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| author | Thomas Munro <tmunro@postgresql.org> | 2021-04-08 23:03:23 +1200 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2021-04-08 23:20:42 +1200 |
| commit | 323cbe7c7ddcf18aaf24b7f6d682a45a61d4e31b (patch) | |
| tree | 5290af3834511b9bd1773841b1068e485ba52fe6 /src/backend/access/transam/twophase.c | |
| parent | 5ac9c4307337313bedeafc21dbbab93ba809241c (diff) | |
| download | postgresql-323cbe7c7ddcf18aaf24b7f6d682a45a61d4e31b.tar.gz postgresql-323cbe7c7ddcf18aaf24b7f6d682a45a61d4e31b.zip | |
Remove read_page callback from XLogReader.
Previously, the XLogReader module would fetch new input data using a
callback function. Redesign the interface so that it tells the caller
to insert more data with a special return value instead. This API suits
later patches for prefetching, encryption and maybe other future
projects that would otherwise require continually extending the callback
interface.
As incidental cleanup work, move global variables readOff, readLen and
readSegNo inside XlogReaderState.
Author: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Author: Heikki Linnakangas <hlinnaka@iki.fi> (parts of earlier version)
Reviewed-by: Antonin Houska <ah@cybertec.at>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Takashi Menjo <takashi.menjo@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/20190418.210257.43726183.horiguchi.kyotaro%40lab.ntt.co.jp
Diffstat (limited to 'src/backend/access/transam/twophase.c')
| -rw-r--r-- | src/backend/access/transam/twophase.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c index 89335b64a24..3137cb3ecc1 100644 --- a/src/backend/access/transam/twophase.c +++ b/src/backend/access/transam/twophase.c @@ -1330,11 +1330,8 @@ XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len) char *errormsg; TimeLineID save_currtli = ThisTimeLineID; - xlogreader = XLogReaderAllocate(wal_segment_size, NULL, - XL_ROUTINE(.page_read = &read_local_xlog_page, - .segment_open = &wal_segment_open, - .segment_close = &wal_segment_close), - NULL); + xlogreader = XLogReaderAllocate(wal_segment_size, NULL, wal_segment_close); + if (!xlogreader) ereport(ERROR, (errcode(ERRCODE_OUT_OF_MEMORY), @@ -1342,7 +1339,12 @@ XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len) errdetail("Failed while allocating a WAL reading processor."))); XLogBeginRead(xlogreader, lsn); - record = XLogReadRecord(xlogreader, &errormsg); + while (XLogReadRecord(xlogreader, &record, &errormsg) == + XLREAD_NEED_DATA) + { + if (!read_local_xlog_page(xlogreader)) + break; + } /* * Restore immediately the timeline where it was previously, as |