From 709d003fbd98b975a4fbcb4c5750fa6efaf9ad87 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Tue, 24 Sep 2019 16:08:31 -0300 Subject: Rework WAL-reading supporting structs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The state-tracking of WAL reading in various places was pretty messy, mostly because the ancient physical-replication WAL reading code wasn't using the XLogReader abstraction. This led to some untidy code. Make it prettier by creating two additional supporting structs, WALSegmentContext and WALOpenSegment which keep track of WAL-reading state. This makes code cleaner, as well as supports more future cleanup. Author: Antonin Houska Reviewed-by: Álvaro Herrera and (older versions) Robert Haas Discussion: https://postgr.es/m/14984.1554998742@spoje.net --- src/backend/access/transam/xlog.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'src/backend/access/transam/xlog.c') diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 501f46fd52d..6c69eb6dd76 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -885,8 +885,7 @@ static int XLogFileRead(XLogSegNo segno, int emode, TimeLineID tli, int source, bool notfoundOk); static int XLogFileReadAnyTLI(XLogSegNo segno, int emode, int source); static int XLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr, - int reqLen, XLogRecPtr targetRecPtr, char *readBuf, - TimeLineID *readTLI); + int reqLen, XLogRecPtr targetRecPtr, char *readBuf); static bool WaitForWALToBecomeAvailable(XLogRecPtr RecPtr, bool randAccess, bool fetching_ckpt, XLogRecPtr tliRecPtr); static int emode_for_corrupt_record(int emode, XLogRecPtr RecPtr); @@ -1195,7 +1194,8 @@ XLogInsertRecord(XLogRecData *rdata, appendBinaryStringInfo(&recordBuf, rdata->data, rdata->len); if (!debug_reader) - debug_reader = XLogReaderAllocate(wal_segment_size, NULL, NULL); + debug_reader = XLogReaderAllocate(wal_segment_size, NULL, + NULL, NULL); if (!debug_reader) { @@ -4296,7 +4296,7 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode, XLByteToSeg(xlogreader->latestPagePtr, segno, wal_segment_size); offset = XLogSegmentOffset(xlogreader->latestPagePtr, wal_segment_size); - XLogFileName(fname, xlogreader->readPageTLI, segno, + XLogFileName(fname, xlogreader->seg.ws_tli, segno, wal_segment_size); ereport(emode_for_corrupt_record(emode, RecPtr ? RecPtr : EndRecPtr), @@ -6353,7 +6353,8 @@ StartupXLOG(void) /* Set up XLOG reader facility */ MemSet(&private, 0, sizeof(XLogPageReadPrivate)); - xlogreader = XLogReaderAllocate(wal_segment_size, &XLogPageRead, &private); + xlogreader = XLogReaderAllocate(wal_segment_size, NULL, + &XLogPageRead, &private); if (!xlogreader) ereport(ERROR, (errcode(ERRCODE_OUT_OF_MEMORY), @@ -7355,7 +7356,7 @@ StartupXLOG(void) * and we were reading the old WAL from a segment belonging to a higher * timeline. */ - EndOfLogTLI = xlogreader->readPageTLI; + EndOfLogTLI = xlogreader->seg.ws_tli; /* * Complain if we did not roll forward far enough to render the backup @@ -11523,7 +11524,7 @@ CancelBackup(void) */ static int XLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr, int reqLen, - XLogRecPtr targetRecPtr, char *readBuf, TimeLineID *readTLI) + XLogRecPtr targetRecPtr, char *readBuf) { XLogPageReadPrivate *private = (XLogPageReadPrivate *) xlogreader->private_data; @@ -11640,7 +11641,7 @@ retry: Assert(targetPageOff == readOff); Assert(reqLen <= readLen); - *readTLI = curFileTLI; + xlogreader->seg.ws_tli = curFileTLI; /* * Check the page header immediately, so that we can retry immediately if -- cgit v1.2.3