From c520e35619ef5093c0cbc6d31943d5b5797aded1 Mon Sep 17 00:00:00 2001 From: Bharath Rupireddy Date: Tue, 20 Feb 2024 05:53:34 +0000 Subject: [PATCH v25 3/4] Use WALReadFromBuffers in more places --- src/backend/access/transam/xlogutils.c | 13 ++++++++++++- src/backend/replication/walsender.c | 16 +++++++++++++--- 2 files changed, 25 insertions(+), 4 deletions(-) diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c index ad93035d50..8fb2e68e85 100644 --- a/src/backend/access/transam/xlogutils.c +++ b/src/backend/access/transam/xlogutils.c @@ -895,6 +895,8 @@ read_local_xlog_page_guts(XLogReaderState *state, XLogRecPtr targetPagePtr, int count; WALReadError errinfo; TimeLineID currTLI; + Size nbytes; + Size rbytes; loc = targetPagePtr + reqLen; @@ -1007,7 +1009,16 @@ read_local_xlog_page_guts(XLogReaderState *state, XLogRecPtr targetPagePtr, count = read_upto - targetPagePtr; } - if (!WALRead(state, cur_page, targetPagePtr, count, tli, + /* attempt to read WAL from WAL buffers first */ + nbytes = count; + rbytes = WALReadFromBuffers(cur_page, targetPagePtr, nbytes, currTLI); + cur_page += rbytes; + targetPagePtr += rbytes; + nbytes -= rbytes; + + /* now read the remaining WAL from WAL file */ + if (nbytes > 0 && + !WALRead(state, cur_page, targetPagePtr, nbytes, tli, &errinfo)) WALReadRaiseError(&errinfo); diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index 631d1e0c9f..7ecc7174a0 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -1059,6 +1059,8 @@ logical_read_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr, int req WALReadError errinfo; XLogSegNo segno; TimeLineID currTLI; + Size nbytes; + Size rbytes; /* * Make sure we have enough WAL available before retrieving the current @@ -1095,11 +1097,19 @@ logical_read_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr, int req else count = flushptr - targetPagePtr; /* part of the page available */ - /* now actually read the data, we know it's there */ - if (!WALRead(state, + /* attempt to read WAL from WAL buffers first */ + nbytes = count; + rbytes = WALReadFromBuffers(cur_page, targetPagePtr, nbytes, currTLI); + cur_page += rbytes; + targetPagePtr += rbytes; + nbytes -= rbytes; + + /* now read the remaining WAL from WAL file */ + if (nbytes > 0 && + !WALRead(state, cur_page, targetPagePtr, - count, + nbytes, currTLI, /* Pass the current TLI because only * WalSndSegmentOpen controls whether new TLI * is needed. */ -- 2.34.1