Generate pgstat_count_slru*() functions for slru using macros

From 3b4a59d7a6265c6fa6f75a54e06ad4d783872727 Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Date: Fri, 29 Aug 2025 14:11:38 +0000
Subject: [PATCH v1] Generate pgstat_count_slru*() functions for slru using
 macros

This change replaces seven functions definitions by macros.
This is the same idea as 850f4b4, 8018ffb or 83a1a1b.
---
 src/backend/access/transam/slru.c        | 12 +++---
 src/backend/utils/activity/pgstat_slru.c | 54 +++++++++---------------
 src/include/pgstat.h                     | 10 ++---
 3 files changed, 31 insertions(+), 45 deletions(-)
  26.9% src/backend/access/transam/
  50.7% src/backend/utils/activity/
  22.3% src/include/

diff --git a/src/backend/access/transam/slru.c b/src/backend/access/transam/slru.c
index 10ec259f382..ca69ee4d4f4 100644
--- a/src/backend/access/transam/slru.c
+++ b/src/backend/access/transam/slru.c
@@ -408,7 +408,7 @@ SimpleLruZeroPage(SlruCtl ctl, int64 pageno)
 	pg_atomic_write_u64(&shared->latest_page_number, pageno);
 
 	/* update the stats counter of zeroed pages */
-	pgstat_count_slru_page_zeroed(shared->slru_stats_idx);
+	pgstat_count_slru_blocks_zeroed(shared->slru_stats_idx);
 
 	return slotno;
 }
@@ -560,7 +560,7 @@ SimpleLruReadPage(SlruCtl ctl, int64 pageno, bool write_ok,
 			SlruRecentlyUsed(shared, slotno);
 
 			/* update the stats counter of pages found in the SLRU */
-			pgstat_count_slru_page_hit(shared->slru_stats_idx);
+			pgstat_count_slru_blocks_hit(shared->slru_stats_idx);
 
 			return slotno;
 		}
@@ -605,7 +605,7 @@ SimpleLruReadPage(SlruCtl ctl, int64 pageno, bool write_ok,
 		SlruRecentlyUsed(shared, slotno);
 
 		/* update the stats counter of pages not found in SLRU */
-		pgstat_count_slru_page_read(shared->slru_stats_idx);
+		pgstat_count_slru_blocks_read(shared->slru_stats_idx);
 
 		return slotno;
 	}
@@ -648,7 +648,7 @@ SimpleLruReadPage_ReadOnly(SlruCtl ctl, int64 pageno, TransactionId xid)
 			SlruRecentlyUsed(shared, slotno);
 
 			/* update the stats counter of pages found in the SLRU */
-			pgstat_count_slru_page_hit(shared->slru_stats_idx);
+			pgstat_count_slru_blocks_hit(shared->slru_stats_idx);
 
 			return slotno;
 		}
@@ -778,7 +778,7 @@ SimpleLruDoesPhysicalPageExist(SlruCtl ctl, int64 pageno)
 	off_t		endpos;
 
 	/* update the stats counter of checked pages */
-	pgstat_count_slru_page_exists(ctl->shared->slru_stats_idx);
+	pgstat_count_slru_blocks_exists(ctl->shared->slru_stats_idx);
 
 	SlruFileName(ctl, path, segno);
 
@@ -907,7 +907,7 @@ SlruPhysicalWritePage(SlruCtl ctl, int64 pageno, int slotno, SlruWriteAll fdata)
 	int			fd = -1;
 
 	/* update the stats counter of written pages */
-	pgstat_count_slru_page_written(shared->slru_stats_idx);
+	pgstat_count_slru_blocks_written(shared->slru_stats_idx);
 
 	/*
 	 * Honor the write-WAL-before-data rule, if appropriate, so that we do not
diff --git a/src/backend/utils/activity/pgstat_slru.c b/src/backend/utils/activity/pgstat_slru.c
index 7bd8744accb..da50f8a0457 100644
--- a/src/backend/utils/activity/pgstat_slru.c
+++ b/src/backend/utils/activity/pgstat_slru.c
@@ -55,47 +55,33 @@ pgstat_reset_slru(const char *name)
  * SLRU statistics count accumulation functions --- called from slru.c
  */
 
-void
-pgstat_count_slru_page_zeroed(int slru_idx)
-{
-	get_slru_entry(slru_idx)->blocks_zeroed += 1;
+#define PGSTAT_COUNT_SLRU(stat)						\
+void												\
+CppConcat(pgstat_count_slru_,stat)(int slru_idx)	\
+{													\
+	get_slru_entry(slru_idx)->stat += 1;			\
 }
 
-void
-pgstat_count_slru_page_hit(int slru_idx)
-{
-	get_slru_entry(slru_idx)->blocks_hit += 1;
-}
+/* pgstat_count_slru_blocks_zeroed */
+PGSTAT_COUNT_SLRU(blocks_zeroed)
 
-void
-pgstat_count_slru_page_exists(int slru_idx)
-{
-	get_slru_entry(slru_idx)->blocks_exists += 1;
-}
+/* pgstat_count_slru_blocks_hit */
+PGSTAT_COUNT_SLRU(blocks_hit)
 
-void
-pgstat_count_slru_page_read(int slru_idx)
-{
-	get_slru_entry(slru_idx)->blocks_read += 1;
-}
+/* pgstat_count_slru_blocks_exists */
+PGSTAT_COUNT_SLRU(blocks_exists)
 
-void
-pgstat_count_slru_page_written(int slru_idx)
-{
-	get_slru_entry(slru_idx)->blocks_written += 1;
-}
+/* pgstat_count_slru_blocks_read */
+PGSTAT_COUNT_SLRU(blocks_read)
 
-void
-pgstat_count_slru_flush(int slru_idx)
-{
-	get_slru_entry(slru_idx)->flush += 1;
-}
+/* pgstat_count_slru_blocks_written */
+PGSTAT_COUNT_SLRU(blocks_written)
 
-void
-pgstat_count_slru_truncate(int slru_idx)
-{
-	get_slru_entry(slru_idx)->truncate += 1;
-}
+/* pgstat_count_slru_flush */
+PGSTAT_COUNT_SLRU(flush)
+
+/* pgstat_count_slru_truncate */
+PGSTAT_COUNT_SLRU(truncate)
 
 /*
  * Support function for the SQL-callable pgstat* functions. Returns
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 202bd2d5ace..f402b17295c 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -747,11 +747,11 @@ extern PgStat_StatReplSlotEntry *pgstat_fetch_replslot(NameData slotname);
  */
 
 extern void pgstat_reset_slru(const char *);
-extern void pgstat_count_slru_page_zeroed(int slru_idx);
-extern void pgstat_count_slru_page_hit(int slru_idx);
-extern void pgstat_count_slru_page_read(int slru_idx);
-extern void pgstat_count_slru_page_written(int slru_idx);
-extern void pgstat_count_slru_page_exists(int slru_idx);
+extern void pgstat_count_slru_blocks_zeroed(int slru_idx);
+extern void pgstat_count_slru_blocks_hit(int slru_idx);
+extern void pgstat_count_slru_blocks_read(int slru_idx);
+extern void pgstat_count_slru_blocks_written(int slru_idx);
+extern void pgstat_count_slru_blocks_exists(int slru_idx);
 extern void pgstat_count_slru_flush(int slru_idx);
 extern void pgstat_count_slru_truncate(int slru_idx);
 extern const char *pgstat_get_slru_name(int slru_idx);
-- 
2.34.1