Rename pubgencols_type to pubgencols in pg_publication.
[pgsql.git] / src / backend / access / transam / timeline.c
bloba27f27cc037d11e92820b4313a60ac28feeb1590
1 /*-------------------------------------------------------------------------
3 * timeline.c
4 * Functions for reading and writing timeline history files.
6 * A timeline history file lists the timeline changes of the timeline, in
7 * a simple text format. They are archived along with the WAL segments.
9 * The files are named like "<tli>.history". For example, if the database
10 * starts up and switches to timeline 5, the timeline history file would be
11 * called "00000005.history".
13 * Each line in the file represents a timeline switch:
15 * <parentTLI> <switchpoint> <reason>
17 * parentTLI ID of the parent timeline
18 * switchpoint XLogRecPtr of the WAL location where the switch happened
19 * reason human-readable explanation of why the timeline was changed
21 * The fields are separated by tabs. Lines beginning with # are comments, and
22 * are ignored. Empty lines are also ignored.
24 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
25 * Portions Copyright (c) 1994, Regents of the University of California
27 * src/backend/access/transam/timeline.c
29 *-------------------------------------------------------------------------
32 #include "postgres.h"
34 #include <sys/stat.h>
35 #include <unistd.h>
37 #include "access/timeline.h"
38 #include "access/xlog.h"
39 #include "access/xlog_internal.h"
40 #include "access/xlogarchive.h"
41 #include "access/xlogdefs.h"
42 #include "pgstat.h"
43 #include "storage/fd.h"
46 * Copies all timeline history files with id's between 'begin' and 'end'
47 * from archive to pg_wal.
49 void
50 restoreTimeLineHistoryFiles(TimeLineID begin, TimeLineID end)
52 char path[MAXPGPATH];
53 char histfname[MAXFNAMELEN];
54 TimeLineID tli;
56 for (tli = begin; tli < end; tli++)
58 if (tli == 1)
59 continue;
61 TLHistoryFileName(histfname, tli);
62 if (RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0, false))
63 KeepFileRestoredFromArchive(path, histfname);
68 * Try to read a timeline's history file.
70 * If successful, return the list of component TLIs (the given TLI followed by
71 * its ancestor TLIs). If we can't find the history file, assume that the
72 * timeline has no parents, and return a list of just the specified timeline
73 * ID.
75 List *
76 readTimeLineHistory(TimeLineID targetTLI)
78 List *result;
79 char path[MAXPGPATH];
80 char histfname[MAXFNAMELEN];
81 FILE *fd;
82 TimeLineHistoryEntry *entry;
83 TimeLineID lasttli = 0;
84 XLogRecPtr prevend;
85 bool fromArchive = false;
87 /* Timeline 1 does not have a history file, so no need to check */
88 if (targetTLI == 1)
90 entry = (TimeLineHistoryEntry *) palloc(sizeof(TimeLineHistoryEntry));
91 entry->tli = targetTLI;
92 entry->begin = entry->end = InvalidXLogRecPtr;
93 return list_make1(entry);
96 if (ArchiveRecoveryRequested)
98 TLHistoryFileName(histfname, targetTLI);
99 fromArchive =
100 RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0, false);
102 else
103 TLHistoryFilePath(path, targetTLI);
105 fd = AllocateFile(path, "r");
106 if (fd == NULL)
108 if (errno != ENOENT)
109 ereport(FATAL,
110 (errcode_for_file_access(),
111 errmsg("could not open file \"%s\": %m", path)));
112 /* Not there, so assume no parents */
113 entry = (TimeLineHistoryEntry *) palloc(sizeof(TimeLineHistoryEntry));
114 entry->tli = targetTLI;
115 entry->begin = entry->end = InvalidXLogRecPtr;
116 return list_make1(entry);
119 result = NIL;
122 * Parse the file...
124 prevend = InvalidXLogRecPtr;
125 for (;;)
127 char fline[MAXPGPATH];
128 char *res;
129 char *ptr;
130 TimeLineID tli;
131 uint32 switchpoint_hi;
132 uint32 switchpoint_lo;
133 int nfields;
135 pgstat_report_wait_start(WAIT_EVENT_TIMELINE_HISTORY_READ);
136 res = fgets(fline, sizeof(fline), fd);
137 pgstat_report_wait_end();
138 if (res == NULL)
140 if (ferror(fd))
141 ereport(ERROR,
142 (errcode_for_file_access(),
143 errmsg("could not read file \"%s\": %m", path)));
145 break;
148 /* skip leading whitespace and check for # comment */
149 for (ptr = fline; *ptr; ptr++)
151 if (!isspace((unsigned char) *ptr))
152 break;
154 if (*ptr == '\0' || *ptr == '#')
155 continue;
157 nfields = sscanf(fline, "%u\t%X/%X", &tli, &switchpoint_hi, &switchpoint_lo);
159 if (nfields < 1)
161 /* expect a numeric timeline ID as first field of line */
162 ereport(FATAL,
163 (errmsg("syntax error in history file: %s", fline),
164 errhint("Expected a numeric timeline ID.")));
166 if (nfields != 3)
167 ereport(FATAL,
168 (errmsg("syntax error in history file: %s", fline),
169 errhint("Expected a write-ahead log switchpoint location.")));
171 if (result && tli <= lasttli)
172 ereport(FATAL,
173 (errmsg("invalid data in history file: %s", fline),
174 errhint("Timeline IDs must be in increasing sequence.")));
176 lasttli = tli;
178 entry = (TimeLineHistoryEntry *) palloc(sizeof(TimeLineHistoryEntry));
179 entry->tli = tli;
180 entry->begin = prevend;
181 entry->end = ((uint64) (switchpoint_hi)) << 32 | (uint64) switchpoint_lo;
182 prevend = entry->end;
184 /* Build list with newest item first */
185 result = lcons(entry, result);
187 /* we ignore the remainder of each line */
190 FreeFile(fd);
192 if (result && targetTLI <= lasttli)
193 ereport(FATAL,
194 (errmsg("invalid data in history file \"%s\"", path),
195 errhint("Timeline IDs must be less than child timeline's ID.")));
198 * Create one more entry for the "tip" of the timeline, which has no entry
199 * in the history file.
201 entry = (TimeLineHistoryEntry *) palloc(sizeof(TimeLineHistoryEntry));
202 entry->tli = targetTLI;
203 entry->begin = prevend;
204 entry->end = InvalidXLogRecPtr;
206 result = lcons(entry, result);
209 * If the history file was fetched from archive, save it in pg_wal for
210 * future reference.
212 if (fromArchive)
213 KeepFileRestoredFromArchive(path, histfname);
215 return result;
219 * Probe whether a timeline history file exists for the given timeline ID
221 bool
222 existsTimeLineHistory(TimeLineID probeTLI)
224 char path[MAXPGPATH];
225 char histfname[MAXFNAMELEN];
226 FILE *fd;
228 /* Timeline 1 does not have a history file, so no need to check */
229 if (probeTLI == 1)
230 return false;
232 if (ArchiveRecoveryRequested)
234 TLHistoryFileName(histfname, probeTLI);
235 RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0, false);
237 else
238 TLHistoryFilePath(path, probeTLI);
240 fd = AllocateFile(path, "r");
241 if (fd != NULL)
243 FreeFile(fd);
244 return true;
246 else
248 if (errno != ENOENT)
249 ereport(FATAL,
250 (errcode_for_file_access(),
251 errmsg("could not open file \"%s\": %m", path)));
252 return false;
257 * Find the newest existing timeline, assuming that startTLI exists.
259 * Note: while this is somewhat heuristic, it does positively guarantee
260 * that (result + 1) is not a known timeline, and therefore it should
261 * be safe to assign that ID to a new timeline.
263 TimeLineID
264 findNewestTimeLine(TimeLineID startTLI)
266 TimeLineID newestTLI;
267 TimeLineID probeTLI;
270 * The algorithm is just to probe for the existence of timeline history
271 * files. XXX is it useful to allow gaps in the sequence?
273 newestTLI = startTLI;
275 for (probeTLI = startTLI + 1;; probeTLI++)
277 if (existsTimeLineHistory(probeTLI))
279 newestTLI = probeTLI; /* probeTLI exists */
281 else
283 /* doesn't exist, assume we're done */
284 break;
288 return newestTLI;
292 * Create a new timeline history file.
294 * newTLI: ID of the new timeline
295 * parentTLI: ID of its immediate parent
296 * switchpoint: WAL location where the system switched to the new timeline
297 * reason: human-readable explanation of why the timeline was switched
299 * Currently this is only used at the end recovery, and so there are no locking
300 * considerations. But we should be just as tense as XLogFileInit to avoid
301 * emplacing a bogus file.
303 void
304 writeTimeLineHistory(TimeLineID newTLI, TimeLineID parentTLI,
305 XLogRecPtr switchpoint, char *reason)
307 char path[MAXPGPATH];
308 char tmppath[MAXPGPATH];
309 char histfname[MAXFNAMELEN];
310 char buffer[BLCKSZ];
311 int srcfd;
312 int fd;
313 int nbytes;
315 Assert(newTLI > parentTLI); /* else bad selection of newTLI */
318 * Write into a temp file name.
320 snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
322 unlink(tmppath);
324 /* do not use get_sync_bit() here --- want to fsync only at end of fill */
325 fd = OpenTransientFile(tmppath, O_RDWR | O_CREAT | O_EXCL);
326 if (fd < 0)
327 ereport(ERROR,
328 (errcode_for_file_access(),
329 errmsg("could not create file \"%s\": %m", tmppath)));
332 * If a history file exists for the parent, copy it verbatim
334 if (ArchiveRecoveryRequested)
336 TLHistoryFileName(histfname, parentTLI);
337 RestoreArchivedFile(path, histfname, "RECOVERYHISTORY", 0, false);
339 else
340 TLHistoryFilePath(path, parentTLI);
342 srcfd = OpenTransientFile(path, O_RDONLY);
343 if (srcfd < 0)
345 if (errno != ENOENT)
346 ereport(ERROR,
347 (errcode_for_file_access(),
348 errmsg("could not open file \"%s\": %m", path)));
349 /* Not there, so assume parent has no parents */
351 else
353 for (;;)
355 errno = 0;
356 pgstat_report_wait_start(WAIT_EVENT_TIMELINE_HISTORY_READ);
357 nbytes = (int) read(srcfd, buffer, sizeof(buffer));
358 pgstat_report_wait_end();
359 if (nbytes < 0 || errno != 0)
360 ereport(ERROR,
361 (errcode_for_file_access(),
362 errmsg("could not read file \"%s\": %m", path)));
363 if (nbytes == 0)
364 break;
365 errno = 0;
366 pgstat_report_wait_start(WAIT_EVENT_TIMELINE_HISTORY_WRITE);
367 if ((int) write(fd, buffer, nbytes) != nbytes)
369 int save_errno = errno;
372 * If we fail to make the file, delete it to release disk
373 * space
375 unlink(tmppath);
378 * if write didn't set errno, assume problem is no disk space
380 errno = save_errno ? save_errno : ENOSPC;
382 ereport(ERROR,
383 (errcode_for_file_access(),
384 errmsg("could not write to file \"%s\": %m", tmppath)));
386 pgstat_report_wait_end();
389 if (CloseTransientFile(srcfd) != 0)
390 ereport(ERROR,
391 (errcode_for_file_access(),
392 errmsg("could not close file \"%s\": %m", path)));
396 * Append one line with the details of this timeline split.
398 * If we did have a parent file, insert an extra newline just in case the
399 * parent file failed to end with one.
401 snprintf(buffer, sizeof(buffer),
402 "%s%u\t%X/%X\t%s\n",
403 (srcfd < 0) ? "" : "\n",
404 parentTLI,
405 LSN_FORMAT_ARGS(switchpoint),
406 reason);
408 nbytes = strlen(buffer);
409 errno = 0;
410 pgstat_report_wait_start(WAIT_EVENT_TIMELINE_HISTORY_WRITE);
411 if ((int) write(fd, buffer, nbytes) != nbytes)
413 int save_errno = errno;
416 * If we fail to make the file, delete it to release disk space
418 unlink(tmppath);
419 /* if write didn't set errno, assume problem is no disk space */
420 errno = save_errno ? save_errno : ENOSPC;
422 ereport(ERROR,
423 (errcode_for_file_access(),
424 errmsg("could not write to file \"%s\": %m", tmppath)));
426 pgstat_report_wait_end();
428 pgstat_report_wait_start(WAIT_EVENT_TIMELINE_HISTORY_SYNC);
429 if (pg_fsync(fd) != 0)
430 ereport(data_sync_elevel(ERROR),
431 (errcode_for_file_access(),
432 errmsg("could not fsync file \"%s\": %m", tmppath)));
433 pgstat_report_wait_end();
435 if (CloseTransientFile(fd) != 0)
436 ereport(ERROR,
437 (errcode_for_file_access(),
438 errmsg("could not close file \"%s\": %m", tmppath)));
441 * Now move the completed history file into place with its final name.
443 TLHistoryFilePath(path, newTLI);
444 Assert(access(path, F_OK) != 0 && errno == ENOENT);
445 durable_rename(tmppath, path, ERROR);
447 /* The history file can be archived immediately. */
448 if (XLogArchivingActive())
450 TLHistoryFileName(histfname, newTLI);
451 XLogArchiveNotify(histfname);
456 * Writes a history file for given timeline and contents.
458 * Currently this is only used in the walreceiver process, and so there are
459 * no locking considerations. But we should be just as tense as XLogFileInit
460 * to avoid emplacing a bogus file.
462 void
463 writeTimeLineHistoryFile(TimeLineID tli, char *content, int size)
465 char path[MAXPGPATH];
466 char tmppath[MAXPGPATH];
467 int fd;
470 * Write into a temp file name.
472 snprintf(tmppath, MAXPGPATH, XLOGDIR "/xlogtemp.%d", (int) getpid());
474 unlink(tmppath);
476 /* do not use get_sync_bit() here --- want to fsync only at end of fill */
477 fd = OpenTransientFile(tmppath, O_RDWR | O_CREAT | O_EXCL);
478 if (fd < 0)
479 ereport(ERROR,
480 (errcode_for_file_access(),
481 errmsg("could not create file \"%s\": %m", tmppath)));
483 errno = 0;
484 pgstat_report_wait_start(WAIT_EVENT_TIMELINE_HISTORY_FILE_WRITE);
485 if ((int) write(fd, content, size) != size)
487 int save_errno = errno;
490 * If we fail to make the file, delete it to release disk space
492 unlink(tmppath);
493 /* if write didn't set errno, assume problem is no disk space */
494 errno = save_errno ? save_errno : ENOSPC;
496 ereport(ERROR,
497 (errcode_for_file_access(),
498 errmsg("could not write to file \"%s\": %m", tmppath)));
500 pgstat_report_wait_end();
502 pgstat_report_wait_start(WAIT_EVENT_TIMELINE_HISTORY_FILE_SYNC);
503 if (pg_fsync(fd) != 0)
504 ereport(data_sync_elevel(ERROR),
505 (errcode_for_file_access(),
506 errmsg("could not fsync file \"%s\": %m", tmppath)));
507 pgstat_report_wait_end();
509 if (CloseTransientFile(fd) != 0)
510 ereport(ERROR,
511 (errcode_for_file_access(),
512 errmsg("could not close file \"%s\": %m", tmppath)));
515 * Now move the completed history file into place with its final name,
516 * replacing any existing file with the same name.
518 TLHistoryFilePath(path, tli);
519 durable_rename(tmppath, path, ERROR);
523 * Returns true if 'expectedTLEs' contains a timeline with id 'tli'
525 bool
526 tliInHistory(TimeLineID tli, List *expectedTLEs)
528 ListCell *cell;
530 foreach(cell, expectedTLEs)
532 if (((TimeLineHistoryEntry *) lfirst(cell))->tli == tli)
533 return true;
536 return false;
540 * Returns the ID of the timeline in use at a particular point in time, in
541 * the given timeline history.
543 TimeLineID
544 tliOfPointInHistory(XLogRecPtr ptr, List *history)
546 ListCell *cell;
548 foreach(cell, history)
550 TimeLineHistoryEntry *tle = (TimeLineHistoryEntry *) lfirst(cell);
552 if ((XLogRecPtrIsInvalid(tle->begin) || tle->begin <= ptr) &&
553 (XLogRecPtrIsInvalid(tle->end) || ptr < tle->end))
555 /* found it */
556 return tle->tli;
560 /* shouldn't happen. */
561 elog(ERROR, "timeline history was not contiguous");
562 return 0; /* keep compiler quiet */
566 * Returns the point in history where we branched off the given timeline,
567 * and the timeline we branched to (*nextTLI). Returns InvalidXLogRecPtr if
568 * the timeline is current, ie. we have not branched off from it, and throws
569 * an error if the timeline is not part of this server's history.
571 XLogRecPtr
572 tliSwitchPoint(TimeLineID tli, List *history, TimeLineID *nextTLI)
574 ListCell *cell;
576 if (nextTLI)
577 *nextTLI = 0;
578 foreach(cell, history)
580 TimeLineHistoryEntry *tle = (TimeLineHistoryEntry *) lfirst(cell);
582 if (tle->tli == tli)
583 return tle->end;
584 if (nextTLI)
585 *nextTLI = tle->tli;
588 ereport(ERROR,
589 (errmsg("requested timeline %u is not in this server's history",
590 tli)));
591 return InvalidXLogRecPtr; /* keep compiler quiet */