1/*
2 * timeline.h
3 *
4 * Functions for reading and writing timeline history files.
5 *
6 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 * src/include/access/timeline.h
10 */
11#ifndef TIMELINE_H
12#define TIMELINE_H
13
14#include "access/xlogdefs.h"
15#include "nodes/pg_list.h"
16
17/*
18 * A list of these structs describes the timeline history of the server. Each
19 * TimeLineHistoryEntry represents a piece of WAL belonging to the history,
20 * from newest to oldest. All WAL locations between 'begin' and 'end' belong to
21 * the timeline represented by the entry. Together the 'begin' and 'end'
22 * pointers of all the entries form a contiguous line from beginning of time
23 * to infinity.
24 */
25typedef struct
26{
27 TimeLineID tli;
28 XLogRecPtr begin; /* inclusive */
29 XLogRecPtr end; /* exclusive, InvalidXLogRecPtr means infinity */
30} TimeLineHistoryEntry;
31
32extern List *readTimeLineHistory(TimeLineID targetTLI);
33extern bool existsTimeLineHistory(TimeLineID probeTLI);
34extern TimeLineID findNewestTimeLine(TimeLineID startTLI);
35extern void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
36 XLogRecPtr switchpoint, char *reason);
37extern void writeTimeLineHistoryFile(TimeLineID tli, char *content, int size);
38extern void restoreTimeLineHistoryFiles(TimeLineID begin, TimeLineID end);
39extern bool tliInHistory(TimeLineID tli, List *expectedTLIs);
40extern TimeLineID tliOfPointInHistory(XLogRecPtr ptr, List *history);
41extern XLogRecPtr tliSwitchPoint(TimeLineID tli, List *history,
42 TimeLineID *nextTLI);
43
44#endif /* TIMELINE_H */
45