Refactor code dedicated to index vacuuming in vacuumlazy.c

The part in charge of doing the vacuum on all the indexes of a relation
was duplicated, with the same handling for progress reporting done.
While on it, update the progress reporting for heap vacuuming in the
subroutine doing the actual work, keeping the status update local.  This
way, any future caller of lazy_vacuum_heap() does not have to worry
about doing any progress reporting update.

Author: Justin Pryzby, Michael Paquier
Discussion: https://postgr.es/m/20191120210600.GC30362@telsasoft.com

src/backend/access/heap/vacuumlazy.c

@@ -158,6 +158,9 @@ static bool lazy_check_needs_freeze(Buffer buf, bool *hastup);
 static void lazy_vacuum_index(Relation indrel,
 							  IndexBulkDeleteResult **stats,
 							  LVRelStats *vacrelstats);
+static void lazy_vacuum_all_indexes(Relation onerel, LVRelStats *vacrelstats,
+									Relation *Irel, int nindexes,
+									IndexBulkDeleteResult **indstats);
 static void lazy_cleanup_index(Relation indrel,
 							   IndexBulkDeleteResult *stats,
 							   LVRelStats *vacrelstats);
@@ -740,12 +743,6 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 		if ((vacrelstats->max_dead_tuples - vacrelstats->num_dead_tuples) < MaxHeapTuplesPerPage &&
 			vacrelstats->num_dead_tuples > 0)
 		{
-			const int	hvp_index[] = {
-				PROGRESS_VACUUM_PHASE,
-				PROGRESS_VACUUM_NUM_INDEX_VACUUMS
-			};
-			int64		hvp_val[2];
-
 			/*
 			 * Before beginning index vacuuming, we release any pin we may
 			 * hold on the visibility map page.  This isn't necessary for
@@ -758,28 +755,9 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 				vmbuffer = InvalidBuffer;
 			}
 
-			/* Log cleanup info before we touch indexes */
-			vacuum_log_cleanup_info(onerel, vacrelstats);
-
-			/* Report that we are now vacuuming indexes */
-			pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
-										 PROGRESS_VACUUM_PHASE_VACUUM_INDEX);
-
-			/* Remove index entries */
-			for (i = 0; i < nindexes; i++)
-				lazy_vacuum_index(Irel[i],
-								  &indstats[i],
-								  vacrelstats);
-
-			/*
-			 * Report that we are now vacuuming the heap.  We also increase
-			 * the number of index scans here; note that by using
-			 * pgstat_progress_update_multi_param we can update both
-			 * parameters atomically.
-			 */
-			hvp_val[0] = PROGRESS_VACUUM_PHASE_VACUUM_HEAP;
-			hvp_val[1] = vacrelstats->num_index_scans + 1;
-			pgstat_progress_update_multi_param(2, hvp_index, hvp_val);
+			/* Work on all the indexes, then the heap */
+			lazy_vacuum_all_indexes(onerel, vacrelstats, Irel,
+									nindexes, indstats);
 
 			/* Remove tuples from heap */
 			lazy_vacuum_heap(onerel, vacrelstats);
@@ -790,7 +768,6 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 			 * valid.
 			 */
 			vacrelstats->num_dead_tuples = 0;
-			vacrelstats->num_index_scans++;
 
 			/*
 			 * Vacuum the Free Space Map to make newly-freed space visible on
@@ -1420,33 +1397,12 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 	/* XXX put a threshold on min number of tuples here? */
 	if (vacrelstats->num_dead_tuples > 0)
 	{
-		const int	hvp_index[] = {
-			PROGRESS_VACUUM_PHASE,
-			PROGRESS_VACUUM_NUM_INDEX_VACUUMS
-		};
-		int64		hvp_val[2];
-
-		/* Log cleanup info before we touch indexes */
-		vacuum_log_cleanup_info(onerel, vacrelstats);
-
-		/* Report that we are now vacuuming indexes */
-		pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
-									 PROGRESS_VACUUM_PHASE_VACUUM_INDEX);
-
-		/* Remove index entries */
-		for (i = 0; i < nindexes; i++)
-			lazy_vacuum_index(Irel[i],
-							  &indstats[i],
-							  vacrelstats);
-
-		/* Report that we are now vacuuming the heap */
-		hvp_val[0] = PROGRESS_VACUUM_PHASE_VACUUM_HEAP;
-		hvp_val[1] = vacrelstats->num_index_scans + 1;
-		pgstat_progress_update_multi_param(2, hvp_index, hvp_val);
+		/* Work on all the indexes, and then the heap */
+		lazy_vacuum_all_indexes(onerel, vacrelstats, Irel, nindexes,
+								indstats);
 
 		/* Remove tuples from heap */
 		lazy_vacuum_heap(onerel, vacrelstats);
-		vacrelstats->num_index_scans++;
 	}
 
 	/*
@@ -1508,6 +1464,36 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 	pfree(buf.data);
 }
 
+/*
+ *	lazy_vacuum_all_indexes() -- vacuum all indexes of relation.
+ *
+ *		This is a utility wrapper for lazy_vacuum_index(), able to do
+ *		progress reporting.
+ */
+static void
+lazy_vacuum_all_indexes(Relation onerel, LVRelStats *vacrelstats,
+						Relation *Irel, int nindexes,
+						IndexBulkDeleteResult **indstats)
+{
+	int			i;
+
+	/* Log cleanup info before we touch indexes */
+	vacuum_log_cleanup_info(onerel, vacrelstats);
+
+	/* Report that we are now vacuuming indexes */
+	pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
+								 PROGRESS_VACUUM_PHASE_VACUUM_INDEX);
+
+	/* Remove index entries */
+	for (i = 0; i < nindexes; i++)
+		lazy_vacuum_index(Irel[i], &indstats[i], vacrelstats);
+
+	/* Increase and report the number of index scans */
+	vacrelstats->num_index_scans++;
+	pgstat_progress_update_param(PROGRESS_VACUUM_NUM_INDEX_VACUUMS,
+								 vacrelstats->num_index_scans);
+}
+
 
 /*
  *	lazy_vacuum_heap() -- second pass over the heap
@@ -1528,6 +1514,10 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 	PGRUsage	ru0;
 	Buffer		vmbuffer = InvalidBuffer;
 
+	/* Report that we are now vacuuming the heap */
+	pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
+								 PROGRESS_VACUUM_PHASE_VACUUM_HEAP);
+
 	pg_rusage_init(&ru0);
 	npages = 0;