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decode.h File Reference
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Data Structures

struct  XLogRecordBuffer
 

Typedefs

typedef struct XLogRecordBuffer XLogRecordBuffer
 

Functions

void xlog_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
void heap_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
void heap2_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
void xact_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
void standby_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
void logicalmsg_decode (LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 
void LogicalDecodingProcessRecord (LogicalDecodingContext *ctx, XLogReaderState *record)
 

Typedef Documentation

◆ XLogRecordBuffer

Function Documentation

◆ heap2_decode()

void heap2_decode ( LogicalDecodingContext ctx,
XLogRecordBuffer buf 
)

Definition at line 407 of file decode.c.

408 {
409  uint8 info = XLogRecGetInfo(buf->record) & XLOG_HEAP_OPMASK;
410  TransactionId xid = XLogRecGetXid(buf->record);
411  SnapBuild *builder = ctx->snapshot_builder;
412 
413  ReorderBufferProcessXid(ctx->reorder, xid, buf->origptr);
414 
415  /*
416  * If we don't have snapshot or we are just fast-forwarding, there is no
417  * point in decoding changes.
418  */
420  ctx->fast_forward)
421  return;
422 
423  switch (info)
424  {
426  if (SnapBuildProcessChange(builder, xid, buf->origptr))
427  DecodeMultiInsert(ctx, buf);
428  break;
429  case XLOG_HEAP2_NEW_CID:
430  {
431  xl_heap_new_cid *xlrec;
432 
433  xlrec = (xl_heap_new_cid *) XLogRecGetData(buf->record);
434  SnapBuildProcessNewCid(builder, xid, buf->origptr, xlrec);
435 
436  break;
437  }
438  case XLOG_HEAP2_REWRITE:
439 
440  /*
441  * Although these records only exist to serve the needs of logical
442  * decoding, all the work happens as part of crash or archive
443  * recovery, so we don't need to do anything here.
444  */
445  break;
446 
447  /*
448  * Everything else here is just low level physical stuff we're not
449  * interested in.
450  */
452  case XLOG_HEAP2_PRUNE:
453  case XLOG_HEAP2_VACUUM:
454  case XLOG_HEAP2_VISIBLE:
456  break;
457  default:
458  elog(ERROR, "unexpected RM_HEAP2_ID record type: %u", info);
459  }
460 }
unsigned char uint8
Definition: c.h:493
uint32 TransactionId
Definition: c.h:641
static void DecodeMultiInsert(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
Definition: decode.c:1114
#define ERROR
Definition: elog.h:39
#define XLOG_HEAP2_PRUNE
Definition: heapam_xlog.h:54
#define XLOG_HEAP2_MULTI_INSERT
Definition: heapam_xlog.h:58
#define XLOG_HEAP2_VACUUM
Definition: heapam_xlog.h:55
#define XLOG_HEAP2_REWRITE
Definition: heapam_xlog.h:53
#define XLOG_HEAP_OPMASK
Definition: heapam_xlog.h:41
#define XLOG_HEAP2_LOCK_UPDATED
Definition: heapam_xlog.h:59
#define XLOG_HEAP2_FREEZE_PAGE
Definition: heapam_xlog.h:56
#define XLOG_HEAP2_NEW_CID
Definition: heapam_xlog.h:60
#define XLOG_HEAP2_VISIBLE
Definition: heapam_xlog.h:57
static char * buf
Definition: pg_test_fsync.c:73
void ReorderBufferProcessXid(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
bool SnapBuildProcessChange(SnapBuild *builder, TransactionId xid, XLogRecPtr lsn)
Definition: snapbuild.c:769
SnapBuildState SnapBuildCurrentState(SnapBuild *builder)
Definition: snapbuild.c:407
void SnapBuildProcessNewCid(SnapBuild *builder, TransactionId xid, XLogRecPtr lsn, xl_heap_new_cid *xlrec)
Definition: snapbuild.c:819
@ SNAPBUILD_FULL_SNAPSHOT
Definition: snapbuild.h:39
struct SnapBuild * snapshot_builder
Definition: logical.h:44
struct ReorderBuffer * reorder
Definition: logical.h:43
#define XLogRecGetInfo(decoder)
Definition: xlogreader.h:410
#define XLogRecGetData(decoder)
Definition: xlogreader.h:415
#define XLogRecGetXid(decoder)
Definition: xlogreader.h:412

References buf, DecodeMultiInsert(), elog(), ERROR, LogicalDecodingContext::fast_forward, LogicalDecodingContext::reorder, ReorderBufferProcessXid(), SNAPBUILD_FULL_SNAPSHOT, SnapBuildCurrentState(), SnapBuildProcessChange(), SnapBuildProcessNewCid(), LogicalDecodingContext::snapshot_builder, XLOG_HEAP2_FREEZE_PAGE, XLOG_HEAP2_LOCK_UPDATED, XLOG_HEAP2_MULTI_INSERT, XLOG_HEAP2_NEW_CID, XLOG_HEAP2_PRUNE, XLOG_HEAP2_REWRITE, XLOG_HEAP2_VACUUM, XLOG_HEAP2_VISIBLE, XLOG_HEAP_OPMASK, XLogRecGetData, XLogRecGetInfo, and XLogRecGetXid.

◆ heap_decode()

void heap_decode ( LogicalDecodingContext ctx,
XLogRecordBuffer buf 
)

Definition at line 466 of file decode.c.

467 {
468  uint8 info = XLogRecGetInfo(buf->record) & XLOG_HEAP_OPMASK;
469  TransactionId xid = XLogRecGetXid(buf->record);
470  SnapBuild *builder = ctx->snapshot_builder;
471 
472  ReorderBufferProcessXid(ctx->reorder, xid, buf->origptr);
473 
474  /*
475  * If we don't have snapshot or we are just fast-forwarding, there is no
476  * point in decoding data changes.
477  */
479  ctx->fast_forward)
480  return;
481 
482  switch (info)
483  {
484  case XLOG_HEAP_INSERT:
485  if (SnapBuildProcessChange(builder, xid, buf->origptr))
486  DecodeInsert(ctx, buf);
487  break;
488 
489  /*
490  * Treat HOT update as normal updates. There is no useful
491  * information in the fact that we could make it a HOT update
492  * locally and the WAL layout is compatible.
493  */
495  case XLOG_HEAP_UPDATE:
496  if (SnapBuildProcessChange(builder, xid, buf->origptr))
497  DecodeUpdate(ctx, buf);
498  break;
499 
500  case XLOG_HEAP_DELETE:
501  if (SnapBuildProcessChange(builder, xid, buf->origptr))
502  DecodeDelete(ctx, buf);
503  break;
504 
505  case XLOG_HEAP_TRUNCATE:
506  if (SnapBuildProcessChange(builder, xid, buf->origptr))
507  DecodeTruncate(ctx, buf);
508  break;
509 
510  case XLOG_HEAP_INPLACE:
511 
512  /*
513  * Inplace updates are only ever performed on catalog tuples and
514  * can, per definition, not change tuple visibility. Since we
515  * don't decode catalog tuples, we're not interested in the
516  * record's contents.
517  *
518  * In-place updates can be used either by XID-bearing transactions
519  * (e.g. in CREATE INDEX CONCURRENTLY) or by XID-less
520  * transactions (e.g. VACUUM). In the former case, the commit
521  * record will include cache invalidations, so we mark the
522  * transaction as catalog modifying here. Currently that's
523  * redundant because the commit will do that as well, but once we
524  * support decoding in-progress relations, this will be important.
525  */
526  if (!TransactionIdIsValid(xid))
527  break;
528 
529  (void) SnapBuildProcessChange(builder, xid, buf->origptr);
530  ReorderBufferXidSetCatalogChanges(ctx->reorder, xid, buf->origptr);
531  break;
532 
533  case XLOG_HEAP_CONFIRM:
534  if (SnapBuildProcessChange(builder, xid, buf->origptr))
535  DecodeSpecConfirm(ctx, buf);
536  break;
537 
538  case XLOG_HEAP_LOCK:
539  /* we don't care about row level locks for now */
540  break;
541 
542  default:
543  elog(ERROR, "unexpected RM_HEAP_ID record type: %u", info);
544  break;
545  }
546 }
static void DecodeDelete(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
Definition: decode.c:1022
static void DecodeInsert(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
Definition: decode.c:896
static void DecodeTruncate(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
Definition: decode.c:1076
static void DecodeUpdate(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
Definition: decode.c:955
static void DecodeSpecConfirm(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
Definition: decode.c:1220
#define XLOG_HEAP_HOT_UPDATE
Definition: heapam_xlog.h:36
#define XLOG_HEAP_DELETE
Definition: heapam_xlog.h:33
#define XLOG_HEAP_TRUNCATE
Definition: heapam_xlog.h:35
#define XLOG_HEAP_UPDATE
Definition: heapam_xlog.h:34
#define XLOG_HEAP_INPLACE
Definition: heapam_xlog.h:39
#define XLOG_HEAP_LOCK
Definition: heapam_xlog.h:38
#define XLOG_HEAP_INSERT
Definition: heapam_xlog.h:32
#define XLOG_HEAP_CONFIRM
Definition: heapam_xlog.h:37
void ReorderBufferXidSetCatalogChanges(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn)
#define TransactionIdIsValid(xid)
Definition: transam.h:41

References buf, DecodeDelete(), DecodeInsert(), DecodeSpecConfirm(), DecodeTruncate(), DecodeUpdate(), elog(), ERROR, LogicalDecodingContext::fast_forward, LogicalDecodingContext::reorder, ReorderBufferProcessXid(), ReorderBufferXidSetCatalogChanges(), SNAPBUILD_FULL_SNAPSHOT, SnapBuildCurrentState(), SnapBuildProcessChange(), LogicalDecodingContext::snapshot_builder, TransactionIdIsValid, XLOG_HEAP_CONFIRM, XLOG_HEAP_DELETE, XLOG_HEAP_HOT_UPDATE, XLOG_HEAP_INPLACE, XLOG_HEAP_INSERT, XLOG_HEAP_LOCK, XLOG_HEAP_OPMASK, XLOG_HEAP_TRUNCATE, XLOG_HEAP_UPDATE, XLogRecGetInfo, and XLogRecGetXid.

◆ LogicalDecodingProcessRecord()

void LogicalDecodingProcessRecord ( LogicalDecodingContext ctx,
XLogReaderState record 
)

Definition at line 91 of file decode.c.

92 {
94  TransactionId txid;
95  RmgrData rmgr;
96 
97  buf.origptr = ctx->reader->ReadRecPtr;
98  buf.endptr = ctx->reader->EndRecPtr;
99  buf.record = record;
100 
101  txid = XLogRecGetTopXid(record);
102 
103  /*
104  * If the top-level xid is valid, we need to assign the subxact to the
105  * top-level xact. We need to do this for all records, hence we do it
106  * before the switch.
107  */
108  if (TransactionIdIsValid(txid))
109  {
111  txid,
112  XLogRecGetXid(record),
113  buf.origptr);
114  }
115 
116  rmgr = GetRmgr(XLogRecGetRmid(record));
117 
118  if (rmgr.rm_decode != NULL)
119  rmgr.rm_decode(ctx, &buf);
120  else
121  {
122  /* just deal with xid, and done */
124  buf.origptr);
125  }
126 }
void ReorderBufferAssignChild(ReorderBuffer *rb, TransactionId xid, TransactionId subxid, XLogRecPtr lsn)
XLogReaderState * reader
Definition: logical.h:42
void(* rm_decode)(struct LogicalDecodingContext *ctx, struct XLogRecordBuffer *buf)
XLogRecPtr EndRecPtr
Definition: xlogreader.h:207
XLogRecPtr ReadRecPtr
Definition: xlogreader.h:206
static RmgrData GetRmgr(RmgrId rmid)
#define XLogRecGetRmid(decoder)
Definition: xlogreader.h:411
#define XLogRecGetTopXid(decoder)
Definition: xlogreader.h:414

References buf, XLogReaderState::EndRecPtr, GetRmgr(), LogicalDecodingContext::reader, XLogReaderState::ReadRecPtr, LogicalDecodingContext::reorder, ReorderBufferAssignChild(), ReorderBufferProcessXid(), RmgrData::rm_decode, TransactionIdIsValid, XLogRecGetRmid, XLogRecGetTopXid, and XLogRecGetXid.

Referenced by DecodingContextFindStartpoint(), LogicalReplicationSlotHasPendingWal(), pg_logical_replication_slot_advance(), pg_logical_slot_get_changes_guts(), and XLogSendLogical().

◆ logicalmsg_decode()

void logicalmsg_decode ( LogicalDecodingContext ctx,
XLogRecordBuffer buf 
)

Definition at line 588 of file decode.c.

589 {
590  SnapBuild *builder = ctx->snapshot_builder;
591  XLogReaderState *r = buf->record;
592  TransactionId xid = XLogRecGetXid(r);
593  uint8 info = XLogRecGetInfo(r) & ~XLR_INFO_MASK;
594  RepOriginId origin_id = XLogRecGetOrigin(r);
595  Snapshot snapshot = NULL;
596  xl_logical_message *message;
597 
598  if (info != XLOG_LOGICAL_MESSAGE)
599  elog(ERROR, "unexpected RM_LOGICALMSG_ID record type: %u", info);
600 
601  ReorderBufferProcessXid(ctx->reorder, XLogRecGetXid(r), buf->origptr);
602 
603  /* If we don't have snapshot, there is no point in decoding messages */
605  return;
606 
607  message = (xl_logical_message *) XLogRecGetData(r);
608 
609  if (message->dbId != ctx->slot->data.database ||
610  FilterByOrigin(ctx, origin_id))
611  return;
612 
613  if (message->transactional &&
614  !SnapBuildProcessChange(builder, xid, buf->origptr))
615  return;
616  else if (!message->transactional &&
618  SnapBuildXactNeedsSkip(builder, buf->origptr)))
619  return;
620 
621  /*
622  * We also skip decoding in fast_forward mode. This check must be last
623  * because we don't want to set the processing_required flag unless we
624  * have a decodable message.
625  */
626  if (ctx->fast_forward)
627  {
628  /*
629  * We need to set processing_required flag to notify the message's
630  * existence to the caller. Usually, the flag is set when either the
631  * COMMIT or ABORT records are decoded, but this must be turned on
632  * here because the non-transactional logical message is decoded
633  * without waiting for these records.
634  */
635  if (!message->transactional)
636  ctx->processing_required = true;
637 
638  return;
639  }
640 
641  /*
642  * If this is a non-transactional change, get the snapshot we're expected
643  * to use. We only get here when the snapshot is consistent, and the
644  * change is not meant to be skipped.
645  *
646  * For transactional changes we don't need a snapshot, we'll use the
647  * regular snapshot maintained by ReorderBuffer. We just leave it NULL.
648  */
649  if (!message->transactional)
650  snapshot = SnapBuildGetOrBuildSnapshot(builder);
651 
652  ReorderBufferQueueMessage(ctx->reorder, xid, snapshot, buf->endptr,
653  message->transactional,
654  message->message, /* first part of message is
655  * prefix */
656  message->message_size,
657  message->message + message->prefix_size);
658 }
static bool FilterByOrigin(LogicalDecodingContext *ctx, RepOriginId origin_id)
Definition: decode.c:576
#define XLOG_LOGICAL_MESSAGE
Definition: message.h:37
void ReorderBufferQueueMessage(ReorderBuffer *rb, TransactionId xid, Snapshot snap, XLogRecPtr lsn, bool transactional, const char *prefix, Size message_size, const char *message)
bool SnapBuildXactNeedsSkip(SnapBuild *builder, XLogRecPtr ptr)
Definition: snapbuild.c:434
Snapshot SnapBuildGetOrBuildSnapshot(SnapBuild *builder)
Definition: snapbuild.c:709
@ SNAPBUILD_CONSISTENT
Definition: snapbuild.h:46
ReplicationSlot * slot
Definition: logical.h:39
ReplicationSlotPersistentData data
Definition: slot.h:178
bool transactional
Definition: message.h:23
char message[FLEXIBLE_ARRAY_MEMBER]
Definition: message.h:27
uint16 RepOriginId
Definition: xlogdefs.h:65
#define XLogRecGetOrigin(decoder)
Definition: xlogreader.h:413
#define XLR_INFO_MASK
Definition: xlogrecord.h:62

References buf, ReplicationSlot::data, ReplicationSlotPersistentData::database, xl_logical_message::dbId, elog(), ERROR, LogicalDecodingContext::fast_forward, FilterByOrigin(), xl_logical_message::message, xl_logical_message::message_size, xl_logical_message::prefix_size, LogicalDecodingContext::processing_required, LogicalDecodingContext::reorder, ReorderBufferProcessXid(), ReorderBufferQueueMessage(), LogicalDecodingContext::slot, SNAPBUILD_CONSISTENT, SNAPBUILD_FULL_SNAPSHOT, SnapBuildCurrentState(), SnapBuildGetOrBuildSnapshot(), SnapBuildProcessChange(), SnapBuildXactNeedsSkip(), LogicalDecodingContext::snapshot_builder, xl_logical_message::transactional, XLOG_LOGICAL_MESSAGE, XLogRecGetData, XLogRecGetInfo, XLogRecGetOrigin, XLogRecGetXid, and XLR_INFO_MASK.

◆ standby_decode()

void standby_decode ( LogicalDecodingContext ctx,
XLogRecordBuffer buf 
)

Definition at line 361 of file decode.c.

362 {
363  SnapBuild *builder = ctx->snapshot_builder;
364  XLogReaderState *r = buf->record;
365  uint8 info = XLogRecGetInfo(r) & ~XLR_INFO_MASK;
366 
367  ReorderBufferProcessXid(ctx->reorder, XLogRecGetXid(r), buf->origptr);
368 
369  switch (info)
370  {
371  case XLOG_RUNNING_XACTS:
372  {
374 
375  SnapBuildProcessRunningXacts(builder, buf->origptr, running);
376 
377  /*
378  * Abort all transactions that we keep track of, that are
379  * older than the record's oldestRunningXid. This is the most
380  * convenient spot for doing so since, in contrast to shutdown
381  * or end-of-recovery checkpoints, we have information about
382  * all running transactions which includes prepared ones,
383  * while shutdown checkpoints just know that no non-prepared
384  * transactions are in progress.
385  */
387  }
388  break;
389  case XLOG_STANDBY_LOCK:
390  break;
391  case XLOG_INVALIDATIONS:
392 
393  /*
394  * We are processing the invalidations at the command level via
395  * XLOG_XACT_INVALIDATIONS. So we don't need to do anything here.
396  */
397  break;
398  default:
399  elog(ERROR, "unexpected RM_STANDBY_ID record type: %u", info);
400  }
401 }
void ReorderBufferAbortOld(ReorderBuffer *rb, TransactionId oldestRunningXid)
void SnapBuildProcessRunningXacts(SnapBuild *builder, XLogRecPtr lsn, xl_running_xacts *running)
Definition: snapbuild.c:1218
#define XLOG_INVALIDATIONS
Definition: standbydefs.h:36
#define XLOG_STANDBY_LOCK
Definition: standbydefs.h:34
#define XLOG_RUNNING_XACTS
Definition: standbydefs.h:35
TransactionId oldestRunningXid
Definition: standbydefs.h:53

References buf, elog(), ERROR, xl_running_xacts::oldestRunningXid, LogicalDecodingContext::reorder, ReorderBufferAbortOld(), ReorderBufferProcessXid(), SnapBuildProcessRunningXacts(), LogicalDecodingContext::snapshot_builder, XLOG_INVALIDATIONS, XLOG_RUNNING_XACTS, XLOG_STANDBY_LOCK, XLogRecGetData, XLogRecGetInfo, XLogRecGetXid, and XLR_INFO_MASK.

◆ xact_decode()

void xact_decode ( LogicalDecodingContext ctx,
XLogRecordBuffer buf 
)

Definition at line 204 of file decode.c.

205 {
206  SnapBuild *builder = ctx->snapshot_builder;
207  ReorderBuffer *reorder = ctx->reorder;
208  XLogReaderState *r = buf->record;
210 
211  /*
212  * If the snapshot isn't yet fully built, we cannot decode anything, so
213  * bail out.
214  */
216  return;
217 
218  switch (info)
219  {
220  case XLOG_XACT_COMMIT:
222  {
223  xl_xact_commit *xlrec;
224  xl_xact_parsed_commit parsed;
225  TransactionId xid;
226  bool two_phase = false;
227 
228  xlrec = (xl_xact_commit *) XLogRecGetData(r);
229  ParseCommitRecord(XLogRecGetInfo(buf->record), xlrec, &parsed);
230 
231  if (!TransactionIdIsValid(parsed.twophase_xid))
232  xid = XLogRecGetXid(r);
233  else
234  xid = parsed.twophase_xid;
235 
236  /*
237  * We would like to process the transaction in a two-phase
238  * manner iff output plugin supports two-phase commits and
239  * doesn't filter the transaction at prepare time.
240  */
241  if (info == XLOG_XACT_COMMIT_PREPARED)
242  two_phase = !(FilterPrepare(ctx, xid,
243  parsed.twophase_gid));
244 
245  DecodeCommit(ctx, buf, &parsed, xid, two_phase);
246  break;
247  }
248  case XLOG_XACT_ABORT:
250  {
251  xl_xact_abort *xlrec;
252  xl_xact_parsed_abort parsed;
253  TransactionId xid;
254  bool two_phase = false;
255 
256  xlrec = (xl_xact_abort *) XLogRecGetData(r);
257  ParseAbortRecord(XLogRecGetInfo(buf->record), xlrec, &parsed);
258 
259  if (!TransactionIdIsValid(parsed.twophase_xid))
260  xid = XLogRecGetXid(r);
261  else
262  xid = parsed.twophase_xid;
263 
264  /*
265  * We would like to process the transaction in a two-phase
266  * manner iff output plugin supports two-phase commits and
267  * doesn't filter the transaction at prepare time.
268  */
269  if (info == XLOG_XACT_ABORT_PREPARED)
270  two_phase = !(FilterPrepare(ctx, xid,
271  parsed.twophase_gid));
272 
273  DecodeAbort(ctx, buf, &parsed, xid, two_phase);
274  break;
275  }
277 
278  /*
279  * We assign subxact to the toplevel xact while processing each
280  * record if required. So, we don't need to do anything here. See
281  * LogicalDecodingProcessRecord.
282  */
283  break;
285  {
286  TransactionId xid;
287  xl_xact_invals *invals;
288 
289  xid = XLogRecGetXid(r);
290  invals = (xl_xact_invals *) XLogRecGetData(r);
291 
292  /*
293  * Execute the invalidations for xid-less transactions,
294  * otherwise, accumulate them so that they can be processed at
295  * the commit time.
296  */
297  if (TransactionIdIsValid(xid))
298  {
299  if (!ctx->fast_forward)
300  ReorderBufferAddInvalidations(reorder, xid,
301  buf->origptr,
302  invals->nmsgs,
303  invals->msgs);
305  buf->origptr);
306  }
307  else if ((!ctx->fast_forward))
309  invals->nmsgs,
310  invals->msgs);
311  }
312  break;
313  case XLOG_XACT_PREPARE:
314  {
315  xl_xact_parsed_prepare parsed;
316  xl_xact_prepare *xlrec;
317 
318  /* ok, parse it */
319  xlrec = (xl_xact_prepare *) XLogRecGetData(r);
321  xlrec, &parsed);
322 
323  /*
324  * We would like to process the transaction in a two-phase
325  * manner iff output plugin supports two-phase commits and
326  * doesn't filter the transaction at prepare time.
327  */
328  if (FilterPrepare(ctx, parsed.twophase_xid,
329  parsed.twophase_gid))
330  {
331  ReorderBufferProcessXid(reorder, parsed.twophase_xid,
332  buf->origptr);
333  break;
334  }
335 
336  /*
337  * Note that if the prepared transaction has locked [user]
338  * catalog tables exclusively then decoding prepare can block
339  * till the main transaction is committed because it needs to
340  * lock the catalog tables.
341  *
342  * XXX Now, this can even lead to a deadlock if the prepare
343  * transaction is waiting to get it logically replicated for
344  * distributed 2PC. This can be avoided by disallowing
345  * preparing transactions that have locked [user] catalog
346  * tables exclusively but as of now, we ask users not to do
347  * such an operation.
348  */
349  DecodePrepare(ctx, buf, &parsed);
350  break;
351  }
352  default:
353  elog(ERROR, "unexpected RM_XACT_ID record type: %u", info);
354  }
355 }
static void DecodeAbort(LogicalDecodingContext *ctx, XLogRecordBuffer *buf, xl_xact_parsed_abort *parsed, TransactionId xid, bool two_phase)
Definition: decode.c:840
static bool FilterPrepare(LogicalDecodingContext *ctx, TransactionId xid, const char *gid)
Definition: decode.c:553
static void DecodeCommit(LogicalDecodingContext *ctx, XLogRecordBuffer *buf, xl_xact_parsed_commit *parsed, TransactionId xid, bool two_phase)
Definition: decode.c:669
static void DecodePrepare(LogicalDecodingContext *ctx, XLogRecordBuffer *buf, xl_xact_parsed_prepare *parsed)
Definition: decode.c:765
static bool two_phase
void ReorderBufferAddInvalidations(ReorderBuffer *rb, TransactionId xid, XLogRecPtr lsn, Size nmsgs, SharedInvalidationMessage *msgs)
void ReorderBufferImmediateInvalidation(ReorderBuffer *rb, uint32 ninvalidations, SharedInvalidationMessage *invalidations)
SharedInvalidationMessage msgs[FLEXIBLE_ARRAY_MEMBER]
Definition: xact.h:299
int nmsgs
Definition: xact.h:298
TransactionId twophase_xid
Definition: xact.h:421
char twophase_gid[GIDSIZE]
Definition: xact.h:422
TransactionId twophase_xid
Definition: xact.h:391
char twophase_gid[GIDSIZE]
Definition: xact.h:392
#define XLOG_XACT_COMMIT_PREPARED
Definition: xact.h:172
#define XLOG_XACT_INVALIDATIONS
Definition: xact.h:175
#define XLOG_XACT_PREPARE
Definition: xact.h:170
#define XLOG_XACT_COMMIT
Definition: xact.h:169
#define XLOG_XACT_OPMASK
Definition: xact.h:179
#define XLOG_XACT_ABORT
Definition: xact.h:171
#define XLOG_XACT_ASSIGNMENT
Definition: xact.h:174
#define XLOG_XACT_ABORT_PREPARED
Definition: xact.h:173
void ParseCommitRecord(uint8 info, xl_xact_commit *xlrec, xl_xact_parsed_commit *parsed)
Definition: xactdesc.c:35
void ParseAbortRecord(uint8 info, xl_xact_abort *xlrec, xl_xact_parsed_abort *parsed)
Definition: xactdesc.c:141
void ParsePrepareRecord(uint8 info, xl_xact_prepare *xlrec, xl_xact_parsed_prepare *parsed)
Definition: xactdesc.c:239

References buf, DecodeAbort(), DecodeCommit(), DecodePrepare(), elog(), ERROR, LogicalDecodingContext::fast_forward, FilterPrepare(), xl_xact_invals::msgs, xl_xact_invals::nmsgs, ParseAbortRecord(), ParseCommitRecord(), ParsePrepareRecord(), LogicalDecodingContext::reorder, ReorderBufferAddInvalidations(), ReorderBufferImmediateInvalidation(), ReorderBufferProcessXid(), ReorderBufferXidSetCatalogChanges(), SNAPBUILD_FULL_SNAPSHOT, SnapBuildCurrentState(), LogicalDecodingContext::snapshot_builder, TransactionIdIsValid, two_phase, xl_xact_parsed_commit::twophase_gid, xl_xact_parsed_abort::twophase_gid, xl_xact_parsed_commit::twophase_xid, xl_xact_parsed_abort::twophase_xid, XLOG_XACT_ABORT, XLOG_XACT_ABORT_PREPARED, XLOG_XACT_ASSIGNMENT, XLOG_XACT_COMMIT, XLOG_XACT_COMMIT_PREPARED, XLOG_XACT_INVALIDATIONS, XLOG_XACT_OPMASK, XLOG_XACT_PREPARE, XLogRecGetData, XLogRecGetInfo, and XLogRecGetXid.

◆ xlog_decode()

void xlog_decode ( LogicalDecodingContext ctx,
XLogRecordBuffer buf 
)

Definition at line 132 of file decode.c.

133 {
134  SnapBuild *builder = ctx->snapshot_builder;
135  uint8 info = XLogRecGetInfo(buf->record) & ~XLR_INFO_MASK;
136 
138  buf->origptr);
139 
140  switch (info)
141  {
142  /* this is also used in END_OF_RECOVERY checkpoints */
145  SnapBuildSerializationPoint(builder, buf->origptr);
146 
147  break;
149 
150  /*
151  * a RUNNING_XACTS record will have been logged near to this, we
152  * can restart from there.
153  */
154  break;
156  {
157  xl_parameter_change *xlrec =
159 
160  /*
161  * If wal_level on the primary is reduced to less than
162  * logical, we want to prevent existing logical slots from
163  * being used. Existing logical slots on the standby get
164  * invalidated when this WAL record is replayed; and further,
165  * slot creation fails when wal_level is not sufficient; but
166  * all these operations are not synchronized, so a logical
167  * slot may creep in while the wal_level is being reduced.
168  * Hence this extra check.
169  */
170  if (xlrec->wal_level < WAL_LEVEL_LOGICAL)
171  {
172  /*
173  * This can occur only on a standby, as a primary would
174  * not allow to restart after changing wal_level < logical
175  * if there is pre-existing logical slot.
176  */
178  ereport(ERROR,
179  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
180  errmsg("logical decoding on standby requires wal_level >= logical on the primary")));
181  }
182  break;
183  }
184  case XLOG_NOOP:
185  case XLOG_NEXTOID:
186  case XLOG_SWITCH:
187  case XLOG_BACKUP_END:
188  case XLOG_RESTORE_POINT:
189  case XLOG_FPW_CHANGE:
190  case XLOG_FPI_FOR_HINT:
191  case XLOG_FPI:
194  break;
195  default:
196  elog(ERROR, "unexpected RM_XLOG_ID record type: %u", info);
197  }
198 }
int errcode(int sqlerrcode)
Definition: elog.c:860
int errmsg(const char *fmt,...)
Definition: elog.c:1075
#define ereport(elevel,...)
Definition: elog.h:149
Assert(fmt[strlen(fmt) - 1] !='\n')
#define XLOG_RESTORE_POINT
Definition: pg_control.h:74
#define XLOG_FPW_CHANGE
Definition: pg_control.h:75
#define XLOG_CHECKPOINT_REDO
Definition: pg_control.h:81
#define XLOG_OVERWRITE_CONTRECORD
Definition: pg_control.h:80
#define XLOG_FPI
Definition: pg_control.h:78
#define XLOG_FPI_FOR_HINT
Definition: pg_control.h:77
#define XLOG_NEXTOID
Definition: pg_control.h:70
#define XLOG_NOOP
Definition: pg_control.h:69
#define XLOG_CHECKPOINT_SHUTDOWN
Definition: pg_control.h:67
#define XLOG_SWITCH
Definition: pg_control.h:71
#define XLOG_BACKUP_END
Definition: pg_control.h:72
#define XLOG_PARAMETER_CHANGE
Definition: pg_control.h:73
#define XLOG_CHECKPOINT_ONLINE
Definition: pg_control.h:68
#define XLOG_END_OF_RECOVERY
Definition: pg_control.h:76
void SnapBuildSerializationPoint(SnapBuild *builder, XLogRecPtr lsn)
Definition: snapbuild.c:1593
bool RecoveryInProgress(void)
Definition: xlog.c:6211
@ WAL_LEVEL_LOGICAL
Definition: xlog.h:74

References Assert(), buf, elog(), ereport, errcode(), errmsg(), ERROR, RecoveryInProgress(), LogicalDecodingContext::reorder, ReorderBufferProcessXid(), SnapBuildSerializationPoint(), LogicalDecodingContext::snapshot_builder, xl_parameter_change::wal_level, WAL_LEVEL_LOGICAL, XLOG_BACKUP_END, XLOG_CHECKPOINT_ONLINE, XLOG_CHECKPOINT_REDO, XLOG_CHECKPOINT_SHUTDOWN, XLOG_END_OF_RECOVERY, XLOG_FPI, XLOG_FPI_FOR_HINT, XLOG_FPW_CHANGE, XLOG_NEXTOID, XLOG_NOOP, XLOG_OVERWRITE_CONTRECORD, XLOG_PARAMETER_CHANGE, XLOG_RESTORE_POINT, XLOG_SWITCH, XLogRecGetData, XLogRecGetInfo, XLogRecGetXid, and XLR_INFO_MASK.