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visibilitymap.c
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1 /*-------------------------------------------------------------------------
2  *
3  * visibilitymap.c
4  * bitmap for tracking visibility of heap tuples
5  *
6  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/access/heap/visibilitymap.c
12  *
13  * INTERFACE ROUTINES
14  * visibilitymap_clear - clear bits for one page in the visibility map
15  * visibilitymap_pin - pin a map page for setting a bit
16  * visibilitymap_pin_ok - check whether correct map page is already pinned
17  * visibilitymap_set - set a bit in a previously pinned page
18  * visibilitymap_get_status - get status of bits
19  * visibilitymap_count - count number of bits set in visibility map
20  * visibilitymap_prepare_truncate -
21  * prepare for truncation of the visibility map
22  *
23  * NOTES
24  *
25  * The visibility map is a bitmap with two bits (all-visible and all-frozen)
26  * per heap page. A set all-visible bit means that all tuples on the page are
27  * known visible to all transactions, and therefore the page doesn't need to
28  * be vacuumed. A set all-frozen bit means that all tuples on the page are
29  * completely frozen, and therefore the page doesn't need to be vacuumed even
30  * if whole table scanning vacuum is required (e.g. anti-wraparound vacuum).
31  * The all-frozen bit must be set only when the page is already all-visible.
32  *
33  * The map is conservative in the sense that we make sure that whenever a bit
34  * is set, we know the condition is true, but if a bit is not set, it might or
35  * might not be true.
36  *
37  * Clearing visibility map bits is not separately WAL-logged. The callers
38  * must make sure that whenever a bit is cleared, the bit is cleared on WAL
39  * replay of the updating operation as well.
40  *
41  * When we *set* a visibility map during VACUUM, we must write WAL. This may
42  * seem counterintuitive, since the bit is basically a hint: if it is clear,
43  * it may still be the case that every tuple on the page is visible to all
44  * transactions; we just don't know that for certain. The difficulty is that
45  * there are two bits which are typically set together: the PD_ALL_VISIBLE bit
46  * on the page itself, and the visibility map bit. If a crash occurs after the
47  * visibility map page makes it to disk and before the updated heap page makes
48  * it to disk, redo must set the bit on the heap page. Otherwise, the next
49  * insert, update, or delete on the heap page will fail to realize that the
50  * visibility map bit must be cleared, possibly causing index-only scans to
51  * return wrong answers.
52  *
53  * VACUUM will normally skip pages for which the visibility map bit is set;
54  * such pages can't contain any dead tuples and therefore don't need vacuuming.
55  *
56  * LOCKING
57  *
58  * In heapam.c, whenever a page is modified so that not all tuples on the
59  * page are visible to everyone anymore, the corresponding bit in the
60  * visibility map is cleared. In order to be crash-safe, we need to do this
61  * while still holding a lock on the heap page and in the same critical
62  * section that logs the page modification. However, we don't want to hold
63  * the buffer lock over any I/O that may be required to read in the visibility
64  * map page. To avoid this, we examine the heap page before locking it;
65  * if the page-level PD_ALL_VISIBLE bit is set, we pin the visibility map
66  * bit. Then, we lock the buffer. But this creates a race condition: there
67  * is a possibility that in the time it takes to lock the buffer, the
68  * PD_ALL_VISIBLE bit gets set. If that happens, we have to unlock the
69  * buffer, pin the visibility map page, and relock the buffer. This shouldn't
70  * happen often, because only VACUUM currently sets visibility map bits,
71  * and the race will only occur if VACUUM processes a given page at almost
72  * exactly the same time that someone tries to further modify it.
73  *
74  * To set a bit, you need to hold a lock on the heap page. That prevents
75  * the race condition where VACUUM sees that all tuples on the page are
76  * visible to everyone, but another backend modifies the page before VACUUM
77  * sets the bit in the visibility map.
78  *
79  * When a bit is set, the LSN of the visibility map page is updated to make
80  * sure that the visibility map update doesn't get written to disk before the
81  * WAL record of the changes that made it possible to set the bit is flushed.
82  * But when a bit is cleared, we don't have to do that because it's always
83  * safe to clear a bit in the map from correctness point of view.
84  *
85  *-------------------------------------------------------------------------
86  */
87 #include "postgres.h"
88 
89 #include "access/heapam_xlog.h"
90 #include "access/visibilitymap.h"
91 #include "access/xloginsert.h"
92 #include "access/xlogutils.h"
93 #include "miscadmin.h"
94 #include "port/pg_bitutils.h"
95 #include "storage/bufmgr.h"
96 #include "storage/lmgr.h"
97 #include "storage/smgr.h"
98 #include "utils/inval.h"
99 
100 
101 /*#define TRACE_VISIBILITYMAP */
102 
103 /*
104  * Size of the bitmap on each visibility map page, in bytes. There's no
105  * extra headers, so the whole page minus the standard page header is
106  * used for the bitmap.
107  */
108 #define MAPSIZE (BLCKSZ - MAXALIGN(SizeOfPageHeaderData))
109 
110 /* Number of heap blocks we can represent in one byte */
111 #define HEAPBLOCKS_PER_BYTE (BITS_PER_BYTE / BITS_PER_HEAPBLOCK)
112 
113 /* Number of heap blocks we can represent in one visibility map page. */
114 #define HEAPBLOCKS_PER_PAGE (MAPSIZE * HEAPBLOCKS_PER_BYTE)
115 
116 /* Mapping from heap block number to the right bit in the visibility map */
117 #define HEAPBLK_TO_MAPBLOCK(x) ((x) / HEAPBLOCKS_PER_PAGE)
118 #define HEAPBLK_TO_MAPBYTE(x) (((x) % HEAPBLOCKS_PER_PAGE) / HEAPBLOCKS_PER_BYTE)
119 #define HEAPBLK_TO_OFFSET(x) (((x) % HEAPBLOCKS_PER_BYTE) * BITS_PER_HEAPBLOCK)
120 
121 /* Masks for counting subsets of bits in the visibility map. */
122 #define VISIBLE_MASK64 UINT64CONST(0x5555555555555555) /* The lower bit of each
123  * bit pair */
124 #define FROZEN_MASK64 UINT64CONST(0xaaaaaaaaaaaaaaaa) /* The upper bit of each
125  * bit pair */
126 
127 /* prototypes for internal routines */
128 static Buffer vm_readbuf(Relation rel, BlockNumber blkno, bool extend);
129 static Buffer vm_extend(Relation rel, BlockNumber vm_nblocks);
130 
131 
132 /*
133  * visibilitymap_clear - clear specified bits for one page in visibility map
134  *
135  * You must pass a buffer containing the correct map page to this function.
136  * Call visibilitymap_pin first to pin the right one. This function doesn't do
137  * any I/O. Returns true if any bits have been cleared and false otherwise.
138  */
139 bool
140 visibilitymap_clear(Relation rel, BlockNumber heapBlk, Buffer vmbuf, uint8 flags)
141 {
142  BlockNumber mapBlock = HEAPBLK_TO_MAPBLOCK(heapBlk);
143  int mapByte = HEAPBLK_TO_MAPBYTE(heapBlk);
144  int mapOffset = HEAPBLK_TO_OFFSET(heapBlk);
145  uint8 mask = flags << mapOffset;
146  char *map;
147  bool cleared = false;
148 
149  /* Must never clear all_visible bit while leaving all_frozen bit set */
152 
153 #ifdef TRACE_VISIBILITYMAP
154  elog(DEBUG1, "vm_clear %s %d", RelationGetRelationName(rel), heapBlk);
155 #endif
156 
157  if (!BufferIsValid(vmbuf) || BufferGetBlockNumber(vmbuf) != mapBlock)
158  elog(ERROR, "wrong buffer passed to visibilitymap_clear");
159 
161  map = PageGetContents(BufferGetPage(vmbuf));
162 
163  if (map[mapByte] & mask)
164  {
165  map[mapByte] &= ~mask;
166 
167  MarkBufferDirty(vmbuf);
168  cleared = true;
169  }
170 
172 
173  return cleared;
174 }
175 
176 /*
177  * visibilitymap_pin - pin a map page for setting a bit
178  *
179  * Setting a bit in the visibility map is a two-phase operation. First, call
180  * visibilitymap_pin, to pin the visibility map page containing the bit for
181  * the heap page. Because that can require I/O to read the map page, you
182  * shouldn't hold a lock on the heap page while doing that. Then, call
183  * visibilitymap_set to actually set the bit.
184  *
185  * On entry, *vmbuf should be InvalidBuffer or a valid buffer returned by
186  * an earlier call to visibilitymap_pin or visibilitymap_get_status on the same
187  * relation. On return, *vmbuf is a valid buffer with the map page containing
188  * the bit for heapBlk.
189  *
190  * If the page doesn't exist in the map file yet, it is extended.
191  */
192 void
193 visibilitymap_pin(Relation rel, BlockNumber heapBlk, Buffer *vmbuf)
194 {
195  BlockNumber mapBlock = HEAPBLK_TO_MAPBLOCK(heapBlk);
196 
197  /* Reuse the old pinned buffer if possible */
198  if (BufferIsValid(*vmbuf))
199  {
200  if (BufferGetBlockNumber(*vmbuf) == mapBlock)
201  return;
202 
203  ReleaseBuffer(*vmbuf);
204  }
205  *vmbuf = vm_readbuf(rel, mapBlock, true);
206 }
207 
208 /*
209  * visibilitymap_pin_ok - do we already have the correct page pinned?
210  *
211  * On entry, vmbuf should be InvalidBuffer or a valid buffer returned by
212  * an earlier call to visibilitymap_pin or visibilitymap_get_status on the same
213  * relation. The return value indicates whether the buffer covers the
214  * given heapBlk.
215  */
216 bool
218 {
219  BlockNumber mapBlock = HEAPBLK_TO_MAPBLOCK(heapBlk);
220 
221  return BufferIsValid(vmbuf) && BufferGetBlockNumber(vmbuf) == mapBlock;
222 }
223 
224 /*
225  * visibilitymap_set - set bit(s) on a previously pinned page
226  *
227  * recptr is the LSN of the XLOG record we're replaying, if we're in recovery,
228  * or InvalidXLogRecPtr in normal running. The VM page LSN is advanced to the
229  * one provided; in normal running, we generate a new XLOG record and set the
230  * page LSN to that value (though the heap page's LSN may *not* be updated;
231  * see below). cutoff_xid is the largest xmin on the page being marked
232  * all-visible; it is needed for Hot Standby, and can be InvalidTransactionId
233  * if the page contains no tuples. It can also be set to InvalidTransactionId
234  * when a page that is already all-visible is being marked all-frozen.
235  *
236  * Caller is expected to set the heap page's PD_ALL_VISIBLE bit before calling
237  * this function. Except in recovery, caller should also pass the heap
238  * buffer. When checksums are enabled and we're not in recovery, we must add
239  * the heap buffer to the WAL chain to protect it from being torn.
240  *
241  * You must pass a buffer containing the correct map page to this function.
242  * Call visibilitymap_pin first to pin the right one. This function doesn't do
243  * any I/O.
244  */
245 void
246 visibilitymap_set(Relation rel, BlockNumber heapBlk, Buffer heapBuf,
247  XLogRecPtr recptr, Buffer vmBuf, TransactionId cutoff_xid,
248  uint8 flags)
249 {
250  BlockNumber mapBlock = HEAPBLK_TO_MAPBLOCK(heapBlk);
251  uint32 mapByte = HEAPBLK_TO_MAPBYTE(heapBlk);
252  uint8 mapOffset = HEAPBLK_TO_OFFSET(heapBlk);
253  Page page;
254  uint8 *map;
255 
256 #ifdef TRACE_VISIBILITYMAP
257  elog(DEBUG1, "vm_set %s %d", RelationGetRelationName(rel), heapBlk);
258 #endif
259 
262  Assert((flags & VISIBILITYMAP_VALID_BITS) == flags);
263 
264  /* Must never set all_frozen bit without also setting all_visible bit */
266 
267  /* Check that we have the right heap page pinned, if present */
268  if (BufferIsValid(heapBuf) && BufferGetBlockNumber(heapBuf) != heapBlk)
269  elog(ERROR, "wrong heap buffer passed to visibilitymap_set");
270 
271  /* Check that we have the right VM page pinned */
272  if (!BufferIsValid(vmBuf) || BufferGetBlockNumber(vmBuf) != mapBlock)
273  elog(ERROR, "wrong VM buffer passed to visibilitymap_set");
274 
275  page = BufferGetPage(vmBuf);
276  map = (uint8 *) PageGetContents(page);
278 
279  if (flags != (map[mapByte] >> mapOffset & VISIBILITYMAP_VALID_BITS))
280  {
282 
283  map[mapByte] |= (flags << mapOffset);
284  MarkBufferDirty(vmBuf);
285 
286  if (RelationNeedsWAL(rel))
287  {
288  if (XLogRecPtrIsInvalid(recptr))
289  {
290  Assert(!InRecovery);
291  recptr = log_heap_visible(rel, heapBuf, vmBuf, cutoff_xid, flags);
292 
293  /*
294  * If data checksums are enabled (or wal_log_hints=on), we
295  * need to protect the heap page from being torn.
296  *
297  * If not, then we must *not* update the heap page's LSN. In
298  * this case, the FPI for the heap page was omitted from the
299  * WAL record inserted above, so it would be incorrect to
300  * update the heap page's LSN.
301  */
302  if (XLogHintBitIsNeeded())
303  {
304  Page heapPage = BufferGetPage(heapBuf);
305 
306  PageSetLSN(heapPage, recptr);
307  }
308  }
309  PageSetLSN(page, recptr);
310  }
311 
313  }
314 
316 }
317 
318 /*
319  * visibilitymap_get_status - get status of bits
320  *
321  * Are all tuples on heapBlk visible to all or are marked frozen, according
322  * to the visibility map?
323  *
324  * On entry, *vmbuf should be InvalidBuffer or a valid buffer returned by an
325  * earlier call to visibilitymap_pin or visibilitymap_get_status on the same
326  * relation. On return, *vmbuf is a valid buffer with the map page containing
327  * the bit for heapBlk, or InvalidBuffer. The caller is responsible for
328  * releasing *vmbuf after it's done testing and setting bits.
329  *
330  * NOTE: This function is typically called without a lock on the heap page,
331  * so somebody else could change the bit just after we look at it. In fact,
332  * since we don't lock the visibility map page either, it's even possible that
333  * someone else could have changed the bit just before we look at it, but yet
334  * we might see the old value. It is the caller's responsibility to deal with
335  * all concurrency issues!
336  */
337 uint8
339 {
340  BlockNumber mapBlock = HEAPBLK_TO_MAPBLOCK(heapBlk);
341  uint32 mapByte = HEAPBLK_TO_MAPBYTE(heapBlk);
342  uint8 mapOffset = HEAPBLK_TO_OFFSET(heapBlk);
343  char *map;
344  uint8 result;
345 
346 #ifdef TRACE_VISIBILITYMAP
347  elog(DEBUG1, "vm_get_status %s %d", RelationGetRelationName(rel), heapBlk);
348 #endif
349 
350  /* Reuse the old pinned buffer if possible */
351  if (BufferIsValid(*vmbuf))
352  {
353  if (BufferGetBlockNumber(*vmbuf) != mapBlock)
354  {
355  ReleaseBuffer(*vmbuf);
356  *vmbuf = InvalidBuffer;
357  }
358  }
359 
360  if (!BufferIsValid(*vmbuf))
361  {
362  *vmbuf = vm_readbuf(rel, mapBlock, false);
363  if (!BufferIsValid(*vmbuf))
364  return false;
365  }
366 
367  map = PageGetContents(BufferGetPage(*vmbuf));
368 
369  /*
370  * A single byte read is atomic. There could be memory-ordering effects
371  * here, but for performance reasons we make it the caller's job to worry
372  * about that.
373  */
374  result = ((map[mapByte] >> mapOffset) & VISIBILITYMAP_VALID_BITS);
375  return result;
376 }
377 
378 /*
379  * visibilitymap_count - count number of bits set in visibility map
380  *
381  * Note: we ignore the possibility of race conditions when the table is being
382  * extended concurrently with the call. New pages added to the table aren't
383  * going to be marked all-visible or all-frozen, so they won't affect the result.
384  */
385 void
386 visibilitymap_count(Relation rel, BlockNumber *all_visible, BlockNumber *all_frozen)
387 {
388  BlockNumber mapBlock;
389  BlockNumber nvisible = 0;
390  BlockNumber nfrozen = 0;
391 
392  /* all_visible must be specified */
393  Assert(all_visible);
394 
395  for (mapBlock = 0;; mapBlock++)
396  {
397  Buffer mapBuffer;
398  uint64 *map;
399  int i;
400 
401  /*
402  * Read till we fall off the end of the map. We assume that any extra
403  * bytes in the last page are zeroed, so we don't bother excluding
404  * them from the count.
405  */
406  mapBuffer = vm_readbuf(rel, mapBlock, false);
407  if (!BufferIsValid(mapBuffer))
408  break;
409 
410  /*
411  * We choose not to lock the page, since the result is going to be
412  * immediately stale anyway if anyone is concurrently setting or
413  * clearing bits, and we only really need an approximate value.
414  */
415  map = (uint64 *) PageGetContents(BufferGetPage(mapBuffer));
416 
417  StaticAssertStmt(MAPSIZE % sizeof(uint64) == 0,
418  "unsupported MAPSIZE");
419  if (all_frozen == NULL)
420  {
421  for (i = 0; i < MAPSIZE / sizeof(uint64); i++)
422  nvisible += pg_popcount64(map[i] & VISIBLE_MASK64);
423  }
424  else
425  {
426  for (i = 0; i < MAPSIZE / sizeof(uint64); i++)
427  {
428  nvisible += pg_popcount64(map[i] & VISIBLE_MASK64);
429  nfrozen += pg_popcount64(map[i] & FROZEN_MASK64);
430  }
431  }
432 
433  ReleaseBuffer(mapBuffer);
434  }
435 
436  *all_visible = nvisible;
437  if (all_frozen)
438  *all_frozen = nfrozen;
439 }
440 
441 /*
442  * visibilitymap_prepare_truncate -
443  * prepare for truncation of the visibility map
444  *
445  * nheapblocks is the new size of the heap.
446  *
447  * Return the number of blocks of new visibility map.
448  * If it's InvalidBlockNumber, there is nothing to truncate;
449  * otherwise the caller is responsible for calling smgrtruncate()
450  * to truncate the visibility map pages.
451  */
454 {
455  BlockNumber newnblocks;
456 
457  /* last remaining block, byte, and bit */
458  BlockNumber truncBlock = HEAPBLK_TO_MAPBLOCK(nheapblocks);
459  uint32 truncByte = HEAPBLK_TO_MAPBYTE(nheapblocks);
460  uint8 truncOffset = HEAPBLK_TO_OFFSET(nheapblocks);
461 
462 #ifdef TRACE_VISIBILITYMAP
463  elog(DEBUG1, "vm_truncate %s %d", RelationGetRelationName(rel), nheapblocks);
464 #endif
465 
466  /*
467  * If no visibility map has been created yet for this relation, there's
468  * nothing to truncate.
469  */
471  return InvalidBlockNumber;
472 
473  /*
474  * Unless the new size is exactly at a visibility map page boundary, the
475  * tail bits in the last remaining map page, representing truncated heap
476  * blocks, need to be cleared. This is not only tidy, but also necessary
477  * because we don't get a chance to clear the bits if the heap is extended
478  * again.
479  */
480  if (truncByte != 0 || truncOffset != 0)
481  {
482  Buffer mapBuffer;
483  Page page;
484  char *map;
485 
486  newnblocks = truncBlock + 1;
487 
488  mapBuffer = vm_readbuf(rel, truncBlock, false);
489  if (!BufferIsValid(mapBuffer))
490  {
491  /* nothing to do, the file was already smaller */
492  return InvalidBlockNumber;
493  }
494 
495  page = BufferGetPage(mapBuffer);
496  map = PageGetContents(page);
497 
498  LockBuffer(mapBuffer, BUFFER_LOCK_EXCLUSIVE);
499 
500  /* NO EREPORT(ERROR) from here till changes are logged */
502 
503  /* Clear out the unwanted bytes. */
504  MemSet(&map[truncByte + 1], 0, MAPSIZE - (truncByte + 1));
505 
506  /*----
507  * Mask out the unwanted bits of the last remaining byte.
508  *
509  * ((1 << 0) - 1) = 00000000
510  * ((1 << 1) - 1) = 00000001
511  * ...
512  * ((1 << 6) - 1) = 00111111
513  * ((1 << 7) - 1) = 01111111
514  *----
515  */
516  map[truncByte] &= (1 << truncOffset) - 1;
517 
518  /*
519  * Truncation of a relation is WAL-logged at a higher-level, and we
520  * will be called at WAL replay. But if checksums are enabled, we need
521  * to still write a WAL record to protect against a torn page, if the
522  * page is flushed to disk before the truncation WAL record. We cannot
523  * use MarkBufferDirtyHint here, because that will not dirty the page
524  * during recovery.
525  */
526  MarkBufferDirty(mapBuffer);
528  log_newpage_buffer(mapBuffer, false);
529 
531 
532  UnlockReleaseBuffer(mapBuffer);
533  }
534  else
535  newnblocks = truncBlock;
536 
537  if (smgrnblocks(RelationGetSmgr(rel), VISIBILITYMAP_FORKNUM) <= newnblocks)
538  {
539  /* nothing to do, the file was already smaller than requested size */
540  return InvalidBlockNumber;
541  }
542 
543  return newnblocks;
544 }
545 
546 /*
547  * Read a visibility map page.
548  *
549  * If the page doesn't exist, InvalidBuffer is returned, or if 'extend' is
550  * true, the visibility map file is extended.
551  */
552 static Buffer
553 vm_readbuf(Relation rel, BlockNumber blkno, bool extend)
554 {
555  Buffer buf;
556  SMgrRelation reln;
557 
558  /*
559  * Caution: re-using this smgr pointer could fail if the relcache entry
560  * gets closed. It's safe as long as we only do smgr-level operations
561  * between here and the last use of the pointer.
562  */
563  reln = RelationGetSmgr(rel);
564 
565  /*
566  * If we haven't cached the size of the visibility map fork yet, check it
567  * first.
568  */
570  {
573  else
575  }
576 
577  /*
578  * For reading we use ZERO_ON_ERROR mode, and initialize the page if
579  * necessary. It's always safe to clear bits, so it's better to clear
580  * corrupt pages than error out.
581  *
582  * We use the same path below to initialize pages when extending the
583  * relation, as a concurrent extension can end up with vm_extend()
584  * returning an already-initialized page.
585  */
586  if (blkno >= reln->smgr_cached_nblocks[VISIBILITYMAP_FORKNUM])
587  {
588  if (extend)
589  buf = vm_extend(rel, blkno + 1);
590  else
591  return InvalidBuffer;
592  }
593  else
595  RBM_ZERO_ON_ERROR, NULL);
596 
597  /*
598  * Initializing the page when needed is trickier than it looks, because of
599  * the possibility of multiple backends doing this concurrently, and our
600  * desire to not uselessly take the buffer lock in the normal path where
601  * the page is OK. We must take the lock to initialize the page, so
602  * recheck page newness after we have the lock, in case someone else
603  * already did it. Also, because we initially check PageIsNew with no
604  * lock, it's possible to fall through and return the buffer while someone
605  * else is still initializing the page (i.e., we might see pd_upper as set
606  * but other page header fields are still zeroes). This is harmless for
607  * callers that will take a buffer lock themselves, but some callers
608  * inspect the page without any lock at all. The latter is OK only so
609  * long as it doesn't depend on the page header having correct contents.
610  * Current usage is safe because PageGetContents() does not require that.
611  */
613  {
616  PageInit(BufferGetPage(buf), BLCKSZ, 0);
618  }
619  return buf;
620 }
621 
622 /*
623  * Ensure that the visibility map fork is at least vm_nblocks long, extending
624  * it if necessary with zeroed pages.
625  */
626 static Buffer
627 vm_extend(Relation rel, BlockNumber vm_nblocks)
628 {
629  Buffer buf;
630 
634  vm_nblocks,
636 
637  /*
638  * Send a shared-inval message to force other backends to close any smgr
639  * references they may have for this rel, which we are about to change.
640  * This is a useful optimization because it means that backends don't have
641  * to keep checking for creation or extension of the file, which happens
642  * infrequently.
643  */
644  CacheInvalidateSmgr(RelationGetSmgr(rel)->smgr_rlocator);
645 
646  return buf;
647 }
uint32 BlockNumber
Definition: block.h:31
#define InvalidBlockNumber
Definition: block.h:33
int Buffer
Definition: buf.h:23
#define InvalidBuffer
Definition: buf.h:25
BlockNumber BufferGetBlockNumber(Buffer buffer)
Definition: bufmgr.c:3378
Buffer ExtendBufferedRelTo(BufferManagerRelation bmr, ForkNumber fork, BufferAccessStrategy strategy, uint32 flags, BlockNumber extend_to, ReadBufferMode mode)
Definition: bufmgr.c:903
void ReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:4561
void UnlockReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:4578
void MarkBufferDirty(Buffer buffer)
Definition: bufmgr.c:2190
void LockBuffer(Buffer buffer, int mode)
Definition: bufmgr.c:4796
Buffer ReadBufferExtended(Relation reln, ForkNumber forkNum, BlockNumber blockNum, ReadBufferMode mode, BufferAccessStrategy strategy)
Definition: bufmgr.c:782
#define BUFFER_LOCK_UNLOCK
Definition: bufmgr.h:157
static Page BufferGetPage(Buffer buffer)
Definition: bufmgr.h:350
@ EB_CLEAR_SIZE_CACHE
Definition: bufmgr.h:88
@ EB_CREATE_FORK_IF_NEEDED
Definition: bufmgr.h:82
#define BUFFER_LOCK_EXCLUSIVE
Definition: bufmgr.h:159
@ RBM_ZERO_ON_ERROR
Definition: bufmgr.h:49
#define BMR_REL(p_rel)
Definition: bufmgr.h:106
static bool BufferIsValid(Buffer bufnum)
Definition: bufmgr.h:301
void PageInit(Page page, Size pageSize, Size specialSize)
Definition: bufpage.c:42
static char * PageGetContents(Page page)
Definition: bufpage.h:254
Pointer Page
Definition: bufpage.h:78
static bool PageIsNew(Page page)
Definition: bufpage.h:230
static bool PageIsAllVisible(Page page)
Definition: bufpage.h:426
static void PageSetLSN(Page page, XLogRecPtr lsn)
Definition: bufpage.h:388
unsigned int uint32
Definition: c.h:495
unsigned char uint8
Definition: c.h:493
#define MemSet(start, val, len)
Definition: c.h:1009
#define StaticAssertStmt(condition, errmessage)
Definition: c.h:927
uint32 TransactionId
Definition: c.h:641
#define DEBUG1
Definition: elog.h:30
#define ERROR
Definition: elog.h:39
XLogRecPtr log_heap_visible(Relation rel, Buffer heap_buffer, Buffer vm_buffer, TransactionId snapshotConflictHorizon, uint8 vmflags)
Definition: heapam.c:8334
void CacheInvalidateSmgr(RelFileLocatorBackend rlocator)
Definition: inval.c:1460
int i
Definition: isn.c:73
Assert(fmt[strlen(fmt) - 1] !='\n')
#define START_CRIT_SECTION()
Definition: miscadmin.h:149
#define END_CRIT_SECTION()
Definition: miscadmin.h:151
int pg_popcount64(uint64 word)
Definition: pg_bitutils.c:284
static char * buf
Definition: pg_test_fsync.c:73
static SMgrRelation RelationGetSmgr(Relation rel)
Definition: rel.h:566
#define RelationGetRelationName(relation)
Definition: rel.h:538
#define RelationNeedsWAL(relation)
Definition: rel.h:627
@ VISIBILITYMAP_FORKNUM
Definition: relpath.h:52
BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:658
bool smgrexists(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:401
BlockNumber smgr_cached_nblocks[MAX_FORKNUM+1]
Definition: smgr.h:46
#define MAPSIZE
#define VISIBLE_MASK64
void visibilitymap_set(Relation rel, BlockNumber heapBlk, Buffer heapBuf, XLogRecPtr recptr, Buffer vmBuf, TransactionId cutoff_xid, uint8 flags)
bool visibilitymap_pin_ok(BlockNumber heapBlk, Buffer vmbuf)
bool visibilitymap_clear(Relation rel, BlockNumber heapBlk, Buffer vmbuf, uint8 flags)
#define HEAPBLK_TO_OFFSET(x)
void visibilitymap_pin(Relation rel, BlockNumber heapBlk, Buffer *vmbuf)
uint8 visibilitymap_get_status(Relation rel, BlockNumber heapBlk, Buffer *vmbuf)
static Buffer vm_extend(Relation rel, BlockNumber vm_nblocks)
BlockNumber visibilitymap_prepare_truncate(Relation rel, BlockNumber nheapblocks)
void visibilitymap_count(Relation rel, BlockNumber *all_visible, BlockNumber *all_frozen)
static Buffer vm_readbuf(Relation rel, BlockNumber blkno, bool extend)
#define FROZEN_MASK64
#define HEAPBLK_TO_MAPBLOCK(x)
#define HEAPBLK_TO_MAPBYTE(x)
#define VISIBILITYMAP_VALID_BITS
#define VISIBILITYMAP_ALL_FROZEN
#define VISIBILITYMAP_ALL_VISIBLE
#define XLogHintBitIsNeeded()
Definition: xlog.h:118
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
uint64 XLogRecPtr
Definition: xlogdefs.h:21
XLogRecPtr log_newpage_buffer(Buffer buffer, bool page_std)
Definition: xloginsert.c:1238
bool InRecovery
Definition: xlogutils.c:53