1 /* 2 * timeline.h 3 * 4 * Functions for reading and writing timeline history files. 5 * 6 * Portions Copyright (c) 1996-2021, 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 */ 25 typedef struct 26 { 27 TimeLineID tli; 28 XLogRecPtr begin; /* inclusive */ 29 XLogRecPtr end; /* exclusive, InvalidXLogRecPtr means infinity */ 30 } TimeLineHistoryEntry; 31 32 extern List *readTimeLineHistory(TimeLineID targetTLI); 33 extern bool existsTimeLineHistory(TimeLineID probeTLI); 34 extern TimeLineID findNewestTimeLine(TimeLineID startTLI); 35 extern void writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI, 36 XLogRecPtr switchpoint, char *reason); 37 extern void writeTimeLineHistoryFile(TimeLineID tli, char *content, int size); 38 extern void restoreTimeLineHistoryFiles(TimeLineID begin, TimeLineID end); 39 extern bool tliInHistory(TimeLineID tli, List *expectedTLEs); 40 extern TimeLineID tliOfPointInHistory(XLogRecPtr ptr, List *history); 41 extern XLogRecPtr tliSwitchPoint(TimeLineID tli, List *history, 42 TimeLineID *nextTLI); 43 44 #endif /* TIMELINE_H */ 45