Adding upstream version 15.5.upstream/15.5

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

1 files changed, 585 insertions, 0 deletions

diff --git a/contrib/pgstattuple/pgstattuple.c b/contrib/pgstattuple/pgstattuple.c
new file mode 100644
index 0000000..3bd8b96
--- /dev/null
+++ b/contrib/pgstattuple/pgstattuple.c
@@ -0,0 +1,585 @@
+/*
+ * contrib/pgstattuple/pgstattuple.c
+ *
+ * Copyright (c) 2001,2002	Tatsuo Ishii
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose, without fee, and without a
+ * written agreement is hereby granted, provided that the above
+ * copyright notice and this paragraph and the following two
+ * paragraphs appear in all copies.
+ *
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
+ * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
+ * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
+ * IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
+ * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ */
+
+#include "postgres.h"
+
+#include "access/gist_private.h"
+#include "access/hash.h"
+#include "access/heapam.h"
+#include "access/nbtree.h"
+#include "access/relscan.h"
+#include "access/tableam.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_am_d.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "storage/bufmgr.h"
+#include "storage/lmgr.h"
+#include "utils/builtins.h"
+#include "utils/varlena.h"
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(pgstattuple);
+PG_FUNCTION_INFO_V1(pgstattuple_v1_5);
+PG_FUNCTION_INFO_V1(pgstattuplebyid);
+PG_FUNCTION_INFO_V1(pgstattuplebyid_v1_5);
+
+/*
+ * struct pgstattuple_type
+ *
+ * tuple_percent, dead_tuple_percent and free_percent are computable,
+ * so not defined here.
+ */
+typedef struct pgstattuple_type
+{
+	uint64		table_len;
+	uint64		tuple_count;
+	uint64		tuple_len;
+	uint64		dead_tuple_count;
+	uint64		dead_tuple_len;
+	uint64		free_space;		/* free/reusable space in bytes */
+} pgstattuple_type;
+
+typedef void (*pgstat_page) (pgstattuple_type *, Relation, BlockNumber,
+							 BufferAccessStrategy);
+
+static Datum build_pgstattuple_type(pgstattuple_type *stat,
+									FunctionCallInfo fcinfo);
+static Datum pgstat_relation(Relation rel, FunctionCallInfo fcinfo);
+static Datum pgstat_heap(Relation rel, FunctionCallInfo fcinfo);
+static void pgstat_btree_page(pgstattuple_type *stat,
+							  Relation rel, BlockNumber blkno,
+							  BufferAccessStrategy bstrategy);
+static void pgstat_hash_page(pgstattuple_type *stat,
+							 Relation rel, BlockNumber blkno,
+							 BufferAccessStrategy bstrategy);
+static void pgstat_gist_page(pgstattuple_type *stat,
+							 Relation rel, BlockNumber blkno,
+							 BufferAccessStrategy bstrategy);
+static Datum pgstat_index(Relation rel, BlockNumber start,
+						  pgstat_page pagefn, FunctionCallInfo fcinfo);
+static void pgstat_index_page(pgstattuple_type *stat, Page page,
+							  OffsetNumber minoff, OffsetNumber maxoff);
+
+/*
+ * build_pgstattuple_type -- build a pgstattuple_type tuple
+ */
+static Datum
+build_pgstattuple_type(pgstattuple_type *stat, FunctionCallInfo fcinfo)
+{
+#define NCOLUMNS	9
+#define NCHARS		314
+
+	HeapTuple	tuple;
+	char	   *values[NCOLUMNS];
+	char		values_buf[NCOLUMNS][NCHARS];
+	int			i;
+	double		tuple_percent;
+	double		dead_tuple_percent;
+	double		free_percent;	/* free/reusable space in % */
+	TupleDesc	tupdesc;
+	AttInMetadata *attinmeta;
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+
+	/*
+	 * Generate attribute metadata needed later to produce tuples from raw C
+	 * strings
+	 */
+	attinmeta = TupleDescGetAttInMetadata(tupdesc);
+
+	if (stat->table_len == 0)
+	{
+		tuple_percent = 0.0;
+		dead_tuple_percent = 0.0;
+		free_percent = 0.0;
+	}
+	else
+	{
+		tuple_percent = 100.0 * stat->tuple_len / stat->table_len;
+		dead_tuple_percent = 100.0 * stat->dead_tuple_len / stat->table_len;
+		free_percent = 100.0 * stat->free_space / stat->table_len;
+	}
+
+	/*
+	 * Prepare a values array for constructing the tuple. This should be an
+	 * array of C strings which will be processed later by the appropriate
+	 * "in" functions.
+	 */
+	for (i = 0; i < NCOLUMNS; i++)
+		values[i] = values_buf[i];
+	i = 0;
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->table_len);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->tuple_count);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->tuple_len);
+	snprintf(values[i++], NCHARS, "%.2f", tuple_percent);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->dead_tuple_count);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->dead_tuple_len);
+	snprintf(values[i++], NCHARS, "%.2f", dead_tuple_percent);
+	snprintf(values[i++], NCHARS, INT64_FORMAT, stat->free_space);
+	snprintf(values[i++], NCHARS, "%.2f", free_percent);
+
+	/* build a tuple */
+	tuple = BuildTupleFromCStrings(attinmeta, values);
+
+	/* make the tuple into a datum */
+	return HeapTupleGetDatum(tuple);
+}
+
+/* ----------
+ * pgstattuple:
+ * returns live/dead tuples info
+ *
+ * C FUNCTION definition
+ * pgstattuple(text) returns pgstattuple_type
+ *
+ * The superuser() check here must be kept as the library might be upgraded
+ * without the extension being upgraded, meaning that in pre-1.5 installations
+ * these functions could be called by any user.
+ * ----------
+ */
+
+Datum
+pgstattuple(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_PP(0);
+	RangeVar   *relrv;
+	Relation	rel;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("must be superuser to use pgstattuple functions")));
+
+	/* open relation */
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = relation_openrv(relrv, AccessShareLock);
+
+	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
+}
+
+/*
+ * As of pgstattuple version 1.5, we no longer need to check if the user
+ * is a superuser because we REVOKE EXECUTE on the function from PUBLIC.
+ * Users can then grant access to it based on their policies.
+ *
+ * Otherwise identical to pgstattuple (above).
+ */
+Datum
+pgstattuple_v1_5(PG_FUNCTION_ARGS)
+{
+	text	   *relname = PG_GETARG_TEXT_PP(0);
+	RangeVar   *relrv;
+	Relation	rel;
+
+	/* open relation */
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+	rel = relation_openrv(relrv, AccessShareLock);
+
+	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
+}
+
+/* Must keep superuser() check, see above. */
+Datum
+pgstattuplebyid(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	Relation	rel;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("must be superuser to use pgstattuple functions")));
+
+	/* open relation */
+	rel = relation_open(relid, AccessShareLock);
+
+	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
+}
+
+/* Remove superuser() check for 1.5 version, see above */
+Datum
+pgstattuplebyid_v1_5(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	Relation	rel;
+
+	/* open relation */
+	rel = relation_open(relid, AccessShareLock);
+
+	PG_RETURN_DATUM(pgstat_relation(rel, fcinfo));
+}
+
+/*
+ * pgstat_relation
+ */
+static Datum
+pgstat_relation(Relation rel, FunctionCallInfo fcinfo)
+{
+	const char *err;
+
+	/*
+	 * Reject attempts to read non-local temporary relations; we would be
+	 * likely to get wrong data since we have no visibility into the owning
+	 * session's local buffers.
+	 */
+	if (RELATION_IS_OTHER_TEMP(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot access temporary tables of other sessions")));
+
+	if (RELKIND_HAS_TABLE_AM(rel->rd_rel->relkind) ||
+		rel->rd_rel->relkind == RELKIND_SEQUENCE)
+	{
+		return pgstat_heap(rel, fcinfo);
+	}
+	else if (rel->rd_rel->relkind == RELKIND_INDEX)
+	{
+		/* see pgstatindex_impl */
+		if (!rel->rd_index->indisvalid)
+			ereport(ERROR,
+					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+					 errmsg("index \"%s\" is not valid",
+							RelationGetRelationName(rel))));
+
+		switch (rel->rd_rel->relam)
+		{
+			case BTREE_AM_OID:
+				return pgstat_index(rel, BTREE_METAPAGE + 1,
+									pgstat_btree_page, fcinfo);
+			case HASH_AM_OID:
+				return pgstat_index(rel, HASH_METAPAGE + 1,
+									pgstat_hash_page, fcinfo);
+			case GIST_AM_OID:
+				return pgstat_index(rel, GIST_ROOT_BLKNO + 1,
+									pgstat_gist_page, fcinfo);
+			case GIN_AM_OID:
+				err = "gin index";
+				break;
+			case SPGIST_AM_OID:
+				err = "spgist index";
+				break;
+			case BRIN_AM_OID:
+				err = "brin index";
+				break;
+			default:
+				err = "unknown index";
+				break;
+		}
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("index \"%s\" (%s) is not supported",
+						RelationGetRelationName(rel), err)));
+	}
+	else
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot get tuple-level statistics for relation \"%s\"",
+						RelationGetRelationName(rel)),
+				 errdetail_relkind_not_supported(rel->rd_rel->relkind)));
+	}
+
+	return 0;					/* should not happen */
+}
+
+/*
+ * pgstat_heap -- returns live/dead tuples info in a heap
+ */
+static Datum
+pgstat_heap(Relation rel, FunctionCallInfo fcinfo)
+{
+	TableScanDesc scan;
+	HeapScanDesc hscan;
+	HeapTuple	tuple;
+	BlockNumber nblocks;
+	BlockNumber block = 0;		/* next block to count free space in */
+	BlockNumber tupblock;
+	Buffer		buffer;
+	pgstattuple_type stat = {0};
+	SnapshotData SnapshotDirty;
+
+	if (rel->rd_rel->relam != HEAP_TABLE_AM_OID)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("only heap AM is supported")));
+
+	/* Disable syncscan because we assume we scan from block zero upwards */
+	scan = table_beginscan_strat(rel, SnapshotAny, 0, NULL, true, false);
+	hscan = (HeapScanDesc) scan;
+
+	InitDirtySnapshot(SnapshotDirty);
+
+	nblocks = hscan->rs_nblocks;	/* # blocks to be scanned */
+
+	/* scan the relation */
+	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+	{
+		CHECK_FOR_INTERRUPTS();
+
+		/* must hold a buffer lock to call HeapTupleSatisfiesVisibility */
+		LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_SHARE);
+
+		if (HeapTupleSatisfiesVisibility(tuple, &SnapshotDirty, hscan->rs_cbuf))
+		{
+			stat.tuple_len += tuple->t_len;
+			stat.tuple_count++;
+		}
+		else
+		{
+			stat.dead_tuple_len += tuple->t_len;
+			stat.dead_tuple_count++;
+		}
+
+		LockBuffer(hscan->rs_cbuf, BUFFER_LOCK_UNLOCK);
+
+		/*
+		 * To avoid physically reading the table twice, try to do the
+		 * free-space scan in parallel with the heap scan.  However,
+		 * heap_getnext may find no tuples on a given page, so we cannot
+		 * simply examine the pages returned by the heap scan.
+		 */
+		tupblock = ItemPointerGetBlockNumber(&tuple->t_self);
+
+		while (block <= tupblock)
+		{
+			CHECK_FOR_INTERRUPTS();
+
+			buffer = ReadBufferExtended(rel, MAIN_FORKNUM, block,
+										RBM_NORMAL, hscan->rs_strategy);
+			LockBuffer(buffer, BUFFER_LOCK_SHARE);
+			stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
+			UnlockReleaseBuffer(buffer);
+			block++;
+		}
+	}
+
+	while (block < nblocks)
+	{
+		CHECK_FOR_INTERRUPTS();
+
+		buffer = ReadBufferExtended(rel, MAIN_FORKNUM, block,
+									RBM_NORMAL, hscan->rs_strategy);
+		LockBuffer(buffer, BUFFER_LOCK_SHARE);
+		stat.free_space += PageGetHeapFreeSpace((Page) BufferGetPage(buffer));
+		UnlockReleaseBuffer(buffer);
+		block++;
+	}
+
+	table_endscan(scan);
+	relation_close(rel, AccessShareLock);
+
+	stat.table_len = (uint64) nblocks * BLCKSZ;
+
+	return build_pgstattuple_type(&stat, fcinfo);
+}
+
+/*
+ * pgstat_btree_page -- check tuples in a btree page
+ */
+static void
+pgstat_btree_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno,
+				  BufferAccessStrategy bstrategy)
+{
+	Buffer		buf;
+	Page		page;
+
+	buf = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL, bstrategy);
+	LockBuffer(buf, BT_READ);
+	page = BufferGetPage(buf);
+
+	/* Page is valid, see what to do with it */
+	if (PageIsNew(page))
+	{
+		/* fully empty page */
+		stat->free_space += BLCKSZ;
+	}
+	else
+	{
+		BTPageOpaque opaque;
+
+		opaque = BTPageGetOpaque(page);
+		if (P_IGNORE(opaque))
+		{
+			/* deleted or half-dead page */
+			stat->free_space += BLCKSZ;
+		}
+		else if (P_ISLEAF(opaque))
+		{
+			pgstat_index_page(stat, page, P_FIRSTDATAKEY(opaque),
+							  PageGetMaxOffsetNumber(page));
+		}
+		else
+		{
+			/* internal page */
+		}
+	}
+
+	_bt_relbuf(rel, buf);
+}
+
+/*
+ * pgstat_hash_page -- check tuples in a hash page
+ */
+static void
+pgstat_hash_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno,
+				 BufferAccessStrategy bstrategy)
+{
+	Buffer		buf;
+	Page		page;
+
+	buf = _hash_getbuf_with_strategy(rel, blkno, HASH_READ, 0, bstrategy);
+	page = BufferGetPage(buf);
+
+	if (PageGetSpecialSize(page) == MAXALIGN(sizeof(HashPageOpaqueData)))
+	{
+		HashPageOpaque opaque;
+
+		opaque = HashPageGetOpaque(page);
+		switch (opaque->hasho_flag & LH_PAGE_TYPE)
+		{
+			case LH_UNUSED_PAGE:
+				stat->free_space += BLCKSZ;
+				break;
+			case LH_BUCKET_PAGE:
+			case LH_OVERFLOW_PAGE:
+				pgstat_index_page(stat, page, FirstOffsetNumber,
+								  PageGetMaxOffsetNumber(page));
+				break;
+			case LH_BITMAP_PAGE:
+			case LH_META_PAGE:
+			default:
+				break;
+		}
+	}
+	else
+	{
+		/* maybe corrupted */
+	}
+
+	_hash_relbuf(rel, buf);
+}
+
+/*
+ * pgstat_gist_page -- check tuples in a gist page
+ */
+static void
+pgstat_gist_page(pgstattuple_type *stat, Relation rel, BlockNumber blkno,
+				 BufferAccessStrategy bstrategy)
+{
+	Buffer		buf;
+	Page		page;
+
+	buf = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL, bstrategy);
+	LockBuffer(buf, GIST_SHARE);
+	gistcheckpage(rel, buf);
+	page = BufferGetPage(buf);
+
+	if (GistPageIsLeaf(page))
+	{
+		pgstat_index_page(stat, page, FirstOffsetNumber,
+						  PageGetMaxOffsetNumber(page));
+	}
+	else
+	{
+		/* root or node */
+	}
+
+	UnlockReleaseBuffer(buf);
+}
+
+/*
+ * pgstat_index -- returns live/dead tuples info in a generic index
+ */
+static Datum
+pgstat_index(Relation rel, BlockNumber start, pgstat_page pagefn,
+			 FunctionCallInfo fcinfo)
+{
+	BlockNumber nblocks;
+	BlockNumber blkno;
+	BufferAccessStrategy bstrategy;
+	pgstattuple_type stat = {0};
+
+	/* prepare access strategy for this index */
+	bstrategy = GetAccessStrategy(BAS_BULKREAD);
+
+	blkno = start;
+	for (;;)
+	{
+		/* Get the current relation length */
+		LockRelationForExtension(rel, ExclusiveLock);
+		nblocks = RelationGetNumberOfBlocks(rel);
+		UnlockRelationForExtension(rel, ExclusiveLock);
+
+		/* Quit if we've scanned the whole relation */
+		if (blkno >= nblocks)
+		{
+			stat.table_len = (uint64) nblocks * BLCKSZ;
+
+			break;
+		}
+
+		for (; blkno < nblocks; blkno++)
+		{
+			CHECK_FOR_INTERRUPTS();
+
+			pagefn(&stat, rel, blkno, bstrategy);
+		}
+	}
+
+	relation_close(rel, AccessShareLock);
+
+	return build_pgstattuple_type(&stat, fcinfo);
+}
+
+/*
+ * pgstat_index_page -- for generic index page
+ */
+static void
+pgstat_index_page(pgstattuple_type *stat, Page page,
+				  OffsetNumber minoff, OffsetNumber maxoff)
+{
+	OffsetNumber i;
+
+	stat->free_space += PageGetFreeSpace(page);
+
+	for (i = minoff; i <= maxoff; i = OffsetNumberNext(i))
+	{
+		ItemId		itemid = PageGetItemId(page, i);
+
+		if (ItemIdIsDead(itemid))
+		{
+			stat->dead_tuple_count++;
+			stat->dead_tuple_len += ItemIdGetLength(itemid);
+		}
+		else
+		{
+			stat->tuple_count++;
+			stat->tuple_len += ItemIdGetLength(itemid);
+		}
+	}
+}