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reorderbuffer.c
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1 /*-------------------------------------------------------------------------
2  *
3  * reorderbuffer.c
4  * PostgreSQL logical replay/reorder buffer management
5  *
6  *
7  * Copyright (c) 2012-2018, PostgreSQL Global Development Group
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/replication/reorderbuffer.c
12  *
13  * NOTES
14  * This module gets handed individual pieces of transactions in the order
15  * they are written to the WAL and is responsible to reassemble them into
16  * toplevel transaction sized pieces. When a transaction is completely
17  * reassembled - signalled by reading the transaction commit record - it
18  * will then call the output plugin (cf. ReorderBufferCommit()) with the
19  * individual changes. The output plugins rely on snapshots built by
20  * snapbuild.c which hands them to us.
21  *
22  * Transactions and subtransactions/savepoints in postgres are not
23  * immediately linked to each other from outside the performing
24  * backend. Only at commit/abort (or special xact_assignment records) they
25  * are linked together. Which means that we will have to splice together a
26  * toplevel transaction from its subtransactions. To do that efficiently we
27  * build a binary heap indexed by the smallest current lsn of the individual
28  * subtransactions' changestreams. As the individual streams are inherently
29  * ordered by LSN - since that is where we build them from - the transaction
30  * can easily be reassembled by always using the subtransaction with the
31  * smallest current LSN from the heap.
32  *
33  * In order to cope with large transactions - which can be several times as
34  * big as the available memory - this module supports spooling the contents
35  * of a large transactions to disk. When the transaction is replayed the
36  * contents of individual (sub-)transactions will be read from disk in
37  * chunks.
38  *
39  * This module also has to deal with reassembling toast records from the
40  * individual chunks stored in WAL. When a new (or initial) version of a
41  * tuple is stored in WAL it will always be preceded by the toast chunks
42  * emitted for the columns stored out of line. Within a single toplevel
43  * transaction there will be no other data carrying records between a row's
44  * toast chunks and the row data itself. See ReorderBufferToast* for
45  * details.
46  *
47  * ReorderBuffer uses two special memory context types - SlabContext for
48  * allocations of fixed-length structures (changes and transactions), and
49  * GenerationContext for the variable-length transaction data (allocated
50  * and freed in groups with similar lifespan).
51  *
52  * -------------------------------------------------------------------------
53  */
54 #include "postgres.h"
55 
56 #include <unistd.h>
57 #include <sys/stat.h>
58 
59 #include "access/rewriteheap.h"
60 #include "access/transam.h"
61 #include "access/tuptoaster.h"
62 #include "access/xact.h"
63 #include "access/xlog_internal.h"
64 #include "catalog/catalog.h"
65 #include "lib/binaryheap.h"
66 #include "miscadmin.h"
67 #include "pgstat.h"
68 #include "replication/logical.h"
70 #include "replication/slot.h"
71 #include "replication/snapbuild.h" /* just for SnapBuildSnapDecRefcount */
72 #include "storage/bufmgr.h"
73 #include "storage/fd.h"
74 #include "storage/sinval.h"
75 #include "utils/builtins.h"
76 #include "utils/combocid.h"
77 #include "utils/memdebug.h"
78 #include "utils/memutils.h"
79 #include "utils/rel.h"
80 #include "utils/relfilenodemap.h"
81 #include "utils/tqual.h"
82 
83 
84 /* entry for a hash table we use to map from xid to our transaction state */
86 {
90 
91 /* data structures for (relfilenode, ctid) => (cmin, cmax) mapping */
93 {
97 
99 {
103  CommandId combocid; /* just for debugging */
105 
106 /* k-way in-order change iteration support structures */
108 {
112  int fd;
115 
117 {
121  ReorderBufferIterTXNEntry entries[FLEXIBLE_ARRAY_MEMBER];
123 
124 /* toast datastructures */
125 typedef struct ReorderBufferToastEnt
126 {
127  Oid chunk_id; /* toast_table.chunk_id */
128  int32 last_chunk_seq; /* toast_table.chunk_seq of the last chunk we
129  * have seen */
130  Size num_chunks; /* number of chunks we've already seen */
131  Size size; /* combined size of chunks seen */
132  dlist_head chunks; /* linked list of chunks */
133  struct varlena *reconstructed; /* reconstructed varlena now pointed to in
134  * main tup */
136 
137 /* Disk serialization support datastructures */
139 {
142  /* data follows */
144 
145 /*
146  * Maximum number of changes kept in memory, per transaction. After that,
147  * changes are spooled to disk.
148  *
149  * The current value should be sufficient to decode the entire transaction
150  * without hitting disk in OLTP workloads, while starting to spool to disk in
151  * other workloads reasonably fast.
152  *
153  * At some point in the future it probably makes sense to have a more elaborate
154  * resource management here, but it's not entirely clear what that would look
155  * like.
156  */
157 static const Size max_changes_in_memory = 4096;
158 
159 /* ---------------------------------------
160  * primary reorderbuffer support routines
161  * ---------------------------------------
162  */
166  TransactionId xid, bool create, bool *is_new,
167  XLogRecPtr lsn, bool create_as_top);
168 
169 static void AssertTXNLsnOrder(ReorderBuffer *rb);
170 
171 /* ---------------------------------------
172  * support functions for lsn-order iterating over the ->changes of a
173  * transaction and its subtransactions
174  *
175  * used for iteration over the k-way heap merge of a transaction and its
176  * subtransactions
177  * ---------------------------------------
178  */
184 
185 /*
186  * ---------------------------------------
187  * Disk serialization support functions
188  * ---------------------------------------
189  */
193  int fd, ReorderBufferChange *change);
195  int *fd, XLogSegNo *segno);
197  char *change);
199 
200 static void ReorderBufferFreeSnap(ReorderBuffer *rb, Snapshot snap);
203 
204 /* ---------------------------------------
205  * toast reassembly support
206  * ---------------------------------------
207  */
211  Relation relation, ReorderBufferChange *change);
213  Relation relation, ReorderBufferChange *change);
214 
215 
216 /*
217  * Allocate a new ReorderBuffer
218  */
221 {
223  HASHCTL hash_ctl;
224  MemoryContext new_ctx;
225 
226  /* allocate memory in own context, to have better accountability */
228  "ReorderBuffer",
230 
231  buffer =
232  (ReorderBuffer *) MemoryContextAlloc(new_ctx, sizeof(ReorderBuffer));
233 
234  memset(&hash_ctl, 0, sizeof(hash_ctl));
235 
236  buffer->context = new_ctx;
237 
238  buffer->change_context = SlabContextCreate(new_ctx,
239  "Change",
240  0,
242  sizeof(ReorderBufferChange));
243 
244  buffer->txn_context = SlabContextCreate(new_ctx,
245  "TXN",
246  0,
248  sizeof(ReorderBufferTXN));
249 
250  buffer->tup_context = GenerationContextCreate(new_ctx,
251  "Tuples",
252  0,
254 
255  hash_ctl.keysize = sizeof(TransactionId);
256  hash_ctl.entrysize = sizeof(ReorderBufferTXNByIdEnt);
257  hash_ctl.hcxt = buffer->context;
258 
259  buffer->by_txn = hash_create("ReorderBufferByXid", 1000, &hash_ctl,
261 
263  buffer->by_txn_last_txn = NULL;
264 
265  buffer->outbuf = NULL;
266  buffer->outbufsize = 0;
267 
269 
270  dlist_init(&buffer->toplevel_by_lsn);
271 
272  return buffer;
273 }
274 
275 /*
276  * Free a ReorderBuffer
277  */
278 void
280 {
281  MemoryContext context = rb->context;
282 
283  /*
284  * We free separately allocated data by entirely scrapping reorderbuffer's
285  * memory context.
286  */
287  MemoryContextDelete(context);
288 }
289 
290 /*
291  * Get an unused, possibly preallocated, ReorderBufferTXN.
292  */
293 static ReorderBufferTXN *
295 {
297 
298  txn = (ReorderBufferTXN *)
300 
301  memset(txn, 0, sizeof(ReorderBufferTXN));
302 
303  dlist_init(&txn->changes);
304  dlist_init(&txn->tuplecids);
305  dlist_init(&txn->subtxns);
306 
307  return txn;
308 }
309 
310 /*
311  * Free a ReorderBufferTXN.
312  *
313  * Deallocation might be delayed for efficiency purposes, for details check
314  * the comments above max_cached_changes's definition.
315  */
316 static void
318 {
319  /* clean the lookup cache if we were cached (quite likely) */
320  if (rb->by_txn_last_xid == txn->xid)
321  {
323  rb->by_txn_last_txn = NULL;
324  }
325 
326  /* free data that's contained */
327 
328  if (txn->tuplecid_hash != NULL)
329  {
331  txn->tuplecid_hash = NULL;
332  }
333 
334  if (txn->invalidations)
335  {
336  pfree(txn->invalidations);
337  txn->invalidations = NULL;
338  }
339 
340  pfree(txn);
341 }
342 
343 /*
344  * Get an unused, possibly preallocated, ReorderBufferChange.
345  */
348 {
349  ReorderBufferChange *change;
350 
351  change = (ReorderBufferChange *)
353 
354  memset(change, 0, sizeof(ReorderBufferChange));
355  return change;
356 }
357 
358 /*
359  * Free an ReorderBufferChange.
360  *
361  * Deallocation might be delayed for efficiency purposes, for details check
362  * the comments above max_cached_changes's definition.
363  */
364 void
366 {
367  /* free contained data */
368  switch (change->action)
369  {
374  if (change->data.tp.newtuple)
375  {
376  ReorderBufferReturnTupleBuf(rb, change->data.tp.newtuple);
377  change->data.tp.newtuple = NULL;
378  }
379 
380  if (change->data.tp.oldtuple)
381  {
382  ReorderBufferReturnTupleBuf(rb, change->data.tp.oldtuple);
383  change->data.tp.oldtuple = NULL;
384  }
385  break;
387  if (change->data.msg.prefix != NULL)
388  pfree(change->data.msg.prefix);
389  change->data.msg.prefix = NULL;
390  if (change->data.msg.message != NULL)
391  pfree(change->data.msg.message);
392  change->data.msg.message = NULL;
393  break;
395  if (change->data.snapshot)
396  {
397  ReorderBufferFreeSnap(rb, change->data.snapshot);
398  change->data.snapshot = NULL;
399  }
400  break;
401  /* no data in addition to the struct itself */
405  break;
406  }
407 
408  pfree(change);
409 }
410 
411 /*
412  * Get an unused, possibly preallocated, ReorderBufferTupleBuf fitting at
413  * least a tuple of size tuple_len (excluding header overhead).
414  */
417 {
418  ReorderBufferTupleBuf *tuple;
419  Size alloc_len;
420 
421  alloc_len = tuple_len + SizeofHeapTupleHeader;
422 
423  tuple = (ReorderBufferTupleBuf *)
425  sizeof(ReorderBufferTupleBuf) +
426  MAXIMUM_ALIGNOF + alloc_len);
427  tuple->alloc_tuple_size = alloc_len;
428  tuple->tuple.t_data = ReorderBufferTupleBufData(tuple);
429 
430  return tuple;
431 }
432 
433 /*
434  * Free an ReorderBufferTupleBuf.
435  *
436  * Deallocation might be delayed for efficiency purposes, for details check
437  * the comments above max_cached_changes's definition.
438  */
439 void
441 {
442  pfree(tuple);
443 }
444 
445 /*
446  * Return the ReorderBufferTXN from the given buffer, specified by Xid.
447  * If create is true, and a transaction doesn't already exist, create it
448  * (with the given LSN, and as top transaction if that's specified);
449  * when this happens, is_new is set to true.
450  */
451 static ReorderBufferTXN *
453  bool *is_new, XLogRecPtr lsn, bool create_as_top)
454 {
457  bool found;
458 
460  Assert(!create || lsn != InvalidXLogRecPtr);
461 
462  /*
463  * Check the one-entry lookup cache first
464  */
466  rb->by_txn_last_xid == xid)
467  {
468  txn = rb->by_txn_last_txn;
469 
470  if (txn != NULL)
471  {
472  /* found it, and it's valid */
473  if (is_new)
474  *is_new = false;
475  return txn;
476  }
477 
478  /*
479  * cached as non-existent, and asked not to create? Then nothing else
480  * to do.
481  */
482  if (!create)
483  return NULL;
484  /* otherwise fall through to create it */
485  }
486 
487  /*
488  * If the cache wasn't hit or it yielded an "does-not-exist" and we want
489  * to create an entry.
490  */
491 
492  /* search the lookup table */
493  ent = (ReorderBufferTXNByIdEnt *)
494  hash_search(rb->by_txn,
495  (void *) &xid,
496  create ? HASH_ENTER : HASH_FIND,
497  &found);
498  if (found)
499  txn = ent->txn;
500  else if (create)
501  {
502  /* initialize the new entry, if creation was requested */
503  Assert(ent != NULL);
504 
505  ent->txn = ReorderBufferGetTXN(rb);
506  ent->txn->xid = xid;
507  txn = ent->txn;
508  txn->first_lsn = lsn;
510 
511  if (create_as_top)
512  {
513  dlist_push_tail(&rb->toplevel_by_lsn, &txn->node);
514  AssertTXNLsnOrder(rb);
515  }
516  }
517  else
518  txn = NULL; /* not found and not asked to create */
519 
520  /* update cache */
521  rb->by_txn_last_xid = xid;
522  rb->by_txn_last_txn = txn;
523 
524  if (is_new)
525  *is_new = !found;
526 
527  Assert(!create || txn != NULL);
528  return txn;
529 }
530 
531 /*
532  * Queue a change into a transaction so it can be replayed upon commit.
533  */
534 void
536  ReorderBufferChange *change)
537 {
539 
540  txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
541 
542  change->lsn = lsn;
543  Assert(InvalidXLogRecPtr != lsn);
544  dlist_push_tail(&txn->changes, &change->node);
545  txn->nentries++;
546  txn->nentries_mem++;
547 
549 }
550 
551 /*
552  * Queue message into a transaction so it can be processed upon commit.
553  */
554 void
556  Snapshot snapshot, XLogRecPtr lsn,
557  bool transactional, const char *prefix,
558  Size message_size, const char *message)
559 {
560  if (transactional)
561  {
562  MemoryContext oldcontext;
563  ReorderBufferChange *change;
564 
566 
567  oldcontext = MemoryContextSwitchTo(rb->context);
568 
569  change = ReorderBufferGetChange(rb);
571  change->data.msg.prefix = pstrdup(prefix);
572  change->data.msg.message_size = message_size;
573  change->data.msg.message = palloc(message_size);
574  memcpy(change->data.msg.message, message, message_size);
575 
576  ReorderBufferQueueChange(rb, xid, lsn, change);
577 
578  MemoryContextSwitchTo(oldcontext);
579  }
580  else
581  {
582  ReorderBufferTXN *txn = NULL;
583  volatile Snapshot snapshot_now = snapshot;
584 
585  if (xid != InvalidTransactionId)
586  txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
587 
588  /* setup snapshot to allow catalog access */
589  SetupHistoricSnapshot(snapshot_now, NULL);
590  PG_TRY();
591  {
592  rb->message(rb, txn, lsn, false, prefix, message_size, message);
593 
595  }
596  PG_CATCH();
597  {
599  PG_RE_THROW();
600  }
601  PG_END_TRY();
602  }
603 }
604 
605 
606 static void
608 {
609 #ifdef USE_ASSERT_CHECKING
610  dlist_iter iter;
611  XLogRecPtr prev_first_lsn = InvalidXLogRecPtr;
612 
613  dlist_foreach(iter, &rb->toplevel_by_lsn)
614  {
615  ReorderBufferTXN *cur_txn;
616 
617  cur_txn = dlist_container(ReorderBufferTXN, node, iter.cur);
618  Assert(cur_txn->first_lsn != InvalidXLogRecPtr);
619 
620  if (cur_txn->end_lsn != InvalidXLogRecPtr)
621  Assert(cur_txn->first_lsn <= cur_txn->end_lsn);
622 
623  if (prev_first_lsn != InvalidXLogRecPtr)
624  Assert(prev_first_lsn < cur_txn->first_lsn);
625 
626  Assert(!cur_txn->is_known_as_subxact);
627  prev_first_lsn = cur_txn->first_lsn;
628  }
629 #endif
630 }
631 
634 {
636 
638  return NULL;
639 
640  AssertTXNLsnOrder(rb);
641 
643 
646  return txn;
647 }
648 
649 void
651 {
653 }
654 
655 void
657  TransactionId subxid, XLogRecPtr lsn)
658 {
660  ReorderBufferTXN *subtxn;
661  bool new_top;
662  bool new_sub;
663 
664  txn = ReorderBufferTXNByXid(rb, xid, true, &new_top, lsn, true);
665  subtxn = ReorderBufferTXNByXid(rb, subxid, true, &new_sub, lsn, false);
666 
667  if (new_sub)
668  {
669  /*
670  * we assign subtransactions to top level transaction even if we don't
671  * have data for it yet, assignment records frequently reference xids
672  * that have not yet produced any records. Knowing those aren't top
673  * level xids allows us to make processing cheaper in some places.
674  */
675  dlist_push_tail(&txn->subtxns, &subtxn->node);
676  txn->nsubtxns++;
677  }
678  else if (!subtxn->is_known_as_subxact)
679  {
680  subtxn->is_known_as_subxact = true;
681  Assert(subtxn->nsubtxns == 0);
682 
683  /* remove from lsn order list of top-level transactions */
684  dlist_delete(&subtxn->node);
685 
686  /* add to toplevel transaction */
687  dlist_push_tail(&txn->subtxns, &subtxn->node);
688  txn->nsubtxns++;
689  }
690  else if (new_top)
691  {
692  elog(ERROR, "existing subxact assigned to unknown toplevel xact");
693  }
694 }
695 
696 /*
697  * Associate a subtransaction with its toplevel transaction at commit
698  * time. There may be no further changes added after this.
699  */
700 void
702  TransactionId subxid, XLogRecPtr commit_lsn,
703  XLogRecPtr end_lsn)
704 {
706  ReorderBufferTXN *subtxn;
707 
708  subtxn = ReorderBufferTXNByXid(rb, subxid, false, NULL,
709  InvalidXLogRecPtr, false);
710 
711  /*
712  * No need to do anything if that subtxn didn't contain any changes
713  */
714  if (!subtxn)
715  return;
716 
717  txn = ReorderBufferTXNByXid(rb, xid, false, NULL, commit_lsn, true);
718 
719  if (txn == NULL)
720  elog(ERROR, "subxact logged without previous toplevel record");
721 
722  /*
723  * Pass our base snapshot to the parent transaction if it doesn't have
724  * one, or ours is older. That can happen if there are no changes in the
725  * toplevel transaction but in one of the child transactions. This allows
726  * the parent to simply use its base snapshot initially.
727  */
728  if (subtxn->base_snapshot != NULL &&
729  (txn->base_snapshot == NULL ||
730  txn->base_snapshot_lsn > subtxn->base_snapshot_lsn))
731  {
732  txn->base_snapshot = subtxn->base_snapshot;
733  txn->base_snapshot_lsn = subtxn->base_snapshot_lsn;
734  subtxn->base_snapshot = NULL;
736  }
737 
738  subtxn->final_lsn = commit_lsn;
739  subtxn->end_lsn = end_lsn;
740 
741  if (!subtxn->is_known_as_subxact)
742  {
743  subtxn->is_known_as_subxact = true;
744  Assert(subtxn->nsubtxns == 0);
745 
746  /* remove from lsn order list of top-level transactions */
747  dlist_delete(&subtxn->node);
748 
749  /* add to subtransaction list */
750  dlist_push_tail(&txn->subtxns, &subtxn->node);
751  txn->nsubtxns++;
752  }
753 }
754 
755 
756 /*
757  * Support for efficiently iterating over a transaction's and its
758  * subtransactions' changes.
759  *
760  * We do by doing a k-way merge between transactions/subtransactions. For that
761  * we model the current heads of the different transactions as a binary heap
762  * so we easily know which (sub-)transaction has the change with the smallest
763  * lsn next.
764  *
765  * We assume the changes in individual transactions are already sorted by LSN.
766  */
767 
768 /*
769  * Binary heap comparison function.
770  */
771 static int
773 {
775  XLogRecPtr pos_a = state->entries[DatumGetInt32(a)].lsn;
776  XLogRecPtr pos_b = state->entries[DatumGetInt32(b)].lsn;
777 
778  if (pos_a < pos_b)
779  return 1;
780  else if (pos_a == pos_b)
781  return 0;
782  return -1;
783 }
784 
785 /*
786  * Allocate & initialize an iterator which iterates in lsn order over a
787  * transaction and all its subtransactions.
788  */
791 {
792  Size nr_txns = 0;
794  dlist_iter cur_txn_i;
795  int32 off;
796 
797  /*
798  * Calculate the size of our heap: one element for every transaction that
799  * contains changes. (Besides the transactions already in the reorder
800  * buffer, we count the one we were directly passed.)
801  */
802  if (txn->nentries > 0)
803  nr_txns++;
804 
805  dlist_foreach(cur_txn_i, &txn->subtxns)
806  {
807  ReorderBufferTXN *cur_txn;
808 
809  cur_txn = dlist_container(ReorderBufferTXN, node, cur_txn_i.cur);
810 
811  if (cur_txn->nentries > 0)
812  nr_txns++;
813  }
814 
815  /*
816  * TODO: Consider adding fastpath for the rather common nr_txns=1 case, no
817  * need to allocate/build a heap then.
818  */
819 
820  /* allocate iteration state */
821  state = (ReorderBufferIterTXNState *)
823  sizeof(ReorderBufferIterTXNState) +
824  sizeof(ReorderBufferIterTXNEntry) * nr_txns);
825 
826  state->nr_txns = nr_txns;
827  dlist_init(&state->old_change);
828 
829  for (off = 0; off < state->nr_txns; off++)
830  {
831  state->entries[off].fd = -1;
832  state->entries[off].segno = 0;
833  }
834 
835  /* allocate heap */
836  state->heap = binaryheap_allocate(state->nr_txns,
838  state);
839 
840  /*
841  * Now insert items into the binary heap, in an unordered fashion. (We
842  * will run a heap assembly step at the end; this is more efficient.)
843  */
844 
845  off = 0;
846 
847  /* add toplevel transaction if it contains changes */
848  if (txn->nentries > 0)
849  {
850  ReorderBufferChange *cur_change;
851 
852  if (txn->serialized)
853  {
854  /* serialize remaining changes */
855  ReorderBufferSerializeTXN(rb, txn);
856  ReorderBufferRestoreChanges(rb, txn, &state->entries[off].fd,
857  &state->entries[off].segno);
858  }
859 
860  cur_change = dlist_head_element(ReorderBufferChange, node,
861  &txn->changes);
862 
863  state->entries[off].lsn = cur_change->lsn;
864  state->entries[off].change = cur_change;
865  state->entries[off].txn = txn;
866 
868  }
869 
870  /* add subtransactions if they contain changes */
871  dlist_foreach(cur_txn_i, &txn->subtxns)
872  {
873  ReorderBufferTXN *cur_txn;
874 
875  cur_txn = dlist_container(ReorderBufferTXN, node, cur_txn_i.cur);
876 
877  if (cur_txn->nentries > 0)
878  {
879  ReorderBufferChange *cur_change;
880 
881  if (cur_txn->serialized)
882  {
883  /* serialize remaining changes */
884  ReorderBufferSerializeTXN(rb, cur_txn);
885  ReorderBufferRestoreChanges(rb, cur_txn,
886  &state->entries[off].fd,
887  &state->entries[off].segno);
888  }
889  cur_change = dlist_head_element(ReorderBufferChange, node,
890  &cur_txn->changes);
891 
892  state->entries[off].lsn = cur_change->lsn;
893  state->entries[off].change = cur_change;
894  state->entries[off].txn = cur_txn;
895 
897  }
898  }
899 
900  /* assemble a valid binary heap */
901  binaryheap_build(state->heap);
902 
903  return state;
904 }
905 
906 /*
907  * Return the next change when iterating over a transaction and its
908  * subtransactions.
909  *
910  * Returns NULL when no further changes exist.
911  */
912 static ReorderBufferChange *
914 {
915  ReorderBufferChange *change;
917  int32 off;
918 
919  /* nothing there anymore */
920  if (state->heap->bh_size == 0)
921  return NULL;
922 
923  off = DatumGetInt32(binaryheap_first(state->heap));
924  entry = &state->entries[off];
925 
926  /* free memory we might have "leaked" in the previous *Next call */
927  if (!dlist_is_empty(&state->old_change))
928  {
929  change = dlist_container(ReorderBufferChange, node,
931  ReorderBufferReturnChange(rb, change);
932  Assert(dlist_is_empty(&state->old_change));
933  }
934 
935  change = entry->change;
936 
937  /*
938  * update heap with information about which transaction has the next
939  * relevant change in LSN order
940  */
941 
942  /* there are in-memory changes */
943  if (dlist_has_next(&entry->txn->changes, &entry->change->node))
944  {
945  dlist_node *next = dlist_next_node(&entry->txn->changes, &change->node);
946  ReorderBufferChange *next_change =
948 
949  /* txn stays the same */
950  state->entries[off].lsn = next_change->lsn;
951  state->entries[off].change = next_change;
952 
954  return change;
955  }
956 
957  /* try to load changes from disk */
958  if (entry->txn->nentries != entry->txn->nentries_mem)
959  {
960  /*
961  * Ugly: restoring changes will reuse *Change records, thus delete the
962  * current one from the per-tx list and only free in the next call.
963  */
964  dlist_delete(&change->node);
965  dlist_push_tail(&state->old_change, &change->node);
966 
967  if (ReorderBufferRestoreChanges(rb, entry->txn, &entry->fd,
968  &state->entries[off].segno))
969  {
970  /* successfully restored changes from disk */
971  ReorderBufferChange *next_change =
973  &entry->txn->changes);
974 
975  elog(DEBUG2, "restored %u/%u changes from disk",
976  (uint32) entry->txn->nentries_mem,
977  (uint32) entry->txn->nentries);
978 
979  Assert(entry->txn->nentries_mem);
980  /* txn stays the same */
981  state->entries[off].lsn = next_change->lsn;
982  state->entries[off].change = next_change;
984 
985  return change;
986  }
987  }
988 
989  /* ok, no changes there anymore, remove */
991 
992  return change;
993 }
994 
995 /*
996  * Deallocate the iterator
997  */
998 static void
1001 {
1002  int32 off;
1003 
1004  for (off = 0; off < state->nr_txns; off++)
1005  {
1006  if (state->entries[off].fd != -1)
1007  CloseTransientFile(state->entries[off].fd);
1008  }
1009 
1010  /* free memory we might have "leaked" in the last *Next call */
1011  if (!dlist_is_empty(&state->old_change))
1012  {
1013  ReorderBufferChange *change;
1014 
1015  change = dlist_container(ReorderBufferChange, node,
1016  dlist_pop_head_node(&state->old_change));
1017  ReorderBufferReturnChange(rb, change);
1018  Assert(dlist_is_empty(&state->old_change));
1019  }
1020 
1021  binaryheap_free(state->heap);
1022  pfree(state);
1023 }
1024 
1025 /*
1026  * Cleanup the contents of a transaction, usually after the transaction
1027  * committed or aborted.
1028  */
1029 static void
1031 {
1032  bool found;
1033  dlist_mutable_iter iter;
1034 
1035  /* cleanup subtransactions & their changes */
1036  dlist_foreach_modify(iter, &txn->subtxns)
1037  {
1038  ReorderBufferTXN *subtxn;
1039 
1040  subtxn = dlist_container(ReorderBufferTXN, node, iter.cur);
1041 
1042  /*
1043  * Subtransactions are always associated to the toplevel TXN, even if
1044  * they originally were happening inside another subtxn, so we won't
1045  * ever recurse more than one level deep here.
1046  */
1047  Assert(subtxn->is_known_as_subxact);
1048  Assert(subtxn->nsubtxns == 0);
1049 
1050  ReorderBufferCleanupTXN(rb, subtxn);
1051  }
1052 
1053  /* cleanup changes in the toplevel txn */
1054  dlist_foreach_modify(iter, &txn->changes)
1055  {
1056  ReorderBufferChange *change;
1057 
1058  change = dlist_container(ReorderBufferChange, node, iter.cur);
1059 
1060  ReorderBufferReturnChange(rb, change);
1061  }
1062 
1063  /*
1064  * Cleanup the tuplecids we stored for decoding catalog snapshot access.
1065  * They are always stored in the toplevel transaction.
1066  */
1067  dlist_foreach_modify(iter, &txn->tuplecids)
1068  {
1069  ReorderBufferChange *change;
1070 
1071  change = dlist_container(ReorderBufferChange, node, iter.cur);
1073  ReorderBufferReturnChange(rb, change);
1074  }
1075 
1076  if (txn->base_snapshot != NULL)
1077  {
1079  txn->base_snapshot = NULL;
1081  }
1082 
1083  /*
1084  * Remove TXN from its containing list.
1085  *
1086  * Note: if txn->is_known_as_subxact, we are deleting the TXN from its
1087  * parent's list of known subxacts; this leaves the parent's nsubxacts
1088  * count too high, but we don't care. Otherwise, we are deleting the TXN
1089  * from the LSN-ordered list of toplevel TXNs.
1090  */
1091  dlist_delete(&txn->node);
1092 
1093  /* now remove reference from buffer */
1094  hash_search(rb->by_txn,
1095  (void *) &txn->xid,
1096  HASH_REMOVE,
1097  &found);
1098  Assert(found);
1099 
1100  /* remove entries spilled to disk */
1101  if (txn->serialized)
1102  ReorderBufferRestoreCleanup(rb, txn);
1103 
1104  /* deallocate */
1105  ReorderBufferReturnTXN(rb, txn);
1106 }
1107 
1108 /*
1109  * Build a hash with a (relfilenode, ctid) -> (cmin, cmax) mapping for use by
1110  * tqual.c's HeapTupleSatisfiesHistoricMVCC.
1111  */
1112 static void
1114 {
1115  dlist_iter iter;
1116  HASHCTL hash_ctl;
1117 
1118  if (!txn->has_catalog_changes || dlist_is_empty(&txn->tuplecids))
1119  return;
1120 
1121  memset(&hash_ctl, 0, sizeof(hash_ctl));
1122 
1123  hash_ctl.keysize = sizeof(ReorderBufferTupleCidKey);
1124  hash_ctl.entrysize = sizeof(ReorderBufferTupleCidEnt);
1125  hash_ctl.hcxt = rb->context;
1126 
1127  /*
1128  * create the hash with the exact number of to-be-stored tuplecids from
1129  * the start
1130  */
1131  txn->tuplecid_hash =
1132  hash_create("ReorderBufferTupleCid", txn->ntuplecids, &hash_ctl,
1134 
1135  dlist_foreach(iter, &txn->tuplecids)
1136  {
1139  bool found;
1140  ReorderBufferChange *change;
1141 
1142  change = dlist_container(ReorderBufferChange, node, iter.cur);
1143 
1145 
1146  /* be careful about padding */
1147  memset(&key, 0, sizeof(ReorderBufferTupleCidKey));
1148 
1149  key.relnode = change->data.tuplecid.node;
1150 
1151  ItemPointerCopy(&change->data.tuplecid.tid,
1152  &key.tid);
1153 
1154  ent = (ReorderBufferTupleCidEnt *)
1156  (void *) &key,
1158  &found);
1159  if (!found)
1160  {
1161  ent->cmin = change->data.tuplecid.cmin;
1162  ent->cmax = change->data.tuplecid.cmax;
1163  ent->combocid = change->data.tuplecid.combocid;
1164  }
1165  else
1166  {
1167  Assert(ent->cmin == change->data.tuplecid.cmin);
1168  Assert(ent->cmax == InvalidCommandId ||
1169  ent->cmax == change->data.tuplecid.cmax);
1170 
1171  /*
1172  * if the tuple got valid in this transaction and now got deleted
1173  * we already have a valid cmin stored. The cmax will be
1174  * InvalidCommandId though.
1175  */
1176  ent->cmax = change->data.tuplecid.cmax;
1177  }
1178  }
1179 }
1180 
1181 /*
1182  * Copy a provided snapshot so we can modify it privately. This is needed so
1183  * that catalog modifying transactions can look into intermediate catalog
1184  * states.
1185  */
1186 static Snapshot
1189 {
1190  Snapshot snap;
1191  dlist_iter iter;
1192  int i = 0;
1193  Size size;
1194 
1195  size = sizeof(SnapshotData) +
1196  sizeof(TransactionId) * orig_snap->xcnt +
1197  sizeof(TransactionId) * (txn->nsubtxns + 1);
1198 
1199  snap = MemoryContextAllocZero(rb->context, size);
1200  memcpy(snap, orig_snap, sizeof(SnapshotData));
1201 
1202  snap->copied = true;
1203  snap->active_count = 1; /* mark as active so nobody frees it */
1204  snap->regd_count = 0;
1205  snap->xip = (TransactionId *) (snap + 1);
1206 
1207  memcpy(snap->xip, orig_snap->xip, sizeof(TransactionId) * snap->xcnt);
1208 
1209  /*
1210  * snap->subxip contains all txids that belong to our transaction which we
1211  * need to check via cmin/cmax. That's why we store the toplevel
1212  * transaction in there as well.
1213  */
1214  snap->subxip = snap->xip + snap->xcnt;
1215  snap->subxip[i++] = txn->xid;
1216 
1217  /*
1218  * nsubxcnt isn't decreased when subtransactions abort, so count manually.
1219  * Since it's an upper boundary it is safe to use it for the allocation
1220  * above.
1221  */
1222  snap->subxcnt = 1;
1223 
1224  dlist_foreach(iter, &txn->subtxns)
1225  {
1226  ReorderBufferTXN *sub_txn;
1227 
1228  sub_txn = dlist_container(ReorderBufferTXN, node, iter.cur);
1229  snap->subxip[i++] = sub_txn->xid;
1230  snap->subxcnt++;
1231  }
1232 
1233  /* sort so we can bsearch() later */
1234  qsort(snap->subxip, snap->subxcnt, sizeof(TransactionId), xidComparator);
1235 
1236  /* store the specified current CommandId */
1237  snap->curcid = cid;
1238 
1239  return snap;
1240 }
1241 
1242 /*
1243  * Free a previously ReorderBufferCopySnap'ed snapshot
1244  */
1245 static void
1247 {
1248  if (snap->copied)
1249  pfree(snap);
1250  else
1252 }
1253 
1254 /*
1255  * Perform the replay of a transaction and it's non-aborted subtransactions.
1256  *
1257  * Subtransactions previously have to be processed by
1258  * ReorderBufferCommitChild(), even if previously assigned to the toplevel
1259  * transaction with ReorderBufferAssignChild.
1260  *
1261  * We currently can only decode a transaction's contents in when their commit
1262  * record is read because that's currently the only place where we know about
1263  * cache invalidations. Thus, once a toplevel commit is read, we iterate over
1264  * the top and subtransactions (using a k-way merge) and replay the changes in
1265  * lsn order.
1266  */
1267 void
1269  XLogRecPtr commit_lsn, XLogRecPtr end_lsn,
1270  TimestampTz commit_time,
1271  RepOriginId origin_id, XLogRecPtr origin_lsn)
1272 {
1274  volatile Snapshot snapshot_now;
1275  volatile CommandId command_id = FirstCommandId;
1276  bool using_subtxn;
1277  ReorderBufferIterTXNState *volatile iterstate = NULL;
1278 
1279  txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
1280  false);
1281 
1282  /* unknown transaction, nothing to replay */
1283  if (txn == NULL)
1284  return;
1285 
1286  txn->final_lsn = commit_lsn;
1287  txn->end_lsn = end_lsn;
1288  txn->commit_time = commit_time;
1289  txn->origin_id = origin_id;
1290  txn->origin_lsn = origin_lsn;
1291 
1292  /*
1293  * If this transaction didn't have any real changes in our database, it's
1294  * OK not to have a snapshot. Note that ReorderBufferCommitChild will have
1295  * transferred its snapshot to this transaction if it had one and the
1296  * toplevel tx didn't.
1297  */
1298  if (txn->base_snapshot == NULL)
1299  {
1300  Assert(txn->ninvalidations == 0);
1301  ReorderBufferCleanupTXN(rb, txn);
1302  return;
1303  }
1304 
1305  snapshot_now = txn->base_snapshot;
1306 
1307  /* build data to be able to lookup the CommandIds of catalog tuples */
1309 
1310  /* setup the initial snapshot */
1311  SetupHistoricSnapshot(snapshot_now, txn->tuplecid_hash);
1312 
1313  /*
1314  * Decoding needs access to syscaches et al., which in turn use
1315  * heavyweight locks and such. Thus we need to have enough state around to
1316  * keep track of those. The easiest way is to simply use a transaction
1317  * internally. That also allows us to easily enforce that nothing writes
1318  * to the database by checking for xid assignments.
1319  *
1320  * When we're called via the SQL SRF there's already a transaction
1321  * started, so start an explicit subtransaction there.
1322  */
1323  using_subtxn = IsTransactionOrTransactionBlock();
1324 
1325  PG_TRY();
1326  {
1327  ReorderBufferChange *change;
1328  ReorderBufferChange *specinsert = NULL;
1329 
1330  if (using_subtxn)
1331  BeginInternalSubTransaction("replay");
1332  else
1334 
1335  rb->begin(rb, txn);
1336 
1337  iterstate = ReorderBufferIterTXNInit(rb, txn);
1338  while ((change = ReorderBufferIterTXNNext(rb, iterstate)) != NULL)
1339  {
1340  Relation relation = NULL;
1341  Oid reloid;
1342 
1343  switch (change->action)
1344  {
1346 
1347  /*
1348  * Confirmation for speculative insertion arrived. Simply
1349  * use as a normal record. It'll be cleaned up at the end
1350  * of INSERT processing.
1351  */
1352  Assert(specinsert->data.tp.oldtuple == NULL);
1353  change = specinsert;
1355 
1356  /* intentionally fall through */
1360  Assert(snapshot_now);
1361 
1362  reloid = RelidByRelfilenode(change->data.tp.relnode.spcNode,
1363  change->data.tp.relnode.relNode);
1364 
1365  /*
1366  * Catalog tuple without data, emitted while catalog was
1367  * in the process of being rewritten.
1368  */
1369  if (reloid == InvalidOid &&
1370  change->data.tp.newtuple == NULL &&
1371  change->data.tp.oldtuple == NULL)
1372  goto change_done;
1373  else if (reloid == InvalidOid)
1374  elog(ERROR, "could not map filenode \"%s\" to relation OID",
1375  relpathperm(change->data.tp.relnode,
1376  MAIN_FORKNUM));
1377 
1378  relation = RelationIdGetRelation(reloid);
1379 
1380  if (relation == NULL)
1381  elog(ERROR, "could not open relation with OID %u (for filenode \"%s\")",
1382  reloid,
1383  relpathperm(change->data.tp.relnode,
1384  MAIN_FORKNUM));
1385 
1386  if (!RelationIsLogicallyLogged(relation))
1387  goto change_done;
1388 
1389  /*
1390  * For now ignore sequence changes entirely. Most of the
1391  * time they don't log changes using records we
1392  * understand, so it doesn't make sense to handle the few
1393  * cases we do.
1394  */
1395  if (relation->rd_rel->relkind == RELKIND_SEQUENCE)
1396  goto change_done;
1397 
1398  /* user-triggered change */
1399  if (!IsToastRelation(relation))
1400  {
1401  ReorderBufferToastReplace(rb, txn, relation, change);
1402  rb->apply_change(rb, txn, relation, change);
1403 
1404  /*
1405  * Only clear reassembled toast chunks if we're sure
1406  * they're not required anymore. The creator of the
1407  * tuple tells us.
1408  */
1409  if (change->data.tp.clear_toast_afterwards)
1410  ReorderBufferToastReset(rb, txn);
1411  }
1412  /* we're not interested in toast deletions */
1413  else if (change->action == REORDER_BUFFER_CHANGE_INSERT)
1414  {
1415  /*
1416  * Need to reassemble the full toasted Datum in
1417  * memory, to ensure the chunks don't get reused till
1418  * we're done remove it from the list of this
1419  * transaction's changes. Otherwise it will get
1420  * freed/reused while restoring spooled data from
1421  * disk.
1422  */
1423  dlist_delete(&change->node);
1424  ReorderBufferToastAppendChunk(rb, txn, relation,
1425  change);
1426  }
1427 
1428  change_done:
1429 
1430  /*
1431  * Either speculative insertion was confirmed, or it was
1432  * unsuccessful and the record isn't needed anymore.
1433  */
1434  if (specinsert != NULL)
1435  {
1436  ReorderBufferReturnChange(rb, specinsert);
1437  specinsert = NULL;
1438  }
1439 
1440  if (relation != NULL)
1441  {
1442  RelationClose(relation);
1443  relation = NULL;
1444  }
1445  break;
1446 
1448 
1449  /*
1450  * Speculative insertions are dealt with by delaying the
1451  * processing of the insert until the confirmation record
1452  * arrives. For that we simply unlink the record from the
1453  * chain, so it does not get freed/reused while restoring
1454  * spooled data from disk.
1455  *
1456  * This is safe in the face of concurrent catalog changes
1457  * because the relevant relation can't be changed between
1458  * speculative insertion and confirmation due to
1459  * CheckTableNotInUse() and locking.
1460  */
1461 
1462  /* clear out a pending (and thus failed) speculation */
1463  if (specinsert != NULL)
1464  {
1465  ReorderBufferReturnChange(rb, specinsert);
1466  specinsert = NULL;
1467  }
1468 
1469  /* and memorize the pending insertion */
1470  dlist_delete(&change->node);
1471  specinsert = change;
1472  break;
1473 
1475  rb->message(rb, txn, change->lsn, true,
1476  change->data.msg.prefix,
1477  change->data.msg.message_size,
1478  change->data.msg.message);
1479  break;
1480 
1482  /* get rid of the old */
1483  TeardownHistoricSnapshot(false);
1484 
1485  if (snapshot_now->copied)
1486  {
1487  ReorderBufferFreeSnap(rb, snapshot_now);
1488  snapshot_now =
1489  ReorderBufferCopySnap(rb, change->data.snapshot,
1490  txn, command_id);
1491  }
1492 
1493  /*
1494  * Restored from disk, need to be careful not to double
1495  * free. We could introduce refcounting for that, but for
1496  * now this seems infrequent enough not to care.
1497  */
1498  else if (change->data.snapshot->copied)
1499  {
1500  snapshot_now =
1501  ReorderBufferCopySnap(rb, change->data.snapshot,
1502  txn, command_id);
1503  }
1504  else
1505  {
1506  snapshot_now = change->data.snapshot;
1507  }
1508 
1509 
1510  /* and continue with the new one */
1511  SetupHistoricSnapshot(snapshot_now, txn->tuplecid_hash);
1512  break;
1513 
1515  Assert(change->data.command_id != InvalidCommandId);
1516 
1517  if (command_id < change->data.command_id)
1518  {
1519  command_id = change->data.command_id;
1520 
1521  if (!snapshot_now->copied)
1522  {
1523  /* we don't use the global one anymore */
1524  snapshot_now = ReorderBufferCopySnap(rb, snapshot_now,
1525  txn, command_id);
1526  }
1527 
1528  snapshot_now->curcid = command_id;
1529 
1530  TeardownHistoricSnapshot(false);
1531  SetupHistoricSnapshot(snapshot_now, txn->tuplecid_hash);
1532 
1533  /*
1534  * Every time the CommandId is incremented, we could
1535  * see new catalog contents, so execute all
1536  * invalidations.
1537  */
1539  }
1540 
1541  break;
1542 
1544  elog(ERROR, "tuplecid value in changequeue");
1545  break;
1546  }
1547  }
1548 
1549  /*
1550  * There's a speculative insertion remaining, just clean in up, it
1551  * can't have been successful, otherwise we'd gotten a confirmation
1552  * record.
1553  */
1554  if (specinsert)
1555  {
1556  ReorderBufferReturnChange(rb, specinsert);
1557  specinsert = NULL;
1558  }
1559 
1560  /* clean up the iterator */
1561  ReorderBufferIterTXNFinish(rb, iterstate);
1562  iterstate = NULL;
1563 
1564  /* call commit callback */
1565  rb->commit(rb, txn, commit_lsn);
1566 
1567  /* this is just a sanity check against bad output plugin behaviour */
1569  elog(ERROR, "output plugin used XID %u",
1571 
1572  /* cleanup */
1573  TeardownHistoricSnapshot(false);
1574 
1575  /*
1576  * Aborting the current (sub-)transaction as a whole has the right
1577  * semantics. We want all locks acquired in here to be released, not
1578  * reassigned to the parent and we do not want any database access
1579  * have persistent effects.
1580  */
1582 
1583  /* make sure there's no cache pollution */
1585 
1586  if (using_subtxn)
1588 
1589  if (snapshot_now->copied)
1590  ReorderBufferFreeSnap(rb, snapshot_now);
1591 
1592  /* remove potential on-disk data, and deallocate */
1593  ReorderBufferCleanupTXN(rb, txn);
1594  }
1595  PG_CATCH();
1596  {
1597  /* TODO: Encapsulate cleanup from the PG_TRY and PG_CATCH blocks */
1598  if (iterstate)
1599  ReorderBufferIterTXNFinish(rb, iterstate);
1600 
1602 
1603  /*
1604  * Force cache invalidation to happen outside of a valid transaction
1605  * to prevent catalog access as we just caught an error.
1606  */
1608 
1609  /* make sure there's no cache pollution */
1611 
1612  if (using_subtxn)
1614 
1615  if (snapshot_now->copied)
1616  ReorderBufferFreeSnap(rb, snapshot_now);
1617 
1618  /* remove potential on-disk data, and deallocate */
1619  ReorderBufferCleanupTXN(rb, txn);
1620 
1621  PG_RE_THROW();
1622  }
1623  PG_END_TRY();
1624 }
1625 
1626 /*
1627  * Abort a transaction that possibly has previous changes. Needs to be first
1628  * called for subtransactions and then for the toplevel xid.
1629  *
1630  * NB: Transactions handled here have to have actively aborted (i.e. have
1631  * produced an abort record). Implicitly aborted transactions are handled via
1632  * ReorderBufferAbortOld(); transactions we're just not interested in, but
1633  * which have committed are handled in ReorderBufferForget().
1634  *
1635  * This function purges this transaction and its contents from memory and
1636  * disk.
1637  */
1638 void
1640 {
1642 
1643  txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
1644  false);
1645 
1646  /* unknown, nothing to remove */
1647  if (txn == NULL)
1648  return;
1649 
1650  /* cosmetic... */
1651  txn->final_lsn = lsn;
1652 
1653  /* remove potential on-disk data, and deallocate */
1654  ReorderBufferCleanupTXN(rb, txn);
1655 }
1656 
1657 /*
1658  * Abort all transactions that aren't actually running anymore because the
1659  * server restarted.
1660  *
1661  * NB: These really have to be transactions that have aborted due to a server
1662  * crash/immediate restart, as we don't deal with invalidations here.
1663  */
1664 void
1666 {
1667  dlist_mutable_iter it;
1668 
1669  /*
1670  * Iterate through all (potential) toplevel TXNs and abort all that are
1671  * older than what possibly can be running. Once we've found the first
1672  * that is alive we stop, there might be some that acquired an xid earlier
1673  * but started writing later, but it's unlikely and they will be cleaned
1674  * up in a later call to this function.
1675  */
1677  {
1679 
1680  txn = dlist_container(ReorderBufferTXN, node, it.cur);
1681 
1682  if (TransactionIdPrecedes(txn->xid, oldestRunningXid))
1683  {
1684  /*
1685  * We set final_lsn on a transaction when we decode its commit or
1686  * abort record, but we never see those records for crashed
1687  * transactions. To ensure cleanup of these transactions, set
1688  * final_lsn to that of their last change; this causes
1689  * ReorderBufferRestoreCleanup to do the right thing.
1690  */
1691  if (txn->serialized && txn->final_lsn == 0)
1692  {
1693  ReorderBufferChange *last =
1695 
1696  txn->final_lsn = last->lsn;
1697  }
1698 
1699  elog(DEBUG2, "aborting old transaction %u", txn->xid);
1700 
1701  /* remove potential on-disk data, and deallocate this tx */
1702  ReorderBufferCleanupTXN(rb, txn);
1703  }
1704  else
1705  return;
1706  }
1707 }
1708 
1709 /*
1710  * Forget the contents of a transaction if we aren't interested in it's
1711  * contents. Needs to be first called for subtransactions and then for the
1712  * toplevel xid.
1713  *
1714  * This is significantly different to ReorderBufferAbort() because
1715  * transactions that have committed need to be treated differently from aborted
1716  * ones since they may have modified the catalog.
1717  *
1718  * Note that this is only allowed to be called in the moment a transaction
1719  * commit has just been read, not earlier; otherwise later records referring
1720  * to this xid might re-create the transaction incompletely.
1721  */
1722 void
1724 {
1726 
1727  txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
1728  false);
1729 
1730  /* unknown, nothing to forget */
1731  if (txn == NULL)
1732  return;
1733 
1734  /* cosmetic... */
1735  txn->final_lsn = lsn;
1736 
1737  /*
1738  * Process cache invalidation messages if there are any. Even if we're not
1739  * interested in the transaction's contents, it could have manipulated the
1740  * catalog and we need to update the caches according to that.
1741  */
1742  if (txn->base_snapshot != NULL && txn->ninvalidations > 0)
1744  txn->invalidations);
1745  else
1746  Assert(txn->ninvalidations == 0);
1747 
1748  /* remove potential on-disk data, and deallocate */
1749  ReorderBufferCleanupTXN(rb, txn);
1750 }
1751 
1752 /*
1753  * Execute invalidations happening outside the context of a decoded
1754  * transaction. That currently happens either for xid-less commits
1755  * (cf. RecordTransactionCommit()) or for invalidations in uninteresting
1756  * transactions (via ReorderBufferForget()).
1757  */
1758 void
1760  SharedInvalidationMessage *invalidations)
1761 {
1762  bool use_subtxn = IsTransactionOrTransactionBlock();
1763  int i;
1764 
1765  if (use_subtxn)
1766  BeginInternalSubTransaction("replay");
1767 
1768  /*
1769  * Force invalidations to happen outside of a valid transaction - that way
1770  * entries will just be marked as invalid without accessing the catalog.
1771  * That's advantageous because we don't need to setup the full state
1772  * necessary for catalog access.
1773  */
1774  if (use_subtxn)
1776 
1777  for (i = 0; i < ninvalidations; i++)
1778  LocalExecuteInvalidationMessage(&invalidations[i]);
1779 
1780  if (use_subtxn)
1782 }
1783 
1784 /*
1785  * Tell reorderbuffer about an xid seen in the WAL stream. Has to be called at
1786  * least once for every xid in XLogRecord->xl_xid (other places in records
1787  * may, but do not have to be passed through here).
1788  *
1789  * Reorderbuffer keeps some datastructures about transactions in LSN order,
1790  * for efficiency. To do that it has to know about when transactions are seen
1791  * first in the WAL. As many types of records are not actually interesting for
1792  * logical decoding, they do not necessarily pass though here.
1793  */
1794 void
1796 {
1797  /* many records won't have an xid assigned, centralize check here */
1798  if (xid != InvalidTransactionId)
1799  ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
1800 }
1801 
1802 /*
1803  * Add a new snapshot to this transaction that may only used after lsn 'lsn'
1804  * because the previous snapshot doesn't describe the catalog correctly for
1805  * following rows.
1806  */
1807 void
1809  XLogRecPtr lsn, Snapshot snap)
1810 {
1812 
1813  change->data.snapshot = snap;
1815 
1816  ReorderBufferQueueChange(rb, xid, lsn, change);
1817 }
1818 
1819 /*
1820  * Setup the base snapshot of a transaction. The base snapshot is the snapshot
1821  * that is used to decode all changes until either this transaction modifies
1822  * the catalog or another catalog modifying transaction commits.
1823  *
1824  * Needs to be called before any changes are added with
1825  * ReorderBufferQueueChange().
1826  */
1827 void
1829  XLogRecPtr lsn, Snapshot snap)
1830 {
1832  bool is_new;
1833 
1834  txn = ReorderBufferTXNByXid(rb, xid, true, &is_new, lsn, true);
1835  Assert(txn->base_snapshot == NULL);
1836  Assert(snap != NULL);
1837 
1838  txn->base_snapshot = snap;
1839  txn->base_snapshot_lsn = lsn;
1840 }
1841 
1842 /*
1843  * Access the catalog with this CommandId at this point in the changestream.
1844  *
1845  * May only be called for command ids > 1
1846  */
1847 void
1849  XLogRecPtr lsn, CommandId cid)
1850 {
1852 
1853  change->data.command_id = cid;
1855 
1856  ReorderBufferQueueChange(rb, xid, lsn, change);
1857 }
1858 
1859 
1860 /*
1861  * Add new (relfilenode, tid) -> (cmin, cmax) mappings.
1862  */
1863 void
1865  XLogRecPtr lsn, RelFileNode node,
1866  ItemPointerData tid, CommandId cmin,
1867  CommandId cmax, CommandId combocid)
1868 {
1871 
1872  txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
1873 
1874  change->data.tuplecid.node = node;
1875  change->data.tuplecid.tid = tid;
1876  change->data.tuplecid.cmin = cmin;
1877  change->data.tuplecid.cmax = cmax;
1878  change->data.tuplecid.combocid = combocid;
1879  change->lsn = lsn;
1881 
1882  dlist_push_tail(&txn->tuplecids, &change->node);
1883  txn->ntuplecids++;
1884 }
1885 
1886 /*
1887  * Setup the invalidation of the toplevel transaction.
1888  *
1889  * This needs to be done before ReorderBufferCommit is called!
1890  */
1891 void
1893  XLogRecPtr lsn, Size nmsgs,
1895 {
1897 
1898  txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
1899 
1900  if (txn->ninvalidations != 0)
1901  elog(ERROR, "only ever add one set of invalidations");
1902 
1903  Assert(nmsgs > 0);
1904 
1905  txn->ninvalidations = nmsgs;
1908  sizeof(SharedInvalidationMessage) * nmsgs);
1909  memcpy(txn->invalidations, msgs,
1910  sizeof(SharedInvalidationMessage) * nmsgs);
1911 }
1912 
1913 /*
1914  * Apply all invalidations we know. Possibly we only need parts at this point
1915  * in the changestream but we don't know which those are.
1916  */
1917 static void
1919 {
1920  int i;
1921 
1922  for (i = 0; i < txn->ninvalidations; i++)
1924 }
1925 
1926 /*
1927  * Mark a transaction as containing catalog changes
1928  */
1929 void
1931  XLogRecPtr lsn)
1932 {
1934 
1935  txn = ReorderBufferTXNByXid(rb, xid, true, NULL, lsn, true);
1936 
1937  txn->has_catalog_changes = true;
1938 }
1939 
1940 /*
1941  * Query whether a transaction is already *known* to contain catalog
1942  * changes. This can be wrong until directly before the commit!
1943  */
1944 bool
1946 {
1948 
1949  txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
1950  false);
1951  if (txn == NULL)
1952  return false;
1953 
1954  return txn->has_catalog_changes;
1955 }
1956 
1957 /*
1958  * Have we already added the first snapshot?
1959  */
1960 bool
1962 {
1964 
1965  txn = ReorderBufferTXNByXid(rb, xid, false, NULL, InvalidXLogRecPtr,
1966  false);
1967 
1968  /* transaction isn't known yet, ergo no snapshot */
1969  if (txn == NULL)
1970  return false;
1971 
1972  /*
1973  * TODO: It would be a nice improvement if we would check the toplevel
1974  * transaction in subtransactions, but we'd need to keep track of a bit
1975  * more state.
1976  */
1977  return txn->base_snapshot != NULL;
1978 }
1979 
1980 
1981 /*
1982  * ---------------------------------------
1983  * Disk serialization support
1984  * ---------------------------------------
1985  */
1986 
1987 /*
1988  * Ensure the IO buffer is >= sz.
1989  */
1990 static void
1992 {
1993  if (!rb->outbufsize)
1994  {
1995  rb->outbuf = MemoryContextAlloc(rb->context, sz);
1996  rb->outbufsize = sz;
1997  }
1998  else if (rb->outbufsize < sz)
1999  {
2000  rb->outbuf = repalloc(rb->outbuf, sz);
2001  rb->outbufsize = sz;
2002  }
2003 }
2004 
2005 /*
2006  * Check whether the transaction tx should spill its data to disk.
2007  */
2008 static void
2010 {
2011  /*
2012  * TODO: improve accounting so we cheaply can take subtransactions into
2013  * account here.
2014  */
2015  if (txn->nentries_mem >= max_changes_in_memory)
2016  {
2017  ReorderBufferSerializeTXN(rb, txn);
2018  Assert(txn->nentries_mem == 0);
2019  }
2020 }
2021 
2022 /*
2023  * Spill data of a large transaction (and its subtransactions) to disk.
2024  */
2025 static void
2027 {
2028  dlist_iter subtxn_i;
2029  dlist_mutable_iter change_i;
2030  int fd = -1;
2031  XLogSegNo curOpenSegNo = 0;
2032  Size spilled = 0;
2033  char path[MAXPGPATH];
2034 
2035  elog(DEBUG2, "spill %u changes in XID %u to disk",
2036  (uint32) txn->nentries_mem, txn->xid);
2037 
2038  /* do the same to all child TXs */
2039  dlist_foreach(subtxn_i, &txn->subtxns)
2040  {
2041  ReorderBufferTXN *subtxn;
2042 
2043  subtxn = dlist_container(ReorderBufferTXN, node, subtxn_i.cur);
2044  ReorderBufferSerializeTXN(rb, subtxn);
2045  }
2046 
2047  /* serialize changestream */
2048  dlist_foreach_modify(change_i, &txn->changes)
2049  {
2050  ReorderBufferChange *change;
2051 
2052  change = dlist_container(ReorderBufferChange, node, change_i.cur);
2053 
2054  /*
2055  * store in segment in which it belongs by start lsn, don't split over
2056  * multiple segments tho
2057  */
2058  if (fd == -1 ||
2059  !XLByteInSeg(change->lsn, curOpenSegNo, wal_segment_size))
2060  {
2061  XLogRecPtr recptr;
2062 
2063  if (fd != -1)
2064  CloseTransientFile(fd);
2065 
2066  XLByteToSeg(change->lsn, curOpenSegNo, wal_segment_size);
2067  XLogSegNoOffsetToRecPtr(curOpenSegNo, 0, recptr, wal_segment_size);
2068 
2069  /*
2070  * No need to care about TLIs here, only used during a single run,
2071  * so each LSN only maps to a specific WAL record.
2072  */
2073  sprintf(path, "pg_replslot/%s/xid-%u-lsn-%X-%X.snap",
2075  (uint32) (recptr >> 32), (uint32) recptr);
2076 
2077  /* open segment, create it if necessary */
2078  fd = OpenTransientFile(path,
2079  O_CREAT | O_WRONLY | O_APPEND | PG_BINARY);
2080 
2081  if (fd < 0)
2082  ereport(ERROR,
2084  errmsg("could not open file \"%s\": %m",
2085  path)));
2086  }
2087 
2088  ReorderBufferSerializeChange(rb, txn, fd, change);
2089  dlist_delete(&change->node);
2090  ReorderBufferReturnChange(rb, change);
2091 
2092  spilled++;
2093  }
2094 
2095  Assert(spilled == txn->nentries_mem);
2096  Assert(dlist_is_empty(&txn->changes));
2097  txn->nentries_mem = 0;
2098  txn->serialized = true;
2099 
2100  if (fd != -1)
2101  CloseTransientFile(fd);
2102 }
2103 
2104 /*
2105  * Serialize individual change to disk.
2106  */
2107 static void
2109  int fd, ReorderBufferChange *change)
2110 {
2111  ReorderBufferDiskChange *ondisk;
2112  Size sz = sizeof(ReorderBufferDiskChange);
2113 
2115 
2116  ondisk = (ReorderBufferDiskChange *) rb->outbuf;
2117  memcpy(&ondisk->change, change, sizeof(ReorderBufferChange));
2118 
2119  switch (change->action)
2120  {
2121  /* fall through these, they're all similar enough */
2126  {
2127  char *data;
2128  ReorderBufferTupleBuf *oldtup,
2129  *newtup;
2130  Size oldlen = 0;
2131  Size newlen = 0;
2132 
2133  oldtup = change->data.tp.oldtuple;
2134  newtup = change->data.tp.newtuple;
2135 
2136  if (oldtup)
2137  {
2138  sz += sizeof(HeapTupleData);
2139  oldlen = oldtup->tuple.t_len;
2140  sz += oldlen;
2141  }
2142 
2143  if (newtup)
2144  {
2145  sz += sizeof(HeapTupleData);
2146  newlen = newtup->tuple.t_len;
2147  sz += newlen;
2148  }
2149 
2150  /* make sure we have enough space */
2152 
2153  data = ((char *) rb->outbuf) + sizeof(ReorderBufferDiskChange);
2154  /* might have been reallocated above */
2155  ondisk = (ReorderBufferDiskChange *) rb->outbuf;
2156 
2157  if (oldlen)
2158  {
2159  memcpy(data, &oldtup->tuple, sizeof(HeapTupleData));
2160  data += sizeof(HeapTupleData);
2161 
2162  memcpy(data, oldtup->tuple.t_data, oldlen);
2163  data += oldlen;
2164  }
2165 
2166  if (newlen)
2167  {
2168  memcpy(data, &newtup->tuple, sizeof(HeapTupleData));
2169  data += sizeof(HeapTupleData);
2170 
2171  memcpy(data, newtup->tuple.t_data, newlen);
2172  data += newlen;
2173  }
2174  break;
2175  }
2177  {
2178  char *data;
2179  Size prefix_size = strlen(change->data.msg.prefix) + 1;
2180 
2181  sz += prefix_size + change->data.msg.message_size +
2182  sizeof(Size) + sizeof(Size);
2184 
2185  data = ((char *) rb->outbuf) + sizeof(ReorderBufferDiskChange);
2186 
2187  /* might have been reallocated above */
2188  ondisk = (ReorderBufferDiskChange *) rb->outbuf;
2189 
2190  /* write the prefix including the size */
2191  memcpy(data, &prefix_size, sizeof(Size));
2192  data += sizeof(Size);
2193  memcpy(data, change->data.msg.prefix,
2194  prefix_size);
2195  data += prefix_size;
2196 
2197  /* write the message including the size */
2198  memcpy(data, &change->data.msg.message_size, sizeof(Size));
2199  data += sizeof(Size);
2200  memcpy(data, change->data.msg.message,
2201  change->data.msg.message_size);
2202  data += change->data.msg.message_size;
2203 
2204  break;
2205  }
2207  {
2208  Snapshot snap;
2209  char *data;
2210 
2211  snap = change->data.snapshot;
2212 
2213  sz += sizeof(SnapshotData) +
2214  sizeof(TransactionId) * snap->xcnt +
2215  sizeof(TransactionId) * snap->subxcnt
2216  ;
2217 
2218  /* make sure we have enough space */
2220  data = ((char *) rb->outbuf) + sizeof(ReorderBufferDiskChange);
2221  /* might have been reallocated above */
2222  ondisk = (ReorderBufferDiskChange *) rb->outbuf;
2223 
2224  memcpy(data, snap, sizeof(SnapshotData));
2225  data += sizeof(SnapshotData);
2226 
2227  if (snap->xcnt)
2228  {
2229  memcpy(data, snap->xip,
2230  sizeof(TransactionId) * snap->xcnt);
2231  data += sizeof(TransactionId) * snap->xcnt;
2232  }
2233 
2234  if (snap->subxcnt)
2235  {
2236  memcpy(data, snap->subxip,
2237  sizeof(TransactionId) * snap->subxcnt);
2238  data += sizeof(TransactionId) * snap->subxcnt;
2239  }
2240  break;
2241  }
2245  /* ReorderBufferChange contains everything important */
2246  break;
2247  }
2248 
2249  ondisk->size = sz;
2250 
2252  if (write(fd, rb->outbuf, ondisk->size) != ondisk->size)
2253  {
2254  int save_errno = errno;
2255 
2256  CloseTransientFile(fd);
2257  errno = save_errno;
2258  ereport(ERROR,
2260  errmsg("could not write to data file for XID %u: %m",
2261  txn->xid)));
2262  }
2264 
2265  Assert(ondisk->change.action == change->action);
2266 }
2267 
2268 /*
2269  * Restore a number of changes spilled to disk back into memory.
2270  */
2271 static Size
2273  int *fd, XLogSegNo *segno)
2274 {
2275  Size restored = 0;
2276  XLogSegNo last_segno;
2277  dlist_mutable_iter cleanup_iter;
2278 
2281 
2282  /* free current entries, so we have memory for more */
2283  dlist_foreach_modify(cleanup_iter, &txn->changes)
2284  {
2286  dlist_container(ReorderBufferChange, node, cleanup_iter.cur);
2287 
2288  dlist_delete(&cleanup->node);
2289  ReorderBufferReturnChange(rb, cleanup);
2290  }
2291  txn->nentries_mem = 0;
2292  Assert(dlist_is_empty(&txn->changes));
2293 
2294  XLByteToSeg(txn->final_lsn, last_segno, wal_segment_size);
2295 
2296  while (restored < max_changes_in_memory && *segno <= last_segno)
2297  {
2298  int readBytes;
2299  ReorderBufferDiskChange *ondisk;
2300 
2301  if (*fd == -1)
2302  {
2303  XLogRecPtr recptr;
2304  char path[MAXPGPATH];
2305 
2306  /* first time in */
2307  if (*segno == 0)
2308  {
2309  XLByteToSeg(txn->first_lsn, *segno, wal_segment_size);
2310  }
2311 
2312  Assert(*segno != 0 || dlist_is_empty(&txn->changes));
2313  XLogSegNoOffsetToRecPtr(*segno, 0, recptr, wal_segment_size);
2314 
2315  /*
2316  * No need to care about TLIs here, only used during a single run,
2317  * so each LSN only maps to a specific WAL record.
2318  */
2319  sprintf(path, "pg_replslot/%s/xid-%u-lsn-%X-%X.snap",
2321  (uint32) (recptr >> 32), (uint32) recptr);
2322 
2323  *fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
2324  if (*fd < 0 && errno == ENOENT)
2325  {
2326  *fd = -1;
2327  (*segno)++;
2328  continue;
2329  }
2330  else if (*fd < 0)
2331  ereport(ERROR,
2333  errmsg("could not open file \"%s\": %m",
2334  path)));
2335 
2336  }
2337 
2338  /*
2339  * Read the statically sized part of a change which has information
2340  * about the total size. If we couldn't read a record, we're at the
2341  * end of this file.
2342  */
2345  readBytes = read(*fd, rb->outbuf, sizeof(ReorderBufferDiskChange));
2347 
2348  /* eof */
2349  if (readBytes == 0)
2350  {
2351  CloseTransientFile(*fd);
2352  *fd = -1;
2353  (*segno)++;
2354  continue;
2355  }
2356  else if (readBytes < 0)
2357  ereport(ERROR,
2359  errmsg("could not read from reorderbuffer spill file: %m")));
2360  else if (readBytes != sizeof(ReorderBufferDiskChange))
2361  ereport(ERROR,
2363  errmsg("could not read from reorderbuffer spill file: read %d instead of %u bytes",
2364  readBytes,
2365  (uint32) sizeof(ReorderBufferDiskChange))));
2366 
2367  ondisk = (ReorderBufferDiskChange *) rb->outbuf;
2368 
2370  sizeof(ReorderBufferDiskChange) + ondisk->size);
2371  ondisk = (ReorderBufferDiskChange *) rb->outbuf;
2372 
2374  readBytes = read(*fd, rb->outbuf + sizeof(ReorderBufferDiskChange),
2375  ondisk->size - sizeof(ReorderBufferDiskChange));
2377 
2378  if (readBytes < 0)
2379  ereport(ERROR,
2381  errmsg("could not read from reorderbuffer spill file: %m")));
2382  else if (readBytes != ondisk->size - sizeof(ReorderBufferDiskChange))
2383  ereport(ERROR,
2385  errmsg("could not read from reorderbuffer spill file: read %d instead of %u bytes",
2386  readBytes,
2387  (uint32) (ondisk->size - sizeof(ReorderBufferDiskChange)))));
2388 
2389  /*
2390  * ok, read a full change from disk, now restore it into proper
2391  * in-memory format
2392  */
2393  ReorderBufferRestoreChange(rb, txn, rb->outbuf);
2394  restored++;
2395  }
2396 
2397  return restored;
2398 }
2399 
2400 /*
2401  * Convert change from its on-disk format to in-memory format and queue it onto
2402  * the TXN's ->changes list.
2403  *
2404  * Note: although "data" is declared char*, at entry it points to a
2405  * maxalign'd buffer, making it safe in most of this function to assume
2406  * that the pointed-to data is suitably aligned for direct access.
2407  */
2408 static void
2410  char *data)
2411 {
2412  ReorderBufferDiskChange *ondisk;
2413  ReorderBufferChange *change;
2414 
2415  ondisk = (ReorderBufferDiskChange *) data;
2416 
2417  change = ReorderBufferGetChange(rb);
2418 
2419  /* copy static part */
2420  memcpy(change, &ondisk->change, sizeof(ReorderBufferChange));
2421 
2422  data += sizeof(ReorderBufferDiskChange);
2423 
2424  /* restore individual stuff */
2425  switch (change->action)
2426  {
2427  /* fall through these, they're all similar enough */
2432  if (change->data.tp.oldtuple)
2433  {
2434  uint32 tuplelen = ((HeapTuple) data)->t_len;
2435 
2436  change->data.tp.oldtuple =
2438 
2439  /* restore ->tuple */
2440  memcpy(&change->data.tp.oldtuple->tuple, data,
2441  sizeof(HeapTupleData));
2442  data += sizeof(HeapTupleData);
2443 
2444  /* reset t_data pointer into the new tuplebuf */
2445  change->data.tp.oldtuple->tuple.t_data =
2446  ReorderBufferTupleBufData(change->data.tp.oldtuple);
2447 
2448  /* restore tuple data itself */
2449  memcpy(change->data.tp.oldtuple->tuple.t_data, data, tuplelen);
2450  data += tuplelen;
2451  }
2452 
2453  if (change->data.tp.newtuple)
2454  {
2455  /* here, data might not be suitably aligned! */
2456  uint32 tuplelen;
2457 
2458  memcpy(&tuplelen, data + offsetof(HeapTupleData, t_len),
2459  sizeof(uint32));
2460 
2461  change->data.tp.newtuple =
2463 
2464  /* restore ->tuple */
2465  memcpy(&change->data.tp.newtuple->tuple, data,
2466  sizeof(HeapTupleData));
2467  data += sizeof(HeapTupleData);
2468 
2469  /* reset t_data pointer into the new tuplebuf */
2470  change->data.tp.newtuple->tuple.t_data =
2471  ReorderBufferTupleBufData(change->data.tp.newtuple);
2472 
2473  /* restore tuple data itself */
2474  memcpy(change->data.tp.newtuple->tuple.t_data, data, tuplelen);
2475  data += tuplelen;
2476  }
2477 
2478  break;
2480  {
2481  Size prefix_size;
2482 
2483  /* read prefix */
2484  memcpy(&prefix_size, data, sizeof(Size));
2485  data += sizeof(Size);
2486  change->data.msg.prefix = MemoryContextAlloc(rb->context,
2487  prefix_size);
2488  memcpy(change->data.msg.prefix, data, prefix_size);
2489  Assert(change->data.msg.prefix[prefix_size - 1] == '\0');
2490  data += prefix_size;
2491 
2492  /* read the message */
2493  memcpy(&change->data.msg.message_size, data, sizeof(Size));
2494  data += sizeof(Size);
2495  change->data.msg.message = MemoryContextAlloc(rb->context,
2496  change->data.msg.message_size);
2497  memcpy(change->data.msg.message, data,
2498  change->data.msg.message_size);
2499  data += change->data.msg.message_size;
2500 
2501  break;
2502  }
2504  {
2505  Snapshot oldsnap;
2506  Snapshot newsnap;
2507  Size size;
2508 
2509  oldsnap = (Snapshot) data;
2510 
2511  size = sizeof(SnapshotData) +
2512  sizeof(TransactionId) * oldsnap->xcnt +
2513  sizeof(TransactionId) * (oldsnap->subxcnt + 0);
2514 
2515  change->data.snapshot = MemoryContextAllocZero(rb->context, size);
2516 
2517  newsnap = change->data.snapshot;
2518 
2519  memcpy(newsnap, data, size);
2520  newsnap->xip = (TransactionId *)
2521  (((char *) newsnap) + sizeof(SnapshotData));
2522  newsnap->subxip = newsnap->xip + newsnap->xcnt;
2523  newsnap->copied = true;
2524  break;
2525  }
2526  /* the base struct contains all the data, easy peasy */
2530  break;
2531  }
2532 
2533  dlist_push_tail(&txn->changes, &change->node);
2534  txn->nentries_mem++;
2535 }
2536 
2537 /*
2538  * Remove all on-disk stored for the passed in transaction.
2539  */
2540 static void
2542 {
2543  XLogSegNo first;
2544  XLogSegNo cur;
2545  XLogSegNo last;
2546 
2549 
2550  XLByteToSeg(txn->first_lsn, first, wal_segment_size);
2551  XLByteToSeg(txn->final_lsn, last, wal_segment_size);
2552 
2553  /* iterate over all possible filenames, and delete them */
2554  for (cur = first; cur <= last; cur++)
2555  {
2556  char path[MAXPGPATH];
2557  XLogRecPtr recptr;
2558 
2559  XLogSegNoOffsetToRecPtr(cur, 0, recptr, wal_segment_size);
2560 
2561  sprintf(path, "pg_replslot/%s/xid-%u-lsn-%X-%X.snap",
2563  (uint32) (recptr >> 32), (uint32) recptr);
2564  if (unlink(path) != 0 && errno != ENOENT)
2565  ereport(ERROR,
2567  errmsg("could not remove file \"%s\": %m", path)));
2568  }
2569 }
2570 
2571 /*
2572  * Delete all data spilled to disk after we've restarted/crashed. It will be
2573  * recreated when the respective slots are reused.
2574  */
2575 void
2577 {
2578  DIR *logical_dir;
2579  struct dirent *logical_de;
2580 
2581  DIR *spill_dir;
2582  struct dirent *spill_de;
2583 
2584  logical_dir = AllocateDir("pg_replslot");
2585  while ((logical_de = ReadDir(logical_dir, "pg_replslot")) != NULL)
2586  {
2587  struct stat statbuf;
2588  char path[MAXPGPATH * 2 + 12];
2589 
2590  if (strcmp(logical_de->d_name, ".") == 0 ||
2591  strcmp(logical_de->d_name, "..") == 0)
2592  continue;
2593 
2594  /* if it cannot be a slot, skip the directory */
2595  if (!ReplicationSlotValidateName(logical_de->d_name, DEBUG2))
2596  continue;
2597 
2598  /*
2599  * ok, has to be a surviving logical slot, iterate and delete
2600  * everything starting with xid-*
2601  */
2602  sprintf(path, "pg_replslot/%s", logical_de->d_name);
2603 
2604  /* we're only creating directories here, skip if it's not our's */
2605  if (lstat(path, &statbuf) == 0 && !S_ISDIR(statbuf.st_mode))
2606  continue;
2607 
2608  spill_dir = AllocateDir(path);
2609  while ((spill_de = ReadDir(spill_dir, path)) != NULL)
2610  {
2611  if (strcmp(spill_de->d_name, ".") == 0 ||
2612  strcmp(spill_de->d_name, "..") == 0)
2613  continue;
2614 
2615  /* only look at names that can be ours */
2616  if (strncmp(spill_de->d_name, "xid", 3) == 0)
2617  {
2618  sprintf(path, "pg_replslot/%s/%s", logical_de->d_name,
2619  spill_de->d_name);
2620 
2621  if (unlink(path) != 0)
2622  ereport(PANIC,
2624  errmsg("could not remove file \"%s\": %m",
2625  path)));
2626  }
2627  }
2628  FreeDir(spill_dir);
2629  }
2630  FreeDir(logical_dir);
2631 }
2632 
2633 /* ---------------------------------------
2634  * toast reassembly support
2635  * ---------------------------------------
2636  */
2637 
2638 /*
2639  * Initialize per tuple toast reconstruction support.
2640  */
2641 static void
2643 {
2644  HASHCTL hash_ctl;
2645 
2646  Assert(txn->toast_hash == NULL);
2647 
2648  memset(&hash_ctl, 0, sizeof(hash_ctl));
2649  hash_ctl.keysize = sizeof(Oid);
2650  hash_ctl.entrysize = sizeof(ReorderBufferToastEnt);
2651  hash_ctl.hcxt = rb->context;
2652  txn->toast_hash = hash_create("ReorderBufferToastHash", 5, &hash_ctl,
2654 }
2655 
2656 /*
2657  * Per toast-chunk handling for toast reconstruction
2658  *
2659  * Appends a toast chunk so we can reconstruct it when the tuple "owning" the
2660  * toasted Datum comes along.
2661  */
2662 static void
2664  Relation relation, ReorderBufferChange *change)
2665 {
2666  ReorderBufferToastEnt *ent;
2667  ReorderBufferTupleBuf *newtup;
2668  bool found;
2669  int32 chunksize;
2670  bool isnull;
2671  Pointer chunk;
2672  TupleDesc desc = RelationGetDescr(relation);
2673  Oid chunk_id;
2674  int32 chunk_seq;
2675 
2676  if (txn->toast_hash == NULL)
2677  ReorderBufferToastInitHash(rb, txn);
2678 
2679  Assert(IsToastRelation(relation));
2680 
2681  newtup = change->data.tp.newtuple;
2682  chunk_id = DatumGetObjectId(fastgetattr(&newtup->tuple, 1, desc, &isnull));
2683  Assert(!isnull);
2684  chunk_seq = DatumGetInt32(fastgetattr(&newtup->tuple, 2, desc, &isnull));
2685  Assert(!isnull);
2686 
2687  ent = (ReorderBufferToastEnt *)
2688  hash_search(txn->toast_hash,
2689  (void *) &chunk_id,
2690  HASH_ENTER,
2691  &found);
2692 
2693  if (!found)
2694  {
2695  Assert(ent->chunk_id == chunk_id);
2696  ent->num_chunks = 0;
2697  ent->last_chunk_seq = 0;
2698  ent->size = 0;
2699  ent->reconstructed = NULL;
2700  dlist_init(&ent->chunks);
2701 
2702  if (chunk_seq != 0)
2703  elog(ERROR, "got sequence entry %d for toast chunk %u instead of seq 0",
2704  chunk_seq, chunk_id);
2705  }
2706  else if (found && chunk_seq != ent->last_chunk_seq + 1)
2707  elog(ERROR, "got sequence entry %d for toast chunk %u instead of seq %d",
2708  chunk_seq, chunk_id, ent->last_chunk_seq + 1);
2709 
2710  chunk = DatumGetPointer(fastgetattr(&newtup->tuple, 3, desc, &isnull));
2711  Assert(!isnull);
2712 
2713  /* calculate size so we can allocate the right size at once later */
2714  if (!VARATT_IS_EXTENDED(chunk))
2715  chunksize = VARSIZE(chunk) - VARHDRSZ;
2716  else if (VARATT_IS_SHORT(chunk))
2717  /* could happen due to heap_form_tuple doing its thing */
2718  chunksize = VARSIZE_SHORT(chunk) - VARHDRSZ_SHORT;
2719  else
2720  elog(ERROR, "unexpected type of toast chunk");
2721 
2722  ent->size += chunksize;
2723  ent->last_chunk_seq = chunk_seq;
2724  ent->num_chunks++;
2725  dlist_push_tail(&ent->chunks, &change->node);
2726 }
2727 
2728 /*
2729  * Rejigger change->newtuple to point to in-memory toast tuples instead to
2730  * on-disk toast tuples that may not longer exist (think DROP TABLE or VACUUM).
2731  *
2732  * We cannot replace unchanged toast tuples though, so those will still point
2733  * to on-disk toast data.
2734  */
2735 static void
2737  Relation relation, ReorderBufferChange *change)
2738 {
2739  TupleDesc desc;
2740  int natt;
2741  Datum *attrs;
2742  bool *isnull;
2743  bool *free;
2744  HeapTuple tmphtup;
2745  Relation toast_rel;
2746  TupleDesc toast_desc;
2747  MemoryContext oldcontext;
2748  ReorderBufferTupleBuf *newtup;
2749 
2750  /* no toast tuples changed */
2751  if (txn->toast_hash == NULL)
2752  return;
2753 
2754  oldcontext = MemoryContextSwitchTo(rb->context);
2755 
2756  /* we should only have toast tuples in an INSERT or UPDATE */
2757  Assert(change->data.tp.newtuple);
2758 
2759  desc = RelationGetDescr(relation);
2760 
2761  toast_rel = RelationIdGetRelation(relation->rd_rel->reltoastrelid);
2762  toast_desc = RelationGetDescr(toast_rel);
2763 
2764  /* should we allocate from stack instead? */
2765  attrs = palloc0(sizeof(Datum) * desc->natts);
2766  isnull = palloc0(sizeof(bool) * desc->natts);
2767  free = palloc0(sizeof(bool) * desc->natts);
2768 
2769  newtup = change->data.tp.newtuple;
2770 
2771  heap_deform_tuple(&newtup->tuple, desc, attrs, isnull);
2772 
2773  for (natt = 0; natt < desc->natts; natt++)
2774  {
2775  Form_pg_attribute attr = TupleDescAttr(desc, natt);
2776  ReorderBufferToastEnt *ent;
2777  struct varlena *varlena;
2778 
2779  /* va_rawsize is the size of the original datum -- including header */
2780  struct varatt_external toast_pointer;
2781  struct varatt_indirect redirect_pointer;
2782  struct varlena *new_datum = NULL;
2783  struct varlena *reconstructed;
2784  dlist_iter it;
2785  Size data_done = 0;
2786 
2787  /* system columns aren't toasted */
2788  if (attr->attnum < 0)
2789  continue;
2790 
2791  if (attr->attisdropped)
2792  continue;
2793 
2794  /* not a varlena datatype */
2795  if (attr->attlen != -1)
2796  continue;
2797 
2798  /* no data */
2799  if (isnull[natt])
2800  continue;
2801 
2802  /* ok, we know we have a toast datum */
2803  varlena = (struct varlena *) DatumGetPointer(attrs[natt]);
2804 
2805  /* no need to do anything if the tuple isn't external */
2806  if (!VARATT_IS_EXTERNAL(varlena))
2807  continue;
2808 
2809  VARATT_EXTERNAL_GET_POINTER(toast_pointer, varlena);
2810 
2811  /*
2812  * Check whether the toast tuple changed, replace if so.
2813  */
2814  ent = (ReorderBufferToastEnt *)
2815  hash_search(txn->toast_hash,
2816  (void *) &toast_pointer.va_valueid,
2817  HASH_FIND,
2818  NULL);
2819  if (ent == NULL)
2820  continue;
2821 
2822  new_datum =
2823  (struct varlena *) palloc0(INDIRECT_POINTER_SIZE);
2824 
2825  free[natt] = true;
2826 
2827  reconstructed = palloc0(toast_pointer.va_rawsize);
2828 
2829  ent->reconstructed = reconstructed;
2830 
2831  /* stitch toast tuple back together from its parts */
2832  dlist_foreach(it, &ent->chunks)
2833  {
2834  bool isnull;
2835  ReorderBufferChange *cchange;
2836  ReorderBufferTupleBuf *ctup;
2837  Pointer chunk;
2838 
2839  cchange = dlist_container(ReorderBufferChange, node, it.cur);
2840  ctup = cchange->data.tp.newtuple;
2841  chunk = DatumGetPointer(
2842  fastgetattr(&ctup->tuple, 3, toast_desc, &isnull));
2843 
2844  Assert(!isnull);
2845  Assert(!VARATT_IS_EXTERNAL(chunk));
2846  Assert(!VARATT_IS_SHORT(chunk));
2847 
2848  memcpy(VARDATA(reconstructed) + data_done,
2849  VARDATA(chunk),
2850  VARSIZE(chunk) - VARHDRSZ);
2851  data_done += VARSIZE(chunk) - VARHDRSZ;
2852  }
2853  Assert(data_done == toast_pointer.va_extsize);
2854 
2855  /* make sure its marked as compressed or not */
2856  if (VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
2857  SET_VARSIZE_COMPRESSED(reconstructed, data_done + VARHDRSZ);
2858  else
2859  SET_VARSIZE(reconstructed, data_done + VARHDRSZ);
2860 
2861  memset(&redirect_pointer, 0, sizeof(redirect_pointer));
2862  redirect_pointer.pointer = reconstructed;
2863 
2865  memcpy(VARDATA_EXTERNAL(new_datum), &redirect_pointer,
2866  sizeof(redirect_pointer));
2867 
2868  attrs[natt] = PointerGetDatum(new_datum);
2869  }
2870 
2871  /*
2872  * Build tuple in separate memory & copy tuple back into the tuplebuf
2873  * passed to the output plugin. We can't directly heap_fill_tuple() into
2874  * the tuplebuf because attrs[] will point back into the current content.
2875  */
2876  tmphtup = heap_form_tuple(desc, attrs, isnull);
2877  Assert(newtup->tuple.t_len <= MaxHeapTupleSize);
2878  Assert(ReorderBufferTupleBufData(newtup) == newtup->tuple.t_data);
2879 
2880  memcpy(newtup->tuple.t_data, tmphtup->t_data, tmphtup->t_len);
2881  newtup->tuple.t_len = tmphtup->t_len;
2882 
2883  /*
2884  * free resources we won't further need, more persistent stuff will be
2885  * free'd in ReorderBufferToastReset().
2886  */
2887  RelationClose(toast_rel);
2888  pfree(tmphtup);
2889  for (natt = 0; natt < desc->natts; natt++)
2890  {
2891  if (free[natt])
2892  pfree(DatumGetPointer(attrs[natt]));
2893  }
2894  pfree(attrs);
2895  pfree(free);
2896  pfree(isnull);
2897 
2898  MemoryContextSwitchTo(oldcontext);
2899 }
2900 
2901 /*
2902  * Free all resources allocated for toast reconstruction.
2903  */
2904 static void
2906 {
2907  HASH_SEQ_STATUS hstat;
2908  ReorderBufferToastEnt *ent;
2909 
2910  if (txn->toast_hash == NULL)
2911  return;
2912 
2913  /* sequentially walk over the hash and free everything */
2914  hash_seq_init(&hstat, txn->toast_hash);
2915  while ((ent = (ReorderBufferToastEnt *) hash_seq_search(&hstat)) != NULL)
2916  {
2917  dlist_mutable_iter it;
2918 
2919  if (ent->reconstructed != NULL)
2920  pfree(ent->reconstructed);
2921 
2922  dlist_foreach_modify(it, &ent->chunks)
2923  {
2924  ReorderBufferChange *change =
2926 
2927  dlist_delete(&change->node);
2928  ReorderBufferReturnChange(rb, change);
2929  }
2930  }
2931 
2932  hash_destroy(txn->toast_hash);
2933  txn->toast_hash = NULL;
2934 }
2935 
2936 
2937 /* ---------------------------------------
2938  * Visibility support for logical decoding
2939  *
2940  *
2941  * Lookup actual cmin/cmax values when using decoding snapshot. We can't
2942  * always rely on stored cmin/cmax values because of two scenarios:
2943  *
2944  * * A tuple got changed multiple times during a single transaction and thus
2945  * has got a combocid. Combocid's are only valid for the duration of a
2946  * single transaction.
2947  * * A tuple with a cmin but no cmax (and thus no combocid) got
2948  * deleted/updated in another transaction than the one which created it
2949  * which we are looking at right now. As only one of cmin, cmax or combocid
2950  * is actually stored in the heap we don't have access to the value we
2951  * need anymore.
2952  *
2953  * To resolve those problems we have a per-transaction hash of (cmin,
2954  * cmax) tuples keyed by (relfilenode, ctid) which contains the actual
2955  * (cmin, cmax) values. That also takes care of combocids by simply
2956  * not caring about them at all. As we have the real cmin/cmax values
2957  * combocids aren't interesting.
2958  *
2959  * As we only care about catalog tuples here the overhead of this
2960  * hashtable should be acceptable.
2961  *
2962  * Heap rewrites complicate this a bit, check rewriteheap.c for
2963  * details.
2964  * -------------------------------------------------------------------------
2965  */
2966 
2967 /* struct for qsort()ing mapping files by lsn somewhat efficiently */
2968 typedef struct RewriteMappingFile
2969 {
2971  char fname[MAXPGPATH];
2973 
2974 #if NOT_USED
2975 static void
2976 DisplayMapping(HTAB *tuplecid_data)
2977 {
2978  HASH_SEQ_STATUS hstat;
2980 
2981  hash_seq_init(&hstat, tuplecid_data);
2982  while ((ent = (ReorderBufferTupleCidEnt *) hash_seq_search(&hstat)) != NULL)
2983  {
2984  elog(DEBUG3, "mapping: node: %u/%u/%u tid: %u/%u cmin: %u, cmax: %u",
2985  ent->key.relnode.dbNode,
2986  ent->key.relnode.spcNode,
2987  ent->key.relnode.relNode,
2990  ent->cmin,
2991  ent->cmax
2992  );
2993  }
2994 }
2995 #endif
2996 
2997 /*
2998  * Apply a single mapping file to tuplecid_data.
2999  *
3000  * The mapping file has to have been verified to be a) committed b) for our
3001  * transaction c) applied in LSN order.
3002  */
3003 static void
3004 ApplyLogicalMappingFile(HTAB *tuplecid_data, Oid relid, const char *fname)
3005 {
3006  char path[MAXPGPATH];
3007  int fd;
3008  int readBytes;
3010 
3011  sprintf(path, "pg_logical/mappings/%s", fname);
3012  fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
3013  if (fd < 0)
3014  ereport(ERROR,
3016  errmsg("could not open file \"%s\": %m", path)));
3017 
3018  while (true)
3019  {
3022  ReorderBufferTupleCidEnt *new_ent;
3023  bool found;
3024 
3025  /* be careful about padding */
3026  memset(&key, 0, sizeof(ReorderBufferTupleCidKey));
3027 
3028  /* read all mappings till the end of the file */
3030  readBytes = read(fd, &map, sizeof(LogicalRewriteMappingData));
3032 
3033  if (readBytes < 0)
3034  ereport(ERROR,
3036  errmsg("could not read file \"%s\": %m",
3037  path)));
3038  else if (readBytes == 0) /* EOF */
3039  break;
3040  else if (readBytes != sizeof(LogicalRewriteMappingData))
3041  ereport(ERROR,
3043  errmsg("could not read from file \"%s\": read %d instead of %d bytes",
3044  path, readBytes,
3045  (int32) sizeof(LogicalRewriteMappingData))));
3046 
3047  key.relnode = map.old_node;
3048  ItemPointerCopy(&map.old_tid,
3049  &key.tid);
3050 
3051 
3052  ent = (ReorderBufferTupleCidEnt *)
3053  hash_search(tuplecid_data,
3054  (void *) &key,
3055  HASH_FIND,
3056  NULL);
3057 
3058  /* no existing mapping, no need to update */
3059  if (!ent)
3060  continue;
3061 
3062  key.relnode = map.new_node;
3063  ItemPointerCopy(&map.new_tid,
3064  &key.tid);
3065 
3066  new_ent = (ReorderBufferTupleCidEnt *)
3067  hash_search(tuplecid_data,
3068  (void *) &key,
3069  HASH_ENTER,
3070  &found);
3071 
3072  if (found)
3073  {
3074  /*
3075  * Make sure the existing mapping makes sense. We sometime update
3076  * old records that did not yet have a cmax (e.g. pg_class' own
3077  * entry while rewriting it) during rewrites, so allow that.
3078  */
3079  Assert(ent->cmin == InvalidCommandId || ent->cmin == new_ent->cmin);
3080  Assert(ent->cmax == InvalidCommandId || ent->cmax == new_ent->cmax);
3081  }
3082  else
3083  {
3084  /* update mapping */
3085  new_ent->cmin = ent->cmin;
3086  new_ent->cmax = ent->cmax;
3087  new_ent->combocid = ent->combocid;
3088  }
3089  }
3090 }
3091 
3092 
3093 /*
3094  * Check whether the TransactionOId 'xid' is in the pre-sorted array 'xip'.
3095  */
3096 static bool
3098 {
3099  return bsearch(&xid, xip, num,
3100  sizeof(TransactionId), xidComparator) != NULL;
3101 }
3102 
3103 /*
3104  * qsort() comparator for sorting RewriteMappingFiles in LSN order.
3105  */
3106 static int
3107 file_sort_by_lsn(const void *a_p, const void *b_p)
3108 {
3109  RewriteMappingFile *a = *(RewriteMappingFile **) a_p;
3110  RewriteMappingFile *b = *(RewriteMappingFile **) b_p;
3111 
3112  if (a->lsn < b->lsn)
3113  return -1;
3114  else if (a->lsn > b->lsn)
3115  return 1;
3116  return 0;
3117 }
3118 
3119 /*
3120  * Apply any existing logical remapping files if there are any targeted at our
3121  * transaction for relid.
3122  */
3123 static void
3125 {
3126  DIR *mapping_dir;
3127  struct dirent *mapping_de;
3128  List *files = NIL;
3129  ListCell *file;
3130  RewriteMappingFile **files_a;
3131  size_t off;
3132  Oid dboid = IsSharedRelation(relid) ? InvalidOid : MyDatabaseId;
3133 
3134  mapping_dir = AllocateDir("pg_logical/mappings");
3135  while ((mapping_de = ReadDir(mapping_dir, "pg_logical/mappings")) != NULL)
3136  {
3137  Oid f_dboid;
3138  Oid f_relid;
3139  TransactionId f_mapped_xid;
3140  TransactionId f_create_xid;
3141  XLogRecPtr f_lsn;
3142  uint32 f_hi,
3143  f_lo;
3144  RewriteMappingFile *f;
3145 
3146  if (strcmp(mapping_de->d_name, ".") == 0 ||
3147  strcmp(mapping_de->d_name, "..") == 0)
3148  continue;
3149 
3150  /* Ignore files that aren't ours */
3151  if (strncmp(mapping_de->d_name, "map-", 4) != 0)
3152  continue;
3153 
3154  if (sscanf(mapping_de->d_name, LOGICAL_REWRITE_FORMAT,
3155  &f_dboid, &f_relid, &f_hi, &f_lo,
3156  &f_mapped_xid, &f_create_xid) != 6)
3157  elog(ERROR, "could not parse filename \"%s\"", mapping_de->d_name);
3158 
3159  f_lsn = ((uint64) f_hi) << 32 | f_lo;
3160 
3161  /* mapping for another database */
3162  if (f_dboid != dboid)
3163  continue;
3164 
3165  /* mapping for another relation */
3166  if (f_relid != relid)
3167  continue;
3168 
3169  /* did the creating transaction abort? */
3170  if (!TransactionIdDidCommit(f_create_xid))
3171  continue;
3172 
3173  /* not for our transaction */
3174  if (!TransactionIdInArray(f_mapped_xid, snapshot->subxip, snapshot->subxcnt))
3175  continue;
3176 
3177  /* ok, relevant, queue for apply */
3178  f = palloc(sizeof(RewriteMappingFile));
3179  f->lsn = f_lsn;
3180  strcpy(f->fname, mapping_de->d_name);
3181  files = lappend(files, f);
3182  }
3183  FreeDir(mapping_dir);
3184 
3185  /* build array we can easily sort */
3186  files_a = palloc(list_length(files) * sizeof(RewriteMappingFile *));
3187  off = 0;
3188  foreach(file, files)
3189  {
3190  files_a[off++] = lfirst(file);
3191  }
3192 
3193  /* sort files so we apply them in LSN order */
3194  qsort(files_a, list_length(files), sizeof(RewriteMappingFile *),
3196 
3197  for (off = 0; off < list_length(files); off++)
3198  {
3199  RewriteMappingFile *f = files_a[off];
3200 
3201  elog(DEBUG1, "applying mapping: \"%s\" in %u", f->fname,
3202  snapshot->subxip[0]);
3203  ApplyLogicalMappingFile(tuplecid_data, relid, f->fname);
3204  pfree(f);
3205  }
3206 }
3207 
3208 /*
3209  * Lookup cmin/cmax of a tuple, during logical decoding where we can't rely on
3210  * combocids.
3211  */
3212 bool
3214  Snapshot snapshot,
3215  HeapTuple htup, Buffer buffer,
3216  CommandId *cmin, CommandId *cmax)
3217 {
3220  ForkNumber forkno;
3221  BlockNumber blockno;
3222  bool updated_mapping = false;
3223 
3224  /* be careful about padding */
3225  memset(&key, 0, sizeof(key));
3226 
3227  Assert(!BufferIsLocal(buffer));
3228 
3229  /*
3230  * get relfilenode from the buffer, no convenient way to access it other
3231  * than that.
3232  */
3233  BufferGetTag(buffer, &key.relnode, &forkno, &blockno);
3234 
3235  /* tuples can only be in the main fork */
3236  Assert(forkno == MAIN_FORKNUM);
3237  Assert(blockno == ItemPointerGetBlockNumber(&htup->t_self));
3238 
3239  ItemPointerCopy(&htup->t_self,
3240  &key.tid);
3241 
3242 restart:
3243  ent = (ReorderBufferTupleCidEnt *)
3244  hash_search(tuplecid_data,
3245  (void *) &key,
3246  HASH_FIND,
3247  NULL);
3248 
3249  /*
3250  * failed to find a mapping, check whether the table was rewritten and
3251  * apply mapping if so, but only do that once - there can be no new
3252  * mappings while we are in here since we have to hold a lock on the
3253  * relation.
3254  */
3255  if (ent == NULL && !updated_mapping)
3256  {
3257  UpdateLogicalMappings(tuplecid_data, htup->t_tableOid, snapshot);
3258  /* now check but don't update for a mapping again */
3259  updated_mapping = true;
3260  goto restart;
3261  }
3262  else if (ent == NULL)
3263  return false;
3264 
3265  if (cmin)
3266  *cmin = ent->cmin;
3267  if (cmax)
3268  *cmax = ent->cmax;
3269  return true;
3270 }
static void ReorderBufferBuildTupleCidHash(ReorderBuffer *rb, ReorderBufferTXN *txn)
XLogRecPtr first_lsn
bool ReorderBufferXidHasBaseSnapshot(ReorderBuffer *rb, TransactionId xid)
#define NIL
Definition: pg_list.h:69
uint32 CommandId
Definition: c.h:469
void ReorderBufferReturnChange(ReorderBuffer *rb, ReorderBufferChange *change)
TimestampTz commit_time
struct ReorderBufferToastEnt ReorderBufferToastEnt
void AbortCurrentTransaction(void)
Definition: xact.c:2985
ReorderBufferIterTXNEntry entries[FLEXIBLE_ARRAY_MEMBER]
#define SizeofHeapTupleHeader
Definition: htup_details.h:175
bool IsToastRelation(Relation relation)
Definition: catalog.c:136
void hash_destroy(HTAB *hashp)
Definition: dynahash.c:812
void ReorderBufferQueueMessage(ReorderBuffer *rb, TransactionId xid, Snapshot snapshot, XLogRecPtr lsn, bool transactional, const char *prefix, Size message_size, const char *message)
#define relpathperm(rnode, forknum)
Definition: relpath.h:67
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
Snapshot base_snapshot
ReorderBufferApplyChangeCB apply_change
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:198
HeapTupleData * HeapTuple
Definition: htup.h:70
#define DEBUG1
Definition: elog.h:25
dlist_node * cur
Definition: ilist.h:180
static void ReorderBufferToastAppendChunk(ReorderBuffer *rb, ReorderBufferTXN *txn, Relation relation, ReorderBufferChange *change)
RepOriginId origin_id
void StartupReorderBuffer(void)
#define VARDATA(PTR)
Definition: postgres.h:303
#define fastgetattr(tup, attnum, tupleDesc, isnull)
Definition: htup_details.h:724
static int32 next
Definition: blutils.c:210
#define HASH_CONTEXT
Definition: hsearch.h:93
#define HASH_ELEM
Definition: hsearch.h:87
int wal_segment_size
Definition: xlog.c:113
void ReorderBufferAbortOld(ReorderBuffer *rb, TransactionId oldestRunningXid)
#define dlist_foreach_modify(iter, lhead)
Definition: ilist.h:524
uint32 TransactionId
Definition: c.h:455
void ReorderBufferForget(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
bool copied
Definition: snapshot.h:96
void ReorderBufferCommit(ReorderBuffer *rb, TransactionId xid, XLogRecPtr commit_lsn, XLogRecPtr end_lsn, TimestampTz commit_time, RepOriginId origin_id, XLogRecPtr origin_lsn)
MemoryContext hcxt
Definition: hsearch.h:78
#define DatumGetInt32(X)
Definition: postgres.h:478
#define RelationGetDescr(relation)
Definition: rel.h:437
#define VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer)
Definition: tuptoaster.h:111
#define DEBUG3
Definition: elog.h:23
#define write(a, b, c)
Definition: win32.h:14
#define VARHDRSZ_SHORT
Definition: postgres.h:269
TransactionId by_txn_last_xid
#define VARSIZE(PTR)
Definition: postgres.h:304
int64 TimestampTz
Definition: timestamp.h:39
#define PointerGetDatum(X)
Definition: postgres.h:562
#define TupleDescAttr(tupdesc, i)
Definition: tupdesc.h:90
ReorderBufferTXN * txn
static bool TransactionIdInArray(TransactionId xid, TransactionId *xip, Size num)
#define VARHDRSZ
Definition: c.h:503
#define dlist_foreach(iter, lhead)
Definition: ilist.h:507
XLogRecPtr current_restart_decoding_lsn
#define DatumGetObjectId(X)
Definition: postgres.h:506
char * pstrdup(const char *in)
Definition: mcxt.c:1063
static ReorderBufferTXN * ReorderBufferGetTXN(ReorderBuffer *rb)
static void dlist_push_tail(dlist_head *head, dlist_node *node)
Definition: ilist.h:317
Oid RelidByRelfilenode(Oid reltablespace, Oid relfilenode)
void ReorderBufferSetBaseSnapshot(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn, Snapshot snap)
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
void ReorderBufferFree(ReorderBuffer *rb)
uint16 RepOriginId
Definition: xlogdefs.h:51
Size entrysize
Definition: hsearch.h:73
struct cursor * cur
Definition: ecpg.c:28
char fname[MAXPGPATH]
int32 va_rawsize
Definition: postgres.h:70
bool IsTransactionOrTransactionBlock(void)
Definition: xact.c:4466
void binaryheap_replace_first(binaryheap *heap, Datum d)
Definition: binaryheap.c:204
void ReorderBufferAddNewTupleCids(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn, RelFileNode node, ItemPointerData tid, CommandId cmin, CommandId cmax, CommandId combocid)
static void ReorderBufferIterTXNFinish(ReorderBuffer *rb, ReorderBufferIterTXNState *state)
uint32 BlockNumber
Definition: block.h:31
void TeardownHistoricSnapshot(bool is_error)
Definition: snapmgr.c:2017
ReorderBufferCommitCB commit
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, Datum *values, bool *isnull)
Definition: heaptuple.c:695
ReorderBufferChange * ReorderBufferGetChange(ReorderBuffer *rb)
#define RelationIsLogicallyLogged(relation)
Definition: rel.h:584
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:904
bool TransactionIdDidCommit(TransactionId transactionId)
Definition: transam.c:125
ReplicationSlotPersistentData data
Definition: slot.h:120
static Size ReorderBufferRestoreChanges(ReorderBuffer *rb, ReorderBufferTXN *txn, int *fd, XLogSegNo *segno)
struct ReorderBufferTupleCidKey ReorderBufferTupleCidKey
struct SnapshotData * Snapshot
Definition: snapshot.h:23
Form_pg_class rd_rel
Definition: rel.h:114
unsigned int Oid
Definition: postgres_ext.h:31
XLogRecPtr base_snapshot_lsn
Definition: dirent.h:9
uint32 regd_count
Definition: snapshot.h:110
#define PANIC
Definition: elog.h:53
enum ReorderBufferChangeType action
Definition: reorderbuffer.h:77
void binaryheap_add_unordered(binaryheap *heap, Datum d)
Definition: binaryheap.c:110
MemoryContext change_context
static int fd(const char *x, int i)
Definition: preproc-init.c:105
#define VARDATA_EXTERNAL(PTR)
Definition: postgres.h:311
#define PG_BINARY
Definition: c.h:1049
int natts
Definition: tupdesc.h:79
XLogRecPtr origin_lsn
static void ApplyLogicalMappingFile(HTAB *tuplecid_data, Oid relid, const char *fname)
signed int int32
Definition: c.h:294
static int file_sort_by_lsn(const void *a_p, const void *b_p)
#define FirstCommandId
Definition: c.h:471
MemoryContext SlabContextCreate(MemoryContext parent, const char *name, int flags, Size blockSize, Size chunkSize)
Definition: slab.c:190
#define XLByteInSeg(xlrp, logSegNo, wal_segsz_bytes)
void ReorderBufferSetRestartPoint(ReorderBuffer *rb, XLogRecPtr ptr)
HeapTupleHeader t_data
Definition: htup.h:67
#define VARATT_IS_EXTERNAL(PTR)
Definition: postgres.h:314
bool ReplicationSlotValidateName(const char *name, int elevel)
Definition: slot.c:174
MemoryContext GenerationContextCreate(MemoryContext parent, const char *name, int flags, Size blockSize)
Definition: generation.c:208
static dlist_node * dlist_next_node(dlist_head *head, dlist_node *node)
Definition: ilist.h:421
Definition: dynahash.c:208
#define ReorderBufferTupleBufData(p)
Definition: reorderbuffer.h:36
#define dlist_container(type, membername, ptr)
Definition: ilist.h:477
struct ReorderBufferChange::@102::@103 tp
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Definition: mcxt.c:936
char * Pointer
Definition: c.h:283
#define dlist_tail_element(type, membername, lhead)
Definition: ilist.h:496
Definition: dirent.c:25
#define ERROR
Definition: elog.h:43
int OpenTransientFile(const char *fileName, int fileFlags)
Definition: fd.c:2393
#define SLAB_LARGE_BLOCK_SIZE
Definition: memutils.h:227
#define VARATT_IS_SHORT(PTR)
Definition: postgres.h:325
dlist_head changes
Datum binaryheap_first(binaryheap *heap)
Definition: binaryheap.c:159
#define MAXPGPATH
ItemPointerData t_self
Definition: htup.h:65
ReorderBufferTupleCidKey key
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:197
#define DEBUG2
Definition: elog.h:24
TransactionId GetCurrentTransactionId(void)
Definition: xact.c:418
void ReorderBufferImmediateInvalidation(ReorderBuffer *rb, uint32 ninvalidations, SharedInvalidationMessage *invalidations)
uint32 t_len
Definition: htup.h:64
#define MaxHeapTupleSize
Definition: htup_details.h:566
struct varlena * reconstructed
void RollbackAndReleaseCurrentSubTransaction(void)
Definition: xact.c:4277
#define SET_VARTAG_EXTERNAL(PTR, tag)
Definition: postgres.h:332
uint64 XLogSegNo
Definition: xlogdefs.h:34
int errcode_for_file_access(void)
Definition: elog.c:598
HeapTupleData tuple
Definition: reorderbuffer.h:27
struct SnapshotData SnapshotData
TransactionId GetCurrentTransactionIdIfAny(void)
Definition: xact.c:435
#define XLogSegNoOffsetToRecPtr(segno, offset, dest, wal_segsz_bytes)
#define InvalidTransactionId
Definition: transam.h:31
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:187
bool ReorderBufferXidHasCatalogChanges(ReorderBuffer *rb, TransactionId xid)
unsigned int uint32
Definition: c.h:306
XLogRecPtr final_lsn
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2597
Oid t_tableOid
Definition: htup.h:66
static void pgstat_report_wait_end(void)
Definition: pgstat.h:1259
void RelationClose(Relation relation)
Definition: relcache.c:2122
MemoryContext CurrentMemoryContext
Definition: mcxt.c:37
static void dlist_delete(dlist_node *node)
Definition: ilist.h:358
ReorderBufferMessageCB message
#define ereport(elevel, rest)
Definition: elog.h:122
int bh_size
Definition: binaryheap.h:32
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
TransactionId * xip
Definition: snapshot.h:79
static Snapshot ReorderBufferCopySnap(ReorderBuffer *rb, Snapshot orig_snap, ReorderBufferTXN *txn, CommandId cid)
#define VARSIZE_SHORT(PTR)
Definition: postgres.h:306
ForkNumber
Definition: relpath.h:24
List * lappend(List *list, void *datum)
Definition: list.c:128
static HTAB * tuplecid_data
Definition: snapmgr.c:170
int CloseTransientFile(int fd)
Definition: fd.c:2563
static void ReorderBufferSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
#define AllocSetContextCreate(parent, name, allocparams)
Definition: memutils.h:165
#define stat(a, b)
Definition: win32_port.h:266
struct ReorderBufferTupleCidEnt ReorderBufferTupleCidEnt
void ReorderBufferAssignChild(ReorderBuffer *rb, TransactionId xid, TransactionId subxid, XLogRecPtr lsn)
#define INDIRECT_POINTER_SIZE
Definition: tuptoaster.h:102
static void ReorderBufferRestoreChange(ReorderBuffer *rb, ReorderBufferTXN *txn, char *change)
#define dlist_head_element(type, membername, lhead)
Definition: ilist.h:487
#define HASH_BLOBS
Definition: hsearch.h:88
ReorderBufferChange * change
static int ReorderBufferIterCompare(Datum a, Datum b, void *arg)
MemoryContext context
void ReorderBufferCommitChild(ReorderBuffer *rb, TransactionId xid, TransactionId subxid, XLogRecPtr commit_lsn, XLogRecPtr end_lsn)
void * palloc0(Size size)
Definition: mcxt.c:864
static bool dlist_has_next(dlist_head *head, dlist_node *node)
Definition: ilist.h:402
#define InvalidCommandId
Definition: c.h:472
uintptr_t Datum
Definition: postgres.h:372
HTAB * hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
Definition: dynahash.c:316
ReorderBufferTXN * by_txn_last_txn
union ReorderBufferChange::@102 data
static void ReorderBufferCleanupTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
static void cleanup(void)
Definition: bootstrap.c:873
dlist_head toplevel_by_lsn
struct RewriteMappingFile RewriteMappingFile
Oid MyDatabaseId
Definition: globals.c:77
TransactionId xid
static void ReorderBufferToastReplace(ReorderBuffer *rb, ReorderBufferTXN *txn, Relation relation, ReorderBufferChange *change)
bool IsSharedRelation(Oid relationId)
Definition: catalog.c:220
Size keysize
Definition: hsearch.h:72
dlist_node * cur
Definition: ilist.h:161
struct ReorderBufferChange::@102::@104 msg
void * MemoryContextAllocZero(MemoryContext context, Size size)
Definition: mcxt.c:728
static void AssertTXNLsnOrder(ReorderBuffer *rb)
void ReorderBufferAddSnapshot(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn, Snapshot snap)
#define InvalidOid
Definition: postgres_ext.h:36
static void dlist_init(dlist_head *head)
Definition: ilist.h:278
CommandId curcid
Definition: snapshot.h:98
struct ReorderBufferIterTXNState ReorderBufferIterTXNState
static void ReorderBufferExecuteInvalidations(ReorderBuffer *rb, ReorderBufferTXN *txn)
struct ReorderBufferDiskChange ReorderBufferDiskChange
void binaryheap_build(binaryheap *heap)
Definition: binaryheap.c:126
#define free(a)
Definition: header.h:65
struct ReorderBufferIterTXNEntry ReorderBufferIterTXNEntry
#define PG_CATCH()
Definition: elog.h:293
ReplicationSlot * MyReplicationSlot
Definition: slot.c:96
ItemPointerData new_tid
Definition: rewriteheap.h:40
uint64 XLogRecPtr
Definition: xlogdefs.h:21
#define Assert(condition)
Definition: c.h:680
#define lfirst(lc)
Definition: pg_list.h:106
ReorderBufferTXN * ReorderBufferGetOldestTXN(ReorderBuffer *rb)
static void ReorderBufferSerializeChange(ReorderBuffer *rb, ReorderBufferTXN *txn, int fd, ReorderBufferChange *change)
static void ReorderBufferToastReset(ReorderBuffer *rb, ReorderBufferTXN *txn)
Definition: regguts.h:298
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2663
static ReorderBufferChange * ReorderBufferIterTXNNext(ReorderBuffer *rb, ReorderBufferIterTXNState *state)
#define VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr)
Definition: tuptoaster.h:121
int32 va_extsize
Definition: postgres.h:71
XLogRecPtr end_lsn
void StartTransactionCommand(void)
Definition: xact.c:2674
void BeginInternalSubTransaction(const char *name)
Definition: xact.c:4172
WalTimeSample buffer[LAG_TRACKER_BUFFER_SIZE]
Definition: walsender.c:215
void ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn, Size nmsgs, SharedInvalidationMessage *msgs)
static bool dlist_is_empty(dlist_head *head)
Definition: ilist.h:289
size_t Size
Definition: c.h:414
static void pgstat_report_wait_start(uint32 wait_event_info)
Definition: pgstat.h:1235
void binaryheap_free(binaryheap *heap)
Definition: binaryheap.c:69
SharedInvalidationMessage * invalidations
static int list_length(const List *l)
Definition: pg_list.h:89
#define BufferIsLocal(buffer)
Definition: buf.h:37
#define SLAB_DEFAULT_BLOCK_SIZE
Definition: memutils.h:226
#define ItemPointerGetOffsetNumber(pointer)
Definition: itemptr.h:95
void ReorderBufferReturnTupleBuf(ReorderBuffer *rb, ReorderBufferTupleBuf *tuple)
#define PG_RE_THROW()
Definition: elog.h:314
ReorderBuffer * ReorderBufferAllocate(void)
void * hash_seq_search(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1387
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:949
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1377
static void ReorderBufferSerializeReserve(ReorderBuffer *rb, Size sz)
struct varlena * pointer
Definition: postgres.h:87
void ReorderBufferQueueChange(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn, ReorderBufferChange *change)
void SnapBuildSnapDecRefcount(Snapshot snap)
Definition: snapbuild.c:434
#define LOGICAL_REWRITE_FORMAT
Definition: rewriteheap.h:54
dlist_head subtxns
binaryheap * binaryheap_allocate(int capacity, binaryheap_comparator compare, void *arg)
Definition: binaryheap.c:33
#define VARATT_IS_EXTENDED(PTR)
Definition: postgres.h:326
#define S_ISDIR(m)
Definition: win32_port.h:307
#define DatumGetPointer(X)
Definition: postgres.h:555
#define lstat(path, sb)
Definition: win32_port.h:255
void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc, Datum *values, bool *isnull)
Definition: heaptuple.c:936
void LocalExecuteInvalidationMessage(SharedInvalidationMessage *msg)
Definition: inval.c:554
#define Int32GetDatum(X)
Definition: postgres.h:485
static void ReorderBufferRestoreCleanup(ReorderBuffer *rb, ReorderBufferTXN *txn)
static ReorderBufferTXN * ReorderBufferTXNByXid(ReorderBuffer *rb, TransactionId xid, bool create, bool *is_new, XLogRecPtr lsn, bool create_as_top)
uint32 xcnt
Definition: snapshot.h:80
void * palloc(Size size)
Definition: mcxt.c:835
int errmsg(const char *fmt,...)
Definition: elog.c:797
static void UpdateLogicalMappings(HTAB *tuplecid_data, Oid relid, Snapshot snapshot)
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:693
static void ReorderBufferCheckSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
ReorderBufferTXN * txn
Definition: reorderbuffer.c:88
void ReorderBufferAbort(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
static dlist_node * dlist_pop_head_node(dlist_head *head)
Definition: ilist.h:368
void SetupHistoricSnapshot(Snapshot historic_snapshot, HTAB *tuplecids)
Definition: snapmgr.c:2001
int i
struct ReorderBufferChange::@102::@105 tuplecid
XLogRecPtr restart_decoding_lsn
#define NameStr(name)
Definition: c.h:557
#define SET_VARSIZE_COMPRESSED(PTR, len)
Definition: postgres.h:330
void * arg
Datum binaryheap_remove_first(binaryheap *heap)
Definition: binaryheap.c:174
static const Size max_changes_in_memory
Definition: c.h:497
struct ReorderBufferTXNByIdEnt ReorderBufferTXNByIdEnt
void ReorderBufferXidSetCatalogChanges(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
MemoryContext tup_context
#define SET_VARSIZE(PTR, len)
Definition: postgres.h:328
char d_name[MAX_PATH]
Definition: dirent.h:14
#define elog
Definition: elog.h:219
#define ItemPointerGetBlockNumber(pointer)
Definition: itemptr.h:76
static void ReorderBufferReturnTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
#define qsort(a, b, c, d)
Definition: port.h:408
#define TransactionIdIsValid(xid)
Definition: transam.h:41
ReorderBufferChange change
ReorderBufferBeginCB begin
static void ReorderBufferToastInitHash(ReorderBuffer *rb, ReorderBufferTXN *txn)
void BufferGetTag(Buffer buffer, RelFileNode *rnode, ForkNumber *forknum, BlockNumber *blknum)
Definition: bufmgr.c:2626
#define PG_TRY()
Definition: elog.h:284
static void ReorderBufferFreeSnap(ReorderBuffer *rb, Snapshot snap)
void ReorderBufferProcessXid(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
#define RELKIND_SEQUENCE
Definition: pg_class.h:162
Definition: pg_list.h:45
int Buffer
Definition: buf.h:23
static ReorderBufferIterTXNState * ReorderBufferIterTXNInit(ReorderBuffer *rb, ReorderBufferTXN *txn)
Relation RelationIdGetRelation(Oid relationId)
Definition: relcache.c:2033
#define PG_END_TRY()
Definition: elog.h:300
#define read(a, b, c)
Definition: win32.h:13
int FreeDir(DIR *dir)
Definition: fd.c:2715
struct HeapTupleData HeapTupleData
#define offsetof(type, field)
Definition: c.h:603
MemoryContext txn_context
dlist_head tuplecids
#define ItemPointerCopy(fromPointer, toPointer)
Definition: itemptr.h:139
TransactionId * subxip
Definition: snapshot.h:91
uint32 active_count
Definition: snapshot.h:109
int xidComparator(const void *arg1, const void *arg2)
Definition: xid.c:138
int32 subxcnt
Definition: snapshot.h:92
void ReorderBufferAddNewCommandId(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn, CommandId cid)
ReorderBufferTupleBuf * ReorderBufferGetTupleBuf(ReorderBuffer *rb, Size tuple_len)
bool ResolveCminCmaxDuringDecoding(HTAB *tuplecid_data, Snapshot snapshot, HeapTuple htup, Buffer buffer, CommandId *cmin, CommandId *cmax)
#define XLByteToSeg(xlrp, logSegNo, wal_segsz_bytes)
ItemPointerData old_tid
Definition: rewriteheap.h:39