postgres.git / summary / log / commit / refs

commit    c2a6724823c14fd442c5441eb169b2581781fef0
Author:   Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date:     Wed Mar 26 16:04:57 2014 +0000
First released in: 9.4.0

    Pass more than the first XLogRecData entry to rm_desc, with WAL_DEBUG.
    
    If you compile with WAL_DEBUG and enable it with wal_debug=on, we used to
    only pass the first XLogRecData entry to the rm_desc routine. I think the
    original assumprion was that the first XLogRecData entry contains all the
    necessary information for the rm_desc routine, but that's a pretty shaky
    assumption. At least standby_redo didn't get the memo.
    
    To fix, piece together all the data in a temporary buffer, and pass that to
    the rm_desc routine.
    
    It's been like this forever, but the patch didn't apply cleanly to
    back-branches. Probably wouldn't be hard to fix the conflicts, but it's
    not worth the trouble.


 src/backend/access/transam/xlog.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index b573185122f..f9d6609d44f 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1262,8 +1262,23 @@ begin:;
 		xlog_outrec(&buf, rechdr);
 		if (rdata->data != NULL)
 		{
+			StringInfoData recordbuf;
+
+			/*
+			 * We have to piece together the WAL record data from the
+			 * XLogRecData entries, so that we can pass it to the rm_desc
+			 * function as one contiguous chunk. (but we can leave out any
+			 * extra entries we created for backup blocks)
+			 */
+			rdt_lastnormal->next = NULL;
+
+			initStringInfo(&recordbuf);
+			for (;rdata != NULL; rdata = rdata->next)
+				appendBinaryStringInfo(&recordbuf, rdata->data, rdata->len);
+
 			appendStringInfoString(&buf, " - ");
-			RmgrTable[rechdr->xl_rmid].rm_desc(&buf, rechdr->xl_info, rdata->data);
+			RmgrTable[rechdr->xl_rmid].rm_desc(&buf, rechdr->xl_info, recordbuf.data);
+			pfree(recordbuf.data);
 		}
 		elog(LOG, "%s", buf.data);
 		pfree(buf.data);


[parent: b69c4e65bea9]