From 32f4de0adfb2037f1402e40b54a5c4043227363f Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas
Date: Tue, 4 Dec 2012 15:28:58 +0200
Subject: Write exact xlog position of timeline switch in the timeline history
 file.

This allows us to do some more rigorous sanity checking for various
incorrect point-in-time recovery scenarios, and provides more information
for debugging purposes. It will also come handy in the upcoming patch to
allow timeline switches to be replicated by streaming replication.
---
 src/include/access/timeline.h | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

(limited to 'src/include/access')

diff --git a/src/include/access/timeline.h b/src/include/access/timeline.h
index f2a7658bc45..785195bd36a 100644
--- a/src/include/access/timeline.h
+++ b/src/include/access/timeline.h
@@ -14,10 +14,28 @@
 #include "access/xlogdefs.h"
 #include "nodes/pg_list.h"
 
+/*
+ * A list of these structs describes the timeline history of the server. Each
+ * TimeLineHistoryEntry represents a piece of WAL belonging to the history,
+ * from newest to oldest. All WAL positions between 'begin' and 'end' belong to
+ * the timeline represented by the entry. Together the 'begin' and 'end'
+ * pointers of all the entries form a contiguous line from beginning of time
+ * to infinity.
+ */
+typedef struct
+{
+	TimeLineID	tli;
+	XLogRecPtr	begin;	/* inclusive */
+	XLogRecPtr	end;	/* exclusive, 0 means infinity */
+} TimeLineHistoryEntry;
+
 extern List *readTimeLineHistory(TimeLineID targetTLI);
 extern bool existsTimeLineHistory(TimeLineID probeTLI);
 extern TimeLineID findNewestTimeLine(TimeLineID startTLI);
 extern void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
-					 TimeLineID endTLI, XLogSegNo endLogSegNo, char *reason);
+					 XLogRecPtr switchpoint, char *reason);
+extern bool tliInHistory(TimeLineID tli, List *expectedTLIs);
+extern TimeLineID tliOfPointInHistory(XLogRecPtr ptr, List *history);
+extern XLogRecPtr tliSwitchPoint(TimeLineID tli, List *history);
 
 #endif   /* TIMELINE_H */
-- 
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