Adding upstream version 14.5.upstream/14.5upstream

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

1 files changed, 415 insertions, 0 deletions

diff --git a/src/backend/utils/adt/tid.c b/src/backend/utils/adt/tid.c
new file mode 100644
index 0000000..e9f1fc7
--- /dev/null
+++ b/src/backend/utils/adt/tid.c
@@ -0,0 +1,415 @@
+/*-------------------------------------------------------------------------
+ *
+ * tid.c
+ *	  Functions for the built-in type tuple id
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/adt/tid.c
+ *
+ * NOTES
+ *	  input routine largely stolen from boxin().
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include <math.h>
+#include <limits.h>
+
+#include "access/heapam.h"
+#include "access/sysattr.h"
+#include "access/tableam.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "common/hashfn.h"
+#include "libpq/pqformat.h"
+#include "miscadmin.h"
+#include "parser/parsetree.h"
+#include "utils/acl.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/rel.h"
+#include "utils/snapmgr.h"
+#include "utils/varlena.h"
+
+
+#define DatumGetItemPointer(X)	 ((ItemPointer) DatumGetPointer(X))
+#define ItemPointerGetDatum(X)	 PointerGetDatum(X)
+#define PG_GETARG_ITEMPOINTER(n) DatumGetItemPointer(PG_GETARG_DATUM(n))
+#define PG_RETURN_ITEMPOINTER(x) return ItemPointerGetDatum(x)
+
+#define LDELIM			'('
+#define RDELIM			')'
+#define DELIM			','
+#define NTIDARGS		2
+
+static ItemPointer currtid_for_view(Relation viewrel, ItemPointer tid);
+
+/* ----------------------------------------------------------------
+ *		tidin
+ * ----------------------------------------------------------------
+ */
+Datum
+tidin(PG_FUNCTION_ARGS)
+{
+	char	   *str = PG_GETARG_CSTRING(0);
+	char	   *p,
+			   *coord[NTIDARGS];
+	int			i;
+	ItemPointer result;
+	BlockNumber blockNumber;
+	OffsetNumber offsetNumber;
+	char	   *badp;
+	int			hold_offset;
+
+	for (i = 0, p = str; *p && i < NTIDARGS && *p != RDELIM; p++)
+		if (*p == DELIM || (*p == LDELIM && !i))
+			coord[i++] = p + 1;
+
+	if (i < NTIDARGS)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input syntax for type %s: \"%s\"",
+						"tid", str)));
+
+	errno = 0;
+	blockNumber = strtoul(coord[0], &badp, 10);
+	if (errno || *badp != DELIM)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input syntax for type %s: \"%s\"",
+						"tid", str)));
+
+	hold_offset = strtol(coord[1], &badp, 10);
+	if (errno || *badp != RDELIM ||
+		hold_offset > USHRT_MAX || hold_offset < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("invalid input syntax for type %s: \"%s\"",
+						"tid", str)));
+
+	offsetNumber = hold_offset;
+
+	result = (ItemPointer) palloc(sizeof(ItemPointerData));
+
+	ItemPointerSet(result, blockNumber, offsetNumber);
+
+	PG_RETURN_ITEMPOINTER(result);
+}
+
+/* ----------------------------------------------------------------
+ *		tidout
+ * ----------------------------------------------------------------
+ */
+Datum
+tidout(PG_FUNCTION_ARGS)
+{
+	ItemPointer itemPtr = PG_GETARG_ITEMPOINTER(0);
+	BlockNumber blockNumber;
+	OffsetNumber offsetNumber;
+	char		buf[32];
+
+	blockNumber = ItemPointerGetBlockNumberNoCheck(itemPtr);
+	offsetNumber = ItemPointerGetOffsetNumberNoCheck(itemPtr);
+
+	/* Perhaps someday we should output this as a record. */
+	snprintf(buf, sizeof(buf), "(%u,%u)", blockNumber, offsetNumber);
+
+	PG_RETURN_CSTRING(pstrdup(buf));
+}
+
+/*
+ *		tidrecv			- converts external binary format to tid
+ */
+Datum
+tidrecv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+	ItemPointer result;
+	BlockNumber blockNumber;
+	OffsetNumber offsetNumber;
+
+	blockNumber = pq_getmsgint(buf, sizeof(blockNumber));
+	offsetNumber = pq_getmsgint(buf, sizeof(offsetNumber));
+
+	result = (ItemPointer) palloc(sizeof(ItemPointerData));
+
+	ItemPointerSet(result, blockNumber, offsetNumber);
+
+	PG_RETURN_ITEMPOINTER(result);
+}
+
+/*
+ *		tidsend			- converts tid to binary format
+ */
+Datum
+tidsend(PG_FUNCTION_ARGS)
+{
+	ItemPointer itemPtr = PG_GETARG_ITEMPOINTER(0);
+	StringInfoData buf;
+
+	pq_begintypsend(&buf);
+	pq_sendint32(&buf, ItemPointerGetBlockNumberNoCheck(itemPtr));
+	pq_sendint16(&buf, ItemPointerGetOffsetNumberNoCheck(itemPtr));
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+/*****************************************************************************
+ *	 PUBLIC ROUTINES														 *
+ *****************************************************************************/
+
+Datum
+tideq(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_BOOL(ItemPointerCompare(arg1, arg2) == 0);
+}
+
+Datum
+tidne(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_BOOL(ItemPointerCompare(arg1, arg2) != 0);
+}
+
+Datum
+tidlt(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_BOOL(ItemPointerCompare(arg1, arg2) < 0);
+}
+
+Datum
+tidle(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_BOOL(ItemPointerCompare(arg1, arg2) <= 0);
+}
+
+Datum
+tidgt(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_BOOL(ItemPointerCompare(arg1, arg2) > 0);
+}
+
+Datum
+tidge(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_BOOL(ItemPointerCompare(arg1, arg2) >= 0);
+}
+
+Datum
+bttidcmp(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_INT32(ItemPointerCompare(arg1, arg2));
+}
+
+Datum
+tidlarger(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_ITEMPOINTER(ItemPointerCompare(arg1, arg2) >= 0 ? arg1 : arg2);
+}
+
+Datum
+tidsmaller(PG_FUNCTION_ARGS)
+{
+	ItemPointer arg1 = PG_GETARG_ITEMPOINTER(0);
+	ItemPointer arg2 = PG_GETARG_ITEMPOINTER(1);
+
+	PG_RETURN_ITEMPOINTER(ItemPointerCompare(arg1, arg2) <= 0 ? arg1 : arg2);
+}
+
+Datum
+hashtid(PG_FUNCTION_ARGS)
+{
+	ItemPointer key = PG_GETARG_ITEMPOINTER(0);
+
+	/*
+	 * While you'll probably have a lot of trouble with a compiler that
+	 * insists on appending pad space to struct ItemPointerData, we can at
+	 * least make this code work, by not using sizeof(ItemPointerData).
+	 * Instead rely on knowing the sizes of the component fields.
+	 */
+	return hash_any((unsigned char *) key,
+					sizeof(BlockIdData) + sizeof(OffsetNumber));
+}
+
+Datum
+hashtidextended(PG_FUNCTION_ARGS)
+{
+	ItemPointer key = PG_GETARG_ITEMPOINTER(0);
+	uint64		seed = PG_GETARG_INT64(1);
+
+	/* As above */
+	return hash_any_extended((unsigned char *) key,
+							 sizeof(BlockIdData) + sizeof(OffsetNumber),
+							 seed);
+}
+
+
+/*
+ *	Functions to get latest tid of a specified tuple.
+ *
+ *	Maybe these implementations should be moved to another place
+ */
+
+/*
+ * Utility wrapper for current CTID functions.
+ *		Returns the latest version of a tuple pointing at "tid" for
+ *		relation "rel".
+ */
+static ItemPointer
+currtid_internal(Relation rel, ItemPointer tid)
+{
+	ItemPointer result;
+	AclResult	aclresult;
+	Snapshot	snapshot;
+	TableScanDesc scan;
+
+	result = (ItemPointer) palloc(sizeof(ItemPointerData));
+
+	aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
+								  ACL_SELECT);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, get_relkind_objtype(rel->rd_rel->relkind),
+					   RelationGetRelationName(rel));
+
+	if (rel->rd_rel->relkind == RELKIND_VIEW)
+		return currtid_for_view(rel, tid);
+
+	if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind))
+		elog(ERROR, "cannot look at latest visible tid for relation \"%s.%s\"",
+			 get_namespace_name(RelationGetNamespace(rel)),
+			 RelationGetRelationName(rel));
+
+	ItemPointerCopy(tid, result);
+
+	snapshot = RegisterSnapshot(GetLatestSnapshot());
+	scan = table_beginscan_tid(rel, snapshot);
+	table_tuple_get_latest_tid(scan, result);
+	table_endscan(scan);
+	UnregisterSnapshot(snapshot);
+
+	return result;
+}
+
+/*
+ *	Handle CTIDs of views.
+ *		CTID should be defined in the view and it must
+ *		correspond to the CTID of a base relation.
+ */
+static ItemPointer
+currtid_for_view(Relation viewrel, ItemPointer tid)
+{
+	TupleDesc	att = RelationGetDescr(viewrel);
+	RuleLock   *rulelock;
+	RewriteRule *rewrite;
+	int			i,
+				natts = att->natts,
+				tididx = -1;
+
+	for (i = 0; i < natts; i++)
+	{
+		Form_pg_attribute attr = TupleDescAttr(att, i);
+
+		if (strcmp(NameStr(attr->attname), "ctid") == 0)
+		{
+			if (attr->atttypid != TIDOID)
+				elog(ERROR, "ctid isn't of type TID");
+			tididx = i;
+			break;
+		}
+	}
+	if (tididx < 0)
+		elog(ERROR, "currtid cannot handle views with no CTID");
+	rulelock = viewrel->rd_rules;
+	if (!rulelock)
+		elog(ERROR, "the view has no rules");
+	for (i = 0; i < rulelock->numLocks; i++)
+	{
+		rewrite = rulelock->rules[i];
+		if (rewrite->event == CMD_SELECT)
+		{
+			Query	   *query;
+			TargetEntry *tle;
+
+			if (list_length(rewrite->actions) != 1)
+				elog(ERROR, "only one select rule is allowed in views");
+			query = (Query *) linitial(rewrite->actions);
+			tle = get_tle_by_resno(query->targetList, tididx + 1);
+			if (tle && tle->expr && IsA(tle->expr, Var))
+			{
+				Var		   *var = (Var *) tle->expr;
+				RangeTblEntry *rte;
+
+				if (!IS_SPECIAL_VARNO(var->varno) &&
+					var->varattno == SelfItemPointerAttributeNumber)
+				{
+					rte = rt_fetch(var->varno, query->rtable);
+					if (rte)
+					{
+						ItemPointer result;
+						Relation	rel;
+
+						rel = table_open(rte->relid, AccessShareLock);
+						result = currtid_internal(rel, tid);
+						table_close(rel, AccessShareLock);
+						return result;
+					}
+				}
+			}
+			break;
+		}
+	}
+	elog(ERROR, "currtid cannot handle this view");
+	return NULL;
+}
+
+/*
+ * currtid_byrelname
+ *		Get the latest tuple version of the tuple pointing at a CTID, for a
+ *		given relation name.
+ */
+Datum
+currtid_byrelname(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_PP(0);
+	ItemPointer tid = PG_GETARG_ITEMPOINTER(1);
+	ItemPointer result;
+	RangeVar   *relrv;
+	Relation	rel;
+
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = table_openrv(relrv, AccessShareLock);
+
+	/* grab the latest tuple version associated to this CTID */
+	result = currtid_internal(rel, tid);
+
+	table_close(rel, AccessShareLock);
+
+	PG_RETURN_ITEMPOINTER(result);
+}