if (good_drop > 100)
+		good_drop = 100;
+
+	need_rate = strategy->min_comp_rate;
+	if (need_rate < 0)
+		need_rate = 0;
+	else if (need_rate > 99)
+		need_rate = 99;
+
+	/*
+	 * Compute the maximum result size allowed by the strategy, namely the
+	 * input size minus the minimum wanted compression rate.  This had better
+	 * be <= slen, else we might overrun the provided output buffer.
+	 */
+	if (slen > (INT_MAX / 100))
+	{
+		/* Approximate to avoid overflow */
+		result_max = (slen / 100) * (100 - need_rate);
+	}
+	else
+		result_max = (slen * (100 - need_rate)) / 100;
+
+	/*
+	 * Experiments suggest that these hash sizes work pretty well. A large
+	 * hash table minimizes collision, but has a higher startup cost. For a
+	 * small input, the startup cost dominates. The table size must be a power
+	 * of two.
+	 */
+	if (slen < 128)
+		hashsz = 512;
+	else if (slen < 256)
+		hashsz = 1024;
+	else if (slen < 512)
+		hashsz = 2048;
+	else if (slen < 1024)
+		hashsz = 4096;
+	else
+		hashsz = 8192;
+	mask = hashsz - 1;
+
+	/*
+	 * Initialize the history lists to empty.  We do not need to zero the
+	 * hist_entries[] array; its entries are initialized as they are used.
+	 */
+	memset(hist_start, 0, hashsz * sizeof(int16));
+
+	/*
+	 * Compress the source directly into the output buffer.
+	 */
+	while (dp < dend)
+	{
+		/*
+		 * If we already exceeded the maximum result size, fail.
+		 *
+		 * We check once per loop; since the loop body could emit as many as 4
+		 * bytes (a control byte and 3-byte tag), PGLZ_MAX_OUTPUT() had better
+		 * allow 4 slop bytes.
+		 */
+		if (bp - bstart >= result_max)
+			return -1;
+
+		/*
+		 * If we've emitted more than first_success_by bytes without finding
+		 * anything compressible at all, fail.  This lets us fall out
+		 * reasonably quickly when looking at incompressible input (such as
+		 * pre-compressed data).
+		 */
+		if (!found_match && bp - bstart >= strategy->first_success_by)
+			return -1;
+
+		/*
+		 * Try to find a match in the history
+		 */
+		if (pglz_find_match(hist_start, dp, dend, &match_len,
+							&match_off, good_match, good_drop, mask))
+		{
+			/*
+			 * Create the tag and add history entries for all matched
+			 * characters.
+			 */
+			pglz_out_tag(ctrlp, ctrlb, ctrl, bp, match_len, match_off);
+			while (match_len--)
+			{
+				pglz_hist_add(hist_start, hist_entries,
+							  hist_next, hist_recycle,
+							  dp, dend, mask);
+				dp++;			/* Do not do this ++ in the line above! */
+				/* The macro would do it four times - Jan.  */
+			}
+			found_match = true;
+		}
+		else
+		{
+			/*
+			 * No match found. Copy one literal byte.
+			 */
+			pglz_out_literal(ctrlp, ctrlb, ctrl, bp, *dp);
+			pglz_hist_add(hist_start, hist_entries,
+						  hist_next, hist_recycle,
+						  dp, dend, mask);
+			dp++;				/* Do not do this ++ in the line above! */
+			/* The macro would do it four times - Jan.  */
+		}
+	}
+
+	/*
+	 * Write out the last control byte and check that we haven't overrun the
+	 * output size allowed by the strategy.
+	 */
+	*ctrlp = ctrlb;
+	result_size = bp - bstart;
+	if (result_size >= result_max)
+		return -1;
+
+	/* success */
+	return result_size;
+}
+
+
+/* ----------
+ * pglz_decompress -
+ *
+ *		Decompresses source into dest. Returns the number of bytes
+ *		decompressed into the destination buffer, or -1 if the
+ *		compressed data is corrupted.
+ *
+ *		If check_complete is true, the data is considered corrupted
+ *		if we don't exactly fill the destination buffer.  Callers that
+ *		are extracting a slice typically can't apply this check.
+ * ----------
+ */
+int32
+pglz_decompress(const char *source, int32 slen, char *dest,
+				int32 rawsize, bool check_complete)
+{
+	const unsigned char *sp;
+	const unsigned char *srcend;
+	unsigned char *dp;
+	unsigned char *destend;
+
+	sp = (const unsigned char *) source;
+	srcend = ((const unsigned char *) source) + slen;
+	dp = (unsigned char *) dest;
+	destend = dp + rawsize;
+
+	while (sp < srcend && dp < destend)
+	{
+		/*
+		 * Read one control byte and process the next 8 items (or as many as
+		 * remain in the compressed input).
+		 */
+		unsigned char ctrl = *sp++;
+		int			ctrlc;
+
+		for (ctrlc = 0; ctrlc < 8 && sp < srcend && dp < destend; ctrlc++)
+		{
+			if (ctrl & 1)
+			{
+				/*
+				 * Set control bit means we must read a match tag. The match
+				 * is coded with two bytes. First byte uses lower nibble to
+				 * code length - 3. Higher nibble contains upper 4 bits of the
+				 * offset. The next following byte contains the lower 8 bits
+				 * of the offset. If the length is coded as 18, another
+				 * extension tag byte tells how much longer the match really
+				 * was (0-255).
+				 */
+				int32		len;
+				int32		off;
+
+				len = (sp[0] & 0x0f) + 3;
+				off = ((sp[0] & 0xf0) << 4) | sp[1];
+				sp += 2;
+				if (len == 18)
+					len += *sp++;
+
+				/*
+				 * Check for corrupt data: if we fell off the end of the
+				 * source, or if we obtained off = 0, we have problems.  (We
+				 * must check this, else we risk an infinite loop below in the
+				 * face of corrupt data.)
+				 */
+				if (unlikely(sp > srcend || off == 0))
+					return -1;
+
+				/*
+				 * Don't emit more data than requested.
+				 */
+				len = Min(len, destend - dp);
+
+				/*
+				 * Now we copy the bytes specified by the tag from OUTPUT to
+				 * OUTPUT (copy len bytes from dp - off to dp).  The copied
+				 * areas could overlap, so to avoid undefined behavior in
+				 * memcpy(), be careful to copy only non-overlapping regions.
+				 *
+				 * Note that we cannot use memmove() instead, since while its
+				 * behavior is well-defined, it's also not what we want.
+				 */
+				while (off < len)
+				{
+					/*
+					 * We can safely copy "off" bytes since that clearly
+					 * results in non-overlapping source and destination.
+					 */
+					memcpy(dp, dp - off, off);
+					len -= off;
+					dp += off;
+
+					/*----------
+					 * This bit is less obvious: we can double "off" after
+					 * each such step.  Consider this raw input:
+					 *		112341234123412341234
+					 * This will be encoded as 5 literal bytes "11234" and
+					 * then a match tag with length 16 and offset 4.  After
+					 * memcpy'ing the first 4 bytes, we will have emitted
+					 *		112341234
+					 * so we can double "off" to 8, then after the next step
+					 * we have emitted
+					 *		11234123412341234
+					 * Then we can double "off" again, after which it is more
+					 * than the remaining "len" so we fall out of this loop
+					 * and finish with a non-overlapping copy of the
+					 * remainder.  In general, a match tag with off < len
+					 * implies that the decoded data has a repeat length of
+					 * "off".  We can handle 1, 2, 4, etc repetitions of the
+					 * repeated string per memcpy until we get to a situation
+					 * where the final copy step is non-overlapping.
+					 *
+					 * (Another way to understand this is that we are keeping
+					 * the copy source point dp - off the same throughout.)
+					 *----------
+					 */
+					off += off;
+				}
+				memcpy(dp, dp - off, len);
+				dp += len;
+			}
+			else
+			{
+				/*
+				 * An unset control bit means LITERAL BYTE. So we just copy
+				 * one from INPUT to OUTPUT.
+				 */
+				*dp++ = *sp++;
+			}
+
+			/*
+			 * Advance the control bit
+			 */
+			ctrl >>= 1;
+		}
+	}
+
+	/*
+	 * If requested, check we decompressed the right amount.
+	 */
+	if (check_complete && (dp != destend || sp != srcend))
+		return -1;
+
+	/*
+	 * That's it.
+	 */
+	return (char *) dp - dest;
+}
+
+
+/* ----------
+ * pglz_max_compressed_size -
+ *
+ *		Calculate the maximum compressed size for a given amount of raw data.
+ *		Return the maximum size, or total compressed size if maximum size is
+ *		larger than total compressed size.
+ *
+ * We can't use PGLZ_MAX_OUTPUT for this purpose, because that's used to size
+ * the compression buffer (and abort the compression). It does not really say
+ * what's the maximum compressed size for an input of a given length, and it
+ * may happen that while the whole value is compressible (and thus fits into
+ * PGLZ_MAX_OUTPUT nicely), the prefix is not compressible at all.
+ * ----------
+ */
+int32
+pglz_maximum_compressed_size(int32 rawsize, int32 total_compressed_size)
+{
+	int64		compressed_size;
+
+	/*
+	 * pglz uses one control bit per byte, so if the entire desired prefix is
+	 * represented as literal bytes, we'll need (rawsize * 9) bits.  We care
+	 * about bytes though, so be sure to round up not down.
+	 *
+	 * Use int64 here to prevent overflow during calculation.
+	 */
+	compressed_size = ((int64) rawsize * 9 + 7) / 8;
+
+	/*
+	 * The above fails to account for a corner case: we could have compressed
+	 * data that starts with N-1 or N-2 literal bytes and then has a match tag
+	 * of 2 or 3 bytes.  It's therefore possible that we need to fetch 1 or 2
+	 * more bytes in order to have the whole match tag.  (Match tags earlier
+	 * in the compressed data don't cause a problem, since they should
+	 * represent more decompressed bytes than they occupy themselves.)
+	 */
+	compressed_size += 2;
+
+	/*
+	 * Maximum compressed size can't be larger than total compressed size.
+	 * (This also ensures that our result fits in int32.)
+	 */
+	compressed_size = Min(compressed_size, total_compressed_size);
+
+	return (int32) compressed_size;
+}
diff --git a/src/common/pgfnames.c b/src/common/pgfnames.c
new file mode 100644
index 0000000..395927c
--- /dev/null
+++ b/src/common/pgfnames.c
@@ -0,0 +1,94 @@
+/*-------------------------------------------------------------------------
+ *
+ * pgfnames.c
+ *	  directory handling functions
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/pgfnames.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <dirent.h>
+
+#ifndef FRONTEND
+#define pg_log_warning(...) elog(WARNING, __VA_ARGS__)
+#else
+#include "common/logging.h"
+#endif
+
+/*
+ * pgfnames
+ *
+ * return a list of the names of objects in the argument directory.  Caller
+ * must call pgfnames_cleanup later to free the memory allocated by this
+ * function.
+ */
+char	  **
+pgfnames(const char *path)
+{
+	DIR		   *dir;
+	struct dirent *file;
+	char	  **filenames;
+	int			numnames = 0;
+	int			fnsize = 200;	/* enough for many small dbs */
+
+	dir = opendir(path);
+	if (dir == NULL)
+	{
+		pg_log_warning("could not open directory \"%s\": %m", path);
+		return NULL;
+	}
+
+	filenames = (char **) palloc(fnsize * sizeof(char *));
+
+	while (errno = 0, (file = readdir(dir)) != NULL)
+	{
+		if (strcmp(file->d_name, ".") != 0 && strcmp(file->d_name, "..") != 0)
+		{
+			if (numnames + 1 >= fnsize)
+			{
+				fnsize *= 2;
+				filenames = (char **) repalloc(filenames,
+											   fnsize * sizeof(char *));
+			}
+			filenames[numnames++] = pstrdup(file->d_name);
+		}
+	}
+
+	if (errno)
+		pg_log_warning("could not read directory \"%s\": %m", path);
+
+	filenames[numnames] = NULL;
+
+	if (closedir(dir))
+		pg_log_warning("could not close directory \"%s\": %m", path);
+
+	return filenames;
+}
+
+
+/*
+ *	pgfnames_cleanup
+ *
+ *	deallocate memory used for filenames
+ */
+void
+pgfnames_cleanup(char **filenames)
+{
+	char	  **fn;
+
+	for (fn = filenames; *fn; fn++)
+		pfree(*fn);
+
+	pfree(filenames);
+}
diff --git a/src/common/protocol_openssl.c b/src/common/protocol_openssl.c
new file mode 100644
index 0000000..92a0a22
--- /dev/null
+++ b/src/common/protocol_openssl.c
@@ -0,0 +1,117 @@
+/*-------------------------------------------------------------------------
+ *
+ * protocol_openssl.c
+ *	  OpenSSL functionality shared between frontend and backend
+ *
+ * This should only be used if code is compiled with OpenSSL support.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *		  src/common/protocol_openssl.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/openssl.h"
+
+/*
+ * Replacements for APIs introduced in OpenSSL 1.1.0.
+ */
+#ifndef SSL_CTX_set_min_proto_version
+
+/*
+ * OpenSSL versions that support TLS 1.3 shouldn't get here because they
+ * already have these functions.  So we don't have to keep updating the below
+ * code for every new TLS version, and eventually it can go away.  But let's
+ * just check this to make sure ...
+ */
+#ifdef TLS1_3_VERSION
+#error OpenSSL version mismatch
+#endif
+
+int
+SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version)
+{
+	int			ssl_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3;
+
+	if (version > TLS1_VERSION)
+		ssl_options |= SSL_OP_NO_TLSv1;
+
+	/*
+	 * Some OpenSSL versions define TLS*_VERSION macros but not the
+	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
+	 * unsuccessfully here.
+	 */
+#ifdef TLS1_1_VERSION
+	if (version > TLS1_1_VERSION)
+	{
+#ifdef SSL_OP_NO_TLSv1_1
+		ssl_options |= SSL_OP_NO_TLSv1_1;
+#else
+		return 0;
+#endif
+	}
+#endif
+#ifdef TLS1_2_VERSION
+	if (version > TLS1_2_VERSION)
+	{
+#ifdef SSL_OP_NO_TLSv1_2
+		ssl_options |= SSL_OP_NO_TLSv1_2;
+#else
+		return 0;
+#endif
+	}
+#endif
+
+	SSL_CTX_set_options(ctx, ssl_options);
+
+	return 1;					/* success */
+}
+
+int
+SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version)
+{
+	int			ssl_options = 0;
+
+	AssertArg(version != 0);
+
+	/*
+	 * Some OpenSSL versions define TLS*_VERSION macros but not the
+	 * corresponding SSL_OP_NO_* macro, so in those cases we have to return
+	 * unsuccessfully here.
+	 */
+#ifdef TLS1_1_VERSION
+	if (version < TLS1_1_VERSION)
+	{
+#ifdef SSL_OP_NO_TLSv1_1
+		ssl_options |= SSL_OP_NO_TLSv1_1;
+#else
+		return 0;
+#endif
+	}
+#endif
+#ifdef TLS1_2_VERSION
+	if (version < TLS1_2_VERSION)
+	{
+#ifdef SSL_OP_NO_TLSv1_2
+		ssl_options |= SSL_OP_NO_TLSv1_2;
+#else
+		return 0;
+#endif
+	}
+#endif
+
+	SSL_CTX_set_options(ctx, ssl_options);
+
+	return 1;					/* success */
+}
+
+#endif							/* !SSL_CTX_set_min_proto_version */
diff --git a/src/common/psprintf.c b/src/common/psprintf.c
new file mode 100644
index 0000000..52223c3
--- /dev/null
+++ b/src/common/psprintf.c
@@ -0,0 +1,151 @@
+/*-------------------------------------------------------------------------
+ *
+ * psprintf.c
+ *		sprintf into an allocated-on-demand buffer
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/psprintf.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+
+#include "postgres.h"
+
+#include "utils/memutils.h"
+
+#else
+
+#include "postgres_fe.h"
+
+/* It's possible we could use a different value for this in frontend code */
+#define MaxAllocSize	((Size) 0x3fffffff) /* 1 gigabyte - 1 */
+
+#endif
+
+
+/*
+ * psprintf
+ *
+ * Format text data under the control of fmt (an sprintf-style format string)
+ * and return it in an allocated-on-demand buffer.  The buffer is allocated
+ * with palloc in the backend, or malloc in frontend builds.  Caller is
+ * responsible to free the buffer when no longer needed, if appropriate.
+ *
+ * Errors are not returned to the caller, but are reported via elog(ERROR)
+ * in the backend, or printf-to-stderr-and-exit() in frontend builds.
+ * One should therefore think twice about using this in libpq.
+ */
+char *
+psprintf(const char *fmt,...)
+{
+	int			save_errno = errno;
+	size_t		len = 128;		/* initial assumption about buffer size */
+
+	for (;;)
+	{
+		char	   *result;
+		va_list		args;
+		size_t		newlen;
+
+		/*
+		 * Allocate result buffer.  Note that in frontend this maps to malloc
+		 * with exit-on-error.
+		 */
+		result = (char *) palloc(len);
+
+		/* Try to format the data. */
+		errno = save_errno;
+		va_start(args, fmt);
+		newlen = pvsnprintf(result, len, fmt, args);
+		va_end(args);
+
+		if (newlen < len)
+			return result;		/* success */
+
+		/* Release buffer and loop around to try again with larger len. */
+		pfree(result);
+		len = newlen;
+	}
+}
+
+/*
+ * pvsnprintf
+ *
+ * Attempt to format text data under the control of fmt (an sprintf-style
+ * format string) and insert it into buf (which has length len).
+ *
+ * If successful, return the number of bytes emitted, not counting the
+ * trailing zero byte.  This will always be strictly less than len.
+ *
+ * If there's not enough space in buf, return an estimate of the buffer size
+ * needed to succeed (this *must* be more than the given len, else callers
+ * might loop infinitely).
+ *
+ * Other error cases do not return, but exit via elog(ERROR) or exit().
+ * Hence, this shouldn't be used inside libpq.
+ *
+ * Caution: callers must be sure to preserve their entry-time errno
+ * when looping, in case the fmt contains "%m".
+ *
+ * Note that the semantics of the return value are not exactly C99's.
+ * First, we don't promise that the estimated buffer size is exactly right;
+ * callers must be prepared to loop multiple times to get the right size.
+ * (Given a C99-compliant vsnprintf, that won't happen, but it is rumored
+ * that some implementations don't always return the same value ...)
+ * Second, we return the recommended buffer size, not one less than that;
+ * this lets overflow concerns be handled here rather than in the callers.
+ */
+size_t
+pvsnprintf(char *buf, size_t len, const char *fmt, va_list args)
+{
+	int			nprinted;
+
+	nprinted = vsnprintf(buf, len, fmt, args);
+
+	/* We assume failure means the fmt is bogus, hence hard failure is OK */
+	if (unlikely(nprinted < 0))
+	{
+#ifndef FRONTEND
+		elog(ERROR, "vsnprintf failed: %m with format string \"%s\"", fmt);
+#else
+		fprintf(stderr, "vsnprintf failed: %s with format string \"%s\"\n",
+				strerror(errno), fmt);
+		exit(EXIT_FAILURE);
+#endif
+	}
+
+	if ((size_t) nprinted < len)
+	{
+		/* Success.  Note nprinted does not include trailing null. */
+		return (size_t) nprinted;
+	}
+
+	/*
+	 * We assume a C99-compliant vsnprintf, so believe its estimate of the
+	 * required space, and add one for the trailing null.  (If it's wrong, the
+	 * logic will still work, but we may loop multiple times.)
+	 *
+	 * Choke if the required space would exceed MaxAllocSize.  Note we use
+	 * this palloc-oriented overflow limit even when in frontend.
+	 */
+	if (unlikely((size_t) nprinted > MaxAllocSize - 1))
+	{
+#ifndef FRONTEND
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("out of memory")));
+#else
+		fprintf(stderr, _("out of memory\n"));
+		exit(EXIT_FAILURE);
+#endif
+	}
+
+	return nprinted + 1;
+}
diff --git a/src/common/relpath.c b/src/common/relpath.c
new file mode 100644
index 0000000..1f5c426
--- /dev/null
+++ b/src/common/relpath.c
@@ -0,0 +1,210 @@
+/*-------------------------------------------------------------------------
+ * relpath.c
+ *		Shared frontend/backend code to compute pathnames of relation files
+ *
+ * This module also contains some logic associated with fork names.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/relpath.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "catalog/pg_tablespace_d.h"
+#include "common/relpath.h"
+#include "storage/backendid.h"
+
+
+/*
+ * Lookup table of fork name by fork number.
+ *
+ * If you add a new entry, remember to update the errhint in
+ * forkname_to_number() below, and update the SGML documentation for
+ * pg_relation_size().
+ */
+const char *const forkNames[] = {
+	"main",						/* MAIN_FORKNUM */
+	"fsm",						/* FSM_FORKNUM */
+	"vm",						/* VISIBILITYMAP_FORKNUM */
+	"init"						/* INIT_FORKNUM */
+};
+
+StaticAssertDecl(lengthof(forkNames) == (MAX_FORKNUM + 1),
+				 "array length mismatch");
+
+/*
+ * forkname_to_number - look up fork number by name
+ *
+ * In backend, we throw an error for no match; in frontend, we just
+ * return InvalidForkNumber.
+ */
+ForkNumber
+forkname_to_number(const char *forkName)
+{
+	ForkNumber	forkNum;
+
+	for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
+		if (strcmp(forkNames[forkNum], forkName) == 0)
+			return forkNum;
+
+#ifndef FRONTEND
+	ereport(ERROR,
+			(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+			 errmsg("invalid fork name"),
+			 errhint("Valid fork names are \"main\", \"fsm\", "
+					 "\"vm\", and \"init\".")));
+#endif
+
+	return InvalidForkNumber;
+}
+
+/*
+ * forkname_chars
+ *		We use this to figure out whether a filename could be a relation
+ *		fork (as opposed to an oddly named stray file that somehow ended
+ *		up in the database directory).  If the passed string begins with
+ *		a fork name (other than the main fork name), we return its length,
+ *		and set *fork (if not NULL) to the fork number.  If not, we return 0.
+ *
+ * Note that the present coding assumes that there are no fork names which
+ * are prefixes of other fork names.
+ */
+int
+forkname_chars(const char *str, ForkNumber *fork)
+{
+	ForkNumber	forkNum;
+
+	for (forkNum = 1; forkNum <= MAX_FORKNUM; forkNum++)
+	{
+		int			len = strlen(forkNames[forkNum]);
+
+		if (strncmp(forkNames[forkNum], str, len) == 0)
+		{
+			if (fork)
+				*fork = forkNum;
+			return len;
+		}
+	}
+	if (fork)
+		*fork = InvalidForkNumber;
+	return 0;
+}
+
+
+/*
+ * GetDatabasePath - construct path to a database directory
+ *
+ * Result is a palloc'd string.
+ *
+ * XXX this must agree with GetRelationPath()!
+ */
+char *
+GetDatabasePath(Oid dbNode, Oid spcNode)
+{
+	if (spcNode == GLOBALTABLESPACE_OID)
+	{
+		/* Shared system relations live in {datadir}/global */
+		Assert(dbNode == 0);
+		return pstrdup("global");
+	}
+	else if (spcNode == DEFAULTTABLESPACE_OID)
+	{
+		/* The default tablespace is {datadir}/base */
+		return psprintf("base/%u", dbNode);
+	}
+	else
+	{
+		/* All other tablespaces are accessed via symlinks */
+		return psprintf("pg_tblspc/%u/%s/%u",
+						spcNode, TABLESPACE_VERSION_DIRECTORY, dbNode);
+	}
+}
+
+/*
+ * GetRelationPath - construct path to a relation's file
+ *
+ * Result is a palloc'd string.
+ *
+ * Note: ideally, backendId would be declared as type BackendId, but relpath.h
+ * would have to include a backend-only header to do that; doesn't seem worth
+ * the trouble considering BackendId is just int anyway.
+ */
+char *
+GetRelationPath(Oid dbNode, Oid spcNode, Oid relNode,
+				int backendId, ForkNumber forkNumber)
+{
+	char	   *path;
+
+	if (spcNode == GLOBALTABLESPACE_OID)
+	{
+		/* Shared system relations live in {datadir}/global */
+		Assert(dbNode == 0);
+		Assert(backendId == InvalidBackendId);
+		if (forkNumber != MAIN_FORKNUM)
+			path = psprintf("global/%u_%s",
+							relNode, forkNames[forkNumber]);
+		else
+			path = psprintf("global/%u", relNode);
+	}
+	else if (spcNode == DEFAULTTABLESPACE_OID)
+	{
+		/* The default tablespace is {datadir}/base */
+		if (backendId == InvalidBackendId)
+		{
+			if (forkNumber != MAIN_FORKNUM)
+				path = psprintf("base/%u/%u_%s",
+								dbNode, relNode,
+								forkNames[forkNumber]);
+			else
+				path = psprintf("base/%u/%u",
+								dbNode, relNode);
+		}
+		else
+		{
+			if (forkNumber != MAIN_FORKNUM)
+				path = psprintf("base/%u/t%d_%u_%s",
+								dbNode, backendId, relNode,
+								forkNames[forkNumber]);
+			else
+				path = psprintf("base/%u/t%d_%u",
+								dbNode, backendId, relNode);
+		}
+	}
+	else
+	{
+		/* All other tablespaces are accessed via symlinks */
+		if (backendId == InvalidBackendId)
+		{
+			if (forkNumber != MAIN_FORKNUM)
+				path = psprintf("pg_tblspc/%u/%s/%u/%u_%s",
+								spcNode, TABLESPACE_VERSION_DIRECTORY,
+								dbNode, relNode,
+								forkNames[forkNumber]);
+			else
+				path = psprintf("pg_tblspc/%u/%s/%u/%u",
+								spcNode, TABLESPACE_VERSION_DIRECTORY,
+								dbNode, relNode);
+		}
+		else
+		{
+			if (forkNumber != MAIN_FORKNUM)
+				path = psprintf("pg_tblspc/%u/%s/%u/t%d_%u_%s",
+								spcNode, TABLESPACE_VERSION_DIRECTORY,
+								dbNode, backendId, relNode,
+								forkNames[forkNumber]);
+			else
+				path = psprintf("pg_tblspc/%u/%s/%u/t%d_%u",
+								spcNode, TABLESPACE_VERSION_DIRECTORY,
+								dbNode, backendId, relNode);
+		}
+	}
+	return path;
+}
diff --git a/src/common/restricted_token.c b/src/common/restricted_token.c
new file mode 100644
index 0000000..667040d
--- /dev/null
+++ b/src/common/restricted_token.c
@@ -0,0 +1,202 @@
+/*-------------------------------------------------------------------------
+ *
+ * restricted_token.c
+ *		helper routine to ensure restricted token on Windows
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/restricted_token.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#error "This file is not expected to be compiled for backend code"
+#endif
+
+#include "postgres_fe.h"
+
+#include "common/logging.h"
+#include "common/restricted_token.h"
+
+#ifdef WIN32
+
+/* internal vars */
+char	   *restrict_env;
+
+typedef BOOL (WINAPI * __CreateRestrictedToken) (HANDLE, DWORD, DWORD, PSID_AND_ATTRIBUTES, DWORD, PLUID_AND_ATTRIBUTES, DWORD, PSID_AND_ATTRIBUTES, PHANDLE);
+
+/* Windows API define missing from some versions of MingW headers */
+#ifndef  DISABLE_MAX_PRIVILEGE
+#define DISABLE_MAX_PRIVILEGE	0x1
+#endif
+
+/*
+ * Create a restricted token and execute the specified process with it.
+ *
+ * Returns restricted token on success and 0 on failure.
+ *
+ * On any system not containing the required functions, do nothing
+ * but still report an error.
+ */
+HANDLE
+CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo)
+{
+	BOOL		b;
+	STARTUPINFO si;
+	HANDLE		origToken;
+	HANDLE		restrictedToken;
+	SID_IDENTIFIER_AUTHORITY NtAuthority = {SECURITY_NT_AUTHORITY};
+	SID_AND_ATTRIBUTES dropSids[2];
+	__CreateRestrictedToken _CreateRestrictedToken;
+	HANDLE		Advapi32Handle;
+
+	ZeroMemory(&si, sizeof(si));
+	si.cb = sizeof(si);
+
+	Advapi32Handle = LoadLibrary("ADVAPI32.DLL");
+	if (Advapi32Handle == NULL)
+	{
+		pg_log_error("could not load library \"%s\": error code %lu",
+					 "ADVAPI32.DLL", GetLastError());
+		return 0;
+	}
+
+	_CreateRestrictedToken = (__CreateRestrictedToken) (pg_funcptr_t) GetProcAddress(Advapi32Handle, "CreateRestrictedToken");
+
+	if (_CreateRestrictedToken == NULL)
+	{
+		pg_log_error("cannot create restricted tokens on this platform: error code %lu",
+					 GetLastError());
+		FreeLibrary(Advapi32Handle);
+		return 0;
+	}
+
+	/* Open the current token to use as a base for the restricted one */
+	if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &origToken))
+	{
+		pg_log_error("could not open process token: error code %lu",
+					 GetLastError());
+		FreeLibrary(Advapi32Handle);
+		return 0;
+	}
+
+	/* Allocate list of SIDs to remove */
+	ZeroMemory(&dropSids, sizeof(dropSids));
+	if (!AllocateAndInitializeSid(&NtAuthority, 2,
+								  SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0,
+								  0, &dropSids[0].Sid) ||
+		!AllocateAndInitializeSid(&NtAuthority, 2,
+								  SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_POWER_USERS, 0, 0, 0, 0, 0,
+								  0, &dropSids[1].Sid))
+	{
+		pg_log_error("could not allocate SIDs: error code %lu",
+					 GetLastError());
+		CloseHandle(origToken);
+		FreeLibrary(Advapi32Handle);
+		return 0;
+	}
+
+	b = _CreateRestrictedToken(origToken,
+							   DISABLE_MAX_PRIVILEGE,
+							   sizeof(dropSids) / sizeof(dropSids[0]),
+							   dropSids,
+							   0, NULL,
+							   0, NULL,
+							   &restrictedToken);
+
+	FreeSid(dropSids[1].Sid);
+	FreeSid(dropSids[0].Sid);
+	CloseHandle(origToken);
+	FreeLibrary(Advapi32Handle);
+
+	if (!b)
+	{
+		pg_log_error("could not create restricted token: error code %lu", GetLastError());
+		return 0;
+	}
+
+#ifndef __CYGWIN__
+	AddUserToTokenDacl(restrictedToken);
+#endif
+
+	if (!CreateProcessAsUser(restrictedToken,
+							 NULL,
+							 cmd,
+							 NULL,
+							 NULL,
+							 TRUE,
+							 CREATE_SUSPENDED,
+							 NULL,
+							 NULL,
+							 &si,
+							 processInfo))
+
+	{
+		pg_log_error("could not start process for command \"%s\": error code %lu", cmd, GetLastError());
+		return 0;
+	}
+
+	ResumeThread(processInfo->hThread);
+	return restrictedToken;
+}
+#endif
+
+/*
+ * On Windows make sure that we are running with a restricted token,
+ * On other platforms do nothing.
+ */
+void
+get_restricted_token(void)
+{
+#ifdef WIN32
+	HANDLE		restrictedToken;
+
+	/*
+	 * Before we execute another program, make sure that we are running with a
+	 * restricted token. If not, re-execute ourselves with one.
+	 */
+
+	if ((restrict_env = getenv("PG_RESTRICT_EXEC")) == NULL
+		|| strcmp(restrict_env, "1") != 0)
+	{
+		PROCESS_INFORMATION pi;
+		char	   *cmdline;
+
+		ZeroMemory(&pi, sizeof(pi));
+
+		cmdline = pg_strdup(GetCommandLine());
+
+		setenv("PG_RESTRICT_EXEC", "1", 1);
+
+		if ((restrictedToken = CreateRestrictedProcess(cmdline, &pi)) == 0)
+		{
+			pg_log_error("could not re-execute with restricted token: error code %lu", GetLastError());
+		}
+		else
+		{
+			/*
+			 * Successfully re-executed. Now wait for child process to capture
+			 * the exit code.
+			 */
+			DWORD		x;
+
+			CloseHandle(restrictedToken);
+			CloseHandle(pi.hThread);
+			WaitForSingleObject(pi.hProcess, INFINITE);
+
+			if (!GetExitCodeProcess(pi.hProcess, &x))
+			{
+				pg_log_error("could not get exit code from subprocess: error code %lu", GetLastError());
+				exit(1);
+			}
+			exit(x);
+		}
+		pg_free(cmdline);
+	}
+#endif
+}
diff --git a/src/common/rmtree.c b/src/common/rmtree.c
new file mode 100644
index 0000000..e090a85
--- /dev/null
+++ b/src/common/rmtree.c
@@ -0,0 +1,122 @@
+/*-------------------------------------------------------------------------
+ *
+ * rmtree.c
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/rmtree.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <unistd.h>
+#include <sys/stat.h>
+
+#ifndef FRONTEND
+#define pg_log_warning(...) elog(WARNING, __VA_ARGS__)
+#else
+#include "common/logging.h"
+#endif
+
+
+/*
+ *	rmtree
+ *
+ *	Delete a directory tree recursively.
+ *	Assumes path points to a valid directory.
+ *	Deletes everything under path.
+ *	If rmtopdir is true deletes the directory too.
+ *	Returns true if successful, false if there was any problem.
+ *	(The details of the problem are reported already, so caller
+ *	doesn't really have to say anything more, but most do.)
+ */
+bool
+rmtree(const char *path, bool rmtopdir)
+{
+	bool		result = true;
+	char		pathbuf[MAXPGPATH];
+	char	  **filenames;
+	char	  **filename;
+	struct stat statbuf;
+
+	/*
+	 * we copy all the names out of the directory before we start modifying
+	 * it.
+	 */
+	filenames = pgfnames(path);
+
+	if (filenames == NULL)
+		return false;
+
+	/* now we have the names we can start removing things */
+	for (filename = filenames; *filename; filename++)
+	{
+		snprintf(pathbuf, MAXPGPATH, "%s/%s", path, *filename);
+
+		/*
+		 * It's ok if the file is not there anymore; we were just about to
+		 * delete it anyway.
+		 *
+		 * This is not an academic possibility. One scenario where this
+		 * happens is when bgwriter has a pending unlink request for a file in
+		 * a database that's being dropped. In dropdb(), we call
+		 * ForgetDatabaseSyncRequests() to flush out any such pending unlink
+		 * requests, but because that's asynchronous, it's not guaranteed that
+		 * the bgwriter receives the message in time.
+		 */
+		if (lstat(pathbuf, &statbuf) != 0)
+		{
+			if (errno != ENOENT)
+			{
+				pg_log_warning("could not stat file or directory \"%s\": %m",
+							   pathbuf);
+				result = false;
+			}
+			continue;
+		}
+
+		if (S_ISDIR(statbuf.st_mode))
+		{
+			/* call ourselves recursively for a directory */
+			if (!rmtree(pathbuf, true))
+			{
+				/* we already reported the error */
+				result = false;
+			}
+		}
+		else
+		{
+			if (unlink(pathbuf) != 0)
+			{
+				if (errno != ENOENT)
+				{
+					pg_log_warning("could not remove file or directory \"%s\": %m",
+								   pathbuf);
+					result = false;
+				}
+			}
+		}
+	}
+
+	if (rmtopdir)
+	{
+		if (rmdir(path) != 0)
+		{
+			pg_log_warning("could not remove file or directory \"%s\": %m",
+						   path);
+			result = false;
+		}
+	}
+
+	pgfnames_cleanup(filenames);
+
+	return result;
+}
diff --git a/src/common/ryu_common.h b/src/common/ryu_common.h
new file mode 100644
index 0000000..34b1e36
--- /dev/null
+++ b/src/common/ryu_common.h
@@ -0,0 +1,133 @@
+/*---------------------------------------------------------------------------
+ *
+ * Common routines for Ryu floating-point output.
+ *
+ * Portions Copyright (c) 2018-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/ryu_common.h
+ *
+ * This is a modification of code taken from github.com/ulfjack/ryu under the
+ * terms of the Boost license (not the Apache license). The original copyright
+ * notice follows:
+ *
+ * Copyright 2018 Ulf Adams
+ *
+ * The contents of this file may be used under the terms of the Apache
+ * License, Version 2.0.
+ *
+ *     (See accompanying file LICENSE-Apache or copy at
+ *      http://www.apache.org/licenses/LICENSE-2.0)
+ *
+ * Alternatively, the contents of this file may be used under the terms of the
+ * Boost Software License, Version 1.0.
+ *
+ *     (See accompanying file LICENSE-Boost or copy at
+ *      https://www.boost.org/LICENSE_1_0.txt)
+ *
+ * Unless required by applicable law or agreed to in writing, this software is
+ * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.
+ *
+ *---------------------------------------------------------------------------
+ */
+#ifndef RYU_COMMON_H
+#define RYU_COMMON_H
+
+/*
+ * Upstream Ryu's output is always the shortest possible. But we adjust that
+ * slightly to improve portability: we avoid outputting the exact midpoint
+ * value between two representable floats, since that relies on the reader
+ * getting the round-to-even rule correct, which seems to be the common
+ * failure mode.
+ *
+ * Defining this to 1 would restore the upstream behavior.
+ */
+#define STRICTLY_SHORTEST 0
+
+#if SIZEOF_SIZE_T < 8
+#define RYU_32_BIT_PLATFORM
+#endif
+
+/*  Returns e == 0 ? 1 : ceil(log_2(5^e)). */
+static inline uint32
+pow5bits(const int32 e)
+{
+	/*
+	 * This approximation works up to the point that the multiplication
+	 * overflows at e = 3529.
+	 *
+	 * If the multiplication were done in 64 bits, it would fail at 5^4004
+	 * which is just greater than 2^9297.
+	 */
+	Assert(e >= 0);
+	Assert(e <= 3528);
+	return ((((uint32) e) * 1217359) >> 19) + 1;
+}
+
+/*  Returns floor(log_10(2^e)). */
+static inline int32
+log10Pow2(const int32 e)
+{
+	/*
+	 * The first value this approximation fails for is 2^1651 which is just
+	 * greater than 10^297.
+	 */
+	Assert(e >= 0);
+	Assert(e <= 1650);
+	return (int32) ((((uint32) e) * 78913) >> 18);
+}
+
+/*  Returns floor(log_10(5^e)). */
+static inline int32
+log10Pow5(const int32 e)
+{
+	/*
+	 * The first value this approximation fails for is 5^2621 which is just
+	 * greater than 10^1832.
+	 */
+	Assert(e >= 0);
+	Assert(e <= 2620);
+	return (int32) ((((uint32) e) * 732923) >> 20);
+}
+
+static inline int
+copy_special_str(char *const result, const bool sign, const bool exponent, const bool mantissa)
+{
+	if (mantissa)
+	{
+		memcpy(result, "NaN", 3);
+		return 3;
+	}
+	if (sign)
+	{
+		result[0] = '-';
+	}
+	if (exponent)
+	{
+		memcpy(result + sign, "Infinity", 8);
+		return sign + 8;
+	}
+	result[sign] = '0';
+	return sign + 1;
+}
+
+static inline uint32
+float_to_bits(const float f)
+{
+	uint32		bits = 0;
+
+	memcpy(&bits, &f, sizeof(float));
+	return bits;
+}
+
+static inline uint64
+double_to_bits(const double d)
+{
+	uint64		bits = 0;
+
+	memcpy(&bits, &d, sizeof(double));
+	return bits;
+}
+
+#endif							/* RYU_COMMON_H */
diff --git a/src/common/saslprep.c b/src/common/saslprep.c
new file mode 100644
index 0000000..8945050
--- /dev/null
+++ b/src/common/saslprep.c
@@ -0,0 +1,1245 @@
+/*-------------------------------------------------------------------------
+ * saslprep.c
+ *		SASLprep normalization, for SCRAM authentication
+ *
+ * The SASLprep algorithm is used to process a user-supplied password into
+ * canonical form.  For more details, see:
+ *
+ * [RFC3454] Preparation of Internationalized Strings ("stringprep"),
+ *	  http://www.ietf.org/rfc/rfc3454.txt
+ *
+ * [RFC4013] SASLprep: Stringprep Profile for User Names and Passwords
+ *	  http://www.ietf.org/rfc/rfc4013.txt
+ *
+ *
+ * Portions Copyright (c) 2017-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/saslprep.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/saslprep.h"
+#include "common/string.h"
+#include "common/unicode_norm.h"
+#include "mb/pg_wchar.h"
+
+/*
+ * In backend, we will use palloc/pfree.  In frontend, use malloc, and
+ * return SASLPREP_OOM on out-of-memory.
+ */
+#ifndef FRONTEND
+#define STRDUP(s) pstrdup(s)
+#define ALLOC(size) palloc(size)
+#define FREE(size) pfree(size)
+#else
+#define STRDUP(s) strdup(s)
+#define ALLOC(size) malloc(size)
+#define FREE(size) free(size)
+#endif
+
+/* Prototypes for local functions */
+static int	codepoint_range_cmp(const void *a, const void *b);
+static bool is_code_in_table(pg_wchar code, const pg_wchar *map, int mapsize);
+static int	pg_utf8_string_len(const char *source);
+
+/*
+ * Stringprep Mapping Tables.
+ *
+ * The stringprep specification includes a number of tables of Unicode
+ * codepoints, used in different parts of the algorithm.  They are below,
+ * as arrays of codepoint ranges.  Each range is a pair of codepoints,
+ * for the first and last codepoint included the range (inclusive!).
+ */
+
+/*
+ * C.1.2 Non-ASCII space characters
+ *
+ * These are all mapped to the ASCII space character (U+00A0).
+ */
+static const pg_wchar non_ascii_space_ranges[] =
+{
+	0x00A0, 0x00A0,
+	0x1680, 0x1680,
+	0x2000, 0x200B,
+	0x202F, 0x202F,
+	0x205F, 0x205F,
+	0x3000, 0x3000
+};
+
+/*
+ * B.1 Commonly mapped to nothing
+ *
+ * If any of these appear in the input, they are removed.
+ */
+static const pg_wchar commonly_mapped_to_nothing_ranges[] =
+{
+	0x00AD, 0x00AD,
+	0x034F, 0x034F,
+	0x1806, 0x1806,
+	0x180B, 0x180D,
+	0x200B, 0x200D,
+	0x2060, 0x2060,
+	0xFE00, 0xFE0F,
+	0xFEFF, 0xFEFF
+};
+
+/*
+ * prohibited_output_ranges is a union of all the characters from
+ * the following tables:
+ *
+ * C.1.2 Non-ASCII space characters
+ * C.2.1 ASCII control characters
+ * C.2.2 Non-ASCII control characters
+ * C.3 Private Use characters
+ * C.4 Non-character code points
+ * C.5 Surrogate code points
+ * C.6 Inappropriate for plain text characters
+ * C.7 Inappropriate for canonical representation characters
+ * C.7 Change display properties or deprecated characters
+ * C.8 Tagging characters
+ *
+ * These are the tables that are listed as "prohibited output"
+ * characters in the SASLprep profile.
+ *
+ * The comment after each code range indicates which source table
+ * the code came from.  Note that there is some overlap in the source
+ * tables, so one code might originate from multiple source tables.
+ * Adjacent ranges have also been merged together, to save space.
+ */
+static const pg_wchar prohibited_output_ranges[] =
+{
+	0x0000, 0x001F,				/* C.2.1 */
+	0x007F, 0x00A0,				/* C.1.2, C.2.1, C.2.2 */
+	0x0340, 0x0341,				/* C.8 */
+	0x06DD, 0x06DD,				/* C.2.2 */
+	0x070F, 0x070F,				/* C.2.2 */
+	0x1680, 0x1680,				/* C.1.2 */
+	0x180E, 0x180E,				/* C.2.2 */
+	0x2000, 0x200F,				/* C.1.2, C.2.2, C.8 */
+	0x2028, 0x202F,				/* C.1.2, C.2.2, C.8 */
+	0x205F, 0x2063,				/* C.1.2, C.2.2 */
+	0x206A, 0x206F,				/* C.2.2, C.8 */
+	0x2FF0, 0x2FFB,				/* C.7 */
+	0x3000, 0x3000,				/* C.1.2 */
+	0xD800, 0xF8FF,				/* C.3, C.5 */
+	0xFDD0, 0xFDEF,				/* C.4 */
+	0xFEFF, 0xFEFF,				/* C.2.2 */
+	0xFFF9, 0xFFFF,				/* C.2.2, C.4, C.6 */
+	0x1D173, 0x1D17A,			/* C.2.2 */
+	0x1FFFE, 0x1FFFF,			/* C.4 */
+	0x2FFFE, 0x2FFFF,			/* C.4 */
+	0x3FFFE, 0x3FFFF,			/* C.4 */
+	0x4FFFE, 0x4FFFF,			/* C.4 */
+	0x5FFFE, 0x5FFFF,			/* C.4 */
+	0x6FFFE, 0x6FFFF,			/* C.4 */
+	0x7FFFE, 0x7FFFF,			/* C.4 */
+	0x8FFFE, 0x8FFFF,			/* C.4 */
+	0x9FFFE, 0x9FFFF,			/* C.4 */
+	0xAFFFE, 0xAFFFF,			/* C.4 */
+	0xBFFFE, 0xBFFFF,			/* C.4 */
+	0xCFFFE, 0xCFFFF,			/* C.4 */
+	0xDFFFE, 0xDFFFF,			/* C.4 */
+	0xE0001, 0xE0001,			/* C.9 */
+	0xE0020, 0xE007F,			/* C.9 */
+	0xEFFFE, 0xEFFFF,			/* C.4 */
+	0xF0000, 0xFFFFF,			/* C.3, C.4 */
+	0x100000, 0x10FFFF			/* C.3, C.4 */
+};
+
+/* A.1 Unassigned code points in Unicode 3.2 */
+static const pg_wchar unassigned_codepoint_ranges[] =
+{
+	0x0221, 0x0221,
+	0x0234, 0x024F,
+	0x02AE, 0x02AF,
+	0x02EF, 0x02FF,
+	0x0350, 0x035F,
+	0x0370, 0x0373,
+	0x0376, 0x0379,
+	0x037B, 0x037D,
+	0x037F, 0x0383,
+	0x038B, 0x038B,
+	0x038D, 0x038D,
+	0x03A2, 0x03A2,
+	0x03CF, 0x03CF,
+	0x03F7, 0x03FF,
+	0x0487, 0x0487,
+	0x04CF, 0x04CF,
+	0x04F6, 0x04F7,
+	0x04FA, 0x04FF,
+	0x0510, 0x0530,
+	0x0557, 0x0558,
+	0x0560, 0x0560,
+	0x0588, 0x0588,
+	0x058B, 0x0590,
+	0x05A2, 0x05A2,
+	0x05BA, 0x05BA,
+	0x05C5, 0x05CF,
+	0x05EB, 0x05EF,
+	0x05F5, 0x060B,
+	0x060D, 0x061A,
+	0x061C, 0x061E,
+	0x0620, 0x0620,
+	0x063B, 0x063F,
+	0x0656, 0x065F,
+	0x06EE, 0x06EF,
+	0x06FF, 0x06FF,
+	0x070E, 0x070E,
+	0x072D, 0x072F,
+	0x074B, 0x077F,
+	0x07B2, 0x0900,
+	0x0904, 0x0904,
+	0x093A, 0x093B,
+	0x094E, 0x094F,
+	0x0955, 0x0957,
+	0x0971, 0x0980,
+	0x0984, 0x0984,
+	0x098D, 0x098E,
+	0x0991, 0x0992,
+	0x09A9, 0x09A9,
+	0x09B1, 0x09B1,
+	0x09B3, 0x09B5,
+	0x09BA, 0x09BB,
+	0x09BD, 0x09BD,
+	0x09C5, 0x09C6,
+	0x09C9, 0x09CA,
+	0x09CE, 0x09D6,
+	0x09D8, 0x09DB,
+	0x09DE, 0x09DE,
+	0x09E4, 0x09E5,
+	0x09FB, 0x0A01,
+	0x0A03, 0x0A04,
+	0x0A0B, 0x0A0E,
+	0x0A11, 0x0A12,
+	0x0A29, 0x0A29,
+	0x0A31, 0x0A31,
+	0x0A34, 0x0A34,
+	0x0A37, 0x0A37,
+	0x0A3A, 0x0A3B,
+	0x0A3D, 0x0A3D,
+	0x0A43, 0x0A46,
+	0x0A49, 0x0A4A,
+	0x0A4E, 0x0A58,
+	0x0A5D, 0x0A5D,
+	0x0A5F, 0x0A65,
+	0x0A75, 0x0A80,
+	0x0A84, 0x0A84,
+	0x0A8C, 0x0A8C,
+	0x0A8E, 0x0A8E,
+	0x0A92, 0x0A92,
+	0x0AA9, 0x0AA9,
+	0x0AB1, 0x0AB1,
+	0x0AB4, 0x0AB4,
+	0x0ABA, 0x0ABB,
+	0x0AC6, 0x0AC6,
+	0x0ACA, 0x0ACA,
+	0x0ACE, 0x0ACF,
+	0x0AD1, 0x0ADF,
+	0x0AE1, 0x0AE5,
+	0x0AF0, 0x0B00,
+	0x0B04, 0x0B04,
+	0x0B0D, 0x0B0E,
+	0x0B11, 0x0B12,
+	0x0B29, 0x0B29,
+	0x0B31, 0x0B31,
+	0x0B34, 0x0B35,
+	0x0B3A, 0x0B3B,
+	0x0B44, 0x0B46,
+	0x0B49, 0x0B4A,
+	0x0B4E, 0x0B55,
+	0x0B58, 0x0B5B,
+	0x0B5E, 0x0B5E,
+	0x0B62, 0x0B65,
+	0x0B71, 0x0B81,
+	0x0B84, 0x0B84,
+	0x0B8B, 0x0B8D,
+	0x0B91, 0x0B91,
+	0x0B96, 0x0B98,
+	0x0B9B, 0x0B9B,
+	0x0B9D, 0x0B9D,
+	0x0BA0, 0x0BA2,
+	0x0BA5, 0x0BA7,
+	0x0BAB, 0x0BAD,
+	0x0BB6, 0x0BB6,
+	0x0BBA, 0x0BBD,
+	0x0BC3, 0x0BC5,
+	0x0BC9, 0x0BC9,
+	0x0BCE, 0x0BD6,
+	0x0BD8, 0x0BE6,
+	0x0BF3, 0x0C00,
+	0x0C04, 0x0C04,
+	0x0C0D, 0x0C0D,
+	0x0C11, 0x0C11,
+	0x0C29, 0x0C29,
+	0x0C34, 0x0C34,
+	0x0C3A, 0x0C3D,
+	0x0C45, 0x0C45,
+	0x0C49, 0x0C49,
+	0x0C4E, 0x0C54,
+	0x0C57, 0x0C5F,
+	0x0C62, 0x0C65,
+	0x0C70, 0x0C81,
+	0x0C84, 0x0C84,
+	0x0C8D, 0x0C8D,
+	0x0C91, 0x0C91,
+	0x0CA9, 0x0CA9,
+	0x0CB4, 0x0CB4,
+	0x0CBA, 0x0CBD,
+	0x0CC5, 0x0CC5,
+	0x0CC9, 0x0CC9,
+	0x0CCE, 0x0CD4,
+	0x0CD7, 0x0CDD,
+	0x0CDF, 0x0CDF,
+	0x0CE2, 0x0CE5,
+	0x0CF0, 0x0D01,
+	0x0D04, 0x0D04,
+	0x0D0D, 0x0D0D,
+	0x0D11, 0x0D11,
+	0x0D29, 0x0D29,
+	0x0D3A, 0x0D3D,
+	0x0D44, 0x0D45,
+	0x0D49, 0x0D49,
+	0x0D4E, 0x0D56,
+	0x0D58, 0x0D5F,
+	0x0D62, 0x0D65,
+	0x0D70, 0x0D81,
+	0x0D84, 0x0D84,
+	0x0D97, 0x0D99,
+	0x0DB2, 0x0DB2,
+	0x0DBC, 0x0DBC,
+	0x0DBE, 0x0DBF,
+	0x0DC7, 0x0DC9,
+	0x0DCB, 0x0DCE,
+	0x0DD5, 0x0DD5,
+	0x0DD7, 0x0DD7,
+	0x0DE0, 0x0DF1,
+	0x0DF5, 0x0E00,
+	0x0E3B, 0x0E3E,
+	0x0E5C, 0x0E80,
+	0x0E83, 0x0E83,
+	0x0E85, 0x0E86,
+	0x0E89, 0x0E89,
+	0x0E8B, 0x0E8C,
+	0x0E8E, 0x0E93,
+	0x0E98, 0x0E98,
+	0x0EA0, 0x0EA0,
+	0x0EA4, 0x0EA4,
+	0x0EA6, 0x0EA6,
+	0x0EA8, 0x0EA9,
+	0x0EAC, 0x0EAC,
+	0x0EBA, 0x0EBA,
+	0x0EBE, 0x0EBF,
+	0x0EC5, 0x0EC5,
+	0x0EC7, 0x0EC7,
+	0x0ECE, 0x0ECF,
+	0x0EDA, 0x0EDB,
+	0x0EDE, 0x0EFF,
+	0x0F48, 0x0F48,
+	0x0F6B, 0x0F70,
+	0x0F8C, 0x0F8F,
+	0x0F98, 0x0F98,
+	0x0FBD, 0x0FBD,
+	0x0FCD, 0x0FCE,
+	0x0FD0, 0x0FFF,
+	0x1022, 0x1022,
+	0x1028, 0x1028,
+	0x102B, 0x102B,
+	0x1033, 0x1035,
+	0x103A, 0x103F,
+	0x105A, 0x109F,
+	0x10C6, 0x10CF,
+	0x10F9, 0x10FA,
+	0x10FC, 0x10FF,
+	0x115A, 0x115E,
+	0x11A3, 0x11A7,
+	0x11FA, 0x11FF,
+	0x1207, 0x1207,
+	0x1247, 0x1247,
+	0x1249, 0x1249,
+	0x124E, 0x124F,
+	0x1257, 0x1257,
+	0x1259, 0x1259,
+	0x125E, 0x125F,
+	0x1287, 0x1287,
+	0x1289, 0x1289,
+	0x128E, 0x128F,
+	0x12AF, 0x12AF,
+	0x12B1, 0x12B1,
+	0x12B6, 0x12B7,
+	0x12BF, 0x12BF,
+	0x12C1, 0x12C1,
+	0x12C6, 0x12C7,
+	0x12CF, 0x12CF,
+	0x12D7, 0x12D7,
+	0x12EF, 0x12EF,
+	0x130F, 0x130F,
+	0x1311, 0x1311,
+	0x1316, 0x1317,
+	0x131F, 0x131F,
+	0x1347, 0x1347,
+	0x135B, 0x1360,
+	0x137D, 0x139F,
+	0x13F5, 0x1400,
+	0x1677, 0x167F,
+	0x169D, 0x169F,
+	0x16F1, 0x16FF,
+	0x170D, 0x170D,
+	0x1715, 0x171F,
+	0x1737, 0x173F,
+	0x1754, 0x175F,
+	0x176D, 0x176D,
+	0x1771, 0x1771,
+	0x1774, 0x177F,
+	0x17DD, 0x17DF,
+	0x17EA, 0x17FF,
+	0x180F, 0x180F,
+	0x181A, 0x181F,
+	0x1878, 0x187F,
+	0x18AA, 0x1DFF,
+	0x1E9C, 0x1E9F,
+	0x1EFA, 0x1EFF,
+	0x1F16, 0x1F17,
+	0x1F1E, 0x1F1F,
+	0x1F46, 0x1F47,
+	0x1F4E, 0x1F4F,
+	0x1F58, 0x1F58,
+	0x1F5A, 0x1F5A,
+	0x1F5C, 0x1F5C,
+	0x1F5E, 0x1F5E,
+	0x1F7E, 0x1F7F,
+	0x1FB5, 0x1FB5,
+	0x1FC5, 0x1FC5,
+	0x1FD4, 0x1FD5,
+	0x1FDC, 0x1FDC,
+	0x1FF0, 0x1FF1,
+	0x1FF5, 0x1FF5,
+	0x1FFF, 0x1FFF,
+	0x2053, 0x2056,
+	0x2058, 0x205E,
+	0x2064, 0x2069,
+	0x2072, 0x2073,
+	0x208F, 0x209F,
+	0x20B2, 0x20CF,
+	0x20EB, 0x20FF,
+	0x213B, 0x213C,
+	0x214C, 0x2152,
+	0x2184, 0x218F,
+	0x23CF, 0x23FF,
+	0x2427, 0x243F,
+	0x244B, 0x245F,
+	0x24FF, 0x24FF,
+	0x2614, 0x2615,
+	0x2618, 0x2618,
+	0x267E, 0x267F,
+	0x268A, 0x2700,
+	0x2705, 0x2705,
+	0x270A, 0x270B,
+	0x2728, 0x2728,
+	0x274C, 0x274C,
+	0x274E, 0x274E,
+	0x2753, 0x2755,
+	0x2757, 0x2757,
+	0x275F, 0x2760,
+	0x2795, 0x2797,
+	0x27B0, 0x27B0,
+	0x27BF, 0x27CF,
+	0x27EC, 0x27EF,
+	0x2B00, 0x2E7F,
+	0x2E9A, 0x2E9A,
+	0x2EF4, 0x2EFF,
+	0x2FD6, 0x2FEF,
+	0x2FFC, 0x2FFF,
+	0x3040, 0x3040,
+	0x3097, 0x3098,
+	0x3100, 0x3104,
+	0x312D, 0x3130,
+	0x318F, 0x318F,
+	0x31B8, 0x31EF,
+	0x321D, 0x321F,
+	0x3244, 0x3250,
+	0x327C, 0x327E,
+	0x32CC, 0x32CF,
+	0x32FF, 0x32FF,
+	0x3377, 0x337A,
+	0x33DE, 0x33DF,
+	0x33FF, 0x33FF,
+	0x4DB6, 0x4DFF,
+	0x9FA6, 0x9FFF,
+	0xA48D, 0xA48F,
+	0xA4C7, 0xABFF,
+	0xD7A4, 0xD7FF,
+	0xFA2E, 0xFA2F,
+	0xFA6B, 0xFAFF,
+	0xFB07, 0xFB12,
+	0xFB18, 0xFB1C,
+	0xFB37, 0xFB37,
+	0xFB3D, 0xFB3D,
+	0xFB3F, 0xFB3F,
+	0xFB42, 0xFB42,
+	0xFB45, 0xFB45,
+	0xFBB2, 0xFBD2,
+	0xFD40, 0xFD4F,
+	0xFD90, 0xFD91,
+	0xFDC8, 0xFDCF,
+	0xFDFD, 0xFDFF,
+	0xFE10, 0xFE1F,
+	0xFE24, 0xFE2F,
+	0xFE47, 0xFE48,
+	0xFE53, 0xFE53,
+	0xFE67, 0xFE67,
+	0xFE6C, 0xFE6F,
+	0xFE75, 0xFE75,
+	0xFEFD, 0xFEFE,
+	0xFF00, 0xFF00,
+	0xFFBF, 0xFFC1,
+	0xFFC8, 0xFFC9,
+	0xFFD0, 0xFFD1,
+	0xFFD8, 0xFFD9,
+	0xFFDD, 0xFFDF,
+	0xFFE7, 0xFFE7,
+	0xFFEF, 0xFFF8,
+	0x10000, 0x102FF,
+	0x1031F, 0x1031F,
+	0x10324, 0x1032F,
+	0x1034B, 0x103FF,
+	0x10426, 0x10427,
+	0x1044E, 0x1CFFF,
+	0x1D0F6, 0x1D0FF,
+	0x1D127, 0x1D129,
+	0x1D1DE, 0x1D3FF,
+	0x1D455, 0x1D455,
+	0x1D49D, 0x1D49D,
+	0x1D4A0, 0x1D4A1,
+	0x1D4A3, 0x1D4A4,
+	0x1D4A7, 0x1D4A8,
+	0x1D4AD, 0x1D4AD,
+	0x1D4BA, 0x1D4BA,
+	0x1D4BC, 0x1D4BC,
+	0x1D4C1, 0x1D4C1,
+	0x1D4C4, 0x1D4C4,
+	0x1D506, 0x1D506,
+	0x1D50B, 0x1D50C,
+	0x1D515, 0x1D515,
+	0x1D51D, 0x1D51D,
+	0x1D53A, 0x1D53A,
+	0x1D53F, 0x1D53F,
+	0x1D545, 0x1D545,
+	0x1D547, 0x1D549,
+	0x1D551, 0x1D551,
+	0x1D6A4, 0x1D6A7,
+	0x1D7CA, 0x1D7CD,
+	0x1D800, 0x1FFFD,
+	0x2A6D7, 0x2F7FF,
+	0x2FA1E, 0x2FFFD,
+	0x30000, 0x3FFFD,
+	0x40000, 0x4FFFD,
+	0x50000, 0x5FFFD,
+	0x60000, 0x6FFFD,
+	0x70000, 0x7FFFD,
+	0x80000, 0x8FFFD,
+	0x90000, 0x9FFFD,
+	0xA0000, 0xAFFFD,
+	0xB0000, 0xBFFFD,
+	0xC0000, 0xCFFFD,
+	0xD0000, 0xDFFFD,
+	0xE0000, 0xE0000,
+	0xE0002, 0xE001F,
+	0xE0080, 0xEFFFD
+};
+
+/* D.1 Characters with bidirectional property "R" or "AL" */
+static const pg_wchar RandALCat_codepoint_ranges[] =
+{
+	0x05BE, 0x05BE,
+	0x05C0, 0x05C0,
+	0x05C3, 0x05C3,
+	0x05D0, 0x05EA,
+	0x05F0, 0x05F4,
+	0x061B, 0x061B,
+	0x061F, 0x061F,
+	0x0621, 0x063A,
+	0x0640, 0x064A,
+	0x066D, 0x066F,
+	0x0671, 0x06D5,
+	0x06DD, 0x06DD,
+	0x06E5, 0x06E6,
+	0x06FA, 0x06FE,
+	0x0700, 0x070D,
+	0x0710, 0x0710,
+	0x0712, 0x072C,
+	0x0780, 0x07A5,
+	0x07B1, 0x07B1,
+	0x200F, 0x200F,
+	0xFB1D, 0xFB1D,
+	0xFB1F, 0xFB28,
+	0xFB2A, 0xFB36,
+	0xFB38, 0xFB3C,
+	0xFB3E, 0xFB3E,
+	0xFB40, 0xFB41,
+	0xFB43, 0xFB44,
+	0xFB46, 0xFBB1,
+	0xFBD3, 0xFD3D,
+	0xFD50, 0xFD8F,
+	0xFD92, 0xFDC7,
+	0xFDF0, 0xFDFC,
+	0xFE70, 0xFE74,
+	0xFE76, 0xFEFC
+};
+
+/* D.2 Characters with bidirectional property "L" */
+static const pg_wchar LCat_codepoint_ranges[] =
+{
+	0x0041, 0x005A,
+	0x0061, 0x007A,
+	0x00AA, 0x00AA,
+	0x00B5, 0x00B5,
+	0x00BA, 0x00BA,
+	0x00C0, 0x00D6,
+	0x00D8, 0x00F6,
+	0x00F8, 0x0220,
+	0x0222, 0x0233,
+	0x0250, 0x02AD,
+	0x02B0, 0x02B8,
+	0x02BB, 0x02C1,
+	0x02D0, 0x02D1,
+	0x02E0, 0x02E4,
+	0x02EE, 0x02EE,
+	0x037A, 0x037A,
+	0x0386, 0x0386,
+	0x0388, 0x038A,
+	0x038C, 0x038C,
+	0x038E, 0x03A1,
+	0x03A3, 0x03CE,
+	0x03D0, 0x03F5,
+	0x0400, 0x0482,
+	0x048A, 0x04CE,
+	0x04D0, 0x04F5,
+	0x04F8, 0x04F9,
+	0x0500, 0x050F,
+	0x0531, 0x0556,
+	0x0559, 0x055F,
+	0x0561, 0x0587,
+	0x0589, 0x0589,
+	0x0903, 0x0903,
+	0x0905, 0x0939,
+	0x093D, 0x0940,
+	0x0949, 0x094C,
+	0x0950, 0x0950,
+	0x0958, 0x0961,
+	0x0964, 0x0970,
+	0x0982, 0x0983,
+	0x0985, 0x098C,
+	0x098F, 0x0990,
+	0x0993, 0x09A8,
+	0x09AA, 0x09B0,
+	0x09B2, 0x09B2,
+	0x09B6, 0x09B9,
+	0x09BE, 0x09C0,
+	0x09C7, 0x09C8,
+	0x09CB, 0x09CC,
+	0x09D7, 0x09D7,
+	0x09DC, 0x09DD,
+	0x09DF, 0x09E1,
+	0x09E6, 0x09F1,
+	0x09F4, 0x09FA,
+	0x0A05, 0x0A0A,
+	0x0A0F, 0x0A10,
+	0x0A13, 0x0A28,
+	0x0A2A, 0x0A30,
+	0x0A32, 0x0A33,
+	0x0A35, 0x0A36,
+	0x0A38, 0x0A39,
+	0x0A3E, 0x0A40,
+	0x0A59, 0x0A5C,
+	0x0A5E, 0x0A5E,
+	0x0A66, 0x0A6F,
+	0x0A72, 0x0A74,
+	0x0A83, 0x0A83,
+	0x0A85, 0x0A8B,
+	0x0A8D, 0x0A8D,
+	0x0A8F, 0x0A91,
+	0x0A93, 0x0AA8,
+	0x0AAA, 0x0AB0,
+	0x0AB2, 0x0AB3,
+	0x0AB5, 0x0AB9,
+	0x0ABD, 0x0AC0,
+	0x0AC9, 0x0AC9,
+	0x0ACB, 0x0ACC,
+	0x0AD0, 0x0AD0,
+	0x0AE0, 0x0AE0,
+	0x0AE6, 0x0AEF,
+	0x0B02, 0x0B03,
+	0x0B05, 0x0B0C,
+	0x0B0F, 0x0B10,
+	0x0B13, 0x0B28,
+	0x0B2A, 0x0B30,
+	0x0B32, 0x0B33,
+	0x0B36, 0x0B39,
+	0x0B3D, 0x0B3E,
+	0x0B40, 0x0B40,
+	0x0B47, 0x0B48,
+	0x0B4B, 0x0B4C,
+	0x0B57, 0x0B57,
+	0x0B5C, 0x0B5D,
+	0x0B5F, 0x0B61,
+	0x0B66, 0x0B70,
+	0x0B83, 0x0B83,
+	0x0B85, 0x0B8A,
+	0x0B8E, 0x0B90,
+	0x0B92, 0x0B95,
+	0x0B99, 0x0B9A,
+	0x0B9C, 0x0B9C,
+	0x0B9E, 0x0B9F,
+	0x0BA3, 0x0BA4,
+	0x0BA8, 0x0BAA,
+	0x0BAE, 0x0BB5,
+	0x0BB7, 0x0BB9,
+	0x0BBE, 0x0BBF,
+	0x0BC1, 0x0BC2,
+	0x0BC6, 0x0BC8,
+	0x0BCA, 0x0BCC,
+	0x0BD7, 0x0BD7,
+	0x0BE7, 0x0BF2,
+	0x0C01, 0x0C03,
+	0x0C05, 0x0C0C,
+	0x0C0E, 0x0C10,
+	0x0C12, 0x0C28,
+	0x0C2A, 0x0C33,
+	0x0C35, 0x0C39,
+	0x0C41, 0x0C44,
+	0x0C60, 0x0C61,
+	0x0C66, 0x0C6F,
+	0x0C82, 0x0C83,
+	0x0C85, 0x0C8C,
+	0x0C8E, 0x0C90,
+	0x0C92, 0x0CA8,
+	0x0CAA, 0x0CB3,
+	0x0CB5, 0x0CB9,
+	0x0CBE, 0x0CBE,
+	0x0CC0, 0x0CC4,
+	0x0CC7, 0x0CC8,
+	0x0CCA, 0x0CCB,
+	0x0CD5, 0x0CD6,
+	0x0CDE, 0x0CDE,
+	0x0CE0, 0x0CE1,
+	0x0CE6, 0x0CEF,
+	0x0D02, 0x0D03,
+	0x0D05, 0x0D0C,
+	0x0D0E, 0x0D10,
+	0x0D12, 0x0D28,
+	0x0D2A, 0x0D39,
+	0x0D3E, 0x0D40,
+	0x0D46, 0x0D48,
+	0x0D4A, 0x0D4C,
+	0x0D57, 0x0D57,
+	0x0D60, 0x0D61,
+	0x0D66, 0x0D6F,
+	0x0D82, 0x0D83,
+	0x0D85, 0x0D96,
+	0x0D9A, 0x0DB1,
+	0x0DB3, 0x0DBB,
+	0x0DBD, 0x0DBD,
+	0x0DC0, 0x0DC6,
+	0x0DCF, 0x0DD1,
+	0x0DD8, 0x0DDF,
+	0x0DF2, 0x0DF4,
+	0x0E01, 0x0E30,
+	0x0E32, 0x0E33,
+	0x0E40, 0x0E46,
+	0x0E4F, 0x0E5B,
+	0x0E81, 0x0E82,
+	0x0E84, 0x0E84,
+	0x0E87, 0x0E88,
+	0x0E8A, 0x0E8A,
+	0x0E8D, 0x0E8D,
+	0x0E94, 0x0E97,
+	0x0E99, 0x0E9F,
+	0x0EA1, 0x0EA3,
+	0x0EA5, 0x0EA5,
+	0x0EA7, 0x0EA7,
+	0x0EAA, 0x0EAB,
+	0x0EAD, 0x0EB0,
+	0x0EB2, 0x0EB3,
+	0x0EBD, 0x0EBD,
+	0x0EC0, 0x0EC4,
+	0x0EC6, 0x0EC6,
+	0x0ED0, 0x0ED9,
+	0x0EDC, 0x0EDD,
+	0x0F00, 0x0F17,
+	0x0F1A, 0x0F34,
+	0x0F36, 0x0F36,
+	0x0F38, 0x0F38,
+	0x0F3E, 0x0F47,
+	0x0F49, 0x0F6A,
+	0x0F7F, 0x0F7F,
+	0x0F85, 0x0F85,
+	0x0F88, 0x0F8B,
+	0x0FBE, 0x0FC5,
+	0x0FC7, 0x0FCC,
+	0x0FCF, 0x0FCF,
+	0x1000, 0x1021,
+	0x1023, 0x1027,
+	0x1029, 0x102A,
+	0x102C, 0x102C,
+	0x1031, 0x1031,
+	0x1038, 0x1038,
+	0x1040, 0x1057,
+	0x10A0, 0x10C5,
+	0x10D0, 0x10F8,
+	0x10FB, 0x10FB,
+	0x1100, 0x1159,
+	0x115F, 0x11A2,
+	0x11A8, 0x11F9,
+	0x1200, 0x1206,
+	0x1208, 0x1246,
+	0x1248, 0x1248,
+	0x124A, 0x124D,
+	0x1250, 0x1256,
+	0x1258, 0x1258,
+	0x125A, 0x125D,
+	0x1260, 0x1286,
+	0x1288, 0x1288,
+	0x128A, 0x128D,
+	0x1290, 0x12AE,
+	0x12B0, 0x12B0,
+	0x12B2, 0x12B5,
+	0x12B8, 0x12BE,
+	0x12C0, 0x12C0,
+	0x12C2, 0x12C5,
+	0x12C8, 0x12CE,
+	0x12D0, 0x12D6,
+	0x12D8, 0x12EE,
+	0x12F0, 0x130E,
+	0x1310, 0x1310,
+	0x1312, 0x1315,
+	0x1318, 0x131E,
+	0x1320, 0x1346,
+	0x1348, 0x135A,
+	0x1361, 0x137C,
+	0x13A0, 0x13F4,
+	0x1401, 0x1676,
+	0x1681, 0x169A,
+	0x16A0, 0x16F0,
+	0x1700, 0x170C,
+	0x170E, 0x1711,
+	0x1720, 0x1731,
+	0x1735, 0x1736,
+	0x1740, 0x1751,
+	0x1760, 0x176C,
+	0x176E, 0x1770,
+	0x1780, 0x17B6,
+	0x17BE, 0x17C5,
+	0x17C7, 0x17C8,
+	0x17D4, 0x17DA,
+	0x17DC, 0x17DC,
+	0x17E0, 0x17E9,
+	0x1810, 0x1819,
+	0x1820, 0x1877,
+	0x1880, 0x18A8,
+	0x1E00, 0x1E9B,
+	0x1EA0, 0x1EF9,
+	0x1F00, 0x1F15,
+	0x1F18, 0x1F1D,
+	0x1F20, 0x1F45,
+	0x1F48, 0x1F4D,
+	0x1F50, 0x1F57,
+	0x1F59, 0x1F59,
+	0x1F5B, 0x1F5B,
+	0x1F5D, 0x1F5D,
+	0x1F5F, 0x1F7D,
+	0x1F80, 0x1FB4,
+	0x1FB6, 0x1FBC,
+	0x1FBE, 0x1FBE,
+	0x1FC2, 0x1FC4,
+	0x1FC6, 0x1FCC,
+	0x1FD0, 0x1FD3,
+	0x1FD6, 0x1FDB,
+	0x1FE0, 0x1FEC,
+	0x1FF2, 0x1FF4,
+	0x1FF6, 0x1FFC,
+	0x200E, 0x200E,
+	0x2071, 0x2071,
+	0x207F, 0x207F,
+	0x2102, 0x2102,
+	0x2107, 0x2107,
+	0x210A, 0x2113,
+	0x2115, 0x2115,
+	0x2119, 0x211D,
+	0x2124, 0x2124,
+	0x2126, 0x2126,
+	0x2128, 0x2128,
+	0x212A, 0x212D,
+	0x212F, 0x2131,
+	0x2133, 0x2139,
+	0x213D, 0x213F,
+	0x2145, 0x2149,
+	0x2160, 0x2183,
+	0x2336, 0x237A,
+	0x2395, 0x2395,
+	0x249C, 0x24E9,
+	0x3005, 0x3007,
+	0x3021, 0x3029,
+	0x3031, 0x3035,
+	0x3038, 0x303C,
+	0x3041, 0x3096,
+	0x309D, 0x309F,
+	0x30A1, 0x30FA,
+	0x30FC, 0x30FF,
+	0x3105, 0x312C,
+	0x3131, 0x318E,
+	0x3190, 0x31B7,
+	0x31F0, 0x321C,
+	0x3220, 0x3243,
+	0x3260, 0x327B,
+	0x327F, 0x32B0,
+	0x32C0, 0x32CB,
+	0x32D0, 0x32FE,
+	0x3300, 0x3376,
+	0x337B, 0x33DD,
+	0x33E0, 0x33FE,
+	0x3400, 0x4DB5,
+	0x4E00, 0x9FA5,
+	0xA000, 0xA48C,
+	0xAC00, 0xD7A3,
+	0xD800, 0xFA2D,
+	0xFA30, 0xFA6A,
+	0xFB00, 0xFB06,
+	0xFB13, 0xFB17,
+	0xFF21, 0xFF3A,
+	0xFF41, 0xFF5A,
+	0xFF66, 0xFFBE,
+	0xFFC2, 0xFFC7,
+	0xFFCA, 0xFFCF,
+	0xFFD2, 0xFFD7,
+	0xFFDA, 0xFFDC,
+	0x10300, 0x1031E,
+	0x10320, 0x10323,
+	0x10330, 0x1034A,
+	0x10400, 0x10425,
+	0x10428, 0x1044D,
+	0x1D000, 0x1D0F5,
+	0x1D100, 0x1D126,
+	0x1D12A, 0x1D166,
+	0x1D16A, 0x1D172,
+	0x1D183, 0x1D184,
+	0x1D18C, 0x1D1A9,
+	0x1D1AE, 0x1D1DD,
+	0x1D400, 0x1D454,
+	0x1D456, 0x1D49C,
+	0x1D49E, 0x1D49F,
+	0x1D4A2, 0x1D4A2,
+	0x1D4A5, 0x1D4A6,
+	0x1D4A9, 0x1D4AC,
+	0x1D4AE, 0x1D4B9,
+	0x1D4BB, 0x1D4BB,
+	0x1D4BD, 0x1D4C0,
+	0x1D4C2, 0x1D4C3,
+	0x1D4C5, 0x1D505,
+	0x1D507, 0x1D50A,
+	0x1D50D, 0x1D514,
+	0x1D516, 0x1D51C,
+	0x1D51E, 0x1D539,
+	0x1D53B, 0x1D53E,
+	0x1D540, 0x1D544,
+	0x1D546, 0x1D546,
+	0x1D54A, 0x1D550,
+	0x1D552, 0x1D6A3,
+	0x1D6A8, 0x1D7C9,
+	0x20000, 0x2A6D6,
+	0x2F800, 0x2FA1D,
+	0xF0000, 0xFFFFD,
+	0x100000, 0x10FFFD
+};
+
+/* End of stringprep tables */
+
+
+/* Is the given Unicode codepoint in the given table of ranges? */
+#define IS_CODE_IN_TABLE(code, map) is_code_in_table(code, map, lengthof(map))
+
+static int
+codepoint_range_cmp(const void *a, const void *b)
+{
+	const pg_wchar *key = (const pg_wchar *) a;
+	const pg_wchar *range = (const pg_wchar *) b;
+
+	if (*key < range[0])
+		return -1;				/* less than lower bound */
+	if (*key > range[1])
+		return 1;				/* greater than upper bound */
+
+	return 0;					/* within range */
+}
+
+static bool
+is_code_in_table(pg_wchar code, const pg_wchar *map, int mapsize)
+{
+	Assert(mapsize % 2 == 0);
+
+	if (code < map[0] || code > map[mapsize - 1])
+		return false;
+
+	if (bsearch(&code, map, mapsize / 2, sizeof(pg_wchar) * 2,
+				codepoint_range_cmp))
+		return true;
+	else
+		return false;
+}
+
+/*
+ * Calculate the length in characters of a null-terminated UTF-8 string.
+ *
+ * Returns -1 if the input is not valid UTF-8.
+ */
+static int
+pg_utf8_string_len(const char *source)
+{
+	const unsigned char *p = (const unsigned char *) source;
+	int			l;
+	int			num_chars = 0;
+
+	while (*p)
+	{
+		l = pg_utf_mblen(p);
+
+		if (!pg_utf8_islegal(p, l))
+			return -1;
+
+		p += l;
+		num_chars++;
+	}
+
+	return num_chars;
+}
+
+
+/*
+ * pg_saslprep - Normalize a password with SASLprep.
+ *
+ * SASLprep requires the input to be in UTF-8 encoding, but PostgreSQL
+ * supports many encodings, so we don't blindly assume that.  pg_saslprep
+ * will check if the input looks like valid UTF-8, and returns
+ * SASLPREP_INVALID_UTF8 if not.
+ *
+ * If the string contains prohibited characters (or more precisely, if the
+ * output string would contain prohibited characters after normalization),
+ * returns SASLPREP_PROHIBITED.
+ *
+ * On success, returns SASLPREP_SUCCESS, and the normalized string in
+ * *output.
+ *
+ * In frontend, the normalized string is malloc'd, and the caller is
+ * responsible for freeing it.  If an allocation fails, returns
+ * SASLPREP_OOM.  In backend, the normalized string is palloc'd instead,
+ * and a failed allocation leads to ereport(ERROR).
+ */
+pg_saslprep_rc
+pg_saslprep(const char *input, char **output)
+{
+	pg_wchar   *input_chars = NULL;
+	pg_wchar   *output_chars = NULL;
+	int			input_size;
+	char	   *result;
+	int			result_size;
+	int			count;
+	int			i;
+	bool		contains_RandALCat;
+	unsigned char *p;
+	pg_wchar   *wp;
+
+	/* Ensure we return *output as NULL on failure */
+	*output = NULL;
+
+	/*
+	 * Quick check if the input is pure ASCII.  An ASCII string requires no
+	 * further processing.
+	 */
+	if (pg_is_ascii(input))
+	{
+		*output = STRDUP(input);
+		if (!(*output))
+			goto oom;
+		return SASLPREP_SUCCESS;
+	}
+
+	/*
+	 * Convert the input from UTF-8 to an array of Unicode codepoints.
+	 *
+	 * This also checks that the input is a legal UTF-8 string.
+	 */
+	input_size = pg_utf8_string_len(input);
+	if (input_size < 0)
+		return SASLPREP_INVALID_UTF8;
+
+	input_chars = ALLOC((input_size + 1) * sizeof(pg_wchar));
+	if (!input_chars)
+		goto oom;
+
+	p = (unsigned char *) input;
+	for (i = 0; i < input_size; i++)
+	{
+		input_chars[i] = utf8_to_unicode(p);
+		p += pg_utf_mblen(p);
+	}
+	input_chars[i] = (pg_wchar) '\0';
+
+	/*
+	 * The steps below correspond to the steps listed in [RFC3454], Section
+	 * "2. Preparation Overview"
+	 */
+
+	/*
+	 * 1) Map -- For each character in the input, check if it has a mapping
+	 * and, if so, replace it with its mapping.
+	 */
+	count = 0;
+	for (i = 0; i < input_size; i++)
+	{
+		pg_wchar	code = input_chars[i];
+
+		if (IS_CODE_IN_TABLE(code, non_ascii_space_ranges))
+			input_chars[count++] = 0x0020;
+		else if (IS_CODE_IN_TABLE(code, commonly_mapped_to_nothing_ranges))
+		{
+			/* map to nothing */
+		}
+		else
+			input_chars[count++] = code;
+	}
+	input_chars[count] = (pg_wchar) '\0';
+	input_size = count;
+
+	if (input_size == 0)
+		goto prohibited;		/* don't allow empty password */
+
+	/*
+	 * 2) Normalize -- Normalize the result of step 1 using Unicode
+	 * normalization.
+	 */
+	output_chars = unicode_normalize(UNICODE_NFKC, input_chars);
+	if (!output_chars)
+		goto oom;
+
+	/*
+	 * 3) Prohibit -- Check for any characters that are not allowed in the
+	 * output.  If any are found, return an error.
+	 */
+	for (i = 0; i < input_size; i++)
+	{
+		pg_wchar	code = input_chars[i];
+
+		if (IS_CODE_IN_TABLE(code, prohibited_output_ranges))
+			goto prohibited;
+		if (IS_CODE_IN_TABLE(code, unassigned_codepoint_ranges))
+			goto prohibited;
+	}
+
+	/*
+	 * 4) Check bidi -- Possibly check for right-to-left characters, and if
+	 * any are found, make sure that the whole string satisfies the
+	 * requirements for bidirectional strings.  If the string does not satisfy
+	 * the requirements for bidirectional strings, return an error.
+	 *
+	 * [RFC3454], Section "6. Bidirectional Characters" explains in more
+	 * detail what that means:
+	 *
+	 * "In any profile that specifies bidirectional character handling, all
+	 * three of the following requirements MUST be met:
+	 *
+	 * 1) The characters in section 5.8 MUST be prohibited.
+	 *
+	 * 2) If a string contains any RandALCat character, the string MUST NOT
+	 * contain any LCat character.
+	 *
+	 * 3) If a string contains any RandALCat character, a RandALCat character
+	 * MUST be the first character of the string, and a RandALCat character
+	 * MUST be the last character of the string."
+	 */
+	contains_RandALCat = false;
+	for (i = 0; i < input_size; i++)
+	{
+		pg_wchar	code = input_chars[i];
+
+		if (IS_CODE_IN_TABLE(code, RandALCat_codepoint_ranges))
+		{
+			contains_RandALCat = true;
+			break;
+		}
+	}
+
+	if (contains_RandALCat)
+	{
+		pg_wchar	first = input_chars[0];
+		pg_wchar	last = input_chars[input_size - 1];
+
+		for (i = 0; i < input_size; i++)
+		{
+			pg_wchar	code = input_chars[i];
+
+			if (IS_CODE_IN_TABLE(code, LCat_codepoint_ranges))
+				goto prohibited;
+		}
+
+		if (!IS_CODE_IN_TABLE(first, RandALCat_codepoint_ranges) ||
+			!IS_CODE_IN_TABLE(last, RandALCat_codepoint_ranges))
+			goto prohibited;
+	}
+
+	/*
+	 * Finally, convert the result back to UTF-8.
+	 */
+	result_size = 0;
+	for (wp = output_chars; *wp; wp++)
+	{
+		unsigned char buf[4];
+
+		unicode_to_utf8(*wp, buf);
+		result_size += pg_utf_mblen(buf);
+	}
+
+	result = ALLOC(result_size + 1);
+	if (!result)
+		goto oom;
+
+	/*
+	 * There are no error exits below here, so the error exit paths don't need
+	 * to worry about possibly freeing "result".
+	 */
+	p = (unsigned char *) result;
+	for (wp = output_chars; *wp; wp++)
+	{
+		unicode_to_utf8(*wp, p);
+		p += pg_utf_mblen(p);
+	}
+	Assert((char *) p == result + result_size);
+	*p = '\0';
+
+	FREE(input_chars);
+	FREE(output_chars);
+
+	*output = result;
+	return SASLPREP_SUCCESS;
+
+prohibited:
+	if (input_chars)
+		FREE(input_chars);
+	if (output_chars)
+		FREE(output_chars);
+
+	return SASLPREP_PROHIBITED;
+
+oom:
+	if (input_chars)
+		FREE(input_chars);
+	if (output_chars)
+		FREE(output_chars);
+
+	return SASLPREP_OOM;
+}
diff --git a/src/common/scram-common.c b/src/common/scram-common.c
new file mode 100644
index 0000000..69a96f6
--- /dev/null
+++ b/src/common/scram-common.c
@@ -0,0 +1,274 @@
+/*-------------------------------------------------------------------------
+ * scram-common.c
+ *		Shared frontend/backend code for SCRAM authentication
+ *
+ * This contains the common low-level functions needed in both frontend and
+ * backend, for implement the Salted Challenge Response Authentication
+ * Mechanism (SCRAM), per IETF's RFC 5802.
+ *
+ * Portions Copyright (c) 2017-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/scram-common.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/base64.h"
+#include "common/hmac.h"
+#include "common/scram-common.h"
+#include "port/pg_bswap.h"
+
+/*
+ * Calculate SaltedPassword.
+ *
+ * The password should already be normalized by SASLprep.  Returns 0 on
+ * success, -1 on failure.
+ */
+int
+scram_SaltedPassword(const char *password,
+					 const char *salt, int saltlen, int iterations,
+					 uint8 *result)
+{
+	int			password_len = strlen(password);
+	uint32		one = pg_hton32(1);
+	int			i,
+				j;
+	uint8		Ui[SCRAM_KEY_LEN];
+	uint8		Ui_prev[SCRAM_KEY_LEN];
+	pg_hmac_ctx *hmac_ctx = pg_hmac_create(PG_SHA256);
+
+	if (hmac_ctx == NULL)
+		return -1;
+
+	/*
+	 * Iterate hash calculation of HMAC entry using given salt.  This is
+	 * essentially PBKDF2 (see RFC2898) with HMAC() as the pseudorandom
+	 * function.
+	 */
+
+	/* First iteration */
+	if (pg_hmac_init(hmac_ctx, (uint8 *) password, password_len) < 0 ||
+		pg_hmac_update(hmac_ctx, (uint8 *) salt, saltlen) < 0 ||
+		pg_hmac_update(hmac_ctx, (uint8 *) &one, sizeof(uint32)) < 0 ||
+		pg_hmac_final(hmac_ctx, Ui_prev, sizeof(Ui_prev)) < 0)
+	{
+		pg_hmac_free(hmac_ctx);
+		return -1;
+	}
+
+	memcpy(result, Ui_prev, SCRAM_KEY_LEN);
+
+	/* Subsequent iterations */
+	for (i = 2; i <= iterations; i++)
+	{
+		if (pg_hmac_init(hmac_ctx, (uint8 *) password, password_len) < 0 ||
+			pg_hmac_update(hmac_ctx, (uint8 *) Ui_prev, SCRAM_KEY_LEN) < 0 ||
+			pg_hmac_final(hmac_ctx, Ui, sizeof(Ui)) < 0)
+		{
+			pg_hmac_free(hmac_ctx);
+			return -1;
+		}
+
+		for (j = 0; j < SCRAM_KEY_LEN; j++)
+			result[j] ^= Ui[j];
+		memcpy(Ui_prev, Ui, SCRAM_KEY_LEN);
+	}
+
+	pg_hmac_free(hmac_ctx);
+	return 0;
+}
+
+
+/*
+ * Calculate SHA-256 hash for a NULL-terminated string. (The NULL terminator is
+ * not included in the hash).  Returns 0 on success, -1 on failure.
+ */
+int
+scram_H(const uint8 *input, int len, uint8 *result)
+{
+	pg_cryptohash_ctx *ctx;
+
+	ctx = pg_cryptohash_create(PG_SHA256);
+	if (ctx == NULL)
+		return -1;
+
+	if (pg_cryptohash_init(ctx) < 0 ||
+		pg_cryptohash_update(ctx, input, len) < 0 ||
+		pg_cryptohash_final(ctx, result, SCRAM_KEY_LEN) < 0)
+	{
+		pg_cryptohash_free(ctx);
+		return -1;
+	}
+
+	pg_cryptohash_free(ctx);
+	return 0;
+}
+
+/*
+ * Calculate ClientKey.  Returns 0 on success, -1 on failure.
+ */
+int
+scram_ClientKey(const uint8 *salted_password, uint8 *result)
+{
+	pg_hmac_ctx *ctx = pg_hmac_create(PG_SHA256);
+
+	if (ctx == NULL)
+		return -1;
+
+	if (pg_hmac_init(ctx, salted_password, SCRAM_KEY_LEN) < 0 ||
+		pg_hmac_update(ctx, (uint8 *) "Client Key", strlen("Client Key")) < 0 ||
+		pg_hmac_final(ctx, result, SCRAM_KEY_LEN) < 0)
+	{
+		pg_hmac_free(ctx);
+		return -1;
+	}
+
+	pg_hmac_free(ctx);
+	return 0;
+}
+
+/*
+ * Calculate ServerKey.  Returns 0 on success, -1 on failure.
+ */
+int
+scram_ServerKey(const uint8 *salted_password, uint8 *result)
+{
+	pg_hmac_ctx *ctx = pg_hmac_create(PG_SHA256);
+
+	if (ctx == NULL)
+		return -1;
+
+	if (pg_hmac_init(ctx, salted_password, SCRAM_KEY_LEN) < 0 ||
+		pg_hmac_update(ctx, (uint8 *) "Server Key", strlen("Server Key")) < 0 ||
+		pg_hmac_final(ctx, result, SCRAM_KEY_LEN) < 0)
+	{
+		pg_hmac_free(ctx);
+		return -1;
+	}
+
+	pg_hmac_free(ctx);
+	return 0;
+}
+
+
+/*
+ * Construct a SCRAM secret, for storing in pg_authid.rolpassword.
+ *
+ * The password should already have been processed with SASLprep, if necessary!
+ *
+ * If iterations is 0, default number of iterations is used.  The result is
+ * palloc'd or malloc'd, so caller is responsible for freeing it.
+ */
+char *
+scram_build_secret(const char *salt, int saltlen, int iterations,
+				   const char *password)
+{
+	uint8		salted_password[SCRAM_KEY_LEN];
+	uint8		stored_key[SCRAM_KEY_LEN];
+	uint8		server_key[SCRAM_KEY_LEN];
+	char	   *result;
+	char	   *p;
+	int			maxlen;
+	int			encoded_salt_len;
+	int			encoded_stored_len;
+	int			encoded_server_len;
+	int			encoded_result;
+
+	if (iterations <= 0)
+		iterations = SCRAM_DEFAULT_ITERATIONS;
+
+	/* Calculate StoredKey and ServerKey */
+	if (scram_SaltedPassword(password, salt, saltlen, iterations,
+							 salted_password) < 0 ||
+		scram_ClientKey(salted_password, stored_key) < 0 ||
+		scram_H(stored_key, SCRAM_KEY_LEN, stored_key) < 0 ||
+		scram_ServerKey(salted_password, server_key) < 0)
+	{
+#ifdef FRONTEND
+		return NULL;
+#else
+		elog(ERROR, "could not calculate stored key and server key");
+#endif
+	}
+
+	/*----------
+	 * The format is:
+	 * SCRAM-SHA-256$<iteration count>:<salt>$<StoredKey>:<ServerKey>
+	 *----------
+	 */
+	encoded_salt_len = pg_b64_enc_len(saltlen);
+	encoded_stored_len = pg_b64_enc_len(SCRAM_KEY_LEN);
+	encoded_server_len = pg_b64_enc_len(SCRAM_KEY_LEN);
+
+	maxlen = strlen("SCRAM-SHA-256") + 1
+		+ 10 + 1				/* iteration count */
+		+ encoded_salt_len + 1	/* Base64-encoded salt */
+		+ encoded_stored_len + 1	/* Base64-encoded StoredKey */
+		+ encoded_server_len + 1;	/* Base64-encoded ServerKey */
+
+#ifdef FRONTEND
+	result = malloc(maxlen);
+	if (!result)
+		return NULL;
+#else
+	result = palloc(maxlen);
+#endif
+
+	p = result + sprintf(result, "SCRAM-SHA-256$%d:", iterations);
+
+	/* salt */
+	encoded_result = pg_b64_encode(salt, saltlen, p, encoded_salt_len);
+	if (encoded_result < 0)
+	{
+#ifdef FRONTEND
+		free(result);
+		return NULL;
+#else
+		elog(ERROR, "could not encode salt");
+#endif
+	}
+	p += encoded_result;
+	*(p++) = '$';
+
+	/* stored key */
+	encoded_result = pg_b64_encode((char *) stored_key, SCRAM_KEY_LEN, p,
+								   encoded_stored_len);
+	if (encoded_result < 0)
+	{
+#ifdef FRONTEND
+		free(result);
+		return NULL;
+#else
+		elog(ERROR, "could not encode stored key");
+#endif
+	}
+
+	p += encoded_result;
+	*(p++) = ':';
+
+	/* server key */
+	encoded_result = pg_b64_encode((char *) server_key, SCRAM_KEY_LEN, p,
+								   encoded_server_len);
+	if (encoded_result < 0)
+	{
+#ifdef FRONTEND
+		free(result);
+		return NULL;
+#else
+		elog(ERROR, "could not encode server key");
+#endif
+	}
+
+	p += encoded_result;
+	*(p++) = '\0';
+
+	Assert(p - result <= maxlen);
+
+	return result;
+}
diff --git a/src/common/sha1.c b/src/common/sha1.c
new file mode 100644
index 0000000..b39173b
--- /dev/null
+++ b/src/common/sha1.c
@@ -0,0 +1,369 @@
+/*-------------------------------------------------------------------------
+ *
+ *	sha1.c
+ *	  Implements the SHA1 Secure Hash Algorithm
+ *
+ * Fallback implementation of SHA1, as specified in RFC 3174.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/sha1.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*	   $KAME: sha1.c,v 1.3 2000/02/22 14:01:18 itojun Exp $    */
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *	  notice, this list of conditions and the following disclaimer in the
+ *	  documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *	  may be used to endorse or promote products derived from this software
+ *	  without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+/*
+ * FIPS pub 180-1: Secure Hash Algorithm (SHA-1)
+ * based on: http://www.itl.nist.gov/fipspubs/fip180-1.htm
+ * implemented by Jun-ichiro itojun Itoh <itojun@itojun.org>
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <sys/param.h>
+
+#include "sha1_int.h"
+
+/* constant table */
+static uint32 _K[] = {0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6};
+
+#define K(t)	_K[(t) / 20]
+
+#define F0(b, c, d) (((b) & (c)) | ((~(b)) & (d)))
+#define F1(b, c, d) (((b) ^ (c)) ^ (d))
+#define F2(b, c, d) (((b) & (c)) | ((b) & (d)) | ((c) & (d)))
+#define F3(b, c, d) (((b) ^ (c)) ^ (d))
+
+#define S(n, x)		(((x) << (n)) | ((x) >> (32 - (n))))
+
+#define H(n)	(ctx->h.b32[(n)])
+#define COUNT	(ctx->count)
+#define BCOUNT	(ctx->c.b64[0] / 8)
+#define W(n)	(ctx->m.b32[(n)])
+
+#define PUTPAD(x) \
+do { \
+	ctx->m.b8[(COUNT % 64)] = (x);		\
+	COUNT++;				\
+	COUNT %= 64;				\
+	if (COUNT % 64 == 0)			\
+		sha1_step(ctx);		\
+} while (0)
+
+static void
+sha1_step(pg_sha1_ctx *ctx)
+{
+	uint32		a,
+				b,
+				c,
+				d,
+				e;
+	size_t		t,
+				s;
+	uint32		tmp;
+
+#ifndef WORDS_BIGENDIAN
+	pg_sha1_ctx tctx;
+
+	memmove(&tctx.m.b8[0], &ctx->m.b8[0], 64);
+	ctx->m.b8[0] = tctx.m.b8[3];
+	ctx->m.b8[1] = tctx.m.b8[2];
+	ctx->m.b8[2] = tctx.m.b8[1];
+	ctx->m.b8[3] = tctx.m.b8[0];
+	ctx->m.b8[4] = tctx.m.b8[7];
+	ctx->m.b8[5] = tctx.m.b8[6];
+	ctx->m.b8[6] = tctx.m.b8[5];
+	ctx->m.b8[7] = tctx.m.b8[4];
+	ctx->m.b8[8] = tctx.m.b8[11];
+	ctx->m.b8[9] = tctx.m.b8[10];
+	ctx->m.b8[10] = tctx.m.b8[9];
+	ctx->m.b8[11] = tctx.m.b8[8];
+	ctx->m.b8[12] = tctx.m.b8[15];
+	ctx->m.b8[13] = tctx.m.b8[14];
+	ctx->m.b8[14] = tctx.m.b8[13];
+	ctx->m.b8[15] = tctx.m.b8[12];
+	ctx->m.b8[16] = tctx.m.b8[19];
+	ctx->m.b8[17] = tctx.m.b8[18];
+	ctx->m.b8[18] = tctx.m.b8[17];
+	ctx->m.b8[19] = tctx.m.b8[16];
+	ctx->m.b8[20] = tctx.m.b8[23];
+	ctx->m.b8[21] = tctx.m.b8[22];
+	ctx->m.b8[22] = tctx.m.b8[21];
+	ctx->m.b8[23] = tctx.m.b8[20];
+	ctx->m.b8[24] = tctx.m.b8[27];
+	ctx->m.b8[25] = tctx.m.b8[26];
+	ctx->m.b8[26] = tctx.m.b8[25];
+	ctx->m.b8[27] = tctx.m.b8[24];
+	ctx->m.b8[28] = tctx.m.b8[31];
+	ctx->m.b8[29] = tctx.m.b8[30];
+	ctx->m.b8[30] = tctx.m.b8[29];
+	ctx->m.b8[31] = tctx.m.b8[28];
+	ctx->m.b8[32] = tctx.m.b8[35];
+	ctx->m.b8[33] = tctx.m.b8[34];
+	ctx->m.b8[34] = tctx.m.b8[33];
+	ctx->m.b8[35] = tctx.m.b8[32];
+	ctx->m.b8[36] = tctx.m.b8[39];
+	ctx->m.b8[37] = tctx.m.b8[38];
+	ctx->m.b8[38] = tctx.m.b8[37];
+	ctx->m.b8[39] = tctx.m.b8[36];
+	ctx->m.b8[40] = tctx.m.b8[43];
+	ctx->m.b8[41] = tctx.m.b8[42];
+	ctx->m.b8[42] = tctx.m.b8[41];
+	ctx->m.b8[43] = tctx.m.b8[40];
+	ctx->m.b8[44] = tctx.m.b8[47];
+	ctx->m.b8[45] = tctx.m.b8[46];
+	ctx->m.b8[46] = tctx.m.b8[45];
+	ctx->m.b8[47] = tctx.m.b8[44];
+	ctx->m.b8[48] = tctx.m.b8[51];
+	ctx->m.b8[49] = tctx.m.b8[50];
+	ctx->m.b8[50] = tctx.m.b8[49];
+	ctx->m.b8[51] = tctx.m.b8[48];
+	ctx->m.b8[52] = tctx.m.b8[55];
+	ctx->m.b8[53] = tctx.m.b8[54];
+	ctx->m.b8[54] = tctx.m.b8[53];
+	ctx->m.b8[55] = tctx.m.b8[52];
+	ctx->m.b8[56] = tctx.m.b8[59];
+	ctx->m.b8[57] = tctx.m.b8[58];
+	ctx->m.b8[58] = tctx.m.b8[57];
+	ctx->m.b8[59] = tctx.m.b8[56];
+	ctx->m.b8[60] = tctx.m.b8[63];
+	ctx->m.b8[61] = tctx.m.b8[62];
+	ctx->m.b8[62] = tctx.m.b8[61];
+	ctx->m.b8[63] = tctx.m.b8[60];
+#endif
+
+	a = H(0);
+	b = H(1);
+	c = H(2);
+	d = H(3);
+	e = H(4);
+
+	for (t = 0; t < 20; t++)
+	{
+		s = t & 0x0f;
+		if (t >= 16)
+			W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));
+		tmp = S(5, a) + F0(b, c, d) + e + W(s) + K(t);
+		e = d;
+		d = c;
+		c = S(30, b);
+		b = a;
+		a = tmp;
+	}
+	for (t = 20; t < 40; t++)
+	{
+		s = t & 0x0f;
+		W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));
+		tmp = S(5, a) + F1(b, c, d) + e + W(s) + K(t);
+		e = d;
+		d = c;
+		c = S(30, b);
+		b = a;
+		a = tmp;
+	}
+	for (t = 40; t < 60; t++)
+	{
+		s = t & 0x0f;
+		W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));
+		tmp = S(5, a) + F2(b, c, d) + e + W(s) + K(t);
+		e = d;
+		d = c;
+		c = S(30, b);
+		b = a;
+		a = tmp;
+	}
+	for (t = 60; t < 80; t++)
+	{
+		s = t & 0x0f;
+		W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));
+		tmp = S(5, a) + F3(b, c, d) + e + W(s) + K(t);
+		e = d;
+		d = c;
+		c = S(30, b);
+		b = a;
+		a = tmp;
+	}
+
+	H(0) = H(0) + a;
+	H(1) = H(1) + b;
+	H(2) = H(2) + c;
+	H(3) = H(3) + d;
+	H(4) = H(4) + e;
+
+	memset(&ctx->m.b8[0], 0, 64);
+}
+
+static void
+sha1_pad(pg_sha1_ctx *ctx)
+{
+	size_t		padlen;			/* pad length in bytes */
+	size_t		padstart;
+
+	PUTPAD(0x80);
+
+	padstart = COUNT % 64;
+	padlen = 64 - padstart;
+	if (padlen < 8)
+	{
+		memset(&ctx->m.b8[padstart], 0, padlen);
+		COUNT += padlen;
+		COUNT %= 64;
+		sha1_step(ctx);
+		padstart = COUNT % 64;	/* should be 0 */
+		padlen = 64 - padstart; /* should be 64 */
+	}
+	memset(&ctx->m.b8[padstart], 0, padlen - 8);
+	COUNT += (padlen - 8);
+	COUNT %= 64;
+#ifdef WORDS_BIGENDIAN
+	PUTPAD(ctx->c.b8[0]);
+	PUTPAD(ctx->c.b8[1]);
+	PUTPAD(ctx->c.b8[2]);
+	PUTPAD(ctx->c.b8[3]);
+	PUTPAD(ctx->c.b8[4]);
+	PUTPAD(ctx->c.b8[5]);
+	PUTPAD(ctx->c.b8[6]);
+	PUTPAD(ctx->c.b8[7]);
+#else
+	PUTPAD(ctx->c.b8[7]);
+	PUTPAD(ctx->c.b8[6]);
+	PUTPAD(ctx->c.b8[5]);
+	PUTPAD(ctx->c.b8[4]);
+	PUTPAD(ctx->c.b8[3]);
+	PUTPAD(ctx->c.b8[2]);
+	PUTPAD(ctx->c.b8[1]);
+	PUTPAD(ctx->c.b8[0]);
+#endif
+}
+
+static void
+sha1_result(uint8 *digest0, pg_sha1_ctx *ctx)
+{
+	uint8	   *digest;
+
+	digest = (uint8 *) digest0;
+
+#ifdef WORDS_BIGENDIAN
+	memmove(digest, &ctx->h.b8[0], 20);
+#else
+	digest[0] = ctx->h.b8[3];
+	digest[1] = ctx->h.b8[2];
+	digest[2] = ctx->h.b8[1];
+	digest[3] = ctx->h.b8[0];
+	digest[4] = ctx->h.b8[7];
+	digest[5] = ctx->h.b8[6];
+	digest[6] = ctx->h.b8[5];
+	digest[7] = ctx->h.b8[4];
+	digest[8] = ctx->h.b8[11];
+	digest[9] = ctx->h.b8[10];
+	digest[10] = ctx->h.b8[9];
+	digest[11] = ctx->h.b8[8];
+	digest[12] = ctx->h.b8[15];
+	digest[13] = ctx->h.b8[14];
+	digest[14] = ctx->h.b8[13];
+	digest[15] = ctx->h.b8[12];
+	digest[16] = ctx->h.b8[19];
+	digest[17] = ctx->h.b8[18];
+	digest[18] = ctx->h.b8[17];
+	digest[19] = ctx->h.b8[16];
+#endif
+}
+
+/* External routines for this SHA1 implementation */
+
+/*
+ * pg_sha1_init
+ *
+ * Initialize a SHA1 context.
+ */
+void
+pg_sha1_init(pg_sha1_ctx *ctx)
+{
+	memset(ctx, 0, sizeof(pg_sha1_ctx));
+	H(0) = 0x67452301;
+	H(1) = 0xefcdab89;
+	H(2) = 0x98badcfe;
+	H(3) = 0x10325476;
+	H(4) = 0xc3d2e1f0;
+}
+
+/*
+ * pg_sha1_update
+ *
+ * Update a SHA1 context.
+ */
+void
+pg_sha1_update(pg_sha1_ctx *ctx, const uint8 *data, size_t len)
+{
+	const uint8 *input;
+	size_t		gaplen;
+	size_t		gapstart;
+	size_t		off;
+	size_t		copysiz;
+
+	input = (const uint8 *) data;
+	off = 0;
+
+	while (off < len)
+	{
+		gapstart = COUNT % 64;
+		gaplen = 64 - gapstart;
+
+		copysiz = (gaplen < len - off) ? gaplen : len - off;
+		memmove(&ctx->m.b8[gapstart], &input[off], copysiz);
+		COUNT += copysiz;
+		COUNT %= 64;
+		ctx->c.b64[0] += copysiz * 8;
+		if (COUNT % 64 == 0)
+			sha1_step(ctx);
+		off += copysiz;
+	}
+}
+
+/*
+ * pg_sha1_final
+ *
+ * Finalize a SHA1 context.
+ */
+void
+pg_sha1_final(pg_sha1_ctx *ctx, uint8 *dest)
+{
+	sha1_pad(ctx);
+	sha1_result(dest, ctx);
+}
diff --git a/src/common/sha1_int.h b/src/common/sha1_int.h
new file mode 100644
index 0000000..1929a2a
--- /dev/null
+++ b/src/common/sha1_int.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * sha1_int.h
+ *	  Internal headers for fallback implementation of SHA1
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *		  src/common/sha1_int.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*	   $KAME: sha1.h,v 1.4 2000/02/22 14:01:18 itojun Exp $    */
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *	  notice, this list of conditions and the following disclaimer in the
+ *	  documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *	  may be used to endorse or promote products derived from this software
+ *	  without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+/*
+ * FIPS pub 180-1: Secure Hash Algorithm (SHA-1)
+ * based on: http://www.itl.nist.gov/fipspubs/fip180-1.htm
+ * implemented by Jun-ichiro itojun Itoh <itojun@itojun.org>
+ */
+
+#ifndef PG_SHA1_INT_H
+#define PG_SHA1_INT_H
+
+#include "common/sha1.h"
+
+typedef struct
+{
+	union
+	{
+		uint8		b8[20];
+		uint32		b32[5];
+	}			h;
+	union
+	{
+		uint8		b8[8];
+		uint64		b64[1];
+	}			c;
+	union
+	{
+		uint8		b8[64];
+		uint32		b32[16];
+	}			m;
+	uint8		count;
+} pg_sha1_ctx;
+
+/* Interface routines for SHA1 */
+extern void pg_sha1_init(pg_sha1_ctx *ctx);
+extern void pg_sha1_update(pg_sha1_ctx *ctx, const uint8 *data, size_t len);
+extern void pg_sha1_final(pg_sha1_ctx *ctx, uint8 *dest);
+
+#endif							/* PG_SHA1_INT_H */
diff --git a/src/common/sha2.c b/src/common/sha2.c
new file mode 100644
index 0000000..ae4936b
--- /dev/null
+++ b/src/common/sha2.c
@@ -0,0 +1,1017 @@
+/*-------------------------------------------------------------------------
+ *
+ * sha2.c
+ *	   SHA functions for SHA-224, SHA-256, SHA-384 and SHA-512.
+ *
+ * This includes the fallback implementation for SHA2 cryptographic
+ * hashes.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/sha2.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*	$OpenBSD: sha2.c,v 1.6 2004/05/03 02:57:36 millert Exp $	*/
+/*
+ * FILE:	sha2.c
+ * AUTHOR:	Aaron D. Gifford <me@aarongifford.com>
+ *
+ * Copyright (c) 2000-2001, Aaron D. Gifford
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *	  notice, this list of conditions and the following disclaimer in the
+ *	  documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of contributors
+ *	  may be used to endorse or promote products derived from this software
+ *	  without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTOR(S) ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTOR(S) BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $From: sha2.c,v 1.1 2001/11/08 00:01:51 adg Exp adg $
+ */
+
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "sha2_int.h"
+
+/*
+ * In backend, use palloc/pfree to ease the error handling.  In frontend,
+ * use malloc to be able to return a failure status back to the caller.
+ */
+#ifndef FRONTEND
+#define ALLOC(size) palloc(size)
+#define FREE(ptr) pfree(ptr)
+#else
+#define ALLOC(size) malloc(size)
+#define FREE(ptr) free(ptr)
+#endif
+
+/*
+ * UNROLLED TRANSFORM LOOP NOTE:
+ * You can define SHA2_UNROLL_TRANSFORM to use the unrolled transform
+ * loop version for the hash transform rounds (defined using macros
+ * later in this file).  Either define on the command line, for example:
+ *
+ *	 cc -DSHA2_UNROLL_TRANSFORM -o sha2 sha2.c sha2prog.c
+ *
+ * or define below:
+ *
+ *	 #define SHA2_UNROLL_TRANSFORM
+ *
+ */
+
+/*** SHA-256/384/512 Various Length Definitions ***********************/
+#define PG_SHA256_SHORT_BLOCK_LENGTH	(PG_SHA256_BLOCK_LENGTH - 8)
+#define PG_SHA384_SHORT_BLOCK_LENGTH	(PG_SHA384_BLOCK_LENGTH - 16)
+#define PG_SHA512_SHORT_BLOCK_LENGTH	(PG_SHA512_BLOCK_LENGTH - 16)
+
+/*** ENDIAN REVERSAL MACROS *******************************************/
+#ifndef WORDS_BIGENDIAN
+#define REVERSE32(w,x)	{ \
+	uint32 tmp = (w); \
+	tmp = (tmp >> 16) | (tmp << 16); \
+	(x) = ((tmp & 0xff00ff00UL) >> 8) | ((tmp & 0x00ff00ffUL) << 8); \
+}
+#define REVERSE64(w,x)	{ \
+	uint64 tmp = (w); \
+	tmp = (tmp >> 32) | (tmp << 32); \
+	tmp = ((tmp & 0xff00ff00ff00ff00ULL) >> 8) | \
+		  ((tmp & 0x00ff00ff00ff00ffULL) << 8); \
+	(x) = ((tmp & 0xffff0000ffff0000ULL) >> 16) | \
+		  ((tmp & 0x0000ffff0000ffffULL) << 16); \
+}
+#endif							/* not bigendian */
+
+/*
+ * Macro for incrementally adding the unsigned 64-bit integer n to the
+ * unsigned 128-bit integer (represented using a two-element array of
+ * 64-bit words):
+ */
+#define ADDINC128(w,n)	{ \
+	(w)[0] += (uint64)(n); \
+	if ((w)[0] < (n)) { \
+		(w)[1]++; \
+	} \
+}
+
+/*** THE SIX LOGICAL FUNCTIONS ****************************************/
+/*
+ * Bit shifting and rotation (used by the six SHA-XYZ logical functions:
+ *
+ *	 NOTE:	The naming of R and S appears backwards here (R is a SHIFT and
+ *	 S is a ROTATION) because the SHA-256/384/512 description document
+ *	 (see http://www.iwar.org.uk/comsec/resources/cipher/sha256-384-512.pdf)
+ *	 uses this same "backwards" definition.
+ */
+/* Shift-right (used in SHA-256, SHA-384, and SHA-512): */
+#define R(b,x)		((x) >> (b))
+/* 32-bit Rotate-right (used in SHA-256): */
+#define S32(b,x)	(((x) >> (b)) | ((x) << (32 - (b))))
+/* 64-bit Rotate-right (used in SHA-384 and SHA-512): */
+#define S64(b,x)	(((x) >> (b)) | ((x) << (64 - (b))))
+
+/* Two of six logical functions used in SHA-256, SHA-384, and SHA-512: */
+#define Ch(x,y,z)	(((x) & (y)) ^ ((~(x)) & (z)))
+#define Maj(x,y,z)	(((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+
+/* Four of six logical functions used in SHA-256: */
+#define Sigma0_256(x)	(S32(2,  (x)) ^ S32(13, (x)) ^ S32(22, (x)))
+#define Sigma1_256(x)	(S32(6,  (x)) ^ S32(11, (x)) ^ S32(25, (x)))
+#define sigma0_256(x)	(S32(7,  (x)) ^ S32(18, (x)) ^ R(3 ,   (x)))
+#define sigma1_256(x)	(S32(17, (x)) ^ S32(19, (x)) ^ R(10,   (x)))
+
+/* Four of six logical functions used in SHA-384 and SHA-512: */
+#define Sigma0_512(x)	(S64(28, (x)) ^ S64(34, (x)) ^ S64(39, (x)))
+#define Sigma1_512(x)	(S64(14, (x)) ^ S64(18, (x)) ^ S64(41, (x)))
+#define sigma0_512(x)	(S64( 1, (x)) ^ S64( 8, (x)) ^ R( 7,   (x)))
+#define sigma1_512(x)	(S64(19, (x)) ^ S64(61, (x)) ^ R( 6,   (x)))
+
+/*** INTERNAL FUNCTION PROTOTYPES *************************************/
+/* NOTE: These should not be accessed directly from outside this
+ * library -- they are intended for private internal visibility/use
+ * only.
+ */
+static void SHA512_Last(pg_sha512_ctx *context);
+static void SHA256_Transform(pg_sha256_ctx *context, const uint8 *data);
+static void SHA512_Transform(pg_sha512_ctx *context, const uint8 *data);
+
+/*** SHA-XYZ INITIAL HASH VALUES AND CONSTANTS ************************/
+/* Hash constant words K for SHA-256: */
+static const uint32 K256[64] = {
+	0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
+	0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
+	0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
+	0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
+	0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
+	0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
+	0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
+	0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,
+	0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
+	0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
+	0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
+	0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
+	0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
+	0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
+	0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
+	0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
+};
+
+/* Initial hash value H for SHA-224: */
+static const uint32 sha224_initial_hash_value[8] = {
+	0xc1059ed8UL,
+	0x367cd507UL,
+	0x3070dd17UL,
+	0xf70e5939UL,
+	0xffc00b31UL,
+	0x68581511UL,
+	0x64f98fa7UL,
+	0xbefa4fa4UL
+};
+
+/* Initial hash value H for SHA-256: */
+static const uint32 sha256_initial_hash_value[8] = {
+	0x6a09e667UL,
+	0xbb67ae85UL,
+	0x3c6ef372UL,
+	0xa54ff53aUL,
+	0x510e527fUL,
+	0x9b05688cUL,
+	0x1f83d9abUL,
+	0x5be0cd19UL
+};
+
+/* Hash constant words K for SHA-384 and SHA-512: */
+static const uint64 K512[80] = {
+	0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,
+	0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
+	0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
+	0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
+	0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
+	0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
+	0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,
+	0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
+	0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
+	0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
+	0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
+	0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
+	0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,
+	0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
+	0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
+	0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
+	0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
+	0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
+	0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,
+	0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
+	0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
+	0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
+	0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
+	0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
+	0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,
+	0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
+	0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
+	0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
+	0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
+	0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
+	0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,
+	0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
+	0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
+	0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
+	0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
+	0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
+	0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,
+	0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
+	0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
+	0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
+};
+
+/* Initial hash value H for SHA-384 */
+static const uint64 sha384_initial_hash_value[8] = {
+	0xcbbb9d5dc1059ed8ULL,
+	0x629a292a367cd507ULL,
+	0x9159015a3070dd17ULL,
+	0x152fecd8f70e5939ULL,
+	0x67332667ffc00b31ULL,
+	0x8eb44a8768581511ULL,
+	0xdb0c2e0d64f98fa7ULL,
+	0x47b5481dbefa4fa4ULL
+};
+
+/* Initial hash value H for SHA-512 */
+static const uint64 sha512_initial_hash_value[8] = {
+	0x6a09e667f3bcc908ULL,
+	0xbb67ae8584caa73bULL,
+	0x3c6ef372fe94f82bULL,
+	0xa54ff53a5f1d36f1ULL,
+	0x510e527fade682d1ULL,
+	0x9b05688c2b3e6c1fULL,
+	0x1f83d9abfb41bd6bULL,
+	0x5be0cd19137e2179ULL
+};
+
+
+/*** SHA-256: *********************************************************/
+void
+pg_sha256_init(pg_sha256_ctx *context)
+{
+	if (context == NULL)
+		return;
+	memcpy(context->state, sha256_initial_hash_value, PG_SHA256_DIGEST_LENGTH);
+	memset(context->buffer, 0, PG_SHA256_BLOCK_LENGTH);
+	context->bitcount = 0;
+}
+
+#ifdef SHA2_UNROLL_TRANSFORM
+
+/* Unrolled SHA-256 round macros: */
+
+#define ROUND256_0_TO_15(a,b,c,d,e,f,g,h) do {					\
+	W256[j] = (uint32)data[3] | ((uint32)data[2] << 8) |		\
+		((uint32)data[1] << 16) | ((uint32)data[0] << 24);		\
+	data += 4;								\
+	T1 = (h) + Sigma1_256((e)) + Ch((e), (f), (g)) + K256[j] + W256[j]; \
+	(d) += T1;								\
+	(h) = T1 + Sigma0_256((a)) + Maj((a), (b), (c));			\
+	j++;									\
+} while(0)
+
+#define ROUND256(a,b,c,d,e,f,g,h) do {						\
+	s0 = W256[(j+1)&0x0f];							\
+	s0 = sigma0_256(s0);							\
+	s1 = W256[(j+14)&0x0f];							\
+	s1 = sigma1_256(s1);							\
+	T1 = (h) + Sigma1_256((e)) + Ch((e), (f), (g)) + K256[j] +		\
+		 (W256[j&0x0f] += s1 + W256[(j+9)&0x0f] + s0);			\
+	(d) += T1;								\
+	(h) = T1 + Sigma0_256((a)) + Maj((a), (b), (c));			\
+	j++;									\
+} while(0)
+
+static void
+SHA256_Transform(pg_sha256_ctx *context, const uint8 *data)
+{
+	uint32		a,
+				b,
+				c,
+				d,
+				e,
+				f,
+				g,
+				h,
+				s0,
+				s1;
+	uint32		T1,
+			   *W256;
+	int			j;
+
+	W256 = (uint32 *) context->buffer;
+
+	/* Initialize registers with the prev. intermediate value */
+	a = context->state[0];
+	b = context->state[1];
+	c = context->state[2];
+	d = context->state[3];
+	e = context->state[4];
+	f = context->state[5];
+	g = context->state[6];
+	h = context->state[7];
+
+	j = 0;
+	do
+	{
+		/* Rounds 0 to 15 (unrolled): */
+		ROUND256_0_TO_15(a, b, c, d, e, f, g, h);
+		ROUND256_0_TO_15(h, a, b, c, d, e, f, g);
+		ROUND256_0_TO_15(g, h, a, b, c, d, e, f);
+		ROUND256_0_TO_15(f, g, h, a, b, c, d, e);
+		ROUND256_0_TO_15(e, f, g, h, a, b, c, d);
+		ROUND256_0_TO_15(d, e, f, g, h, a, b, c);
+		ROUND256_0_TO_15(c, d, e, f, g, h, a, b);
+		ROUND256_0_TO_15(b, c, d, e, f, g, h, a);
+	} while (j < 16);
+
+	/* Now for the remaining rounds to 64: */
+	do
+	{
+		ROUND256(a, b, c, d, e, f, g, h);
+		ROUND256(h, a, b, c, d, e, f, g);
+		ROUND256(g, h, a, b, c, d, e, f);
+		ROUND256(f, g, h, a, b, c, d, e);
+		ROUND256(e, f, g, h, a, b, c, d);
+		ROUND256(d, e, f, g, h, a, b, c);
+		ROUND256(c, d, e, f, g, h, a, b);
+		ROUND256(b, c, d, e, f, g, h, a);
+	} while (j < 64);
+
+	/* Compute the current intermediate hash value */
+	context->state[0] += a;
+	context->state[1] += b;
+	context->state[2] += c;
+	context->state[3] += d;
+	context->state[4] += e;
+	context->state[5] += f;
+	context->state[6] += g;
+	context->state[7] += h;
+
+	/* Clean up */
+	a = b = c = d = e = f = g = h = T1 = 0;
+}
+#else							/* SHA2_UNROLL_TRANSFORM */
+
+static void
+SHA256_Transform(pg_sha256_ctx *context, const uint8 *data)
+{
+	uint32		a,
+				b,
+				c,
+				d,
+				e,
+				f,
+				g,
+				h,
+				s0,
+				s1;
+	uint32		T1,
+				T2,
+			   *W256;
+	int			j;
+
+	W256 = (uint32 *) context->buffer;
+
+	/* Initialize registers with the prev. intermediate value */
+	a = context->state[0];
+	b = context->state[1];
+	c = context->state[2];
+	d = context->state[3];
+	e = context->state[4];
+	f = context->state[5];
+	g = context->state[6];
+	h = context->state[7];
+
+	j = 0;
+	do
+	{
+		W256[j] = (uint32) data[3] | ((uint32) data[2] << 8) |
+			((uint32) data[1] << 16) | ((uint32) data[0] << 24);
+		data += 4;
+		/* Apply the SHA-256 compression function to update a..h */
+		T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] + W256[j];
+		T2 = Sigma0_256(a) + Maj(a, b, c);
+		h = g;
+		g = f;
+		f = e;
+		e = d + T1;
+		d = c;
+		c = b;
+		b = a;
+		a = T1 + T2;
+
+		j++;
+	} while (j < 16);
+
+	do
+	{
+		/* Part of the message block expansion: */
+		s0 = W256[(j + 1) & 0x0f];
+		s0 = sigma0_256(s0);
+		s1 = W256[(j + 14) & 0x0f];
+		s1 = sigma1_256(s1);
+
+		/* Apply the SHA-256 compression function to update a..h */
+		T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] +
+			(W256[j & 0x0f] += s1 + W256[(j + 9) & 0x0f] + s0);
+		T2 = Sigma0_256(a) + Maj(a, b, c);
+		h = g;
+		g = f;
+		f = e;
+		e = d + T1;
+		d = c;
+		c = b;
+		b = a;
+		a = T1 + T2;
+
+		j++;
+	} while (j < 64);
+
+	/* Compute the current intermediate hash value */
+	context->state[0] += a;
+	context->state[1] += b;
+	context->state[2] += c;
+	context->state[3] += d;
+	context->state[4] += e;
+	context->state[5] += f;
+	context->state[6] += g;
+	context->state[7] += h;
+
+	/* Clean up */
+	a = b = c = d = e = f = g = h = T1 = T2 = 0;
+}
+#endif							/* SHA2_UNROLL_TRANSFORM */
+
+void
+pg_sha256_update(pg_sha256_ctx *context, const uint8 *data, size_t len)
+{
+	size_t		freespace,
+				usedspace;
+
+	/* Calling with no data is valid (we do nothing) */
+	if (len == 0)
+		return;
+
+	usedspace = (context->bitcount >> 3) % PG_SHA256_BLOCK_LENGTH;
+	if (usedspace > 0)
+	{
+		/* Calculate how much free space is available in the buffer */
+		freespace = PG_SHA256_BLOCK_LENGTH - usedspace;
+
+		if (len >= freespace)
+		{
+			/* Fill the buffer completely and process it */
+			memcpy(&context->buffer[usedspace], data, freespace);
+			context->bitcount += freespace << 3;
+			len -= freespace;
+			data += freespace;
+			SHA256_Transform(context, context->buffer);
+		}
+		else
+		{
+			/* The buffer is not yet full */
+			memcpy(&context->buffer[usedspace], data, len);
+			context->bitcount += len << 3;
+			/* Clean up: */
+			usedspace = freespace = 0;
+			return;
+		}
+	}
+	while (len >= PG_SHA256_BLOCK_LENGTH)
+	{
+		/* Process as many complete blocks as we can */
+		SHA256_Transform(context, data);
+		context->bitcount += PG_SHA256_BLOCK_LENGTH << 3;
+		len -= PG_SHA256_BLOCK_LENGTH;
+		data += PG_SHA256_BLOCK_LENGTH;
+	}
+	if (len > 0)
+	{
+		/* There's left-overs, so save 'em */
+		memcpy(context->buffer, data, len);
+		context->bitcount += len << 3;
+	}
+	/* Clean up: */
+	usedspace = freespace = 0;
+}
+
+static void
+SHA256_Last(pg_sha256_ctx *context)
+{
+	unsigned int usedspace;
+
+	usedspace = (context->bitcount >> 3) % PG_SHA256_BLOCK_LENGTH;
+#ifndef WORDS_BIGENDIAN
+	/* Convert FROM host byte order */
+	REVERSE64(context->bitcount, context->bitcount);
+#endif
+	if (usedspace > 0)
+	{
+		/* Begin padding with a 1 bit: */
+		context->buffer[usedspace++] = 0x80;
+
+		if (usedspace <= PG_SHA256_SHORT_BLOCK_LENGTH)
+		{
+			/* Set-up for the last transform: */
+			memset(&context->buffer[usedspace], 0, PG_SHA256_SHORT_BLOCK_LENGTH - usedspace);
+		}
+		else
+		{
+			if (usedspace < PG_SHA256_BLOCK_LENGTH)
+			{
+				memset(&context->buffer[usedspace], 0, PG_SHA256_BLOCK_LENGTH - usedspace);
+			}
+			/* Do second-to-last transform: */
+			SHA256_Transform(context, context->buffer);
+
+			/* And set-up for the last transform: */
+			memset(context->buffer, 0, PG_SHA256_SHORT_BLOCK_LENGTH);
+		}
+	}
+	else
+	{
+		/* Set-up for the last transform: */
+		memset(context->buffer, 0, PG_SHA256_SHORT_BLOCK_LENGTH);
+
+		/* Begin padding with a 1 bit: */
+		*context->buffer = 0x80;
+	}
+	/* Set the bit count: */
+	*(uint64 *) &context->buffer[PG_SHA256_SHORT_BLOCK_LENGTH] = context->bitcount;
+
+	/* Final transform: */
+	SHA256_Transform(context, context->buffer);
+}
+
+void
+pg_sha256_final(pg_sha256_ctx *context, uint8 *digest)
+{
+	/* If no digest buffer is passed, we don't bother doing this: */
+	if (digest != NULL)
+	{
+		SHA256_Last(context);
+
+#ifndef WORDS_BIGENDIAN
+		{
+			/* Convert TO host byte order */
+			int			j;
+
+			for (j = 0; j < 8; j++)
+			{
+				REVERSE32(context->state[j], context->state[j]);
+			}
+		}
+#endif
+		memcpy(digest, context->state, PG_SHA256_DIGEST_LENGTH);
+	}
+
+	/* Clean up state data: */
+	memset(context, 0, sizeof(pg_sha256_ctx));
+}
+
+
+/*** SHA-512: *********************************************************/
+void
+pg_sha512_init(pg_sha512_ctx *context)
+{
+	if (context == NULL)
+		return;
+	memcpy(context->state, sha512_initial_hash_value, PG_SHA512_DIGEST_LENGTH);
+	memset(context->buffer, 0, PG_SHA512_BLOCK_LENGTH);
+	context->bitcount[0] = context->bitcount[1] = 0;
+}
+
+#ifdef SHA2_UNROLL_TRANSFORM
+
+/* Unrolled SHA-512 round macros: */
+
+#define ROUND512_0_TO_15(a,b,c,d,e,f,g,h) do {					\
+	W512[j] = (uint64)data[7] | ((uint64)data[6] << 8) |		\
+		((uint64)data[5] << 16) | ((uint64)data[4] << 24) |		\
+		((uint64)data[3] << 32) | ((uint64)data[2] << 40) |		\
+		((uint64)data[1] << 48) | ((uint64)data[0] << 56);		\
+	data += 8;								\
+	T1 = (h) + Sigma1_512((e)) + Ch((e), (f), (g)) + K512[j] + W512[j]; \
+	(d) += T1;								\
+	(h) = T1 + Sigma0_512((a)) + Maj((a), (b), (c));			\
+	j++;									\
+} while(0)
+
+
+#define ROUND512(a,b,c,d,e,f,g,h) do {						\
+	s0 = W512[(j+1)&0x0f];							\
+	s0 = sigma0_512(s0);							\
+	s1 = W512[(j+14)&0x0f];							\
+	s1 = sigma1_512(s1);							\
+	T1 = (h) + Sigma1_512((e)) + Ch((e), (f), (g)) + K512[j] +		\
+			 (W512[j&0x0f] += s1 + W512[(j+9)&0x0f] + s0);			\
+	(d) += T1;								\
+	(h) = T1 + Sigma0_512((a)) + Maj((a), (b), (c));			\
+	j++;									\
+} while(0)
+
+static void
+SHA512_Transform(pg_sha512_ctx *context, const uint8 *data)
+{
+	uint64		a,
+				b,
+				c,
+				d,
+				e,
+				f,
+				g,
+				h,
+				s0,
+				s1;
+	uint64		T1,
+			   *W512 = (uint64 *) context->buffer;
+	int			j;
+
+	/* Initialize registers with the prev. intermediate value */
+	a = context->state[0];
+	b = context->state[1];
+	c = context->state[2];
+	d = context->state[3];
+	e = context->state[4];
+	f = context->state[5];
+	g = context->state[6];
+	h = context->state[7];
+
+	j = 0;
+	do
+	{
+		ROUND512_0_TO_15(a, b, c, d, e, f, g, h);
+		ROUND512_0_TO_15(h, a, b, c, d, e, f, g);
+		ROUND512_0_TO_15(g, h, a, b, c, d, e, f);
+		ROUND512_0_TO_15(f, g, h, a, b, c, d, e);
+		ROUND512_0_TO_15(e, f, g, h, a, b, c, d);
+		ROUND512_0_TO_15(d, e, f, g, h, a, b, c);
+		ROUND512_0_TO_15(c, d, e, f, g, h, a, b);
+		ROUND512_0_TO_15(b, c, d, e, f, g, h, a);
+	} while (j < 16);
+
+	/* Now for the remaining rounds up to 79: */
+	do
+	{
+		ROUND512(a, b, c, d, e, f, g, h);
+		ROUND512(h, a, b, c, d, e, f, g);
+		ROUND512(g, h, a, b, c, d, e, f);
+		ROUND512(f, g, h, a, b, c, d, e);
+		ROUND512(e, f, g, h, a, b, c, d);
+		ROUND512(d, e, f, g, h, a, b, c);
+		ROUND512(c, d, e, f, g, h, a, b);
+		ROUND512(b, c, d, e, f, g, h, a);
+	} while (j < 80);
+
+	/* Compute the current intermediate hash value */
+	context->state[0] += a;
+	context->state[1] += b;
+	context->state[2] += c;
+	context->state[3] += d;
+	context->state[4] += e;
+	context->state[5] += f;
+	context->state[6] += g;
+	context->state[7] += h;
+
+	/* Clean up */
+	a = b = c = d = e = f = g = h = T1 = 0;
+}
+#else							/* SHA2_UNROLL_TRANSFORM */
+
+static void
+SHA512_Transform(pg_sha512_ctx *context, const uint8 *data)
+{
+	uint64		a,
+				b,
+				c,
+				d,
+				e,
+				f,
+				g,
+				h,
+				s0,
+				s1;
+	uint64		T1,
+				T2,
+			   *W512 = (uint64 *) context->buffer;
+	int			j;
+
+	/* Initialize registers with the prev. intermediate value */
+	a = context->state[0];
+	b = context->state[1];
+	c = context->state[2];
+	d = context->state[3];
+	e = context->state[4];
+	f = context->state[5];
+	g = context->state[6];
+	h = context->state[7];
+
+	j = 0;
+	do
+	{
+		W512[j] = (uint64) data[7] | ((uint64) data[6] << 8) |
+			((uint64) data[5] << 16) | ((uint64) data[4] << 24) |
+			((uint64) data[3] << 32) | ((uint64) data[2] << 40) |
+			((uint64) data[1] << 48) | ((uint64) data[0] << 56);
+		data += 8;
+		/* Apply the SHA-512 compression function to update a..h */
+		T1 = h + Sigma1_512(e) + Ch(e, f, g) + K512[j] + W512[j];
+		T2 = Sigma0_512(a) + Maj(a, b, c);
+		h = g;
+		g = f;
+		f = e;
+		e = d + T1;
+		d = c;
+		c = b;
+		b = a;
+		a = T1 + T2;
+
+		j++;
+	} while (j < 16);
+
+	do
+	{
+		/* Part of the message block expansion: */
+		s0 = W512[(j + 1) & 0x0f];
+		s0 = sigma0_512(s0);
+		s1 = W512[(j + 14) & 0x0f];
+		s1 = sigma1_512(s1);
+
+		/* Apply the SHA-512 compression function to update a..h */
+		T1 = h + Sigma1_512(e) + Ch(e, f, g) + K512[j] +
+			(W512[j & 0x0f] += s1 + W512[(j + 9) & 0x0f] + s0);
+		T2 = Sigma0_512(a) + Maj(a, b, c);
+		h = g;
+		g = f;
+		f = e;
+		e = d + T1;
+		d = c;
+		c = b;
+		b = a;
+		a = T1 + T2;
+
+		j++;
+	} while (j < 80);
+
+	/* Compute the current intermediate hash value */
+	context->state[0] += a;
+	context->state[1] += b;
+	context->state[2] += c;
+	context->state[3] += d;
+	context->state[4] += e;
+	context->state[5] += f;
+	context->state[6] += g;
+	context->state[7] += h;
+
+	/* Clean up */
+	a = b = c = d = e = f = g = h = T1 = T2 = 0;
+}
+#endif							/* SHA2_UNROLL_TRANSFORM */
+
+void
+pg_sha512_update(pg_sha512_ctx *context, const uint8 *data, size_t len)
+{
+	size_t		freespace,
+				usedspace;
+
+	/* Calling with no data is valid (we do nothing) */
+	if (len == 0)
+		return;
+
+	usedspace = (context->bitcount[0] >> 3) % PG_SHA512_BLOCK_LENGTH;
+	if (usedspace > 0)
+	{
+		/* Calculate how much free space is available in the buffer */
+		freespace = PG_SHA512_BLOCK_LENGTH - usedspace;
+
+		if (len >= freespace)
+		{
+			/* Fill the buffer completely and process it */
+			memcpy(&context->buffer[usedspace], data, freespace);
+			ADDINC128(context->bitcount, freespace << 3);
+			len -= freespace;
+			data += freespace;
+			SHA512_Transform(context, context->buffer);
+		}
+		else
+		{
+			/* The buffer is not yet full */
+			memcpy(&context->buffer[usedspace], data, len);
+			ADDINC128(context->bitcount, len << 3);
+			/* Clean up: */
+			usedspace = freespace = 0;
+			return;
+		}
+	}
+	while (len >= PG_SHA512_BLOCK_LENGTH)
+	{
+		/* Process as many complete blocks as we can */
+		SHA512_Transform(context, data);
+		ADDINC128(context->bitcount, PG_SHA512_BLOCK_LENGTH << 3);
+		len -= PG_SHA512_BLOCK_LENGTH;
+		data += PG_SHA512_BLOCK_LENGTH;
+	}
+	if (len > 0)
+	{
+		/* There's left-overs, so save 'em */
+		memcpy(context->buffer, data, len);
+		ADDINC128(context->bitcount, len << 3);
+	}
+	/* Clean up: */
+	usedspace = freespace = 0;
+}
+
+static void
+SHA512_Last(pg_sha512_ctx *context)
+{
+	unsigned int usedspace;
+
+	usedspace = (context->bitcount[0] >> 3) % PG_SHA512_BLOCK_LENGTH;
+#ifndef WORDS_BIGENDIAN
+	/* Convert FROM host byte order */
+	REVERSE64(context->bitcount[0], context->bitcount[0]);
+	REVERSE64(context->bitcount[1], context->bitcount[1]);
+#endif
+	if (usedspace > 0)
+	{
+		/* Begin padding with a 1 bit: */
+		context->buffer[usedspace++] = 0x80;
+
+		if (usedspace <= PG_SHA512_SHORT_BLOCK_LENGTH)
+		{
+			/* Set-up for the last transform: */
+			memset(&context->buffer[usedspace], 0, PG_SHA512_SHORT_BLOCK_LENGTH - usedspace);
+		}
+		else
+		{
+			if (usedspace < PG_SHA512_BLOCK_LENGTH)
+			{
+				memset(&context->buffer[usedspace], 0, PG_SHA512_BLOCK_LENGTH - usedspace);
+			}
+			/* Do second-to-last transform: */
+			SHA512_Transform(context, context->buffer);
+
+			/* And set-up for the last transform: */
+			memset(context->buffer, 0, PG_SHA512_BLOCK_LENGTH - 2);
+		}
+	}
+	else
+	{
+		/* Prepare for final transform: */
+		memset(context->buffer, 0, PG_SHA512_SHORT_BLOCK_LENGTH);
+
+		/* Begin padding with a 1 bit: */
+		*context->buffer = 0x80;
+	}
+	/* Store the length of input data (in bits): */
+	*(uint64 *) &context->buffer[PG_SHA512_SHORT_BLOCK_LENGTH] = context->bitcount[1];
+	*(uint64 *) &context->buffer[PG_SHA512_SHORT_BLOCK_LENGTH + 8] = context->bitcount[0];
+
+	/* Final transform: */
+	SHA512_Transform(context, context->buffer);
+}
+
+void
+pg_sha512_final(pg_sha512_ctx *context, uint8 *digest)
+{
+	/* If no digest buffer is passed, we don't bother doing this: */
+	if (digest != NULL)
+	{
+		SHA512_Last(context);
+
+		/* Save the hash data for output: */
+#ifndef WORDS_BIGENDIAN
+		{
+			/* Convert TO host byte order */
+			int			j;
+
+			for (j = 0; j < 8; j++)
+			{
+				REVERSE64(context->state[j], context->state[j]);
+			}
+		}
+#endif
+		memcpy(digest, context->state, PG_SHA512_DIGEST_LENGTH);
+	}
+
+	/* Zero out state data */
+	memset(context, 0, sizeof(pg_sha512_ctx));
+}
+
+
+/*** SHA-384: *********************************************************/
+void
+pg_sha384_init(pg_sha384_ctx *context)
+{
+	if (context == NULL)
+		return;
+	memcpy(context->state, sha384_initial_hash_value, PG_SHA512_DIGEST_LENGTH);
+	memset(context->buffer, 0, PG_SHA384_BLOCK_LENGTH);
+	context->bitcount[0] = context->bitcount[1] = 0;
+}
+
+void
+pg_sha384_update(pg_sha384_ctx *context, const uint8 *data, size_t len)
+{
+	pg_sha512_update((pg_sha512_ctx *) context, data, len);
+}
+
+void
+pg_sha384_final(pg_sha384_ctx *context, uint8 *digest)
+{
+	/* If no digest buffer is passed, we don't bother doing this: */
+	if (digest != NULL)
+	{
+		SHA512_Last((pg_sha512_ctx *) context);
+
+		/* Save the hash data for output: */
+#ifndef WORDS_BIGENDIAN
+		{
+			/* Convert TO host byte order */
+			int			j;
+
+			for (j = 0; j < 6; j++)
+			{
+				REVERSE64(context->state[j], context->state[j]);
+			}
+		}
+#endif
+		memcpy(digest, context->state, PG_SHA384_DIGEST_LENGTH);
+	}
+
+	/* Zero out state data */
+	memset(context, 0, sizeof(pg_sha384_ctx));
+}
+
+/*** SHA-224: *********************************************************/
+void
+pg_sha224_init(pg_sha224_ctx *context)
+{
+	if (context == NULL)
+		return;
+	memcpy(context->state, sha224_initial_hash_value, PG_SHA256_DIGEST_LENGTH);
+	memset(context->buffer, 0, PG_SHA256_BLOCK_LENGTH);
+	context->bitcount = 0;
+}
+
+void
+pg_sha224_update(pg_sha224_ctx *context, const uint8 *data, size_t len)
+{
+	pg_sha256_update((pg_sha256_ctx *) context, data, len);
+}
+
+void
+pg_sha224_final(pg_sha224_ctx *context, uint8 *digest)
+{
+	/* If no digest buffer is passed, we don't bother doing this: */
+	if (digest != NULL)
+	{
+		SHA256_Last(context);
+
+#ifndef WORDS_BIGENDIAN
+		{
+			/* Convert TO host byte order */
+			int			j;
+
+			for (j = 0; j < 8; j++)
+			{
+				REVERSE32(context->state[j], context->state[j]);
+			}
+		}
+#endif
+		memcpy(digest, context->state, PG_SHA224_DIGEST_LENGTH);
+	}
+
+	/* Clean up state data: */
+	memset(context, 0, sizeof(pg_sha224_ctx));
+}
diff --git a/src/common/sha2_int.h b/src/common/sha2_int.h
new file mode 100644
index 0000000..c6d5642
--- /dev/null
+++ b/src/common/sha2_int.h
@@ -0,0 +1,91 @@
+/*-------------------------------------------------------------------------
+ *
+ * sha2_int.h
+ *	  Internal headers for fallback implementation of SHA{224,256,384,512}
+ *
+ * Portions Copyright (c) 2016-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		  src/common/sha2_int.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/* $OpenBSD: sha2.h,v 1.2 2004/04/28 23:11:57 millert Exp $ */
+
+/*
+ * FILE:	sha2.h
+ * AUTHOR:	Aaron D. Gifford <me@aarongifford.com>
+ *
+ * Copyright (c) 2000-2001, Aaron D. Gifford
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *	  notice, this list of conditions and the following disclaimer in the
+ *	  documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of contributors
+ *	  may be used to endorse or promote products derived from this software
+ *	  without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTOR(S) ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTOR(S) BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $From: sha2.h,v 1.1 2001/11/08 00:02:01 adg Exp adg $
+ */
+
+#ifndef PG_SHA2_INT_H
+#define PG_SHA2_INT_H
+
+#include "common/sha2.h"
+
+typedef struct pg_sha256_ctx
+{
+	uint32		state[8];
+	uint64		bitcount;
+	uint8		buffer[PG_SHA256_BLOCK_LENGTH];
+} pg_sha256_ctx;
+typedef struct pg_sha512_ctx
+{
+	uint64		state[8];
+	uint64		bitcount[2];
+	uint8		buffer[PG_SHA512_BLOCK_LENGTH];
+} pg_sha512_ctx;
+typedef struct pg_sha256_ctx pg_sha224_ctx;
+typedef struct pg_sha512_ctx pg_sha384_ctx;
+
+/* Interface routines for SHA224/256/384/512 */
+extern void pg_sha224_init(pg_sha224_ctx *ctx);
+extern void pg_sha224_update(pg_sha224_ctx *ctx, const uint8 *input0,
+							 size_t len);
+extern void pg_sha224_final(pg_sha224_ctx *ctx, uint8 *dest);
+
+extern void pg_sha256_init(pg_sha256_ctx *ctx);
+extern void pg_sha256_update(pg_sha256_ctx *ctx, const uint8 *input0,
+							 size_t len);
+extern void pg_sha256_final(pg_sha256_ctx *ctx, uint8 *dest);
+
+extern void pg_sha384_init(pg_sha384_ctx *ctx);
+extern void pg_sha384_update(pg_sha384_ctx *ctx,
+							 const uint8 *, size_t len);
+extern void pg_sha384_final(pg_sha384_ctx *ctx, uint8 *dest);
+
+extern void pg_sha512_init(pg_sha512_ctx *ctx);
+extern void pg_sha512_update(pg_sha512_ctx *ctx, const uint8 *input0,
+							 size_t len);
+extern void pg_sha512_final(pg_sha512_ctx *ctx, uint8 *dest);
+
+#endif							/* PG_SHA2_INT_H */
diff --git a/src/common/sprompt.c b/src/common/sprompt.c
new file mode 100644
index 0000000..f3a891a
--- /dev/null
+++ b/src/common/sprompt.c
@@ -0,0 +1,159 @@
+/*-------------------------------------------------------------------------
+ *
+ * sprompt.c
+ *	  simple_prompt() routine
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/sprompt.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include "common/fe_memutils.h"
+#include "common/string.h"
+
+#ifdef HAVE_TERMIOS_H
+#include <termios.h>
+#endif
+
+
+/*
+ * simple_prompt
+ *
+ * Generalized function especially intended for reading in usernames and
+ * passwords interactively.  Reads from /dev/tty or stdin/stderr.
+ *
+ * prompt:		The prompt to print, or NULL if none (automatically localized)
+ * echo:		Set to false if you want to hide what is entered (for passwords)
+ *
+ * The input (without trailing newline) is returned as a malloc'd string.
+ * Caller is responsible for freeing it when done.
+ */
+char *
+simple_prompt(const char *prompt, bool echo)
+{
+	char	   *result;
+	FILE	   *termin,
+			   *termout;
+#if defined(HAVE_TERMIOS_H)
+	struct termios t_orig,
+				t;
+#elif defined(WIN32)
+	HANDLE		t = NULL;
+	DWORD		t_orig = 0;
+#endif
+
+#ifdef WIN32
+
+	/*
+	 * A Windows console has an "input code page" and an "output code page";
+	 * these usually match each other, but they rarely match the "Windows ANSI
+	 * code page" defined at system boot and expected of "char *" arguments to
+	 * Windows API functions.  The Microsoft CRT write() implementation
+	 * automatically converts text between these code pages when writing to a
+	 * console.  To identify such file descriptors, it calls GetConsoleMode()
+	 * on the underlying HANDLE, which in turn requires GENERIC_READ access on
+	 * the HANDLE.  Opening termout in mode "w+" allows that detection to
+	 * succeed.  Otherwise, write() would not recognize the descriptor as a
+	 * console, and non-ASCII characters would display incorrectly.
+	 *
+	 * XXX fgets() still receives text in the console's input code page.  This
+	 * makes non-ASCII credentials unportable.
+	 *
+	 * Unintuitively, we also open termin in mode "w+", even though we only
+	 * read it; that's needed for SetConsoleMode() to succeed.
+	 */
+	termin = fopen("CONIN$", "w+");
+	termout = fopen("CONOUT$", "w+");
+#else
+
+	/*
+	 * Do not try to collapse these into one "w+" mode file. Doesn't work on
+	 * some platforms (eg, HPUX 10.20).
+	 */
+	termin = fopen("/dev/tty", "r");
+	termout = fopen("/dev/tty", "w");
+#endif
+	if (!termin || !termout
+#ifdef WIN32
+
+	/*
+	 * Direct console I/O does not work from the MSYS 1.0.10 console.  Writes
+	 * reach nowhere user-visible; reads block indefinitely.  XXX This affects
+	 * most Windows terminal environments, including rxvt, mintty, Cygwin
+	 * xterm, Cygwin sshd, and PowerShell ISE.  Switch to a more-generic test.
+	 */
+		|| (getenv("OSTYPE") && strcmp(getenv("OSTYPE"), "msys") == 0)
+#endif
+		)
+	{
+		if (termin)
+			fclose(termin);
+		if (termout)
+			fclose(termout);
+		termin = stdin;
+		termout = stderr;
+	}
+
+	if (!echo)
+	{
+#if defined(HAVE_TERMIOS_H)
+		/* disable echo via tcgetattr/tcsetattr */
+		tcgetattr(fileno(termin), &t);
+		t_orig = t;
+		t.c_lflag &= ~ECHO;
+		tcsetattr(fileno(termin), TCSAFLUSH, &t);
+#elif defined(WIN32)
+		/* need the file's HANDLE to turn echo off */
+		t = (HANDLE) _get_osfhandle(_fileno(termin));
+
+		/* save the old configuration first */
+		GetConsoleMode(t, &t_orig);
+
+		/* set to the new mode */
+		SetConsoleMode(t, ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT);
+#endif
+	}
+
+	if (prompt)
+	{
+		fputs(_(prompt), termout);
+		fflush(termout);
+	}
+
+	result = pg_get_line(termin);
+
+	/* If we failed to read anything, just return an empty string */
+	if (result == NULL)
+		result = pg_strdup("");
+
+	/* strip trailing newline, including \r in case we're on Windows */
+	(void) pg_strip_crlf(result);
+
+	if (!echo)
+	{
+		/* restore previous echo behavior, then echo \n */
+#if defined(HAVE_TERMIOS_H)
+		tcsetattr(fileno(termin), TCSAFLUSH, &t_orig);
+		fputs("\n", termout);
+		fflush(termout);
+#elif defined(WIN32)
+		SetConsoleMode(t, t_orig);
+		fputs("\n", termout);
+		fflush(termout);
+#endif
+	}
+
+	if (termin != stdin)
+	{
+		fclose(termin);
+		fclose(termout);
+	}
+
+	return result;
+}
diff --git a/src/common/string.c b/src/common/string.c
new file mode 100644
index 0000000..3aa378c
--- /dev/null
+++ b/src/common/string.c
@@ -0,0 +1,130 @@
+/*-------------------------------------------------------------------------
+ *
+ * string.c
+ *		string handling helpers
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/string.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/string.h"
+
+
+/*
+ * Returns whether the string `str' has the postfix `end'.
+ */
+bool
+pg_str_endswith(const char *str, const char *end)
+{
+	size_t		slen = strlen(str);
+	size_t		elen = strlen(end);
+
+	/* can't be a postfix if longer */
+	if (elen > slen)
+		return false;
+
+	/* compare the end of the strings */
+	str += slen - elen;
+	return strcmp(str, end) == 0;
+}
+
+
+/*
+ * strtoint --- just like strtol, but returns int not long
+ */
+int
+strtoint(const char *pg_restrict str, char **pg_restrict endptr, int base)
+{
+	long		val;
+
+	val = strtol(str, endptr, base);
+	if (val != (int) val)
+		errno = ERANGE;
+	return (int) val;
+}
+
+
+/*
+ * pg_clean_ascii -- Replace any non-ASCII chars with a '?' char
+ *
+ * Modifies the string passed in which must be '\0'-terminated.
+ *
+ * This function exists specifically to deal with filtering out
+ * non-ASCII characters in a few places where the client can provide an almost
+ * arbitrary string (and it isn't checked to ensure it's a valid username or
+ * database name or similar) and we don't want to have control characters or other
+ * things ending up in the log file where server admins might end up with a
+ * messed up terminal when looking at them.
+ *
+ * In general, this function should NOT be used- instead, consider how to handle
+ * the string without needing to filter out the non-ASCII characters.
+ *
+ * Ultimately, we'd like to improve the situation to not require stripping out
+ * all non-ASCII but perform more intelligent filtering which would allow UTF or
+ * similar, but it's unclear exactly what we should allow, so stick to ASCII only
+ * for now.
+ */
+void
+pg_clean_ascii(char *str)
+{
+	/* Only allow clean ASCII chars in the string */
+	char	   *p;
+
+	for (p = str; *p != '\0'; p++)
+	{
+		if (*p < 32 || *p > 126)
+			*p = '?';
+	}
+}
+
+
+/*
+ * pg_is_ascii -- Check if string is made only of ASCII characters
+ */
+bool
+pg_is_ascii(const char *str)
+{
+	while (*str)
+	{
+		if (IS_HIGHBIT_SET(*str))
+			return false;
+		str++;
+	}
+	return true;
+}
+
+
+/*
+ * pg_strip_crlf -- Remove any trailing newline and carriage return
+ *
+ * Removes any trailing newline and carriage return characters (\r on
+ * Windows) in the input string, zero-terminating it.
+ *
+ * The passed in string must be zero-terminated.  This function returns
+ * the new length of the string.
+ */
+int
+pg_strip_crlf(char *str)
+{
+	int			len = strlen(str);
+
+	while (len > 0 && (str[len - 1] == '\n' ||
+					   str[len - 1] == '\r'))
+		str[--len] = '\0';
+
+	return len;
+}
diff --git a/src/common/stringinfo.c b/src/common/stringinfo.c
new file mode 100644
index 0000000..445f722
--- /dev/null
+++ b/src/common/stringinfo.c
@@ -0,0 +1,343 @@
+/*-------------------------------------------------------------------------
+ *
+ * stringinfo.c
+ *
+ * StringInfo provides an extensible string data type (currently limited to a
+ * length of 1GB).  It can be used to buffer either ordinary C strings
+ * (null-terminated text) or arbitrary binary data.  All storage is allocated
+ * with palloc() (falling back to malloc in frontend code).
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *	  src/common/stringinfo.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+
+#include "postgres.h"
+#include "utils/memutils.h"
+
+#else
+
+#include "postgres_fe.h"
+
+/* It's possible we could use a different value for this in frontend code */
+#define MaxAllocSize	((Size) 0x3fffffff) /* 1 gigabyte - 1 */
+
+#endif
+
+#include "lib/stringinfo.h"
+
+
+/*
+ * makeStringInfo
+ *
+ * Create an empty 'StringInfoData' & return a pointer to it.
+ */
+StringInfo
+makeStringInfo(void)
+{
+	StringInfo	res;
+
+	res = (StringInfo) palloc(sizeof(StringInfoData));
+
+	initStringInfo(res);
+
+	return res;
+}
+
+/*
+ * initStringInfo
+ *
+ * Initialize a StringInfoData struct (with previously undefined contents)
+ * to describe an empty string.
+ */
+void
+initStringInfo(StringInfo str)
+{
+	int			size = 1024;	/* initial default buffer size */
+
+	str->data = (char *) palloc(size);
+	str->maxlen = size;
+	resetStringInfo(str);
+}
+
+/*
+ * resetStringInfo
+ *
+ * Reset the StringInfo: the data buffer remains valid, but its
+ * previous content, if any, is cleared.
+ */
+void
+resetStringInfo(StringInfo str)
+{
+	str->data[0] = '\0';
+	str->len = 0;
+	str->cursor = 0;
+}
+
+/*
+ * appendStringInfo
+ *
+ * Format text data under the control of fmt (an sprintf-style format string)
+ * and append it to whatever is already in str.  More space is allocated
+ * to str if necessary.  This is sort of like a combination of sprintf and
+ * strcat.
+ */
+void
+appendStringInfo(StringInfo str, const char *fmt,...)
+{
+	int			save_errno = errno;
+
+	for (;;)
+	{
+		va_list		args;
+		int			needed;
+
+		/* Try to format the data. */
+		errno = save_errno;
+		va_start(args, fmt);
+		needed = appendStringInfoVA(str, fmt, args);
+		va_end(args);
+
+		if (needed == 0)
+			break;				/* success */
+
+		/* Increase the buffer size and try again. */
+		enlargeStringInfo(str, needed);
+	}
+}
+
+/*
+ * appendStringInfoVA
+ *
+ * Attempt to format text data under the control of fmt (an sprintf-style
+ * format string) and append it to whatever is already in str.  If successful
+ * return zero; if not (because there's not enough space), return an estimate
+ * of the space needed, without modifying str.  Typically the caller should
+ * pass the return value to enlargeStringInfo() before trying again; see
+ * appendStringInfo for standard usage pattern.
+ *
+ * Caution: callers must be sure to preserve their entry-time errno
+ * when looping, in case the fmt contains "%m".
+ *
+ * XXX This API is ugly, but there seems no alternative given the C spec's
+ * restrictions on what can portably be done with va_list arguments: you have
+ * to redo va_start before you can rescan the argument list, and we can't do
+ * that from here.
+ */
+int
+appendStringInfoVA(StringInfo str, const char *fmt, va_list args)
+{
+	int			avail;
+	size_t		nprinted;
+
+	Assert(str != NULL);
+
+	/*
+	 * If there's hardly any space, don't bother trying, just fail to make the
+	 * caller enlarge the buffer first.  We have to guess at how much to
+	 * enlarge, since we're skipping the formatting work.
+	 */
+	avail = str->maxlen - str->len;
+	if (avail < 16)
+		return 32;
+
+	nprinted = pvsnprintf(str->data + str->len, (size_t) avail, fmt, args);
+
+	if (nprinted < (size_t) avail)
+	{
+		/* Success.  Note nprinted does not include trailing null. */
+		str->len += (int) nprinted;
+		return 0;
+	}
+
+	/* Restore the trailing null so that str is unmodified. */
+	str->data[str->len] = '\0';
+
+	/*
+	 * Return pvsnprintf's estimate of the space needed.  (Although this is
+	 * given as a size_t, we know it will fit in int because it's not more
+	 * than MaxAllocSize.)
+	 */
+	return (int) nprinted;
+}
+
+/*
+ * appendStringInfoString
+ *
+ * Append a null-terminated string to str.
+ * Like appendStringInfo(str, "%s", s) but faster.
+ */
+void
+appendStringInfoString(StringInfo str, const char *s)
+{
+	appendBinaryStringInfo(str, s, strlen(s));
+}
+
+/*
+ * appendStringInfoChar
+ *
+ * Append a single byte to str.
+ * Like appendStringInfo(str, "%c", ch) but much faster.
+ */
+void
+appendStringInfoChar(StringInfo str, char ch)
+{
+	/* Make more room if needed */
+	if (str->len + 1 >= str->maxlen)
+		enlargeStringInfo(str, 1);
+
+	/* OK, append the character */
+	str->data[str->len] = ch;
+	str->len++;
+	str->data[str->len] = '\0';
+}
+
+/*
+ * appendStringInfoSpaces
+ *
+ * Append the specified number of spaces to a buffer.
+ */
+void
+appendStringInfoSpaces(StringInfo str, int count)
+{
+	if (count > 0)
+	{
+		/* Make more room if needed */
+		enlargeStringInfo(str, count);
+
+		/* OK, append the spaces */
+		while (--count >= 0)
+			str->data[str->len++] = ' ';
+		str->data[str->len] = '\0';
+	}
+}
+
+/*
+ * appendBinaryStringInfo
+ *
+ * Append arbitrary binary data to a StringInfo, allocating more space
+ * if necessary. Ensures that a trailing null byte is present.
+ */
+void
+appendBinaryStringInfo(StringInfo str, const char *data, int datalen)
+{
+	Assert(str != NULL);
+
+	/* Make more room if needed */
+	enlargeStringInfo(str, datalen);
+
+	/* OK, append the data */
+	memcpy(str->data + str->len, data, datalen);
+	str->len += datalen;
+
+	/*
+	 * Keep a trailing null in place, even though it's probably useless for
+	 * binary data.  (Some callers are dealing with text but call this because
+	 * their input isn't null-terminated.)
+	 */
+	str->data[str->len] = '\0';
+}
+
+/*
+ * appendBinaryStringInfoNT
+ *
+ * Append arbitrary binary data to a StringInfo, allocating more space
+ * if necessary. Does not ensure a trailing null-byte exists.
+ */
+void
+appendBinaryStringInfoNT(StringInfo str, const char *data, int datalen)
+{
+	Assert(str != NULL);
+
+	/* Make more room if needed */
+	enlargeStringInfo(str, datalen);
+
+	/* OK, append the data */
+	memcpy(str->data + str->len, data, datalen);
+	str->len += datalen;
+}
+
+/*
+ * enlargeStringInfo
+ *
+ * Make sure there is enough space for 'needed' more bytes
+ * ('needed' does not include the terminating null).
+ *
+ * External callers usually need not concern themselves with this, since
+ * all stringinfo.c routines do it automatically.  However, if a caller
+ * knows that a StringInfo will eventually become X bytes large, it
+ * can save some palloc overhead by enlarging the buffer before starting
+ * to store data in it.
+ *
+ * NB: In the backend, because we use repalloc() to enlarge the buffer, the
+ * string buffer will remain allocated in the same memory context that was
+ * current when initStringInfo was called, even if another context is now
+ * current.  This is the desired and indeed critical behavior!
+ */
+void
+enlargeStringInfo(StringInfo str, int needed)
+{
+	int			newlen;
+
+	/*
+	 * Guard against out-of-range "needed" values.  Without this, we can get
+	 * an overflow or infinite loop in the following.
+	 */
+	if (needed < 0)				/* should not happen */
+	{
+#ifndef FRONTEND
+		elog(ERROR, "invalid string enlargement request size: %d", needed);
+#else
+		fprintf(stderr, "invalid string enlargement request size: %d\n", needed);
+		exit(EXIT_FAILURE);
+#endif
+	}
+	if (((Size) needed) >= (MaxAllocSize - (Size) str->len))
+	{
+#ifndef FRONTEND
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("out of memory"),
+				 errdetail("Cannot enlarge string buffer containing %d bytes by %d more bytes.",
+						   str->len, needed)));
+#else
+		fprintf(stderr,
+				_("out of memory\n\nCannot enlarge string buffer containing %d bytes by %d more bytes.\n"),
+				str->len, needed);
+		exit(EXIT_FAILURE);
+#endif
+	}
+
+	needed += str->len + 1;		/* total space required now */
+
+	/* Because of the above test, we now have needed <= MaxAllocSize */
+
+	if (needed <= str->maxlen)
+		return;					/* got enough space already */
+
+	/*
+	 * We don't want to allocate just a little more space with each append;
+	 * for efficiency, double the buffer size each time it overflows.
+	 * Actually, we might need to more than double it if 'needed' is big...
+	 */
+	newlen = 2 * str->maxlen;
+	while (needed > newlen)
+		newlen = 2 * newlen;
+
+	/*
+	 * Clamp to MaxAllocSize in case we went past it.  Note we are assuming
+	 * here that MaxAllocSize <= INT_MAX/2, else the above loop could
+	 * overflow.  We will still have newlen >= needed.
+	 */
+	if (newlen > (int) MaxAllocSize)
+		newlen = (int) MaxAllocSize;
+
+	str->data = (char *) repalloc(str->data, newlen);
+
+	str->maxlen = newlen;
+}
diff --git a/src/common/unicode/.gitignore b/src/common/unicode/.gitignore
new file mode 100644
index 0000000..512862e
--- /dev/null
+++ b/src/common/unicode/.gitignore
@@ -0,0 +1,8 @@
+/norm_test
+/norm_test_table.h
+
+# Downloaded files
+/CompositionExclusions.txt
+/DerivedNormalizationProps.txt
+/NormalizationTest.txt
+/UnicodeData.txt
diff --git a/src/common/unicode/Makefile b/src/common/unicode/Makefile
new file mode 100644
index 0000000..eb14add
--- /dev/null
+++ b/src/common/unicode/Makefile
@@ -0,0 +1,69 @@
+#-------------------------------------------------------------------------
+#
+# Makefile
+#    Makefile for src/common/unicode
+#
+# IDENTIFICATION
+#    src/common/unicode/Makefile
+#
+#-------------------------------------------------------------------------
+
+subdir = src/common/unicode
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+
+override CPPFLAGS := -DFRONTEND $(CPPFLAGS)
+LIBS += $(PTHREAD_LIBS)
+
+# By default, do nothing.
+all:
+
+update-unicode: unicode_norm_table.h unicode_combining_table.h unicode_normprops_table.h unicode_norm_hashfunc.h
+	mv $^ ../../../src/include/common/
+	$(MAKE) normalization-check
+
+# These files are part of the Unicode Character Database. Download
+# them on demand.  The dependency on Makefile.global is for
+# UNICODE_VERSION.
+UnicodeData.txt DerivedNormalizationProps.txt CompositionExclusions.txt NormalizationTest.txt: $(top_builddir)/src/Makefile.global
+	$(DOWNLOAD) https://www.unicode.org/Public/$(UNICODE_VERSION)/ucd/$(@F)
+
+# Generation of conversion tables used for string normalization with
+# UTF-8 strings.
+unicode_norm_hashfunc.h: unicode_norm_table.h
+
+unicode_norm_table.h: generate-unicode_norm_table.pl UnicodeData.txt CompositionExclusions.txt
+	$(PERL) generate-unicode_norm_table.pl
+
+unicode_combining_table.h: generate-unicode_combining_table.pl UnicodeData.txt
+	$(PERL) $^ >$@
+
+unicode_normprops_table.h: generate-unicode_normprops_table.pl DerivedNormalizationProps.txt
+	$(PERL) $^ >$@
+
+# Test suite
+normalization-check: norm_test
+	./norm_test
+
+norm_test: norm_test.o ../unicode_norm.o | submake-common
+
+norm_test.o: norm_test_table.h
+
+.PHONY: submake-common
+
+submake-common:
+	$(MAKE) -C .. all
+
+norm_test_table.h: generate-norm_test_table.pl NormalizationTest.txt
+	perl generate-norm_test_table.pl NormalizationTest.txt $@
+
+.PHONY: normalization-check
+
+
+clean:
+	rm -f $(OBJS) norm_test norm_test.o
+
+distclean: clean
+	rm -f UnicodeData.txt CompositionExclusions.txt NormalizationTest.txt norm_test_table.h unicode_norm_table.h
+
+maintainer-clean: distclean
diff --git a/src/common/unicode/README b/src/common/unicode/README
new file mode 100644
index 0000000..56956f6
--- /dev/null
+++ b/src/common/unicode/README
@@ -0,0 +1,28 @@
+This directory contains tools to generate the tables in
+src/include/common/unicode_norm.h, used for Unicode normalization. The
+generated .h file is included in the source tree, so these are normally not
+needed to build PostgreSQL, only if you need to re-generate the .h file
+from the Unicode data files for some reason, e.g. to update to a new version
+of Unicode.
+
+Generating unicode_norm_table.h
+-------------------------------
+
+Run
+
+    make update-unicode
+
+from the top level of the source tree and commit the result.
+
+Tests
+-----
+
+The Unicode consortium publishes a comprehensive test suite for the
+normalization algorithm, in a file called NormalizationTest.txt. This
+directory also contains a perl script and some C code, to run our
+normalization code with all the test strings in NormalizationTest.txt.
+To download NormalizationTest.txt and run the tests:
+
+    make normalization-check
+
+This is also run as part of the update-unicode target.
diff --git a/src/common/unicode/generate-norm_test_table.pl b/src/common/unicode/generate-norm_test_table.pl
new file mode 100644
index 0000000..844ff08
--- /dev/null
+++ b/src/common/unicode/generate-norm_test_table.pl
@@ -0,0 +1,106 @@
+#!/usr/bin/perl
+#
+# Read Unicode consortium's normalization test suite, NormalizationTest.txt,
+# and generate a C array from it, for norm_test.c.
+#
+# NormalizationTest.txt is part of the Unicode Character Database.
+#
+# Copyright (c) 2000-2021, PostgreSQL Global Development Group
+
+use strict;
+use warnings;
+
+use File::Basename;
+
+die "Usage: $0 INPUT_FILE OUTPUT_FILE\n" if @ARGV != 2;
+my $input_file  = $ARGV[0];
+my $output_file = $ARGV[1];
+my $output_base = basename($output_file);
+
+# Open the input and output files
+open my $INPUT, '<', $input_file
+  or die "Could not open input file $input_file: $!";
+open my $OUTPUT, '>', $output_file
+  or die "Could not open output file $output_file: $!\n";
+
+# Print header of output file.
+print $OUTPUT <<HEADER;
+/*-------------------------------------------------------------------------
+ *
+ * norm_test_table.h
+ *	  Test strings for Unicode normalization.
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/common/unicode/norm_test_table.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*
+ * File auto-generated by src/common/unicode/generate-norm_test_table.pl, do
+ * not edit. There is deliberately not an #ifndef PG_NORM_TEST_TABLE_H
+ * here.
+ */
+
+typedef struct
+{
+	int			linenum;
+	pg_wchar	input[50];
+	pg_wchar	output[4][50];
+} pg_unicode_test;
+
+/* test table */
+HEADER
+print $OUTPUT
+  "static const pg_unicode_test UnicodeNormalizationTests[] =\n{\n";
+
+# Helper routine to convert a space-separated list of Unicode characters to
+# hexadecimal list format, suitable for outputting in a C array.
+sub codepoint_string_to_hex
+{
+	my $codepoint_string = shift;
+
+	my $result;
+
+	foreach (split(' ', $codepoint_string))
+	{
+		my $cp   = $_;
+		my $utf8 = "0x$cp, ";
+		$result .= $utf8;
+	}
+	$result .= '0';    # null-terminated the array
+	return $result;
+}
+
+# Process the input file line by line
+my $linenum = 0;
+while (my $line = <$INPUT>)
+{
+	$linenum = $linenum + 1;
+	if ($line =~ /^\s*#/) { next; }    # ignore comments
+
+	if ($line =~ /^@/) { next; }       # ignore @Part0 like headers
+
+	# Split the line wanted and get the fields needed:
+	#
+	# source; NFC; NFD; NFKC; NFKD
+	my ($source, $nfc, $nfd, $nfkc, $nfkd) = split(';', $line);
+
+	my $source_utf8 = codepoint_string_to_hex($source);
+	my $nfc_utf8    = codepoint_string_to_hex($nfc);
+	my $nfd_utf8    = codepoint_string_to_hex($nfd);
+	my $nfkc_utf8   = codepoint_string_to_hex($nfkc);
+	my $nfkd_utf8   = codepoint_string_to_hex($nfkd);
+
+	print $OUTPUT
+	  "\t{ $linenum, { $source_utf8 }, { { $nfc_utf8 }, { $nfd_utf8 }, { $nfkc_utf8 }, { $nfkd_utf8 } } },\n";
+}
+
+# Output terminator entry
+print $OUTPUT "\t{ 0, { 0 }, { { 0 }, { 0 }, { 0 }, { 0 } } }";
+print $OUTPUT "\n};\n";
+
+close $OUTPUT;
+close $INPUT;
diff --git a/src/common/unicode/generate-unicode_combining_table.pl b/src/common/unicode/generate-unicode_combining_table.pl
new file mode 100644
index 0000000..86aed78
--- /dev/null
+++ b/src/common/unicode/generate-unicode_combining_table.pl
@@ -0,0 +1,53 @@
+#!/usr/bin/perl
+#
+# Generate sorted list of non-overlapping intervals of non-spacing
+# characters, using Unicode data files as input.  Pass UnicodeData.txt
+# as argument.  The output is on stdout.
+#
+# Copyright (c) 2019-2021, PostgreSQL Global Development Group
+
+use strict;
+use warnings;
+
+my $range_start = undef;
+my $codepoint;
+my $prev_codepoint;
+my $count = 0;
+
+print
+  "/* generated by src/common/unicode/generate-unicode_combining_table.pl, do not edit */\n\n";
+
+print "static const struct mbinterval combining[] = {\n";
+
+foreach my $line (<ARGV>)
+{
+	chomp $line;
+	my @fields = split ';', $line;
+	$codepoint = hex $fields[0];
+
+	next if $codepoint > 0xFFFF;
+
+	if ($fields[2] eq 'Me' || $fields[2] eq 'Mn')
+	{
+		# combining character, save for start of range
+		if (!defined($range_start))
+		{
+			$range_start = $codepoint;
+		}
+	}
+	else
+	{
+		# not a combining character, print out previous range if any
+		if (defined($range_start))
+		{
+			printf "\t{0x%04X, 0x%04X},\n", $range_start, $prev_codepoint;
+			$range_start = undef;
+		}
+	}
+}
+continue
+{
+	$prev_codepoint = $codepoint;
+}
+
+print "};\n";
diff --git a/src/common/unicode/generate-unicode_norm_table.pl b/src/common/unicode/generate-unicode_norm_table.pl
new file mode 100644
index 0000000..114ab30
--- /dev/null
+++ b/src/common/unicode/generate-unicode_norm_table.pl
@@ -0,0 +1,406 @@
+#!/usr/bin/perl
+#
+# Generate a composition table and its lookup utilities, using Unicode data
+# files as input.
+#
+# Input: UnicodeData.txt and CompositionExclusions.txt
+# Output: unicode_norm_table.h and unicode_norm_hashfunc.h
+#
+# Copyright (c) 2000-2021, PostgreSQL Global Development Group
+
+use strict;
+use warnings;
+
+use FindBin;
+use lib "$FindBin::RealBin/../../tools/";
+use PerfectHash;
+
+my $output_table_file = "unicode_norm_table.h";
+my $output_func_file  = "unicode_norm_hashfunc.h";
+
+my $FH;
+
+# Read list of codes that should be excluded from re-composition.
+my @composition_exclusion_codes = ();
+open($FH, '<', "CompositionExclusions.txt")
+  or die "Could not open CompositionExclusions.txt: $!.";
+while (my $line = <$FH>)
+{
+	if ($line =~ /^([[:xdigit:]]+)/)
+	{
+		push @composition_exclusion_codes, $1;
+	}
+}
+close $FH;
+
+# Read entries from UnicodeData.txt into a list, and a hash table. We need
+# three fields from each row: the codepoint, canonical combining class,
+# and character decomposition mapping
+my @characters     = ();
+my %character_hash = ();
+open($FH, '<', "UnicodeData.txt")
+  or die "Could not open UnicodeData.txt: $!.";
+while (my $line = <$FH>)
+{
+
+	# Split the line wanted and get the fields needed:
+	# - Unicode code value
+	# - Canonical Combining Class
+	# - Character Decomposition Mapping
+	my @elts   = split(';', $line);
+	my $code   = $elts[0];
+	my $class  = $elts[3];
+	my $decomp = $elts[5];
+
+	# Skip codepoints above U+10FFFF. They cannot be represented in 4 bytes
+	# in UTF-8, and PostgreSQL doesn't support UTF-8 characters longer than
+	# 4 bytes. (This is just pro forma, as there aren't any such entries in
+	# the data file, currently.)
+	next if hex($code) > 0x10FFFF;
+
+	# Skip characters with no decompositions and a class of 0, to reduce the
+	# table size.
+	next if $class eq '0' && $decomp eq '';
+
+	my %char_entry = (code => $code, class => $class, decomp => $decomp);
+	push(@characters, \%char_entry);
+	$character_hash{$code} = \%char_entry;
+}
+close $FH;
+
+my $num_characters = scalar @characters;
+
+# Start writing out the output files
+open my $OT, '>', $output_table_file
+  or die "Could not open output file $output_table_file: $!\n";
+open my $OF, '>', $output_func_file
+  or die "Could not open output file $output_func_file: $!\n";
+
+print $OT <<HEADER;
+/*-------------------------------------------------------------------------
+ *
+ * unicode_norm_table.h
+ *	  Composition table used for Unicode normalization
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/common/unicode_norm_table.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*
+ * File auto-generated by src/common/unicode/generate-unicode_norm_table.pl,
+ * do not edit. There is deliberately not an #ifndef PG_UNICODE_NORM_TABLE_H
+ * here.
+ */
+typedef struct
+{
+	uint32		codepoint;		/* Unicode codepoint */
+	uint8		comb_class;		/* combining class of character */
+	uint8		dec_size_flags; /* size and flags of decomposition code list */
+	uint16		dec_index;		/* index into UnicodeDecomp_codepoints, or the
+								 * decomposition itself if DECOMP_INLINE */
+} pg_unicode_decomposition;
+
+#define DECOMP_NO_COMPOSE	0x80	/* don't use for re-composition */
+#define DECOMP_INLINE		0x40	/* decomposition is stored inline in
+									 * dec_index */
+#define DECOMP_COMPAT		0x20	/* compatibility mapping */
+
+#define DECOMPOSITION_SIZE(x) ((x)->dec_size_flags & 0x1F)
+#define DECOMPOSITION_NO_COMPOSE(x) (((x)->dec_size_flags & (DECOMP_NO_COMPOSE | DECOMP_COMPAT)) != 0)
+#define DECOMPOSITION_IS_INLINE(x) (((x)->dec_size_flags & DECOMP_INLINE) != 0)
+#define DECOMPOSITION_IS_COMPAT(x) (((x)->dec_size_flags & DECOMP_COMPAT) != 0)
+
+/* Table of Unicode codepoints and their decompositions */
+static const pg_unicode_decomposition UnicodeDecompMain[$num_characters] =
+{
+HEADER
+
+print $OF <<HEADER;
+/*-------------------------------------------------------------------------
+ *
+ * unicode_norm_hashfunc.h
+ *	  Perfect hash functions used for Unicode normalization
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/common/unicode_norm_hashfunc.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*
+ * File auto-generated by src/common/unicode/generate-unicode_norm_table.pl,
+ * do not edit. There is deliberately not an #ifndef PG_UNICODE_NORM_HASHFUNC_H
+ * here.
+ */
+
+#include "common/unicode_norm_table.h"
+
+/* Typedef for perfect hash functions */
+typedef int (*cp_hash_func) (const void *key);
+
+/* Information for lookups with perfect hash functions */
+typedef struct
+{
+	const pg_unicode_decomposition *decomps;
+	cp_hash_func	hash;
+	int		num_decomps;
+} pg_unicode_decompinfo;
+
+typedef struct
+{
+	const uint16	*inverse_lookup;
+	cp_hash_func	hash;
+	int		num_recomps;
+} pg_unicode_recompinfo;
+
+HEADER
+
+my $decomp_index  = 0;
+my $decomp_string = "";
+my @dec_cp_packed;
+my $main_index = 0;
+my @rec_info;
+
+my $last_code = $characters[-1]->{code};
+foreach my $char (@characters)
+{
+	my $code   = $char->{code};
+	my $class  = $char->{class};
+	my $decomp = $char->{decomp};
+
+	# Save the code point bytes as a string in network order.
+	push @dec_cp_packed, pack('N', hex($char->{code}));
+
+	# The character decomposition mapping field in UnicodeData.txt is a list
+	# of unicode codepoints, separated by space. But it can be prefixed with
+	# so-called compatibility formatting tag, like "<compat>", or "<font>".
+	# The entries with compatibility formatting tags should not be used for
+	# re-composing characters during normalization, so flag them in the table.
+	# (The tag doesn't matter, only whether there is a tag or not)
+	my $compat = 0;
+	if ($decomp =~ /\<.*\>/)
+	{
+		$compat = 1;
+		$decomp =~ s/\<[^][]*\>//g;
+	}
+	my @decomp_elts = split(" ", $decomp);
+
+	# Decomposition size
+	# Print size of decomposition
+	my $decomp_size = scalar(@decomp_elts);
+	die if $decomp_size > 0x1F;    # to not overrun bitmask
+
+	my $first_decomp = shift @decomp_elts;
+
+	my $flags   = "";
+	my $comment = "";
+
+	if ($compat)
+	{
+		$flags .= " | DECOMP_COMPAT";
+	}
+
+	if ($decomp_size == 2)
+	{
+		# Should this be used for recomposition?
+		if (   $character_hash{$first_decomp}
+			&& $character_hash{$first_decomp}->{class} != 0)
+		{
+			$flags .= " | DECOMP_NO_COMPOSE";
+			$comment = "non-starter decomposition";
+		}
+		else
+		{
+			foreach my $lcode (@composition_exclusion_codes)
+			{
+				if ($lcode eq $code)
+				{
+					$flags .= " | DECOMP_NO_COMPOSE";
+					$comment = "in exclusion list";
+					last;
+				}
+			}
+		}
+
+		# Save info for recomposeable codepoints.
+		# Note that this MUST match the macro DECOMPOSITION_NO_COMPOSE in C
+		# above!  See also the inverse lookup in recompose_code() found in
+		# src/common/unicode_norm.c.
+		if (!($flags =~ /DECOMP_COMPAT/ || $flags =~ /DECOMP_NO_COMPOSE/))
+		{
+			push @rec_info,
+			  {
+				code       => $code,
+				main_index => $main_index,
+				first      => $first_decomp,
+				second     => $decomp_elts[0]
+			  };
+		}
+	}
+
+	if ($decomp_size == 0)
+	{
+		print $OT "\t{0x$code, $class, 0$flags, 0}";
+	}
+	elsif ($decomp_size == 1 && length($first_decomp) <= 4)
+	{
+
+		# The decomposition consists of a single codepoint, and it fits
+		# in a uint16, so we can store it "inline" in the main table.
+		$flags .= " | DECOMP_INLINE";
+		print $OT "\t{0x$code, $class, 1$flags, 0x$first_decomp}";
+	}
+	else
+	{
+		print $OT "\t{0x$code, $class, $decomp_size$flags, $decomp_index}";
+
+		# Now save the decompositions into a dedicated area that will
+		# be written afterwards.  First build the entry dedicated to
+		# a sub-table with the code and decomposition.
+		$decomp_string .= ",\n" if ($decomp_string ne "");
+
+		$decomp_string .= "\t /* $decomp_index */ 0x$first_decomp";
+		foreach (@decomp_elts)
+		{
+			$decomp_string .= ", 0x$_";
+		}
+
+		$decomp_index = $decomp_index + $decomp_size;
+	}
+
+	# Print a comma after all items except the last one.
+	print $OT "," unless ($code eq $last_code);
+
+	print $OT "\t/* $comment */" if ($comment ne "");
+	print $OT "\n";
+
+	$main_index++;
+}
+print $OT "\n};\n\n";
+
+# Print the array of decomposed codes.
+print $OT <<HEADER;
+/* codepoints array  */
+static const uint32 UnicodeDecomp_codepoints[$decomp_index] =
+{
+$decomp_string
+};
+HEADER
+
+# Emit the definition of the decomp hash function.
+my $dec_funcname = 'Decomp_hash_func';
+my $dec_func     = PerfectHash::generate_hash_function(\@dec_cp_packed,
+	$dec_funcname, fixed_key_length => 4);
+print $OF "/* Perfect hash function for decomposition */\n";
+print $OF "static $dec_func\n";
+
+# Emit the structure that wraps the hash lookup information into
+# one variable.
+print $OF <<HEADER;
+/* Hash lookup information for decomposition */
+static const pg_unicode_decompinfo UnicodeDecompInfo =
+{
+	UnicodeDecompMain,
+	$dec_funcname,
+	$num_characters
+};
+
+HEADER
+
+# Find the lowest codepoint that decomposes to each recomposeable
+# code pair and create a mapping to it.
+my $recomp_string = "";
+my @rec_cp_packed;
+my %seenit;
+my $firstentry = 1;
+foreach my $rec (sort recomp_sort @rec_info)
+{
+	# The hash key is formed by concatenating the bytes of the two
+	# codepoints. See also recompose_code() in common/unicode_norm.c.
+	my $hashkey = (hex($rec->{first}) << 32) | hex($rec->{second});
+
+	# We are only interested in the lowest code point that decomposes
+	# to the given code pair.
+	next if $seenit{$hashkey};
+
+	# Save the hash key bytes in network order
+	push @rec_cp_packed, pack('Q>', $hashkey);
+
+	# Append inverse lookup element
+	$recomp_string .= ",\n" if !$firstentry;
+	$recomp_string .= sprintf "\t/* U+%s+%s -> U+%s */ %s",
+	  $rec->{first},
+	  $rec->{second},
+	  $rec->{code},
+	  $rec->{main_index};
+
+	$seenit{$hashkey} = 1;
+	$firstentry = 0;
+}
+
+# Emit the inverse lookup array containing indexes into UnicodeDecompMain.
+my $num_recomps = scalar @rec_cp_packed;
+print $OF <<HEADER;
+/* Inverse lookup array -- contains indexes into UnicodeDecompMain[] */
+static const uint16 RecompInverseLookup[$num_recomps] =
+{
+$recomp_string
+};
+
+HEADER
+
+# Emit the definition of the recomposition hash function.
+my $rec_funcname = 'Recomp_hash_func';
+my $rec_func =
+  PerfectHash::generate_hash_function(\@rec_cp_packed, $rec_funcname,
+	fixed_key_length => 8);
+print $OF "/* Perfect hash function for recomposition */\n";
+print $OF "static $rec_func\n";
+
+# Emit the structure that wraps the hash lookup information into
+# one variable.
+print $OF <<HEADER;
+/* Hash lookup information for recomposition */
+static const pg_unicode_recompinfo UnicodeRecompInfo =
+{
+	RecompInverseLookup,
+	$rec_funcname,
+	$num_recomps
+};
+HEADER
+
+close $OT;
+close $OF;
+
+sub recomp_sort
+{
+	my $a1 = hex($a->{first});
+	my $b1 = hex($b->{first});
+
+	my $a2 = hex($a->{second});
+	my $b2 = hex($b->{second});
+
+	# First sort by the first code point
+	return -1 if $a1 < $b1;
+	return 1  if $a1 > $b1;
+
+	# Then sort by the second code point
+	return -1 if $a2 < $b2;
+	return 1  if $a2 > $b2;
+
+	# Finally sort by the code point that decomposes into first and
+	# second ones.
+	my $acode = hex($a->{code});
+	my $bcode = hex($b->{code});
+
+	return -1 if $acode < $bcode;
+	return 1  if $acode > $bcode;
+
+	die "found duplicate entries of recomposeable code pairs";
+}
diff --git a/src/common/unicode/generate-unicode_normprops_table.pl b/src/common/unicode/generate-unicode_normprops_table.pl
new file mode 100644
index 0000000..c7795d1
--- /dev/null
+++ b/src/common/unicode/generate-unicode_normprops_table.pl
@@ -0,0 +1,125 @@
+#!/usr/bin/perl
+#
+# Generate table of Unicode normalization "quick check" properties
+# (see UAX #15).  Pass DerivedNormalizationProps.txt as argument.  The
+# output is on stdout.
+#
+# Copyright (c) 2020-2021, PostgreSQL Global Development Group
+
+use strict;
+use warnings;
+
+use FindBin;
+use lib "$FindBin::RealBin/../../tools/";
+use PerfectHash;
+
+my %data;
+
+print
+  "/* generated by src/common/unicode/generate-unicode_normprops_table.pl, do not edit */\n\n";
+
+print <<EOS;
+#include "common/unicode_norm.h"
+
+/*
+ * Normalization quick check entry for codepoint.  We use a bit field
+ * here to save space.
+ */
+typedef struct
+{
+	unsigned int codepoint:21;
+	signed int	quickcheck:4;	/* really UnicodeNormalizationQC */
+} pg_unicode_normprops;
+
+/* Typedef for hash function on quick check table */
+typedef int (*qc_hash_func) (const void *key);
+
+/* Information for quick check lookup with perfect hash function */
+typedef struct
+{
+	const pg_unicode_normprops *normprops;
+	qc_hash_func	hash;
+	int		num_normprops;
+} pg_unicode_norminfo;
+EOS
+
+foreach my $line (<ARGV>)
+{
+	chomp $line;
+	$line =~ s/\s*#.*$//;
+	next if $line eq '';
+	my ($codepoint, $prop, $value) = split /\s*;\s*/, $line;
+	next if $prop !~ /_QC/;
+
+	my ($first, $last);
+	if ($codepoint =~ /\.\./)
+	{
+		($first, $last) = split /\.\./, $codepoint;
+	}
+	else
+	{
+		$first = $last = $codepoint;
+	}
+
+	foreach my $cp (hex($first) .. hex($last))
+	{
+		$data{$prop}{$cp} = $value;
+	}
+}
+
+# We create a separate array for each normalization form rather than,
+# say, a two-dimensional array, because that array would be very
+# sparse and would create unnecessary overhead especially for the NFC
+# lookup.
+foreach my $prop (sort keys %data)
+{
+	# Don't build the tables for the "D" forms because they are too
+	# big.  See also unicode_is_normalized_quickcheck().
+	next if $prop eq "NFD_QC" || $prop eq "NFKD_QC";
+
+	print "\n";
+	print
+	  "static const pg_unicode_normprops UnicodeNormProps_${prop}[] = {\n";
+
+	my %subdata = %{ $data{$prop} };
+	my @cp_packed;
+	foreach my $cp (sort { $a <=> $b } keys %subdata)
+	{
+		my $qc;
+		if ($subdata{$cp} eq 'N')
+		{
+			$qc = 'UNICODE_NORM_QC_NO';
+		}
+		elsif ($subdata{$cp} eq 'M')
+		{
+			$qc = 'UNICODE_NORM_QC_MAYBE';
+		}
+		else
+		{
+			die;
+		}
+		printf "\t{0x%04X, %s},\n", $cp, $qc;
+
+		# Save the bytes as a string in network order.
+		push @cp_packed, pack('N', $cp);
+	}
+
+	print "};\n";
+
+	# Emit the definition of the perfect hash function.
+	my $funcname = $prop . '_hash_func';
+	my $f        = PerfectHash::generate_hash_function(\@cp_packed, $funcname,
+		fixed_key_length => 4);
+	printf "\n/* Perfect hash function for %s */", $prop;
+	print "\nstatic $f\n";
+
+	# Emit the structure that wraps the hash lookup information into
+	# one variable.
+	printf "/* Hash lookup information for %s */", $prop;
+	printf "\nstatic const pg_unicode_norminfo ";
+	printf "UnicodeNormInfo_%s = {\n", $prop;
+	printf "\tUnicodeNormProps_%s,\n", $prop;
+	printf "\t%s,\n",                  $funcname;
+	printf "\t%d\n",                   scalar @cp_packed;
+	printf "};\n";
+}
diff --git a/src/common/unicode/norm_test.c b/src/common/unicode/norm_test.c
new file mode 100644
index 0000000..cd2cb29
--- /dev/null
+++ b/src/common/unicode/norm_test.c
@@ -0,0 +1,86 @@
+/*-------------------------------------------------------------------------
+ * norm_test.c
+ *		Program to test Unicode normalization functions.
+ *
+ * Portions Copyright (c) 2017-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/unicode/norm_test.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres_fe.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "common/unicode_norm.h"
+
+#include "norm_test_table.h"
+
+static char *
+print_wchar_str(const pg_wchar *s)
+{
+#define BUF_DIGITS 50
+	static char buf[BUF_DIGITS * 11 + 1];
+	int			i;
+	char	   *p;
+
+	i = 0;
+	p = buf;
+	while (*s && i < BUF_DIGITS)
+	{
+		p += sprintf(p, "U+%04X ", *s);
+		i++;
+		s++;
+	}
+	*p = '\0';
+
+	return buf;
+}
+
+static int
+pg_wcscmp(const pg_wchar *s1, const pg_wchar *s2)
+{
+	for (;;)
+	{
+		if (*s1 < *s2)
+			return -1;
+		if (*s1 > *s2)
+			return 1;
+		if (*s1 == 0)
+			return 0;
+		s1++;
+		s2++;
+	}
+}
+
+int
+main(int argc, char **argv)
+{
+	const		pg_unicode_test *test;
+
+	for (test = UnicodeNormalizationTests; test->input[0] != 0; test++)
+	{
+		for (int form = 0; form < 4; form++)
+		{
+			pg_wchar   *result;
+
+			result = unicode_normalize(form, test->input);
+
+			if (pg_wcscmp(test->output[form], result) != 0)
+			{
+				printf("FAILURE (NormalizationTest.txt line %d form %d):\n", test->linenum, form);
+				printf("input:    %s\n", print_wchar_str(test->input));
+				printf("expected: %s\n", print_wchar_str(test->output[form]));
+				printf("got:      %s\n", print_wchar_str(result));
+				printf("\n");
+				exit(1);
+			}
+		}
+	}
+
+	printf("All tests successful!\n");
+	exit(0);
+}
diff --git a/src/common/unicode_norm.c b/src/common/unicode_norm.c
new file mode 100644
index 0000000..06bf921
--- /dev/null
+++ b/src/common/unicode_norm.c
@@ -0,0 +1,634 @@
+/*-------------------------------------------------------------------------
+ * unicode_norm.c
+ *		Normalize a Unicode string
+ *
+ * This implements Unicode normalization, per the documentation at
+ * https://www.unicode.org/reports/tr15/.
+ *
+ * Portions Copyright (c) 2017-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/unicode_norm.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include "common/unicode_norm.h"
+#ifndef FRONTEND
+#include "common/unicode_norm_hashfunc.h"
+#include "common/unicode_normprops_table.h"
+#include "port/pg_bswap.h"
+#else
+#include "common/unicode_norm_table.h"
+#endif
+
+#ifndef FRONTEND
+#define ALLOC(size) palloc(size)
+#define FREE(size) pfree(size)
+#else
+#define ALLOC(size) malloc(size)
+#define FREE(size) free(size)
+#endif
+
+/* Constants for calculations with Hangul characters */
+#define SBASE		0xAC00		/* U+AC00 */
+#define LBASE		0x1100		/* U+1100 */
+#define VBASE		0x1161		/* U+1161 */
+#define TBASE		0x11A7		/* U+11A7 */
+#define LCOUNT		19
+#define VCOUNT		21
+#define TCOUNT		28
+#define NCOUNT		VCOUNT * TCOUNT
+#define SCOUNT		LCOUNT * NCOUNT
+
+#ifdef FRONTEND
+/* comparison routine for bsearch() of decomposition lookup table. */
+static int
+conv_compare(const void *p1, const void *p2)
+{
+	uint32		v1,
+				v2;
+
+	v1 = *(const uint32 *) p1;
+	v2 = ((const pg_unicode_decomposition *) p2)->codepoint;
+	return (v1 > v2) ? 1 : ((v1 == v2) ? 0 : -1);
+}
+
+#endif
+
+/*
+ * get_code_entry
+ *
+ * Get the entry corresponding to code in the decomposition lookup table.
+ * The backend version of this code uses a perfect hash function for the
+ * lookup, while the frontend version uses a binary search.
+ */
+static const pg_unicode_decomposition *
+get_code_entry(pg_wchar code)
+{
+#ifndef FRONTEND
+	int			h;
+	uint32		hashkey;
+	pg_unicode_decompinfo decompinfo = UnicodeDecompInfo;
+
+	/*
+	 * Compute the hash function. The hash key is the codepoint with the bytes
+	 * in network order.
+	 */
+	hashkey = pg_hton32(code);
+	h = decompinfo.hash(&hashkey);
+
+	/* An out-of-range result implies no match */
+	if (h < 0 || h >= decompinfo.num_decomps)
+		return NULL;
+
+	/*
+	 * Since it's a perfect hash, we need only match to the specific codepoint
+	 * it identifies.
+	 */
+	if (code != decompinfo.decomps[h].codepoint)
+		return NULL;
+
+	/* Success! */
+	return &decompinfo.decomps[h];
+#else
+	return bsearch(&(code),
+				   UnicodeDecompMain,
+				   lengthof(UnicodeDecompMain),
+				   sizeof(pg_unicode_decomposition),
+				   conv_compare);
+#endif
+}
+
+/*
+ * Get the combining class of the given codepoint.
+ */
+static uint8
+get_canonical_class(pg_wchar code)
+{
+	const pg_unicode_decomposition *entry = get_code_entry(code);
+
+	/*
+	 * If no entries are found, the character used is either an Hangul
+	 * character or a character with a class of 0 and no decompositions.
+	 */
+	if (!entry)
+		return 0;
+	else
+		return entry->comb_class;
+}
+
+/*
+ * Given a decomposition entry looked up earlier, get the decomposed
+ * characters.
+ *
+ * Note: the returned pointer can point to statically allocated buffer, and
+ * is only valid until next call to this function!
+ */
+static const pg_wchar *
+get_code_decomposition(const pg_unicode_decomposition *entry, int *dec_size)
+{
+	static pg_wchar x;
+
+	if (DECOMPOSITION_IS_INLINE(entry))
+	{
+		Assert(DECOMPOSITION_SIZE(entry) == 1);
+		x = (pg_wchar) entry->dec_index;
+		*dec_size = 1;
+		return &x;
+	}
+	else
+	{
+		*dec_size = DECOMPOSITION_SIZE(entry);
+		return &UnicodeDecomp_codepoints[entry->dec_index];
+	}
+}
+
+/*
+ * Calculate how many characters a given character will decompose to.
+ *
+ * This needs to recurse, if the character decomposes into characters that
+ * are, in turn, decomposable.
+ */
+static int
+get_decomposed_size(pg_wchar code, bool compat)
+{
+	const pg_unicode_decomposition *entry;
+	int			size = 0;
+	int			i;
+	const uint32 *decomp;
+	int			dec_size;
+
+	/*
+	 * Fast path for Hangul characters not stored in tables to save memory as
+	 * decomposition is algorithmic. See
+	 * https://www.unicode.org/reports/tr15/tr15-18.html, annex 10 for details
+	 * on the matter.
+	 */
+	if (code >= SBASE && code < SBASE + SCOUNT)
+	{
+		uint32		tindex,
+					sindex;
+
+		sindex = code - SBASE;
+		tindex = sindex % TCOUNT;
+
+		if (tindex != 0)
+			return 3;
+		return 2;
+	}
+
+	entry = get_code_entry(code);
+
+	/*
+	 * Just count current code if no other decompositions.  A NULL entry is
+	 * equivalent to a character with class 0 and no decompositions.
+	 */
+	if (entry == NULL || DECOMPOSITION_SIZE(entry) == 0 ||
+		(!compat && DECOMPOSITION_IS_COMPAT(entry)))
+		return 1;
+
+	/*
+	 * If this entry has other decomposition codes look at them as well. First
+	 * get its decomposition in the list of tables available.
+	 */
+	decomp = get_code_decomposition(entry, &dec_size);
+	for (i = 0; i < dec_size; i++)
+	{
+		uint32		lcode = decomp[i];
+
+		size += get_decomposed_size(lcode, compat);
+	}
+
+	return size;
+}
+
+/*
+ * Recompose a set of characters. For hangul characters, the calculation
+ * is algorithmic. For others, an inverse lookup at the decomposition
+ * table is necessary. Returns true if a recomposition can be done, and
+ * false otherwise.
+ */
+static bool
+recompose_code(uint32 start, uint32 code, uint32 *result)
+{
+	/*
+	 * Handle Hangul characters algorithmically, per the Unicode spec.
+	 *
+	 * Check if two current characters are L and V.
+	 */
+	if (start >= LBASE && start < LBASE + LCOUNT &&
+		code >= VBASE && code < VBASE + VCOUNT)
+	{
+		/* make syllable of form LV */
+		uint32		lindex = start - LBASE;
+		uint32		vindex = code - VBASE;
+
+		*result = SBASE + (lindex * VCOUNT + vindex) * TCOUNT;
+		return true;
+	}
+	/* Check if two current characters are LV and T */
+	else if (start >= SBASE && start < (SBASE + SCOUNT) &&
+			 ((start - SBASE) % TCOUNT) == 0 &&
+			 code >= TBASE && code < (TBASE + TCOUNT))
+	{
+		/* make syllable of form LVT */
+		uint32		tindex = code - TBASE;
+
+		*result = start + tindex;
+		return true;
+	}
+	else
+	{
+		const pg_unicode_decomposition *entry;
+
+		/*
+		 * Do an inverse lookup of the decomposition tables to see if anything
+		 * matches. The comparison just needs to be a perfect match on the
+		 * sub-table of size two, because the start character has already been
+		 * recomposed partially.  This lookup uses a perfect hash function for
+		 * the backend code.
+		 */
+#ifndef FRONTEND
+
+		int			h,
+					inv_lookup_index;
+		uint64		hashkey;
+		pg_unicode_recompinfo recompinfo = UnicodeRecompInfo;
+
+		/*
+		 * Compute the hash function. The hash key is formed by concatenating
+		 * bytes of the two codepoints in network order. See also
+		 * src/common/unicode/generate-unicode_norm_table.pl.
+		 */
+		hashkey = pg_hton64(((uint64) start << 32) | (uint64) code);
+		h = recompinfo.hash(&hashkey);
+
+		/* An out-of-range result implies no match */
+		if (h < 0 || h >= recompinfo.num_recomps)
+			return false;
+
+		inv_lookup_index = recompinfo.inverse_lookup[h];
+		entry = &UnicodeDecompMain[inv_lookup_index];
+
+		if (start == UnicodeDecomp_codepoints[entry->dec_index] &&
+			code == UnicodeDecomp_codepoints[entry->dec_index + 1])
+		{
+			*result = entry->codepoint;
+			return true;
+		}
+
+#else
+
+		int			i;
+
+		for (i = 0; i < lengthof(UnicodeDecompMain); i++)
+		{
+			entry = &UnicodeDecompMain[i];
+
+			if (DECOMPOSITION_SIZE(entry) != 2)
+				continue;
+
+			if (DECOMPOSITION_NO_COMPOSE(entry))
+				continue;
+
+			if (start == UnicodeDecomp_codepoints[entry->dec_index] &&
+				code == UnicodeDecomp_codepoints[entry->dec_index + 1])
+			{
+				*result = entry->codepoint;
+				return true;
+			}
+		}
+#endif							/* !FRONTEND */
+	}
+
+	return false;
+}
+
+/*
+ * Decompose the given code into the array given by caller. The
+ * decomposition begins at the position given by caller, saving one
+ * lookup on the decomposition table. The current position needs to be
+ * updated here to let the caller know from where to continue filling
+ * in the array result.
+ */
+static void
+decompose_code(pg_wchar code, bool compat, pg_wchar **result, int *current)
+{
+	const pg_unicode_decomposition *entry;
+	int			i;
+	const uint32 *decomp;
+	int			dec_size;
+
+	/*
+	 * Fast path for Hangul characters not stored in tables to save memory as
+	 * decomposition is algorithmic. See
+	 * https://www.unicode.org/reports/tr15/tr15-18.html, annex 10 for details
+	 * on the matter.
+	 */
+	if (code >= SBASE && code < SBASE + SCOUNT)
+	{
+		uint32		l,
+					v,
+					tindex,
+					sindex;
+		pg_wchar   *res = *result;
+
+		sindex = code - SBASE;
+		l = LBASE + sindex / (VCOUNT * TCOUNT);
+		v = VBASE + (sindex % (VCOUNT * TCOUNT)) / TCOUNT;
+		tindex = sindex % TCOUNT;
+
+		res[*current] = l;
+		(*current)++;
+		res[*current] = v;
+		(*current)++;
+
+		if (tindex != 0)
+		{
+			res[*current] = TBASE + tindex;
+			(*current)++;
+		}
+
+		return;
+	}
+
+	entry = get_code_entry(code);
+
+	/*
+	 * Just fill in with the current decomposition if there are no
+	 * decomposition codes to recurse to.  A NULL entry is equivalent to a
+	 * character with class 0 and no decompositions, so just leave also in
+	 * this case.
+	 */
+	if (entry == NULL || DECOMPOSITION_SIZE(entry) == 0 ||
+		(!compat && DECOMPOSITION_IS_COMPAT(entry)))
+	{
+		pg_wchar   *res = *result;
+
+		res[*current] = code;
+		(*current)++;
+		return;
+	}
+
+	/*
+	 * If this entry has other decomposition codes look at them as well.
+	 */
+	decomp = get_code_decomposition(entry, &dec_size);
+	for (i = 0; i < dec_size; i++)
+	{
+		pg_wchar	lcode = (pg_wchar) decomp[i];
+
+		/* Leave if no more decompositions */
+		decompose_code(lcode, compat, result, current);
+	}
+}
+
+/*
+ * unicode_normalize - Normalize a Unicode string to the specified form.
+ *
+ * The input is a 0-terminated array of codepoints.
+ *
+ * In frontend, returns a 0-terminated array of codepoints, allocated with
+ * malloc. Or NULL if we run out of memory. In backend, the returned
+ * string is palloc'd instead, and OOM is reported with ereport().
+ */
+pg_wchar *
+unicode_normalize(UnicodeNormalizationForm form, const pg_wchar *input)
+{
+	bool		compat = (form == UNICODE_NFKC || form == UNICODE_NFKD);
+	bool		recompose = (form == UNICODE_NFC || form == UNICODE_NFKC);
+	pg_wchar   *decomp_chars;
+	pg_wchar   *recomp_chars;
+	int			decomp_size,
+				current_size;
+	int			count;
+	const pg_wchar *p;
+
+	/* variables for recomposition */
+	int			last_class;
+	int			starter_pos;
+	int			target_pos;
+	uint32		starter_ch;
+
+	/* First, do character decomposition */
+
+	/*
+	 * Calculate how many characters long the decomposed version will be.
+	 */
+	decomp_size = 0;
+	for (p = input; *p; p++)
+		decomp_size += get_decomposed_size(*p, compat);
+
+	decomp_chars = (pg_wchar *) ALLOC((decomp_size + 1) * sizeof(pg_wchar));
+	if (decomp_chars == NULL)
+		return NULL;
+
+	/*
+	 * Now fill in each entry recursively. This needs a second pass on the
+	 * decomposition table.
+	 */
+	current_size = 0;
+	for (p = input; *p; p++)
+		decompose_code(*p, compat, &decomp_chars, &current_size);
+	decomp_chars[decomp_size] = '\0';
+	Assert(decomp_size == current_size);
+
+	/* Leave if there is nothing to decompose */
+	if (decomp_size == 0)
+		return decomp_chars;
+
+	/*
+	 * Now apply canonical ordering.
+	 */
+	for (count = 1; count < decomp_size; count++)
+	{
+		pg_wchar	prev = decomp_chars[count - 1];
+		pg_wchar	next = decomp_chars[count];
+		pg_wchar	tmp;
+		const uint8 prevClass = get_canonical_class(prev);
+		const uint8 nextClass = get_canonical_class(next);
+
+		/*
+		 * Per Unicode (https://www.unicode.org/reports/tr15/tr15-18.html)
+		 * annex 4, a sequence of two adjacent characters in a string is an
+		 * exchangeable pair if the combining class (from the Unicode
+		 * Character Database) for the first character is greater than the
+		 * combining class for the second, and the second is not a starter.  A
+		 * character is a starter if its combining class is 0.
+		 */
+		if (prevClass == 0 || nextClass == 0)
+			continue;
+
+		if (prevClass <= nextClass)
+			continue;
+
+		/* exchange can happen */
+		tmp = decomp_chars[count - 1];
+		decomp_chars[count - 1] = decomp_chars[count];
+		decomp_chars[count] = tmp;
+
+		/* backtrack to check again */
+		if (count > 1)
+			count -= 2;
+	}
+
+	if (!recompose)
+		return decomp_chars;
+
+	/*
+	 * The last phase of NFC and NFKC is the recomposition of the reordered
+	 * Unicode string using combining classes. The recomposed string cannot be
+	 * longer than the decomposed one, so make the allocation of the output
+	 * string based on that assumption.
+	 */
+	recomp_chars = (pg_wchar *) ALLOC((decomp_size + 1) * sizeof(pg_wchar));
+	if (!recomp_chars)
+	{
+		FREE(decomp_chars);
+		return NULL;
+	}
+
+	last_class = -1;			/* this eliminates a special check */
+	starter_pos = 0;
+	target_pos = 1;
+	starter_ch = recomp_chars[0] = decomp_chars[0];
+
+	for (count = 1; count < decomp_size; count++)
+	{
+		pg_wchar	ch = decomp_chars[count];
+		int			ch_class = get_canonical_class(ch);
+		pg_wchar	composite;
+
+		if (last_class < ch_class &&
+			recompose_code(starter_ch, ch, &composite))
+		{
+			recomp_chars[starter_pos] = composite;
+			starter_ch = composite;
+		}
+		else if (ch_class == 0)
+		{
+			starter_pos = target_pos;
+			starter_ch = ch;
+			last_class = -1;
+			recomp_chars[target_pos++] = ch;
+		}
+		else
+		{
+			last_class = ch_class;
+			recomp_chars[target_pos++] = ch;
+		}
+	}
+	recomp_chars[target_pos] = (pg_wchar) '\0';
+
+	FREE(decomp_chars);
+
+	return recomp_chars;
+}
+
+/*
+ * Normalization "quick check" algorithm; see
+ * <http://www.unicode.org/reports/tr15/#Detecting_Normalization_Forms>
+ */
+
+/* We only need this in the backend. */
+#ifndef FRONTEND
+
+static const pg_unicode_normprops *
+qc_hash_lookup(pg_wchar ch, const pg_unicode_norminfo *norminfo)
+{
+	int			h;
+	uint32		hashkey;
+
+	/*
+	 * Compute the hash function. The hash key is the codepoint with the bytes
+	 * in network order.
+	 */
+	hashkey = pg_hton32(ch);
+	h = norminfo->hash(&hashkey);
+
+	/* An out-of-range result implies no match */
+	if (h < 0 || h >= norminfo->num_normprops)
+		return NULL;
+
+	/*
+	 * Since it's a perfect hash, we need only match to the specific codepoint
+	 * it identifies.
+	 */
+	if (ch != norminfo->normprops[h].codepoint)
+		return NULL;
+
+	/* Success! */
+	return &norminfo->normprops[h];
+}
+
+/*
+ * Look up the normalization quick check character property
+ */
+static UnicodeNormalizationQC
+qc_is_allowed(UnicodeNormalizationForm form, pg_wchar ch)
+{
+	const pg_unicode_normprops *found = NULL;
+
+	switch (form)
+	{
+		case UNICODE_NFC:
+			found = qc_hash_lookup(ch, &UnicodeNormInfo_NFC_QC);
+			break;
+		case UNICODE_NFKC:
+			found = qc_hash_lookup(ch, &UnicodeNormInfo_NFKC_QC);
+			break;
+		default:
+			Assert(false);
+			break;
+	}
+
+	if (found)
+		return found->quickcheck;
+	else
+		return UNICODE_NORM_QC_YES;
+}
+
+UnicodeNormalizationQC
+unicode_is_normalized_quickcheck(UnicodeNormalizationForm form, const pg_wchar *input)
+{
+	uint8		lastCanonicalClass = 0;
+	UnicodeNormalizationQC result = UNICODE_NORM_QC_YES;
+
+	/*
+	 * For the "D" forms, we don't run the quickcheck.  We don't include the
+	 * lookup tables for those because they are huge, checking for these
+	 * particular forms is less common, and running the slow path is faster
+	 * for the "D" forms than the "C" forms because you don't need to
+	 * recompose, which is slow.
+	 */
+	if (form == UNICODE_NFD || form == UNICODE_NFKD)
+		return UNICODE_NORM_QC_MAYBE;
+
+	for (const pg_wchar *p = input; *p; p++)
+	{
+		pg_wchar	ch = *p;
+		uint8		canonicalClass;
+		UnicodeNormalizationQC check;
+
+		canonicalClass = get_canonical_class(ch);
+		if (lastCanonicalClass > canonicalClass && canonicalClass != 0)
+			return UNICODE_NORM_QC_NO;
+
+		check = qc_is_allowed(form, ch);
+		if (check == UNICODE_NORM_QC_NO)
+			return UNICODE_NORM_QC_NO;
+		else if (check == UNICODE_NORM_QC_MAYBE)
+			result = UNICODE_NORM_QC_MAYBE;
+
+		lastCanonicalClass = canonicalClass;
+	}
+	return result;
+}
+
+#endif							/* !FRONTEND */
diff --git a/src/common/username.c b/src/common/username.c
new file mode 100644
index 0000000..669b8ab
--- /dev/null
+++ b/src/common/username.c
@@ -0,0 +1,87 @@
+/*-------------------------------------------------------------------------
+ *
+ * username.c
+ *	  get user name
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/common/username.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <pwd.h>
+#include <unistd.h>
+
+#include "common/username.h"
+
+/*
+ * Returns the current user name in a static buffer
+ * On error, returns NULL and sets *errstr to point to a palloc'd message
+ */
+const char *
+get_user_name(char **errstr)
+{
+#ifndef WIN32
+	struct passwd *pw;
+	uid_t		user_id = geteuid();
+
+	*errstr = NULL;
+
+	errno = 0;					/* clear errno before call */
+	pw = getpwuid(user_id);
+	if (!pw)
+	{
+		*errstr = psprintf(_("could not look up effective user ID %ld: %s"),
+						   (long) user_id,
+						   errno ? strerror(errno) : _("user does not exist"));
+		return NULL;
+	}
+
+	return pw->pw_name;
+#else
+	/* Microsoft recommends buffer size of UNLEN+1, where UNLEN = 256 */
+	/* "static" variable remains after function exit */
+	static char username[256 + 1];
+	DWORD		len = sizeof(username);
+
+	*errstr = NULL;
+
+	if (!GetUserName(username, &len))
+	{
+		*errstr = psprintf(_("user name lookup failure: error code %lu"),
+						   GetLastError());
+		return NULL;
+	}
+
+	return username;
+#endif
+}
+
+
+/*
+ * Returns the current user name in a static buffer or exits
+ */
+const char *
+get_user_name_or_exit(const char *progname)
+{
+	const char *user_name;
+	char	   *errstr;
+
+	user_name = get_user_name(&errstr);
+
+	if (!user_name)
+	{
+		fprintf(stderr, "%s: %s\n", progname, errstr);
+		exit(1);
+	}
+	return user_name;
+}
diff --git a/src/common/wait_error.c b/src/common/wait_error.c
new file mode 100644
index 0000000..9f860ee
--- /dev/null
+++ b/src/common/wait_error.c
@@ -0,0 +1,119 @@
+/*-------------------------------------------------------------------------
+ *
+ * wait_error.c
+ *		Convert a wait/waitpid(2) result code to a human-readable string
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/common/wait_error.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef FRONTEND
+#include "postgres.h"
+#else
+#include "postgres_fe.h"
+#endif
+
+#include <signal.h>
+#include <sys/wait.h>
+
+/*
+ * Return a human-readable string explaining the reason a child process
+ * terminated. The argument is a return code returned by wait(2) or
+ * waitpid(2). The result is a translated, palloc'd or malloc'd string.
+ */
+char *
+wait_result_to_str(int exitstatus)
+{
+	char		str[512];
+
+	if (WIFEXITED(exitstatus))
+	{
+		/*
+		 * Give more specific error message for some common exit codes that
+		 * have a special meaning in shells.
+		 */
+		switch (WEXITSTATUS(exitstatus))
+		{
+			case 126:
+				snprintf(str, sizeof(str), _("command not executable"));
+				break;
+
+			case 127:
+				snprintf(str, sizeof(str), _("command not found"));
+				break;
+
+			default:
+				snprintf(str, sizeof(str),
+						 _("child process exited with exit code %d"),
+						 WEXITSTATUS(exitstatus));
+		}
+	}
+	else if (WIFSIGNALED(exitstatus))
+	{
+#if defined(WIN32)
+		snprintf(str, sizeof(str),
+				 _("child process was terminated by exception 0x%X"),
+				 WTERMSIG(exitstatus));
+#else
+		snprintf(str, sizeof(str),
+				 _("child process was terminated by signal %d: %s"),
+				 WTERMSIG(exitstatus), pg_strsignal(WTERMSIG(exitstatus)));
+#endif
+	}
+	else
+		snprintf(str, sizeof(str),
+				 _("child process exited with unrecognized status %d"),
+				 exitstatus);
+
+	return pstrdup(str);
+}
+
+/*
+ * Return true if a wait(2) result indicates that the child process
+ * died due to the specified signal.
+ *
+ * The reason this is worth having a wrapper function for is that
+ * there are two cases: the signal might have been received by our
+ * immediate child process, or there might've been a shell process
+ * between us and the child that died.  The shell will, per POSIX,
+ * report the child death using exit code 128 + signal number.
+ *
+ * If there is no possibility of an intermediate shell, this function
+ * need not (and probably should not) be used.
+ */
+bool
+wait_result_is_signal(int exit_status, int signum)
+{
+	if (WIFSIGNALED(exit_status) && WTERMSIG(exit_status) == signum)
+		return true;
+	if (WIFEXITED(exit_status) && WEXITSTATUS(exit_status) == 128 + signum)
+		return true;
+	return false;
+}
+
+/*
+ * Return true if a wait(2) result indicates that the child process
+ * died due to any signal.  We consider either direct child death
+ * or a shell report of child process death as matching the condition.
+ *
+ * If include_command_not_found is true, also return true for shell
+ * exit codes indicating "command not found" and the like
+ * (specifically, exit codes 126 and 127; see above).
+ */
+bool
+wait_result_is_any_signal(int exit_status, bool include_command_not_found)
+{
+	if (WIFSIGNALED(exit_status))
+		return true;
+	if (WIFEXITED(exit_status) &&
+		WEXITSTATUS(exit_status) > (include_command_not_found ? 125 : 128))
+		return true;
+	return false;
+}
diff --git a/src/common/wchar.c b/src/common/wchar.c
new file mode 100644
index 0000000..0636b87
--- /dev/null
+++ b/src/common/wchar.c
@@ -0,0 +1,1984 @@
+/*-------------------------------------------------------------------------
+ *
+ * wchar.c
+ *	  Functions for working with multibyte characters in various encodings.
+ *
+ * Portions Copyright (c) 1998-2021, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/wchar.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include "mb/pg_wchar.h"
+
+
+/*
+ * Operations on multi-byte encodings are driven by a table of helper
+ * functions.
+ *
+ * To add an encoding support, define mblen(), dsplen(), verifychar() and
+ * verifystr() for the encoding.  For server-encodings, also define mb2wchar()
+ * and wchar2mb() conversion functions.
+ *
+ * These functions generally assume that their input is validly formed.
+ * The "verifier" functions, further down in the file, have to be more
+ * paranoid.
+ *
+ * We expect that mblen() does not need to examine more than the first byte
+ * of the character to discover the correct length.  GB18030 is an exception
+ * to that rule, though, as it also looks at second byte.  But even that
+ * behaves in a predictable way, if you only pass the first byte: it will
+ * treat 4-byte encoded characters as two 2-byte encoded characters, which is
+ * good enough for all current uses.
+ *
+ * Note: for the display output of psql to work properly, the return values
+ * of the dsplen functions must conform to the Unicode standard. In particular
+ * the NUL character is zero width and control characters are generally
+ * width -1. It is recommended that non-ASCII encodings refer their ASCII
+ * subset to the ASCII routines to ensure consistency.
+ */
+
+/*
+ * SQL/ASCII
+ */
+static int
+pg_ascii2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		*to++ = *from++;
+		len--;
+		cnt++;
+	}
+	*to = 0;
+	return cnt;
+}
+
+static int
+pg_ascii_mblen(const unsigned char *s)
+{
+	return 1;
+}
+
+static int
+pg_ascii_dsplen(const unsigned char *s)
+{
+	if (*s == '\0')
+		return 0;
+	if (*s < 0x20 || *s == 0x7f)
+		return -1;
+
+	return 1;
+}
+
+/*
+ * EUC
+ */
+static int
+pg_euc2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		if (*from == SS2 && len >= 2)	/* JIS X 0201 (so called "1 byte
+										 * KANA") */
+		{
+			from++;
+			*to = (SS2 << 8) | *from++;
+			len -= 2;
+		}
+		else if (*from == SS3 && len >= 3)	/* JIS X 0212 KANJI */
+		{
+			from++;
+			*to = (SS3 << 16) | (*from++ << 8);
+			*to |= *from++;
+			len -= 3;
+		}
+		else if (IS_HIGHBIT_SET(*from) && len >= 2) /* JIS X 0208 KANJI */
+		{
+			*to = *from++ << 8;
+			*to |= *from++;
+			len -= 2;
+		}
+		else					/* must be ASCII */
+		{
+			*to = *from++;
+			len--;
+		}
+		to++;
+		cnt++;
+	}
+	*to = 0;
+	return cnt;
+}
+
+static inline int
+pg_euc_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (*s == SS2)
+		len = 2;
+	else if (*s == SS3)
+		len = 3;
+	else if (IS_HIGHBIT_SET(*s))
+		len = 2;
+	else
+		len = 1;
+	return len;
+}
+
+static inline int
+pg_euc_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (*s == SS2)
+		len = 2;
+	else if (*s == SS3)
+		len = 2;
+	else if (IS_HIGHBIT_SET(*s))
+		len = 2;
+	else
+		len = pg_ascii_dsplen(s);
+	return len;
+}
+
+/*
+ * EUC_JP
+ */
+static int
+pg_eucjp2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	return pg_euc2wchar_with_len(from, to, len);
+}
+
+static int
+pg_eucjp_mblen(const unsigned char *s)
+{
+	return pg_euc_mblen(s);
+}
+
+static int
+pg_eucjp_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (*s == SS2)
+		len = 1;
+	else if (*s == SS3)
+		len = 2;
+	else if (IS_HIGHBIT_SET(*s))
+		len = 2;
+	else
+		len = pg_ascii_dsplen(s);
+	return len;
+}
+
+/*
+ * EUC_KR
+ */
+static int
+pg_euckr2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	return pg_euc2wchar_with_len(from, to, len);
+}
+
+static int
+pg_euckr_mblen(const unsigned char *s)
+{
+	return pg_euc_mblen(s);
+}
+
+static int
+pg_euckr_dsplen(const unsigned char *s)
+{
+	return pg_euc_dsplen(s);
+}
+
+/*
+ * EUC_CN
+ *
+ */
+static int
+pg_euccn2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		if (*from == SS2 && len >= 3)	/* code set 2 (unused?) */
+		{
+			from++;
+			*to = (SS2 << 16) | (*from++ << 8);
+			*to |= *from++;
+			len -= 3;
+		}
+		else if (*from == SS3 && len >= 3)	/* code set 3 (unused ?) */
+		{
+			from++;
+			*to = (SS3 << 16) | (*from++ << 8);
+			*to |= *from++;
+			len -= 3;
+		}
+		else if (IS_HIGHBIT_SET(*from) && len >= 2) /* code set 1 */
+		{
+			*to = *from++ << 8;
+			*to |= *from++;
+			len -= 2;
+		}
+		else
+		{
+			*to = *from++;
+			len--;
+		}
+		to++;
+		cnt++;
+	}
+	*to = 0;
+	return cnt;
+}
+
+static int
+pg_euccn_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;
+	else
+		len = 1;
+	return len;
+}
+
+static int
+pg_euccn_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;
+	else
+		len = pg_ascii_dsplen(s);
+	return len;
+}
+
+/*
+ * EUC_TW
+ *
+ */
+static int
+pg_euctw2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		if (*from == SS2 && len >= 4)	/* code set 2 */
+		{
+			from++;
+			*to = (((uint32) SS2) << 24) | (*from++ << 16);
+			*to |= *from++ << 8;
+			*to |= *from++;
+			len -= 4;
+		}
+		else if (*from == SS3 && len >= 3)	/* code set 3 (unused?) */
+		{
+			from++;
+			*to = (SS3 << 16) | (*from++ << 8);
+			*to |= *from++;
+			len -= 3;
+		}
+		else if (IS_HIGHBIT_SET(*from) && len >= 2) /* code set 2 */
+		{
+			*to = *from++ << 8;
+			*to |= *from++;
+			len -= 2;
+		}
+		else
+		{
+			*to = *from++;
+			len--;
+		}
+		to++;
+		cnt++;
+	}
+	*to = 0;
+	return cnt;
+}
+
+static int
+pg_euctw_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (*s == SS2)
+		len = 4;
+	else if (*s == SS3)
+		len = 3;
+	else if (IS_HIGHBIT_SET(*s))
+		len = 2;
+	else
+		len = 1;
+	return len;
+}
+
+static int
+pg_euctw_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (*s == SS2)
+		len = 2;
+	else if (*s == SS3)
+		len = 2;
+	else if (IS_HIGHBIT_SET(*s))
+		len = 2;
+	else
+		len = pg_ascii_dsplen(s);
+	return len;
+}
+
+/*
+ * Convert pg_wchar to EUC_* encoding.
+ * caller must allocate enough space for "to", including a trailing zero!
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_wchar2euc_with_len(const pg_wchar *from, unsigned char *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		unsigned char c;
+
+		if ((c = (*from >> 24)))
+		{
+			*to++ = c;
+			*to++ = (*from >> 16) & 0xff;
+			*to++ = (*from >> 8) & 0xff;
+			*to++ = *from & 0xff;
+			cnt += 4;
+		}
+		else if ((c = (*from >> 16)))
+		{
+			*to++ = c;
+			*to++ = (*from >> 8) & 0xff;
+			*to++ = *from & 0xff;
+			cnt += 3;
+		}
+		else if ((c = (*from >> 8)))
+		{
+			*to++ = c;
+			*to++ = *from & 0xff;
+			cnt += 2;
+		}
+		else
+		{
+			*to++ = *from;
+			cnt++;
+		}
+		from++;
+		len--;
+	}
+	*to = 0;
+	return cnt;
+}
+
+
+/*
+ * JOHAB
+ */
+static int
+pg_johab_mblen(const unsigned char *s)
+{
+	return pg_euc_mblen(s);
+}
+
+static int
+pg_johab_dsplen(const unsigned char *s)
+{
+	return pg_euc_dsplen(s);
+}
+
+/*
+ * convert UTF8 string to pg_wchar (UCS-4)
+ * caller must allocate enough space for "to", including a trailing zero!
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_utf2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	int			cnt = 0;
+	uint32		c1,
+				c2,
+				c3,
+				c4;
+
+	while (len > 0 && *from)
+	{
+		if ((*from & 0x80) == 0)
+		{
+			*to = *from++;
+			len--;
+		}
+		else if ((*from & 0xe0) == 0xc0)
+		{
+			if (len < 2)
+				break;			/* drop trailing incomplete char */
+			c1 = *from++ & 0x1f;
+			c2 = *from++ & 0x3f;
+			*to = (c1 << 6) | c2;
+			len -= 2;
+		}
+		else if ((*from & 0xf0) == 0xe0)
+		{
+			if (len < 3)
+				break;			/* drop trailing incomplete char */
+			c1 = *from++ & 0x0f;
+			c2 = *from++ & 0x3f;
+			c3 = *from++ & 0x3f;
+			*to = (c1 << 12) | (c2 << 6) | c3;
+			len -= 3;
+		}
+		else if ((*from & 0xf8) == 0xf0)
+		{
+			if (len < 4)
+				break;			/* drop trailing incomplete char */
+			c1 = *from++ & 0x07;
+			c2 = *from++ & 0x3f;
+			c3 = *from++ & 0x3f;
+			c4 = *from++ & 0x3f;
+			*to = (c1 << 18) | (c2 << 12) | (c3 << 6) | c4;
+			len -= 4;
+		}
+		else
+		{
+			/* treat a bogus char as length 1; not ours to raise error */
+			*to = *from++;
+			len--;
+		}
+		to++;
+		cnt++;
+	}
+	*to = 0;
+	return cnt;
+}
+
+
+/*
+ * Map a Unicode code point to UTF-8.  utf8string must have 4 bytes of
+ * space allocated.
+ */
+unsigned char *
+unicode_to_utf8(pg_wchar c, unsigned char *utf8string)
+{
+	if (c <= 0x7F)
+	{
+		utf8string[0] = c;
+	}
+	else if (c <= 0x7FF)
+	{
+		utf8string[0] = 0xC0 | ((c >> 6) & 0x1F);
+		utf8string[1] = 0x80 | (c & 0x3F);
+	}
+	else if (c <= 0xFFFF)
+	{
+		utf8string[0] = 0xE0 | ((c >> 12) & 0x0F);
+		utf8string[1] = 0x80 | ((c >> 6) & 0x3F);
+		utf8string[2] = 0x80 | (c & 0x3F);
+	}
+	else
+	{
+		utf8string[0] = 0xF0 | ((c >> 18) & 0x07);
+		utf8string[1] = 0x80 | ((c >> 12) & 0x3F);
+		utf8string[2] = 0x80 | ((c >> 6) & 0x3F);
+		utf8string[3] = 0x80 | (c & 0x3F);
+	}
+
+	return utf8string;
+}
+
+/*
+ * Trivial conversion from pg_wchar to UTF-8.
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_wchar2utf_with_len(const pg_wchar *from, unsigned char *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		int			char_len;
+
+		unicode_to_utf8(*from, to);
+		char_len = pg_utf_mblen(to);
+		cnt += char_len;
+		to += char_len;
+		from++;
+		len--;
+	}
+	*to = 0;
+	return cnt;
+}
+
+/*
+ * Return the byte length of a UTF8 character pointed to by s
+ *
+ * Note: in the current implementation we do not support UTF8 sequences
+ * of more than 4 bytes; hence do NOT return a value larger than 4.
+ * We return "1" for any leading byte that is either flat-out illegal or
+ * indicates a length larger than we support.
+ *
+ * pg_utf2wchar_with_len(), utf8_to_unicode(), pg_utf8_islegal(), and perhaps
+ * other places would need to be fixed to change this.
+ */
+int
+pg_utf_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if ((*s & 0x80) == 0)
+		len = 1;
+	else if ((*s & 0xe0) == 0xc0)
+		len = 2;
+	else if ((*s & 0xf0) == 0xe0)
+		len = 3;
+	else if ((*s & 0xf8) == 0xf0)
+		len = 4;
+#ifdef NOT_USED
+	else if ((*s & 0xfc) == 0xf8)
+		len = 5;
+	else if ((*s & 0xfe) == 0xfc)
+		len = 6;
+#endif
+	else
+		len = 1;
+	return len;
+}
+
+/*
+ * This is an implementation of wcwidth() and wcswidth() as defined in
+ * "The Single UNIX Specification, Version 2, The Open Group, 1997"
+ * <http://www.unix.org/online.html>
+ *
+ * Markus Kuhn -- 2001-09-08 -- public domain
+ *
+ * customised for PostgreSQL
+ *
+ * original available at : http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+
+struct mbinterval
+{
+	unsigned short first;
+	unsigned short last;
+};
+
+/* auxiliary function for binary search in interval table */
+static int
+mbbisearch(pg_wchar ucs, const struct mbinterval *table, int max)
+{
+	int			min = 0;
+	int			mid;
+
+	if (ucs < table[0].first || ucs > table[max].last)
+		return 0;
+	while (max >= min)
+	{
+		mid = (min + max) / 2;
+		if (ucs > table[mid].last)
+			min = mid + 1;
+		else if (ucs < table[mid].first)
+			max = mid - 1;
+		else
+			return 1;
+	}
+
+	return 0;
+}
+
+
+/* The following functions define the column width of an ISO 10646
+ * character as follows:
+ *
+ *	  - The null character (U+0000) has a column width of 0.
+ *
+ *	  - Other C0/C1 control characters and DEL will lead to a return
+ *		value of -1.
+ *
+ *	  - Non-spacing and enclosing combining characters (general
+ *		category code Mn or Me in the Unicode database) have a
+ *		column width of 0.
+ *
+ *	  - Other format characters (general category code Cf in the Unicode
+ *		database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
+ *
+ *	  - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
+ *		have a column width of 0.
+ *
+ *	  - Spacing characters in the East Asian Wide (W) or East Asian
+ *		FullWidth (F) category as defined in Unicode Technical
+ *		Report #11 have a column width of 2.
+ *
+ *	  - All remaining characters (including all printable
+ *		ISO 8859-1 and WGL4 characters, Unicode control characters,
+ *		etc.) have a column width of 1.
+ *
+ * This implementation assumes that wchar_t characters are encoded
+ * in ISO 10646.
+ */
+
+static int
+ucs_wcwidth(pg_wchar ucs)
+{
+#include "common/unicode_combining_table.h"
+
+	/* test for 8-bit control characters */
+	if (ucs == 0)
+		return 0;
+
+	if (ucs < 0x20 || (ucs >= 0x7f && ucs < 0xa0) || ucs > 0x0010ffff)
+		return -1;
+
+	/* binary search in table of non-spacing characters */
+	if (mbbisearch(ucs, combining,
+				   sizeof(combining) / sizeof(struct mbinterval) - 1))
+		return 0;
+
+	/*
+	 * if we arrive here, ucs is not a combining or C0/C1 control character
+	 */
+
+	return 1 +
+		(ucs >= 0x1100 &&
+		 (ucs <= 0x115f ||		/* Hangul Jamo init. consonants */
+		  (ucs >= 0x2e80 && ucs <= 0xa4cf && (ucs & ~0x0011) != 0x300a &&
+		   ucs != 0x303f) ||	/* CJK ... Yi */
+		  (ucs >= 0xac00 && ucs <= 0xd7a3) ||	/* Hangul Syllables */
+		  (ucs >= 0xf900 && ucs <= 0xfaff) ||	/* CJK Compatibility
+												 * Ideographs */
+		  (ucs >= 0xfe30 && ucs <= 0xfe6f) ||	/* CJK Compatibility Forms */
+		  (ucs >= 0xff00 && ucs <= 0xff5f) ||	/* Fullwidth Forms */
+		  (ucs >= 0xffe0 && ucs <= 0xffe6) ||
+		  (ucs >= 0x20000 && ucs <= 0x2ffff)));
+}
+
+/*
+ * Convert a UTF-8 character to a Unicode code point.
+ * This is a one-character version of pg_utf2wchar_with_len.
+ *
+ * No error checks here, c must point to a long-enough string.
+ */
+pg_wchar
+utf8_to_unicode(const unsigned char *c)
+{
+	if ((*c & 0x80) == 0)
+		return (pg_wchar) c[0];
+	else if ((*c & 0xe0) == 0xc0)
+		return (pg_wchar) (((c[0] & 0x1f) << 6) |
+						   (c[1] & 0x3f));
+	else if ((*c & 0xf0) == 0xe0)
+		return (pg_wchar) (((c[0] & 0x0f) << 12) |
+						   ((c[1] & 0x3f) << 6) |
+						   (c[2] & 0x3f));
+	else if ((*c & 0xf8) == 0xf0)
+		return (pg_wchar) (((c[0] & 0x07) << 18) |
+						   ((c[1] & 0x3f) << 12) |
+						   ((c[2] & 0x3f) << 6) |
+						   (c[3] & 0x3f));
+	else
+		/* that is an invalid code on purpose */
+		return 0xffffffff;
+}
+
+static int
+pg_utf_dsplen(const unsigned char *s)
+{
+	return ucs_wcwidth(utf8_to_unicode(s));
+}
+
+/*
+ * convert mule internal code to pg_wchar
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_mule2wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		if (IS_LC1(*from) && len >= 2)
+		{
+			*to = *from++ << 16;
+			*to |= *from++;
+			len -= 2;
+		}
+		else if (IS_LCPRV1(*from) && len >= 3)
+		{
+			from++;
+			*to = *from++ << 16;
+			*to |= *from++;
+			len -= 3;
+		}
+		else if (IS_LC2(*from) && len >= 3)
+		{
+			*to = *from++ << 16;
+			*to |= *from++ << 8;
+			*to |= *from++;
+			len -= 3;
+		}
+		else if (IS_LCPRV2(*from) && len >= 4)
+		{
+			from++;
+			*to = *from++ << 16;
+			*to |= *from++ << 8;
+			*to |= *from++;
+			len -= 4;
+		}
+		else
+		{						/* assume ASCII */
+			*to = (unsigned char) *from++;
+			len--;
+		}
+		to++;
+		cnt++;
+	}
+	*to = 0;
+	return cnt;
+}
+
+/*
+ * convert pg_wchar to mule internal code
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_wchar2mule_with_len(const pg_wchar *from, unsigned char *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		unsigned char lb;
+
+		lb = (*from >> 16) & 0xff;
+		if (IS_LC1(lb))
+		{
+			*to++ = lb;
+			*to++ = *from & 0xff;
+			cnt += 2;
+		}
+		else if (IS_LC2(lb))
+		{
+			*to++ = lb;
+			*to++ = (*from >> 8) & 0xff;
+			*to++ = *from & 0xff;
+			cnt += 3;
+		}
+		else if (IS_LCPRV1_A_RANGE(lb))
+		{
+			*to++ = LCPRV1_A;
+			*to++ = lb;
+			*to++ = *from & 0xff;
+			cnt += 3;
+		}
+		else if (IS_LCPRV1_B_RANGE(lb))
+		{
+			*to++ = LCPRV1_B;
+			*to++ = lb;
+			*to++ = *from & 0xff;
+			cnt += 3;
+		}
+		else if (IS_LCPRV2_A_RANGE(lb))
+		{
+			*to++ = LCPRV2_A;
+			*to++ = lb;
+			*to++ = (*from >> 8) & 0xff;
+			*to++ = *from & 0xff;
+			cnt += 4;
+		}
+		else if (IS_LCPRV2_B_RANGE(lb))
+		{
+			*to++ = LCPRV2_B;
+			*to++ = lb;
+			*to++ = (*from >> 8) & 0xff;
+			*to++ = *from & 0xff;
+			cnt += 4;
+		}
+		else
+		{
+			*to++ = *from & 0xff;
+			cnt += 1;
+		}
+		from++;
+		len--;
+	}
+	*to = 0;
+	return cnt;
+}
+
+/* exported for direct use by conv.c */
+int
+pg_mule_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_LC1(*s))
+		len = 2;
+	else if (IS_LCPRV1(*s))
+		len = 3;
+	else if (IS_LC2(*s))
+		len = 3;
+	else if (IS_LCPRV2(*s))
+		len = 4;
+	else
+		len = 1;				/* assume ASCII */
+	return len;
+}
+
+static int
+pg_mule_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	/*
+	 * Note: it's not really appropriate to assume that all multibyte charsets
+	 * are double-wide on screen.  But this seems an okay approximation for
+	 * the MULE charsets we currently support.
+	 */
+
+	if (IS_LC1(*s))
+		len = 1;
+	else if (IS_LCPRV1(*s))
+		len = 1;
+	else if (IS_LC2(*s))
+		len = 2;
+	else if (IS_LCPRV2(*s))
+		len = 2;
+	else
+		len = 1;				/* assume ASCII */
+
+	return len;
+}
+
+/*
+ * ISO8859-1
+ */
+static int
+pg_latin12wchar_with_len(const unsigned char *from, pg_wchar *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		*to++ = *from++;
+		len--;
+		cnt++;
+	}
+	*to = 0;
+	return cnt;
+}
+
+/*
+ * Trivial conversion from pg_wchar to single byte encoding. Just ignores
+ * high bits.
+ * caller should allocate enough space for "to"
+ * len: length of from.
+ * "from" not necessarily null terminated.
+ */
+static int
+pg_wchar2single_with_len(const pg_wchar *from, unsigned char *to, int len)
+{
+	int			cnt = 0;
+
+	while (len > 0 && *from)
+	{
+		*to++ = *from++;
+		len--;
+		cnt++;
+	}
+	*to = 0;
+	return cnt;
+}
+
+static int
+pg_latin1_mblen(const unsigned char *s)
+{
+	return 1;
+}
+
+static int
+pg_latin1_dsplen(const unsigned char *s)
+{
+	return pg_ascii_dsplen(s);
+}
+
+/*
+ * SJIS
+ */
+static int
+pg_sjis_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (*s >= 0xa1 && *s <= 0xdf)
+		len = 1;				/* 1 byte kana? */
+	else if (IS_HIGHBIT_SET(*s))
+		len = 2;				/* kanji? */
+	else
+		len = 1;				/* should be ASCII */
+	return len;
+}
+
+static int
+pg_sjis_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (*s >= 0xa1 && *s <= 0xdf)
+		len = 1;				/* 1 byte kana? */
+	else if (IS_HIGHBIT_SET(*s))
+		len = 2;				/* kanji? */
+	else
+		len = pg_ascii_dsplen(s);	/* should be ASCII */
+	return len;
+}
+
+/*
+ * Big5
+ */
+static int
+pg_big5_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;				/* kanji? */
+	else
+		len = 1;				/* should be ASCII */
+	return len;
+}
+
+static int
+pg_big5_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;				/* kanji? */
+	else
+		len = pg_ascii_dsplen(s);	/* should be ASCII */
+	return len;
+}
+
+/*
+ * GBK
+ */
+static int
+pg_gbk_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;				/* kanji? */
+	else
+		len = 1;				/* should be ASCII */
+	return len;
+}
+
+static int
+pg_gbk_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;				/* kanji? */
+	else
+		len = pg_ascii_dsplen(s);	/* should be ASCII */
+	return len;
+}
+
+/*
+ * UHC
+ */
+static int
+pg_uhc_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;				/* 2byte? */
+	else
+		len = 1;				/* should be ASCII */
+	return len;
+}
+
+static int
+pg_uhc_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;				/* 2byte? */
+	else
+		len = pg_ascii_dsplen(s);	/* should be ASCII */
+	return len;
+}
+
+/*
+ * GB18030
+ *	Added by Bill Huang <bhuang@redhat.com>,<bill_huanghb@ybb.ne.jp>
+ */
+
+/*
+ * Unlike all other mblen() functions, this also looks at the second byte of
+ * the input.  However, if you only pass the first byte of a multi-byte
+ * string, and \0 as the second byte, this still works in a predictable way:
+ * a 4-byte character will be reported as two 2-byte characters.  That's
+ * enough for all current uses, as a client-only encoding.  It works that
+ * way, because in any valid 4-byte GB18030-encoded character, the third and
+ * fourth byte look like a 2-byte encoded character, when looked at
+ * separately.
+ */
+static int
+pg_gb18030_mblen(const unsigned char *s)
+{
+	int			len;
+
+	if (!IS_HIGHBIT_SET(*s))
+		len = 1;				/* ASCII */
+	else if (*(s + 1) >= 0x30 && *(s + 1) <= 0x39)
+		len = 4;
+	else
+		len = 2;
+	return len;
+}
+
+static int
+pg_gb18030_dsplen(const unsigned char *s)
+{
+	int			len;
+
+	if (IS_HIGHBIT_SET(*s))
+		len = 2;
+	else
+		len = pg_ascii_dsplen(s);	/* ASCII */
+	return len;
+}
+
+/*
+ *-------------------------------------------------------------------
+ * multibyte sequence validators
+ *
+ * The verifychar functions accept "s", a pointer to the first byte of a
+ * string, and "len", the remaining length of the string.  If there is a
+ * validly encoded character beginning at *s, return its length in bytes;
+ * else return -1.
+ *
+ * The verifystr functions also accept "s", a pointer to a string and "len",
+ * the length of the string.  They verify the whole string, and return the
+ * number of input bytes (<= len) that are valid.  In other words, if the
+ * whole string is valid, verifystr returns "len", otherwise it returns the
+ * byte offset of the first invalid character.  The verifystr functions must
+ * test for and reject zeroes in the input.
+ *
+ * The verifychar functions can assume that len > 0 and that *s != '\0', but
+ * they must test for and reject zeroes in any additional bytes of a
+ * multibyte character.  Note that this definition allows the function for a
+ * single-byte encoding to be just "return 1".
+ *-------------------------------------------------------------------
+ */
+static int
+pg_ascii_verifychar(const unsigned char *s, int len)
+{
+	return 1;
+}
+
+static int
+pg_ascii_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *nullpos = memchr(s, 0, len);
+
+	if (nullpos == NULL)
+		return len;
+	else
+		return nullpos - s;
+}
+
+#define IS_EUC_RANGE_VALID(c)	((c) >= 0xa1 && (c) <= 0xfe)
+
+static int
+pg_eucjp_verifychar(const unsigned char *s, int len)
+{
+	int			l;
+	unsigned char c1,
+				c2;
+
+	c1 = *s++;
+
+	switch (c1)
+	{
+		case SS2:				/* JIS X 0201 */
+			l = 2;
+			if (l > len)
+				return -1;
+			c2 = *s++;
+			if (c2 < 0xa1 || c2 > 0xdf)
+				return -1;
+			break;
+
+		case SS3:				/* JIS X 0212 */
+			l = 3;
+			if (l > len)
+				return -1;
+			c2 = *s++;
+			if (!IS_EUC_RANGE_VALID(c2))
+				return -1;
+			c2 = *s++;
+			if (!IS_EUC_RANGE_VALID(c2))
+				return -1;
+			break;
+
+		default:
+			if (IS_HIGHBIT_SET(c1)) /* JIS X 0208? */
+			{
+				l = 2;
+				if (l > len)
+					return -1;
+				if (!IS_EUC_RANGE_VALID(c1))
+					return -1;
+				c2 = *s++;
+				if (!IS_EUC_RANGE_VALID(c2))
+					return -1;
+			}
+			else
+				/* must be ASCII */
+			{
+				l = 1;
+			}
+			break;
+	}
+
+	return l;
+}
+
+static int
+pg_eucjp_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_eucjp_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_euckr_verifychar(const unsigned char *s, int len)
+{
+	int			l;
+	unsigned char c1,
+				c2;
+
+	c1 = *s++;
+
+	if (IS_HIGHBIT_SET(c1))
+	{
+		l = 2;
+		if (l > len)
+			return -1;
+		if (!IS_EUC_RANGE_VALID(c1))
+			return -1;
+		c2 = *s++;
+		if (!IS_EUC_RANGE_VALID(c2))
+			return -1;
+	}
+	else
+		/* must be ASCII */
+	{
+		l = 1;
+	}
+
+	return l;
+}
+
+static int
+pg_euckr_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_euckr_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+/* EUC-CN byte sequences are exactly same as EUC-KR */
+#define pg_euccn_verifychar	pg_euckr_verifychar
+#define pg_euccn_verifystr	pg_euckr_verifystr
+
+static int
+pg_euctw_verifychar(const unsigned char *s, int len)
+{
+	int			l;
+	unsigned char c1,
+				c2;
+
+	c1 = *s++;
+
+	switch (c1)
+	{
+		case SS2:				/* CNS 11643 Plane 1-7 */
+			l = 4;
+			if (l > len)
+				return -1;
+			c2 = *s++;
+			if (c2 < 0xa1 || c2 > 0xa7)
+				return -1;
+			c2 = *s++;
+			if (!IS_EUC_RANGE_VALID(c2))
+				return -1;
+			c2 = *s++;
+			if (!IS_EUC_RANGE_VALID(c2))
+				return -1;
+			break;
+
+		case SS3:				/* unused */
+			return -1;
+
+		default:
+			if (IS_HIGHBIT_SET(c1)) /* CNS 11643 Plane 1 */
+			{
+				l = 2;
+				if (l > len)
+					return -1;
+				/* no further range check on c1? */
+				c2 = *s++;
+				if (!IS_EUC_RANGE_VALID(c2))
+					return -1;
+			}
+			else
+				/* must be ASCII */
+			{
+				l = 1;
+			}
+			break;
+	}
+	return l;
+}
+
+static int
+pg_euctw_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_euctw_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_johab_verifychar(const unsigned char *s, int len)
+{
+	int			l,
+				mbl;
+	unsigned char c;
+
+	l = mbl = pg_johab_mblen(s);
+
+	if (len < l)
+		return -1;
+
+	if (!IS_HIGHBIT_SET(*s))
+		return mbl;
+
+	while (--l > 0)
+	{
+		c = *++s;
+		if (!IS_EUC_RANGE_VALID(c))
+			return -1;
+	}
+	return mbl;
+}
+
+static int
+pg_johab_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_johab_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_mule_verifychar(const unsigned char *s, int len)
+{
+	int			l,
+				mbl;
+	unsigned char c;
+
+	l = mbl = pg_mule_mblen(s);
+
+	if (len < l)
+		return -1;
+
+	while (--l > 0)
+	{
+		c = *++s;
+		if (!IS_HIGHBIT_SET(c))
+			return -1;
+	}
+	return mbl;
+}
+
+static int
+pg_mule_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_mule_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_latin1_verifychar(const unsigned char *s, int len)
+{
+	return 1;
+}
+
+static int
+pg_latin1_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *nullpos = memchr(s, 0, len);
+
+	if (nullpos == NULL)
+		return len;
+	else
+		return nullpos - s;
+}
+
+static int
+pg_sjis_verifychar(const unsigned char *s, int len)
+{
+	int			l,
+				mbl;
+	unsigned char c1,
+				c2;
+
+	l = mbl = pg_sjis_mblen(s);
+
+	if (len < l)
+		return -1;
+
+	if (l == 1)					/* pg_sjis_mblen already verified it */
+		return mbl;
+
+	c1 = *s++;
+	c2 = *s;
+	if (!ISSJISHEAD(c1) || !ISSJISTAIL(c2))
+		return -1;
+	return mbl;
+}
+
+static int
+pg_sjis_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_sjis_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_big5_verifychar(const unsigned char *s, int len)
+{
+	int			l,
+				mbl;
+
+	l = mbl = pg_big5_mblen(s);
+
+	if (len < l)
+		return -1;
+
+	while (--l > 0)
+	{
+		if (*++s == '\0')
+			return -1;
+	}
+
+	return mbl;
+}
+
+static int
+pg_big5_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_big5_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_gbk_verifychar(const unsigned char *s, int len)
+{
+	int			l,
+				mbl;
+
+	l = mbl = pg_gbk_mblen(s);
+
+	if (len < l)
+		return -1;
+
+	while (--l > 0)
+	{
+		if (*++s == '\0')
+			return -1;
+	}
+
+	return mbl;
+}
+
+static int
+pg_gbk_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_gbk_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_uhc_verifychar(const unsigned char *s, int len)
+{
+	int			l,
+				mbl;
+
+	l = mbl = pg_uhc_mblen(s);
+
+	if (len < l)
+		return -1;
+
+	while (--l > 0)
+	{
+		if (*++s == '\0')
+			return -1;
+	}
+
+	return mbl;
+}
+
+static int
+pg_uhc_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_uhc_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_gb18030_verifychar(const unsigned char *s, int len)
+{
+	int			l;
+
+	if (!IS_HIGHBIT_SET(*s))
+		l = 1;					/* ASCII */
+	else if (len >= 4 && *(s + 1) >= 0x30 && *(s + 1) <= 0x39)
+	{
+		/* Should be 4-byte, validate remaining bytes */
+		if (*s >= 0x81 && *s <= 0xfe &&
+			*(s + 2) >= 0x81 && *(s + 2) <= 0xfe &&
+			*(s + 3) >= 0x30 && *(s + 3) <= 0x39)
+			l = 4;
+		else
+			l = -1;
+	}
+	else if (len >= 2 && *s >= 0x81 && *s <= 0xfe)
+	{
+		/* Should be 2-byte, validate */
+		if ((*(s + 1) >= 0x40 && *(s + 1) <= 0x7e) ||
+			(*(s + 1) >= 0x80 && *(s + 1) <= 0xfe))
+			l = 2;
+		else
+			l = -1;
+	}
+	else
+		l = -1;
+	return l;
+}
+
+static int
+pg_gb18030_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_gb18030_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+static int
+pg_utf8_verifychar(const unsigned char *s, int len)
+{
+	int			l;
+
+	if ((*s & 0x80) == 0)
+	{
+		if (*s == '\0')
+			return -1;
+		return 1;
+	}
+	else if ((*s & 0xe0) == 0xc0)
+		l = 2;
+	else if ((*s & 0xf0) == 0xe0)
+		l = 3;
+	else if ((*s & 0xf8) == 0xf0)
+		l = 4;
+	else
+		l = 1;
+
+	if (l > len)
+		return -1;
+
+	if (!pg_utf8_islegal(s, l))
+		return -1;
+
+	return l;
+}
+
+static int
+pg_utf8_verifystr(const unsigned char *s, int len)
+{
+	const unsigned char *start = s;
+
+	while (len > 0)
+	{
+		int			l;
+
+		/* fast path for ASCII-subset characters */
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			if (*s == '\0')
+				break;
+			l = 1;
+		}
+		else
+		{
+			l = pg_utf8_verifychar(s, len);
+			if (l == -1)
+				break;
+		}
+		s += l;
+		len -= l;
+	}
+
+	return s - start;
+}
+
+/*
+ * Check for validity of a single UTF-8 encoded character
+ *
+ * This directly implements the rules in RFC3629.  The bizarre-looking
+ * restrictions on the second byte are meant to ensure that there isn't
+ * more than one encoding of a given Unicode character point; that is,
+ * you may not use a longer-than-necessary byte sequence with high order
+ * zero bits to represent a character that would fit in fewer bytes.
+ * To do otherwise is to create security hazards (eg, create an apparent
+ * non-ASCII character that decodes to plain ASCII).
+ *
+ * length is assumed to have been obtained by pg_utf_mblen(), and the
+ * caller must have checked that that many bytes are present in the buffer.
+ */
+bool
+pg_utf8_islegal(const unsigned char *source, int length)
+{
+	unsigned char a;
+
+	switch (length)
+	{
+		default:
+			/* reject lengths 5 and 6 for now */
+			return false;
+		case 4:
+			a = source[3];
+			if (a < 0x80 || a > 0xBF)
+				return false;
+			/* FALL THRU */
+		case 3:
+			a = source[2];
+			if (a < 0x80 || a > 0xBF)
+				return false;
+			/* FALL THRU */
+		case 2:
+			a = source[1];
+			switch (*source)
+			{
+				case 0xE0:
+					if (a < 0xA0 || a > 0xBF)
+						return false;
+					break;
+				case 0xED:
+					if (a < 0x80 || a > 0x9F)
+						return false;
+					break;
+				case 0xF0:
+					if (a < 0x90 || a > 0xBF)
+						return false;
+					break;
+				case 0xF4:
+					if (a < 0x80 || a > 0x8F)
+						return false;
+					break;
+				default:
+					if (a < 0x80 || a > 0xBF)
+						return false;
+					break;
+			}
+			/* FALL THRU */
+		case 1:
+			a = *source;
+			if (a >= 0x80 && a < 0xC2)
+				return false;
+			if (a > 0xF4)
+				return false;
+			break;
+	}
+	return true;
+}
+
+
+/*
+ *-------------------------------------------------------------------
+ * encoding info table
+ * XXX must be sorted by the same order as enum pg_enc (in mb/pg_wchar.h)
+ *-------------------------------------------------------------------
+ */
+const pg_wchar_tbl pg_wchar_table[] = {
+	{pg_ascii2wchar_with_len, pg_wchar2single_with_len, pg_ascii_mblen, pg_ascii_dsplen, pg_ascii_verifychar, pg_ascii_verifystr, 1},	/* PG_SQL_ASCII */
+	{pg_eucjp2wchar_with_len, pg_wchar2euc_with_len, pg_eucjp_mblen, pg_eucjp_dsplen, pg_eucjp_verifychar, pg_eucjp_verifystr, 3},	/* PG_EUC_JP */
+	{pg_euccn2wchar_with_len, pg_wchar2euc_with_len, pg_euccn_mblen, pg_euccn_dsplen, pg_euccn_verifychar, pg_euccn_verifystr, 2},	/* PG_EUC_CN */
+	{pg_euckr2wchar_with_len, pg_wchar2euc_with_len, pg_euckr_mblen, pg_euckr_dsplen, pg_euckr_verifychar, pg_euckr_verifystr, 3},	/* PG_EUC_KR */
+	{pg_euctw2wchar_with_len, pg_wchar2euc_with_len, pg_euctw_mblen, pg_euctw_dsplen, pg_euctw_verifychar, pg_euctw_verifystr, 4},	/* PG_EUC_TW */
+	{pg_eucjp2wchar_with_len, pg_wchar2euc_with_len, pg_eucjp_mblen, pg_eucjp_dsplen, pg_eucjp_verifychar, pg_eucjp_verifystr, 3},	/* PG_EUC_JIS_2004 */
+	{pg_utf2wchar_with_len, pg_wchar2utf_with_len, pg_utf_mblen, pg_utf_dsplen, pg_utf8_verifychar, pg_utf8_verifystr, 4},	/* PG_UTF8 */
+	{pg_mule2wchar_with_len, pg_wchar2mule_with_len, pg_mule_mblen, pg_mule_dsplen, pg_mule_verifychar, pg_mule_verifystr, 4},	/* PG_MULE_INTERNAL */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN1 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN2 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN3 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN4 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN5 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN6 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN7 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN8 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN9 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_LATIN10 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1256 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1258 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN866 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN874 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_KOI8R */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1251 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1252 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* ISO-8859-5 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* ISO-8859-6 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* ISO-8859-7 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* ISO-8859-8 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1250 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1253 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1254 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1255 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_WIN1257 */
+	{pg_latin12wchar_with_len, pg_wchar2single_with_len, pg_latin1_mblen, pg_latin1_dsplen, pg_latin1_verifychar, pg_latin1_verifystr, 1},	/* PG_KOI8U */
+	{0, 0, pg_sjis_mblen, pg_sjis_dsplen, pg_sjis_verifychar, pg_sjis_verifystr, 2},	/* PG_SJIS */
+	{0, 0, pg_big5_mblen, pg_big5_dsplen, pg_big5_verifychar, pg_big5_verifystr, 2},	/* PG_BIG5 */
+	{0, 0, pg_gbk_mblen, pg_gbk_dsplen, pg_gbk_verifychar, pg_gbk_verifystr, 2},	/* PG_GBK */
+	{0, 0, pg_uhc_mblen, pg_uhc_dsplen, pg_uhc_verifychar, pg_uhc_verifystr, 2},	/* PG_UHC */
+	{0, 0, pg_gb18030_mblen, pg_gb18030_dsplen, pg_gb18030_verifychar, pg_gb18030_verifystr, 4},	/* PG_GB18030 */
+	{0, 0, pg_johab_mblen, pg_johab_dsplen, pg_johab_verifychar, pg_johab_verifystr, 3},	/* PG_JOHAB */
+	{0, 0, pg_sjis_mblen, pg_sjis_dsplen, pg_sjis_verifychar, pg_sjis_verifystr, 2} /* PG_SHIFT_JIS_2004 */
+};
+
+/*
+ * Returns the byte length of a multibyte character.
+ *
+ * Caution: when dealing with text that is not certainly valid in the
+ * specified encoding, the result may exceed the actual remaining
+ * string length.  Callers that are not prepared to deal with that
+ * should use pg_encoding_mblen_bounded() instead.
+ */
+int
+pg_encoding_mblen(int encoding, const char *mbstr)
+{
+	return (PG_VALID_ENCODING(encoding) ?
+			pg_wchar_table[encoding].mblen((const unsigned char *) mbstr) :
+			pg_wchar_table[PG_SQL_ASCII].mblen((const unsigned char *) mbstr));
+}
+
+/*
+ * Returns the byte length of a multibyte character; but not more than
+ * the distance to end of string.
+ */
+int
+pg_encoding_mblen_bounded(int encoding, const char *mbstr)
+{
+	return strnlen(mbstr, pg_encoding_mblen(encoding, mbstr));
+}
+
+/*
+ * Returns the display length of a multibyte character.
+ */
+int
+pg_encoding_dsplen(int encoding, const char *mbstr)
+{
+	return (PG_VALID_ENCODING(encoding) ?
+			pg_wchar_table[encoding].dsplen((const unsigned char *) mbstr) :
+			pg_wchar_table[PG_SQL_ASCII].dsplen((const unsigned char *) mbstr));
+}
+
+/*
+ * Verify the first multibyte character of the given string.
+ * Return its byte length if good, -1 if bad.  (See comments above for
+ * full details of the mbverifychar API.)
+ */
+int
+pg_encoding_verifymbchar(int encoding, const char *mbstr, int len)
+{
+	return (PG_VALID_ENCODING(encoding) ?
+			pg_wchar_table[encoding].mbverifychar((const unsigned char *) mbstr, len) :
+			pg_wchar_table[PG_SQL_ASCII].mbverifychar((const unsigned char *) mbstr, len));
+}
+
+/*
+ * Verify that a string is valid for the given encoding.
+ * Returns the number of input bytes (<= len) that form a valid string.
+ * (See comments above for full details of the mbverifystr API.)
+ */
+int
+pg_encoding_verifymbstr(int encoding, const char *mbstr, int len)
+{
+	return (PG_VALID_ENCODING(encoding) ?
+			pg_wchar_table[encoding].mbverifystr((const unsigned char *) mbstr, len) :
+			pg_wchar_table[PG_SQL_ASCII].mbverifystr((const unsigned char *) mbstr, len));
+}
+
+/*
+ * fetch maximum length of a given encoding
+ */
+int
+pg_encoding_max_length(int encoding)
+{
+	Assert(PG_VALID_ENCODING(encoding));
+
+	return pg_wchar_table[encoding].maxmblen;
+}