Adding upstream version 14.5.upstream/14.5upstream

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

1 files changed, 1084 insertions, 0 deletions

diff --git a/src/interfaces/libpq/fe-lobj.c b/src/interfaces/libpq/fe-lobj.c
new file mode 100644
index 0000000..ffd9926
--- /dev/null
+++ b/src/interfaces/libpq/fe-lobj.c
@@ -0,0 +1,1084 @@
+/*-------------------------------------------------------------------------
+ *
+ * fe-lobj.c
+ *	  Front-end large object interface
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/interfaces/libpq/fe-lobj.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifdef WIN32
+/*
+ *	As unlink/rename are #define'd in port.h (via postgres_fe.h), io.h
+ *	must be included first on MS C.  Might as well do it for all WIN32's
+ *	here.
+ */
+#include <io.h>
+#endif
+
+#include "postgres_fe.h"
+
+#ifdef WIN32
+#include "win32.h"
+#else
+#include <unistd.h>
+#endif
+
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/stat.h>
+
+#include "libpq-fe.h"
+#include "libpq-int.h"
+#include "libpq/libpq-fs.h"		/* must come after sys/stat.h */
+#include "port/pg_bswap.h"
+
+#define LO_BUFSIZE		  8192
+
+static int	lo_initialize(PGconn *conn);
+static Oid	lo_import_internal(PGconn *conn, const char *filename, Oid oid);
+static pg_int64 lo_hton64(pg_int64 host64);
+static pg_int64 lo_ntoh64(pg_int64 net64);
+
+/*
+ * lo_open
+ *	  opens an existing large object
+ *
+ * returns the file descriptor for use in later lo_* calls
+ * return -1 upon failure.
+ */
+int
+lo_open(PGconn *conn, Oid lobjId, int mode)
+{
+	int			fd;
+	int			result_len;
+	PQArgBlock	argv[2];
+	PGresult   *res;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = lobjId;
+
+	argv[1].isint = 1;
+	argv[1].len = 4;
+	argv[1].u.integer = mode;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_open, &fd, &result_len, 1, argv, 2);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return fd;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_close
+ *	  closes an existing large object
+ *
+ * returns 0 upon success
+ * returns -1 upon failure.
+ */
+int
+lo_close(PGconn *conn, int fd)
+{
+	PQArgBlock	argv[1];
+	PGresult   *res;
+	int			retval;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_close,
+			   &retval, &result_len, 1, argv, 1);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return retval;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_truncate
+ *	  truncates an existing large object to the given size
+ *
+ * returns 0 upon success
+ * returns -1 upon failure
+ */
+int
+lo_truncate(PGconn *conn, int fd, size_t len)
+{
+	PQArgBlock	argv[2];
+	PGresult   *res;
+	int			retval;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	/* Must check this on-the-fly because it's not there pre-8.3 */
+	if (conn->lobjfuncs->fn_lo_truncate == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_truncate");
+		return -1;
+	}
+
+	/*
+	 * Long ago, somebody thought it'd be a good idea to declare this function
+	 * as taking size_t ... but the underlying backend function only accepts a
+	 * signed int32 length.  So throw error if the given value overflows
+	 * int32.  (A possible alternative is to automatically redirect the call
+	 * to lo_truncate64; but if the caller wanted to rely on that backend
+	 * function being available, he could have called lo_truncate64 for
+	 * himself.)
+	 */
+	if (len > (size_t) INT_MAX)
+	{
+		appendPQExpBufferStr(&conn->errorMessage,
+							 libpq_gettext("argument of lo_truncate exceeds integer range\n"));
+		return -1;
+	}
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+
+	argv[1].isint = 1;
+	argv[1].len = 4;
+	argv[1].u.integer = (int) len;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_truncate,
+			   &retval, &result_len, 1, argv, 2);
+
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return retval;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_truncate64
+ *	  truncates an existing large object to the given size
+ *
+ * returns 0 upon success
+ * returns -1 upon failure
+ */
+int
+lo_truncate64(PGconn *conn, int fd, pg_int64 len)
+{
+	PQArgBlock	argv[2];
+	PGresult   *res;
+	int			retval;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	if (conn->lobjfuncs->fn_lo_truncate64 == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_truncate64");
+		return -1;
+	}
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+
+	len = lo_hton64(len);
+	argv[1].isint = 0;
+	argv[1].len = 8;
+	argv[1].u.ptr = (int *) &len;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_truncate64,
+			   &retval, &result_len, 1, argv, 2);
+
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return retval;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_read
+ *	  read len bytes of the large object into buf
+ *
+ * returns the number of bytes read, or -1 on failure.
+ * the CALLER must have allocated enough space to hold the result returned
+ */
+
+int
+lo_read(PGconn *conn, int fd, char *buf, size_t len)
+{
+	PQArgBlock	argv[2];
+	PGresult   *res;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	/*
+	 * Long ago, somebody thought it'd be a good idea to declare this function
+	 * as taking size_t ... but the underlying backend function only accepts a
+	 * signed int32 length.  So throw error if the given value overflows
+	 * int32.
+	 */
+	if (len > (size_t) INT_MAX)
+	{
+		appendPQExpBufferStr(&conn->errorMessage,
+							 libpq_gettext("argument of lo_read exceeds integer range\n"));
+		return -1;
+	}
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+
+	argv[1].isint = 1;
+	argv[1].len = 4;
+	argv[1].u.integer = (int) len;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_read,
+			   (void *) buf, &result_len, 0, argv, 2);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return result_len;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_write
+ *	  write len bytes of buf into the large object fd
+ *
+ * returns the number of bytes written, or -1 on failure.
+ */
+int
+lo_write(PGconn *conn, int fd, const char *buf, size_t len)
+{
+	PQArgBlock	argv[2];
+	PGresult   *res;
+	int			result_len;
+	int			retval;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	/*
+	 * Long ago, somebody thought it'd be a good idea to declare this function
+	 * as taking size_t ... but the underlying backend function only accepts a
+	 * signed int32 length.  So throw error if the given value overflows
+	 * int32.
+	 */
+	if (len > (size_t) INT_MAX)
+	{
+		appendPQExpBufferStr(&conn->errorMessage,
+							 libpq_gettext("argument of lo_write exceeds integer range\n"));
+		return -1;
+	}
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+
+	argv[1].isint = 0;
+	argv[1].len = (int) len;
+	argv[1].u.ptr = (int *) unconstify(char *, buf);
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_write,
+			   &retval, &result_len, 1, argv, 2);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return retval;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_lseek
+ *	  change the current read or write location on a large object
+ */
+int
+lo_lseek(PGconn *conn, int fd, int offset, int whence)
+{
+	PQArgBlock	argv[3];
+	PGresult   *res;
+	int			retval;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+
+	argv[1].isint = 1;
+	argv[1].len = 4;
+	argv[1].u.integer = offset;
+
+	argv[2].isint = 1;
+	argv[2].len = 4;
+	argv[2].u.integer = whence;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_lseek,
+			   &retval, &result_len, 1, argv, 3);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return retval;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_lseek64
+ *	  change the current read or write location on a large object
+ */
+pg_int64
+lo_lseek64(PGconn *conn, int fd, pg_int64 offset, int whence)
+{
+	PQArgBlock	argv[3];
+	PGresult   *res;
+	pg_int64	retval;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	if (conn->lobjfuncs->fn_lo_lseek64 == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_lseek64");
+		return -1;
+	}
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+
+	offset = lo_hton64(offset);
+	argv[1].isint = 0;
+	argv[1].len = 8;
+	argv[1].u.ptr = (int *) &offset;
+
+	argv[2].isint = 1;
+	argv[2].len = 4;
+	argv[2].u.integer = whence;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_lseek64,
+			   (void *) &retval, &result_len, 0, argv, 3);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK && result_len == 8)
+	{
+		PQclear(res);
+		return lo_ntoh64(retval);
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_creat
+ *	  create a new large object
+ * the mode is ignored (once upon a time it had a use)
+ *
+ * returns the oid of the large object created or
+ * InvalidOid upon failure
+ */
+Oid
+lo_creat(PGconn *conn, int mode)
+{
+	PQArgBlock	argv[1];
+	PGresult   *res;
+	int			retval;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return InvalidOid;
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = mode;
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_creat,
+			   &retval, &result_len, 1, argv, 1);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return (Oid) retval;
+	}
+	else
+	{
+		PQclear(res);
+		return InvalidOid;
+	}
+}
+
+/*
+ * lo_create
+ *	  create a new large object
+ * if lobjId isn't InvalidOid, it specifies the OID to (attempt to) create
+ *
+ * returns the oid of the large object created or
+ * InvalidOid upon failure
+ */
+Oid
+lo_create(PGconn *conn, Oid lobjId)
+{
+	PQArgBlock	argv[1];
+	PGresult   *res;
+	int			retval;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return InvalidOid;
+
+	/* Must check this on-the-fly because it's not there pre-8.1 */
+	if (conn->lobjfuncs->fn_lo_create == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_create");
+		return InvalidOid;
+	}
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = lobjId;
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_create,
+			   &retval, &result_len, 1, argv, 1);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return (Oid) retval;
+	}
+	else
+	{
+		PQclear(res);
+		return InvalidOid;
+	}
+}
+
+
+/*
+ * lo_tell
+ *	  returns the current seek location of the large object
+ */
+int
+lo_tell(PGconn *conn, int fd)
+{
+	int			retval;
+	PQArgBlock	argv[1];
+	PGresult   *res;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_tell,
+			   &retval, &result_len, 1, argv, 1);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return retval;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_tell64
+ *	  returns the current seek location of the large object
+ */
+pg_int64
+lo_tell64(PGconn *conn, int fd)
+{
+	pg_int64	retval;
+	PQArgBlock	argv[1];
+	PGresult   *res;
+	int			result_len;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	if (conn->lobjfuncs->fn_lo_tell64 == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_tell64");
+		return -1;
+	}
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = fd;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_tell64,
+			   (void *) &retval, &result_len, 0, argv, 1);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK && result_len == 8)
+	{
+		PQclear(res);
+		return lo_ntoh64(retval);
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_unlink
+ *	  delete a file
+ */
+
+int
+lo_unlink(PGconn *conn, Oid lobjId)
+{
+	PQArgBlock	argv[1];
+	PGresult   *res;
+	int			result_len;
+	int			retval;
+
+	if (lo_initialize(conn) < 0)
+		return -1;
+
+	argv[0].isint = 1;
+	argv[0].len = 4;
+	argv[0].u.integer = lobjId;
+
+	res = PQfn(conn, conn->lobjfuncs->fn_lo_unlink,
+			   &retval, &result_len, 1, argv, 1);
+	if (PQresultStatus(res) == PGRES_COMMAND_OK)
+	{
+		PQclear(res);
+		return retval;
+	}
+	else
+	{
+		PQclear(res);
+		return -1;
+	}
+}
+
+/*
+ * lo_import -
+ *	  imports a file as an (inversion) large object.
+ *
+ * returns the oid of that object upon success,
+ * returns InvalidOid upon failure
+ */
+
+Oid
+lo_import(PGconn *conn, const char *filename)
+{
+	return lo_import_internal(conn, filename, InvalidOid);
+}
+
+/*
+ * lo_import_with_oid -
+ *	  imports a file as an (inversion) large object.
+ *	  large object id can be specified.
+ *
+ * returns the oid of that object upon success,
+ * returns InvalidOid upon failure
+ */
+
+Oid
+lo_import_with_oid(PGconn *conn, const char *filename, Oid lobjId)
+{
+	return lo_import_internal(conn, filename, lobjId);
+}
+
+static Oid
+lo_import_internal(PGconn *conn, const char *filename, Oid oid)
+{
+	int			fd;
+	int			nbytes,
+				tmp;
+	char		buf[LO_BUFSIZE];
+	Oid			lobjOid;
+	int			lobj;
+	char		sebuf[PG_STRERROR_R_BUFLEN];
+
+	if (conn == NULL)
+		return InvalidOid;
+
+	/* Since this is the beginning of a query cycle, reset the error buffer */
+	resetPQExpBuffer(&conn->errorMessage);
+
+	/*
+	 * open the file to be read in
+	 */
+	fd = open(filename, O_RDONLY | PG_BINARY, 0666);
+	if (fd < 0)
+	{							/* error */
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("could not open file \"%s\": %s\n"),
+						  filename, strerror_r(errno, sebuf, sizeof(sebuf)));
+		return InvalidOid;
+	}
+
+	/*
+	 * create an inversion object
+	 */
+	if (oid == InvalidOid)
+		lobjOid = lo_creat(conn, INV_READ | INV_WRITE);
+	else
+		lobjOid = lo_create(conn, oid);
+
+	if (lobjOid == InvalidOid)
+	{
+		/* we assume lo_create() already set a suitable error message */
+		(void) close(fd);
+		return InvalidOid;
+	}
+
+	lobj = lo_open(conn, lobjOid, INV_WRITE);
+	if (lobj == -1)
+	{
+		/* we assume lo_open() already set a suitable error message */
+		(void) close(fd);
+		return InvalidOid;
+	}
+
+	/*
+	 * read in from the file and write to the large object
+	 */
+	while ((nbytes = read(fd, buf, LO_BUFSIZE)) > 0)
+	{
+		tmp = lo_write(conn, lobj, buf, nbytes);
+		if (tmp != nbytes)
+		{
+			/*
+			 * If lo_write() failed, we are now in an aborted transaction so
+			 * there's no need for lo_close(); furthermore, if we tried it
+			 * we'd overwrite the useful error result with a useless one. So
+			 * just nail the doors shut and get out of town.
+			 */
+			(void) close(fd);
+			return InvalidOid;
+		}
+	}
+
+	if (nbytes < 0)
+	{
+		/* We must do lo_close before setting the errorMessage */
+		int			save_errno = errno;
+
+		(void) lo_close(conn, lobj);
+		(void) close(fd);
+		/* deliberately overwrite any error from lo_close */
+		printfPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("could not read from file \"%s\": %s\n"),
+						  filename,
+						  strerror_r(save_errno, sebuf, sizeof(sebuf)));
+		return InvalidOid;
+	}
+
+	(void) close(fd);
+
+	if (lo_close(conn, lobj) != 0)
+	{
+		/* we assume lo_close() already set a suitable error message */
+		return InvalidOid;
+	}
+
+	return lobjOid;
+}
+
+/*
+ * lo_export -
+ *	  exports an (inversion) large object.
+ * returns -1 upon failure, 1 if OK
+ */
+int
+lo_export(PGconn *conn, Oid lobjId, const char *filename)
+{
+	int			result = 1;
+	int			fd;
+	int			nbytes,
+				tmp;
+	char		buf[LO_BUFSIZE];
+	int			lobj;
+	char		sebuf[PG_STRERROR_R_BUFLEN];
+
+	/*
+	 * open the large object.
+	 */
+	lobj = lo_open(conn, lobjId, INV_READ);
+	if (lobj == -1)
+	{
+		/* we assume lo_open() already set a suitable error message */
+		return -1;
+	}
+
+	/*
+	 * create the file to be written to
+	 */
+	fd = open(filename, O_CREAT | O_WRONLY | O_TRUNC | PG_BINARY, 0666);
+	if (fd < 0)
+	{
+		/* We must do lo_close before setting the errorMessage */
+		int			save_errno = errno;
+
+		(void) lo_close(conn, lobj);
+		/* deliberately overwrite any error from lo_close */
+		printfPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("could not open file \"%s\": %s\n"),
+						  filename,
+						  strerror_r(save_errno, sebuf, sizeof(sebuf)));
+		return -1;
+	}
+
+	/*
+	 * read in from the large object and write to the file
+	 */
+	while ((nbytes = lo_read(conn, lobj, buf, LO_BUFSIZE)) > 0)
+	{
+		tmp = write(fd, buf, nbytes);
+		if (tmp != nbytes)
+		{
+			/* We must do lo_close before setting the errorMessage */
+			int			save_errno = errno;
+
+			(void) lo_close(conn, lobj);
+			(void) close(fd);
+			/* deliberately overwrite any error from lo_close */
+			printfPQExpBuffer(&conn->errorMessage,
+							  libpq_gettext("could not write to file \"%s\": %s\n"),
+							  filename,
+							  strerror_r(save_errno, sebuf, sizeof(sebuf)));
+			return -1;
+		}
+	}
+
+	/*
+	 * If lo_read() failed, we are now in an aborted transaction so there's no
+	 * need for lo_close(); furthermore, if we tried it we'd overwrite the
+	 * useful error result with a useless one. So skip lo_close() if we got a
+	 * failure result.
+	 */
+	if (nbytes < 0 ||
+		lo_close(conn, lobj) != 0)
+	{
+		/* assume lo_read() or lo_close() left a suitable error message */
+		result = -1;
+	}
+
+	/* if we already failed, don't overwrite that msg with a close error */
+	if (close(fd) != 0 && result >= 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("could not write to file \"%s\": %s\n"),
+						  filename, strerror_r(errno, sebuf, sizeof(sebuf)));
+		result = -1;
+	}
+
+	return result;
+}
+
+
+/*
+ * lo_initialize
+ *
+ * Initialize for a new large-object operation on an existing connection.
+ * Return 0 if OK, -1 on failure.
+ *
+ * If we haven't previously done so, we collect the function OIDs from
+ * pg_proc for all functions that are required for large object operations.
+ */
+static int
+lo_initialize(PGconn *conn)
+{
+	PGresult   *res;
+	PGlobjfuncs *lobjfuncs;
+	int			n;
+	const char *query;
+	const char *fname;
+	Oid			foid;
+
+	/* Nothing we can do with no connection */
+	if (conn == NULL)
+		return -1;
+
+	/* Since this is the beginning of a query cycle, reset the error buffer */
+	resetPQExpBuffer(&conn->errorMessage);
+
+	/* Nothing else to do if we already collected info */
+	if (conn->lobjfuncs != NULL)
+		return 0;
+
+	/*
+	 * Allocate the structure to hold the function OIDs.  We don't store it
+	 * into the PGconn until it's successfully filled.
+	 */
+	lobjfuncs = (PGlobjfuncs *) malloc(sizeof(PGlobjfuncs));
+	if (lobjfuncs == NULL)
+	{
+		appendPQExpBufferStr(&conn->errorMessage,
+							 libpq_gettext("out of memory\n"));
+		return -1;
+	}
+	MemSet((char *) lobjfuncs, 0, sizeof(PGlobjfuncs));
+
+	/*
+	 * Execute the query to get all the functions at once.  (Not all of them
+	 * may exist in older server versions.)
+	 */
+	query = "select proname, oid from pg_catalog.pg_proc "
+		"where proname in ("
+		"'lo_open', "
+		"'lo_close', "
+		"'lo_creat', "
+		"'lo_create', "
+		"'lo_unlink', "
+		"'lo_lseek', "
+		"'lo_lseek64', "
+		"'lo_tell', "
+		"'lo_tell64', "
+		"'lo_truncate', "
+		"'lo_truncate64', "
+		"'loread', "
+		"'lowrite') "
+		"and pronamespace = (select oid from pg_catalog.pg_namespace "
+		"where nspname = 'pg_catalog')";
+
+	res = PQexec(conn, query);
+	if (res == NULL)
+	{
+		free(lobjfuncs);
+		return -1;
+	}
+
+	if (res->resultStatus != PGRES_TUPLES_OK)
+	{
+		free(lobjfuncs);
+		PQclear(res);
+		appendPQExpBufferStr(&conn->errorMessage,
+							 libpq_gettext("query to initialize large object functions did not return data\n"));
+		return -1;
+	}
+
+	/*
+	 * Examine the result and put the OID's into the struct
+	 */
+	for (n = 0; n < PQntuples(res); n++)
+	{
+		fname = PQgetvalue(res, n, 0);
+		foid = (Oid) atoi(PQgetvalue(res, n, 1));
+		if (strcmp(fname, "lo_open") == 0)
+			lobjfuncs->fn_lo_open = foid;
+		else if (strcmp(fname, "lo_close") == 0)
+			lobjfuncs->fn_lo_close = foid;
+		else if (strcmp(fname, "lo_creat") == 0)
+			lobjfuncs->fn_lo_creat = foid;
+		else if (strcmp(fname, "lo_create") == 0)
+			lobjfuncs->fn_lo_create = foid;
+		else if (strcmp(fname, "lo_unlink") == 0)
+			lobjfuncs->fn_lo_unlink = foid;
+		else if (strcmp(fname, "lo_lseek") == 0)
+			lobjfuncs->fn_lo_lseek = foid;
+		else if (strcmp(fname, "lo_lseek64") == 0)
+			lobjfuncs->fn_lo_lseek64 = foid;
+		else if (strcmp(fname, "lo_tell") == 0)
+			lobjfuncs->fn_lo_tell = foid;
+		else if (strcmp(fname, "lo_tell64") == 0)
+			lobjfuncs->fn_lo_tell64 = foid;
+		else if (strcmp(fname, "lo_truncate") == 0)
+			lobjfuncs->fn_lo_truncate = foid;
+		else if (strcmp(fname, "lo_truncate64") == 0)
+			lobjfuncs->fn_lo_truncate64 = foid;
+		else if (strcmp(fname, "loread") == 0)
+			lobjfuncs->fn_lo_read = foid;
+		else if (strcmp(fname, "lowrite") == 0)
+			lobjfuncs->fn_lo_write = foid;
+	}
+
+	PQclear(res);
+
+	/*
+	 * Finally check that we got all required large object interface functions
+	 * (ones that have been added later than the stone age are instead checked
+	 * only if used)
+	 */
+	if (lobjfuncs->fn_lo_open == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_open");
+		free(lobjfuncs);
+		return -1;
+	}
+	if (lobjfuncs->fn_lo_close == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_close");
+		free(lobjfuncs);
+		return -1;
+	}
+	if (lobjfuncs->fn_lo_creat == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_creat");
+		free(lobjfuncs);
+		return -1;
+	}
+	if (lobjfuncs->fn_lo_unlink == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_unlink");
+		free(lobjfuncs);
+		return -1;
+	}
+	if (lobjfuncs->fn_lo_lseek == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_lseek");
+		free(lobjfuncs);
+		return -1;
+	}
+	if (lobjfuncs->fn_lo_tell == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lo_tell");
+		free(lobjfuncs);
+		return -1;
+	}
+	if (lobjfuncs->fn_lo_read == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "loread");
+		free(lobjfuncs);
+		return -1;
+	}
+	if (lobjfuncs->fn_lo_write == 0)
+	{
+		appendPQExpBuffer(&conn->errorMessage,
+						  libpq_gettext("cannot determine OID of function %s\n"),
+						  "lowrite");
+		free(lobjfuncs);
+		return -1;
+	}
+
+	/*
+	 * Put the structure into the connection control
+	 */
+	conn->lobjfuncs = lobjfuncs;
+	return 0;
+}
+
+/*
+ * lo_hton64
+ *	  converts a 64-bit integer from host byte order to network byte order
+ */
+static pg_int64
+lo_hton64(pg_int64 host64)
+{
+	union
+	{
+		pg_int64	i64;
+		uint32		i32[2];
+	}			swap;
+	uint32		t;
+
+	/* High order half first, since we're doing MSB-first */
+	t = (uint32) (host64 >> 32);
+	swap.i32[0] = pg_hton32(t);
+
+	/* Now the low order half */
+	t = (uint32) host64;
+	swap.i32[1] = pg_hton32(t);
+
+	return swap.i64;
+}
+
+/*
+ * lo_ntoh64
+ *	  converts a 64-bit integer from network byte order to host byte order
+ */
+static pg_int64
+lo_ntoh64(pg_int64 net64)
+{
+	union
+	{
+		pg_int64	i64;
+		uint32		i32[2];
+	}			swap;
+	pg_int64	result;
+
+	swap.i64 = net64;
+
+	result = (uint32) pg_ntoh32(swap.i32[0]);
+	result <<= 32;
+	result |= (uint32) pg_ntoh32(swap.i32[1]);
+
+	return result;
+}