v1-0002-Add-more-usages-of-initStringInfoFromString.patch

From 0b31533674adb90644298c638cc7dfe066ab5bd6 Mon Sep 17 00:00:00 2001
From: David Rowley <dgrowley@gmail.com>
Date: Sun, 12 Feb 2023 16:45:15 +1300
Subject: [PATCH v1 2/2] Add more usages of initStringInfoFromString

This slightly reduces some memcpy work in walreceiver.c
---
 src/backend/replication/walreceiver.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index f6446da2d6..366b91f923 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -132,7 +132,6 @@ typedef enum WalRcvWakeupReason
 static TimestampTz wakeup[NUM_WALRCV_WAKEUPS];
 
 static StringInfoData reply_message;
-static StringInfoData incoming_message;
 
 /* Prototypes for private functions */
 static void WalRcvFetchTimeLineHistoryFiles(TimeLineID first, TimeLineID last);
@@ -422,10 +421,12 @@ WalReceiverMain(void)
 								LSN_FORMAT_ARGS(startpoint), startpointTLI)));
 			first_stream = false;
 
-			/* Initialize LogstreamResult and buffers for processing messages */
+			/*
+			 * Initialize LogstreamResult and reply buffer for processing
+			 * messages
+			 */
 			LogstreamResult.Write = LogstreamResult.Flush = GetXLogReplayRecPtr(NULL);
 			initStringInfo(&reply_message);
-			initStringInfo(&incoming_message);
 
 			/* Initialize nap wakeup times. */
 			now = GetCurrentTimestamp();
@@ -843,19 +844,19 @@ XLogWalRcvProcessMsg(unsigned char type, char *buf, Size len, TimeLineID tli)
 	TimestampTz sendTime;
 	bool		replyRequested;
 
-	resetStringInfo(&incoming_message);
-
 	switch (type)
 	{
 		case 'w':				/* WAL records */
 			{
-				/* copy message to StringInfo */
+				StringInfoData incoming_message;
+
+				/* set the message in the incoming_message StringInfo */
 				hdrlen = sizeof(int64) + sizeof(int64) + sizeof(int64);
 				if (len < hdrlen)
 					ereport(ERROR,
 							(errcode(ERRCODE_PROTOCOL_VIOLATION),
 							 errmsg_internal("invalid WAL message received from primary")));
-				appendBinaryStringInfo(&incoming_message, buf, hdrlen);
+				initStringInfoFromString(&incoming_message, buf, hdrlen);
 
 				/* read the fields */
 				dataStart = pq_getmsgint64(&incoming_message);
@@ -870,13 +871,15 @@ XLogWalRcvProcessMsg(unsigned char type, char *buf, Size len, TimeLineID tli)
 			}
 		case 'k':				/* Keepalive */
 			{
-				/* copy message to StringInfo */
+				StringInfoData incoming_message;
+
+				/* set the message in the incoming_message StringInfo */
 				hdrlen = sizeof(int64) + sizeof(int64) + sizeof(char);
 				if (len != hdrlen)
 					ereport(ERROR,
 							(errcode(ERRCODE_PROTOCOL_VIOLATION),
 							 errmsg_internal("invalid keepalive message received from primary")));
-				appendBinaryStringInfo(&incoming_message, buf, hdrlen);
+				initStringInfoFromString(&incoming_message, buf, hdrlen);
 
 				/* read the fields */
 				walEnd = pq_getmsgint64(&incoming_message);
-- 
2.37.2