v2-0005-Streamify-log_newpage_range-WAL-logging-path.patch

From d719cbc20c28634f07106e89b5de0c89cf098a8e Mon Sep 17 00:00:00 2001
From: alterego655 <824662526@qq.com>
Date: Sun, 28 Dec 2025 18:29:07 +0800
Subject: [PATCH v2 5/6] Streamify log_newpage_range() WAL logging path

Refactor log_newpage_range() to use the Read Stream. This allows
prefetching of upcoming relation blocks during bulk WAL logging
perations, overlapping I/O with CPU-intensive XLogInsert and
WAL-writing work.
---
 src/backend/access/transam/xloginsert.c | 28 +++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
index a56d5a55282..04c1a46143a 100644
--- a/src/backend/access/transam/xloginsert.c
+++ b/src/backend/access/transam/xloginsert.c
@@ -39,6 +39,7 @@
 #include "replication/origin.h"
 #include "storage/bufmgr.h"
 #include "storage/proc.h"
+#include "storage/read_stream.h"
 #include "utils/memutils.h"
 #include "utils/pgstat_internal.h"
 
@@ -1295,6 +1296,8 @@ log_newpage_range(Relation rel, ForkNumber forknum,
 {
 	int			flags;
 	BlockNumber blkno;
+	BlockRangeReadStreamPrivate p;
+	ReadStream *stream;
 
 	flags = REGBUF_FORCE_IMAGE;
 	if (page_std)
@@ -1307,6 +1310,23 @@ log_newpage_range(Relation rel, ForkNumber forknum,
 	 */
 	XLogEnsureRecordSpace(XLR_MAX_BLOCK_ID - 1, 0);
 
+	/* Set up a streaming read for the range of blocks */
+	p.current_blocknum = startblk;
+	p.last_exclusive = endblk;
+
+	/*
+	 * It is safe to use batchmode as block_range_read_stream_cb takes no
+	 * locks.
+	 */
+	stream = read_stream_begin_relation(READ_STREAM_MAINTENANCE |
+										READ_STREAM_USE_BATCHING,
+										NULL,
+										rel,
+										forknum,
+										block_range_read_stream_cb,
+										&p,
+										0);
+
 	blkno = startblk;
 	while (blkno < endblk)
 	{
@@ -1321,8 +1341,10 @@ log_newpage_range(Relation rel, ForkNumber forknum,
 		nbufs = 0;
 		while (nbufs < XLR_MAX_BLOCK_ID && blkno < endblk)
 		{
-			Buffer		buf = ReadBufferExtended(rel, forknum, blkno,
-												 RBM_NORMAL, NULL);
+			Buffer		buf = read_stream_next_buffer(stream, NULL);
+
+			if (!BufferIsValid(buf))
+				break;
 
 			LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 
@@ -1361,6 +1383,8 @@ log_newpage_range(Relation rel, ForkNumber forknum,
 		}
 		END_CRIT_SECTION();
 	}
+
+	read_stream_end(stream);
 }
 
 /*
-- 
2.51.0