1 files changed, 150 insertions, 4 deletions

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 5c4bc15b441..3b481bcf860 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -3,10 +3,12 @@
  * vacuum.c
  *	  The postgres vacuum cleaner.
  *
- * This file now includes only control and dispatch code for VACUUM and
- * ANALYZE commands.  Regular VACUUM is implemented in vacuumlazy.c,
- * ANALYZE in analyze.c, and VACUUM FULL is a variant of CLUSTER, handled
- * in cluster.c.
+ * This file includes (a) control and dispatch code for VACUUM and ANALYZE
+ * commands, (b) code to compute various vacuum thresholds, and (c) index
+ * vacuum code.
+ *
+ * VACUUM for heap AM is implemented in vacuumlazy.c, ANALYZE in analyze.c, and
+ * VACUUM FULL is a variant of CLUSTER, handled in cluster.c.
  *
  *
  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
@@ -32,6 +34,7 @@
 #include "access/transam.h"
 #include "access/xact.h"
 #include "catalog/namespace.h"
+#include "catalog/index.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_inherits.h"
 #include "catalog/pg_namespace.h"
@@ -51,6 +54,7 @@
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/memutils.h"
+#include "utils/pg_rusage.h"
 #include "utils/snapmgr.h"
 #include "utils/syscache.h"
 
@@ -89,6 +93,8 @@ static void vac_truncate_clog(TransactionId frozenXID,
 static bool vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params);
 static double compute_parallel_delay(void);
 static VacOptValue get_vacoptval_from_boolean(DefElem *def);
+static bool vac_tid_reaped(ItemPointer itemptr, void *state);
+static int	vac_cmp_itemptr(const void *left, const void *right);
 
 /*
  * Primary entry point for manual VACUUM and ANALYZE commands
@@ -2258,3 +2264,143 @@ get_vacoptval_from_boolean(DefElem *def)
 {
 	return defGetBoolean(def) ? VACOPTVALUE_ENABLED : VACOPTVALUE_DISABLED;
 }
+
+/*
+ *	vac_bulkdel_one_index() -- bulk-deletion for index relation.
+ *
+ * Returns bulk delete stats derived from input stats
+ */
+IndexBulkDeleteResult *
+vac_bulkdel_one_index(IndexVacuumInfo *ivinfo, IndexBulkDeleteResult *istat,
+					  VacDeadItems *dead_items)
+{
+	PGRUsage	ru0;
+
+	pg_rusage_init(&ru0);
+
+	/* Do bulk deletion */
+	istat = index_bulk_delete(ivinfo, istat, vac_tid_reaped,
+							  (void *) dead_items);
+
+	ereport(ivinfo->message_level,
+			(errmsg("scanned index \"%s\" to remove %d row versions",
+					RelationGetRelationName(ivinfo->index),
+					dead_items->num_items),
+			 errdetail_internal("%s", pg_rusage_show(&ru0))));
+
+	return istat;
+}
+
+/*
+ *	vac_cleanup_one_index() -- do post-vacuum cleanup for index relation.
+ *
+ * Returns bulk delete stats derived from input stats
+ */
+IndexBulkDeleteResult *
+vac_cleanup_one_index(IndexVacuumInfo *ivinfo, IndexBulkDeleteResult *istat)
+{
+	PGRUsage	ru0;
+
+	pg_rusage_init(&ru0);
+
+	istat = index_vacuum_cleanup(ivinfo, istat);
+
+	if (istat)
+	{
+		ereport(ivinfo->message_level,
+				(errmsg("index \"%s\" now contains %.0f row versions in %u pages",
+						RelationGetRelationName(ivinfo->index),
+						istat->num_index_tuples,
+						istat->num_pages),
+				 errdetail("%.0f index row versions were removed.\n"
+						   "%u index pages were newly deleted.\n"
+						   "%u index pages are currently deleted, of which %u are currently reusable.\n"
+						   "%s.",
+						   istat->tuples_removed,
+						   istat->pages_newly_deleted,
+						   istat->pages_deleted, istat->pages_free,
+						   pg_rusage_show(&ru0))));
+	}
+
+	return istat;
+}
+
+/*
+ * Returns the total required space for VACUUM's dead_items array given a
+ * max_items value.
+ */
+inline Size
+vac_max_items_to_alloc_size(int max_items)
+{
+	Assert(max_items <= MAXDEADITEMS(MaxAllocSize));
+
+	return offsetof(VacDeadItems, items) + sizeof(ItemPointerData) * max_items;
+}
+
+/*
+ *	vac_tid_reaped() -- is a particular tid deletable?
+ *
+ *		This has the right signature to be an IndexBulkDeleteCallback.
+ *
+ *		Assumes dead_items array is sorted (in ascending TID order).
+ */
+static bool
+vac_tid_reaped(ItemPointer itemptr, void *state)
+{
+	VacDeadItems *dead_items = (VacDeadItems *) state;
+	int64		litem,
+				ritem,
+				item;
+	ItemPointer res;
+
+	litem = itemptr_encode(&dead_items->items[0]);
+	ritem = itemptr_encode(&dead_items->items[dead_items->num_items - 1]);
+	item = itemptr_encode(itemptr);
+
+	/*
+	 * Doing a simple bound check before bsearch() is useful to avoid the
+	 * extra cost of bsearch(), especially if dead items on the heap are
+	 * concentrated in a certain range.  Since this function is called for
+	 * every index tuple, it pays to be really fast.
+	 */
+	if (item < litem || item > ritem)
+		return false;
+
+	res = (ItemPointer) bsearch((void *) itemptr,
+								(void *) dead_items->items,
+								dead_items->num_items,
+								sizeof(ItemPointerData),
+								vac_cmp_itemptr);
+
+	return (res != NULL);
+}
+
+/*
+ * Comparator routines for use with qsort() and bsearch().
+ */
+static int
+vac_cmp_itemptr(const void *left, const void *right)
+{
+	BlockNumber lblk,
+				rblk;
+	OffsetNumber loff,
+				roff;
+
+	lblk = ItemPointerGetBlockNumber((ItemPointer) left);
+	rblk = ItemPointerGetBlockNumber((ItemPointer) right);
+
+	if (lblk < rblk)
+		return -1;
+	if (lblk > rblk)
+		return 1;
+
+	loff = ItemPointerGetOffsetNumber((ItemPointer) left);
+	roff = ItemPointerGetOffsetNumber((ItemPointer) right);
+
+	if (loff < roff)
+		return -1;
+	if (loff > roff)
+		return 1;
+
+	return 0;
+}