Fix history file parsing when fetched from archive

Michael Paquier · Michael Paquier · commit 8aa6b84b9877 · 2013-12-10T17:27:51.000+09:00
History file format has changed from 9.2 to 9.3 to indicate the WAL record
when timeline branched off. In 9.2, the complete WAL file name was used
while in 9.3 the WAL record is used (like 1/4000090). pg_rman contains a
copy of a function of postgres core code to parse the history file that
was not anymore compatible, leading to errors related to timelines.
diff --git a/pg_rman.h b/pg_rman.h
@@ -306,7 +306,6 @@ extern int pgFileCompareMtimeDesc(const void *f1, const void *f2);
 
 /* in xlog.c */
 extern bool xlog_is_complete_wal(const pgFile *file, int server_version);
-extern bool xlog_logfname2lsn(const char *logfname, XLogRecPtr *lsn);
 extern void xlog_fname(char *fname, size_t len, TimeLineID tli, XLogRecPtr *lsn);
 
 /* in data.c */
diff --git a/restore.c b/restore.c
@@ -768,28 +768,41 @@ readTimeLineHistory(TimeLineID targetTLI)
 	 */
 	while (fd && fgets(fline, sizeof(fline), fd) != NULL)
 	{
-		/* skip leading whitespaces and check for # comment */
 		char	   *ptr;
-		char	   *endptr;
+		TimeLineID	tli;
+		uint32		switchpoint_hi;
+		uint32		switchpoint_lo;
+		int			nfields;
 
 		for (ptr = fline; *ptr; ptr++)
 		{
-			if (!IsSpace(*ptr))
+			if (!isspace((unsigned char) *ptr))
 				break;
 		}
 		if (*ptr == '\0' || *ptr == '#')
 			continue;
 
+		/* Parse one entry... */
+		nfields = sscanf(fline, "%u\t%X/%X", &tli, &switchpoint_hi, &switchpoint_lo);
+
 		timeline = pgut_new(pgTimeLine);
 		timeline->tli = 0;
 		timeline->end = 0;
 
 		/* expect a numeric timeline ID as first field of line */
-		timeline->tli = (TimeLineID) strtoul(ptr, &endptr, 0);
-		if (endptr == ptr)
+		timeline->tli = tli;
+
+		if (nfields < 1)
+		{
+			/* expect a numeric timeline ID as first field of line */
 			elog(ERROR_CORRUPTED,
-					_("syntax error(timeline ID) in history file: %s"),
-					fline);
+				 _("syntax error in history file: %s. Expected a numeric timeline ID."),
+				   fline);
+		}
+		if (nfields != 3)
+			elog(ERROR_CORRUPTED,
+				 _("syntax error in history file: %s. Expected a transaction log switchpoint location."),
+				   fline);
 
 		if (last_timeline && timeline->tli <= last_timeline->tli)
 			elog(ERROR_CORRUPTED,
@@ -799,20 +812,9 @@ readTimeLineHistory(TimeLineID targetTLI)
 		parray_insert(result, 0, timeline);
 		last_timeline = timeline;
 
-		/* parse end point(logfname, xid) in the timeline */
-		for (ptr = endptr; *ptr; ptr++)
-		{
-			if (!IsSpace(*ptr))
-				break;
-		}
-		if (*ptr == '\0' || *ptr == '#')
-			elog(ERROR_CORRUPTED,
-			   _("End logfile must follow Timeline ID."));
-
-		if (!xlog_logfname2lsn(ptr, &timeline->end))
-			elog(ERROR_CORRUPTED,
-					_("syntax error(endfname) in history file: %s"), fline);
-		/* we ignore the remainder of each line */
+		/* Calculate the end lsn finally */
+		timeline->end = (XLogRecPtr)
+			((uint64) switchpoint_hi << 32) | switchpoint_lo;
 	}
 
 	if (fd)
diff --git a/xlog.c b/xlog.c
@@ -109,24 +109,6 @@ xlog_is_complete_wal(const pgFile *file, int server_version)
 	return true;
 }
 
-bool
-xlog_logfname2lsn(const char *logfname, XLogRecPtr *lsn)
-{
-	uint32 tli;
-	uint32 xlogid;
-	uint32 xrecoff;
-
-	if (sscanf(logfname, "%08X%08X%08X",
-			&tli, &xlogid, &xrecoff) != 3)
-		return false;
-
-	xrecoff *= XLogSegSize;
-
-	/* Finish calculation of LSN */
-	*lsn = (XLogRecPtr) ((uint64) xlogid << 32) | xrecoff;
-	return true;
-}
-
 /*
  * based on XLogFileName() in xlog_internal.h
  */
