Adding upstream version 14.5.upstream/14.5upstream

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

1 files changed, 210 insertions, 0 deletions

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;
+}