From 2258e76f90bf0254504644df0515cddc0c0a87f9 Mon Sep 17 00:00:00 2001 From: Jeff Davis Date: Fri, 8 Apr 2022 00:02:10 -0700 Subject: Add contrib/pg_walinspect. Provides similar functionality to pg_waldump, but from a SQL interface rather than a separate utility. Author: Bharath Rupireddy Reviewed-by: Greg Stark, Kyotaro Horiguchi, Andres Freund, Ashutosh Sharma, Nitin Jadhav, RKN Sai Krishna Discussion: https://postgr.es/m/CALj2ACUGUYXsEQdKhEdsBzhGEyF3xggvLdD8C0VT72TNEfOiog%40mail.gmail.com --- src/backend/access/transam/xlogutils.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'src/backend/access/transam/xlogutils.c') diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c index bb2d3ec991c..b5d34c61e66 100644 --- a/src/backend/access/transam/xlogutils.c +++ b/src/backend/access/transam/xlogutils.c @@ -80,6 +80,10 @@ typedef struct xl_invalid_page static HTAB *invalid_page_tab = NULL; +static int +read_local_xlog_page_guts(XLogReaderState *state, XLogRecPtr targetPagePtr, + int reqLen, XLogRecPtr targetRecPtr, + char *cur_page, bool wait_for_wal); /* Report a reference to an invalid page */ static void @@ -870,6 +874,31 @@ wal_segment_close(XLogReaderState *state) int read_local_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen, XLogRecPtr targetRecPtr, char *cur_page) +{ + return read_local_xlog_page_guts(state, targetPagePtr, reqLen, + targetRecPtr, cur_page, true); +} + +/* + * Same as read_local_xlog_page except that it doesn't wait for future WAL + * to be available. + */ +int +read_local_xlog_page_no_wait(XLogReaderState *state, XLogRecPtr targetPagePtr, + int reqLen, XLogRecPtr targetRecPtr, + char *cur_page) +{ + return read_local_xlog_page_guts(state, targetPagePtr, reqLen, + targetRecPtr, cur_page, false); +} + +/* + * Implementation of read_local_xlog_page and its no wait version. + */ +static int +read_local_xlog_page_guts(XLogReaderState *state, XLogRecPtr targetPagePtr, + int reqLen, XLogRecPtr targetRecPtr, + char *cur_page, bool wait_for_wal) { XLogRecPtr read_upto, loc; @@ -925,6 +954,10 @@ read_local_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr, if (loc <= read_upto) break; + /* If asked, let's not wait for future WAL. */ + if (!wait_for_wal) + break; + CHECK_FOR_INTERRUPTS(); pg_usleep(1000L); } -- cgit v1.2.3