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1 : : /*-------------------------------------------------------------------------
2 : : * logical.c
3 : : * PostgreSQL logical decoding coordination
4 : : *
5 : : * Copyright (c) 2012-2026, PostgreSQL Global Development Group
6 : : *
7 : : * IDENTIFICATION
8 : : * src/backend/replication/logical/logical.c
9 : : *
10 : : * NOTES
11 : : * This file coordinates interaction between the various modules that
12 : : * together provide logical decoding, primarily by providing so
13 : : * called LogicalDecodingContexts. The goal is to encapsulate most of the
14 : : * internal complexity for consumers of logical decoding, so they can
15 : : * create and consume a changestream with a low amount of code. Builtin
16 : : * consumers are the walsender and SQL SRF interface, but it's possible to
17 : : * add further ones without changing core code, e.g. to consume changes in
18 : : * a bgworker.
19 : : *
20 : : * The idea is that a consumer provides three callbacks, one to read WAL,
21 : : * one to prepare a data write, and a final one for actually writing since
22 : : * their implementation depends on the type of consumer. Check
23 : : * logicalfuncs.c for an example implementation of a fairly simple consumer
24 : : * and an implementation of a WAL reading callback that's suitable for
25 : : * simple consumers.
26 : : *-------------------------------------------------------------------------
27 : : */
28 : :
29 : : #include "postgres.h"
30 : :
31 : : #include "access/xact.h"
32 : : #include "access/xlog_internal.h"
33 : : #include "access/xlogutils.h"
34 : : #include "fmgr.h"
35 : : #include "miscadmin.h"
36 : : #include "pgstat.h"
37 : : #include "replication/decode.h"
38 : : #include "replication/logical.h"
39 : : #include "replication/reorderbuffer.h"
40 : : #include "replication/slotsync.h"
41 : : #include "replication/snapbuild.h"
42 : : #include "storage/proc.h"
43 : : #include "storage/procarray.h"
44 : : #include "utils/builtins.h"
45 : : #include "utils/injection_point.h"
46 : : #include "utils/inval.h"
47 : : #include "utils/memutils.h"
48 : :
49 : : /* data for errcontext callback */
50 : : typedef struct LogicalErrorCallbackState
51 : : {
52 : : LogicalDecodingContext *ctx;
53 : : const char *callback_name;
54 : : XLogRecPtr report_location;
55 : : } LogicalErrorCallbackState;
56 : :
57 : : /* wrappers around output plugin callbacks */
58 : : static void output_plugin_error_callback(void *arg);
59 : : static void startup_cb_wrapper(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
60 : : bool is_init);
61 : : static void shutdown_cb_wrapper(LogicalDecodingContext *ctx);
62 : : static void begin_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn);
63 : : static void commit_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
64 : : XLogRecPtr commit_lsn);
65 : : static void begin_prepare_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn);
66 : : static void prepare_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
67 : : XLogRecPtr prepare_lsn);
68 : : static void commit_prepared_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
69 : : XLogRecPtr commit_lsn);
70 : : static void rollback_prepared_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
71 : : XLogRecPtr prepare_end_lsn, TimestampTz prepare_time);
72 : : static void change_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
73 : : Relation relation, ReorderBufferChange *change);
74 : : static void truncate_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
75 : : int nrelations, Relation relations[], ReorderBufferChange *change);
76 : : static void message_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
77 : : XLogRecPtr message_lsn, bool transactional,
78 : : const char *prefix, Size message_size, const char *message);
79 : :
80 : : /* streaming callbacks */
81 : : static void stream_start_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
82 : : XLogRecPtr first_lsn);
83 : : static void stream_stop_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
84 : : XLogRecPtr last_lsn);
85 : : static void stream_abort_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
86 : : XLogRecPtr abort_lsn);
87 : : static void stream_prepare_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
88 : : XLogRecPtr prepare_lsn);
89 : : static void stream_commit_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
90 : : XLogRecPtr commit_lsn);
91 : : static void stream_change_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
92 : : Relation relation, ReorderBufferChange *change);
93 : : static void stream_message_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
94 : : XLogRecPtr message_lsn, bool transactional,
95 : : const char *prefix, Size message_size, const char *message);
96 : : static void stream_truncate_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
97 : : int nrelations, Relation relations[], ReorderBufferChange *change);
98 : :
99 : : /* callback to update txn's progress */
100 : : static void update_progress_txn_cb_wrapper(ReorderBuffer *cache,
101 : : ReorderBufferTXN *txn,
102 : : XLogRecPtr lsn);
103 : :
104 : : static void LoadOutputPlugin(OutputPluginCallbacks *callbacks, const char *plugin);
105 : :
106 : : /*
107 : : * Make sure the current settings & environment are capable of doing logical
108 : : * decoding.
109 : : */
110 : : void
111 : 0 : CheckLogicalDecodingRequirements(void)
112 : : {
113 : 0 : CheckSlotRequirements();
114 : :
115 : : /*
116 : : * NB: Adding a new requirement likely means that RestoreSlotFromDisk()
117 : : * needs the same check.
118 : : */
119 : :
120 [ # # ]: 0 : if (MyDatabaseId == InvalidOid)
121 [ # # # # ]: 0 : ereport(ERROR,
122 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
123 : : errmsg("logical decoding requires a database connection")));
124 : :
125 : : /* CheckSlotRequirements() has already checked if wal_level >= 'replica' */
126 [ # # ]: 0 : Assert(wal_level >= WAL_LEVEL_REPLICA);
127 : :
128 : : /* Check if logical decoding is available on standby */
129 [ # # # # ]: 0 : if (RecoveryInProgress() && !IsLogicalDecodingEnabled())
130 [ # # # # ]: 0 : ereport(ERROR,
131 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
132 : : errmsg("logical decoding on standby requires \"effective_wal_level\" >= \"logical\" on the primary"),
133 : : errhint("Set \"wal_level\" >= \"logical\" or create at least one logical slot when \"wal_level\" = \"replica\".")));
134 : 0 : }
135 : :
136 : : /*
137 : : * Helper function for CreateInitDecodingContext() and
138 : : * CreateDecodingContext() performing common tasks.
139 : : */
140 : : static LogicalDecodingContext *
141 : 0 : StartupDecodingContext(List *output_plugin_options,
142 : : XLogRecPtr start_lsn,
143 : : TransactionId xmin_horizon,
144 : : bool need_full_snapshot,
145 : : bool fast_forward,
146 : : bool in_create,
147 : : XLogReaderRoutine *xl_routine,
148 : : LogicalOutputPluginWriterPrepareWrite prepare_write,
149 : : LogicalOutputPluginWriterWrite do_write,
150 : : LogicalOutputPluginWriterUpdateProgress update_progress)
151 : : {
152 : 0 : ReplicationSlot *slot;
153 : 0 : MemoryContext context,
154 : : old_context;
155 : 0 : LogicalDecodingContext *ctx;
156 : :
157 : : /* shorter lines... */
158 : 0 : slot = MyReplicationSlot;
159 : :
160 : 0 : context = AllocSetContextCreate(CurrentMemoryContext,
161 : : "Logical decoding context",
162 : : ALLOCSET_DEFAULT_SIZES);
163 : 0 : old_context = MemoryContextSwitchTo(context);
164 : 0 : ctx = palloc0_object(LogicalDecodingContext);
165 : :
166 : 0 : ctx->context = context;
167 : :
168 : : /*
169 : : * (re-)load output plugins, so we detect a bad (removed) output plugin
170 : : * now.
171 : : */
172 [ # # ]: 0 : if (!fast_forward)
173 : 0 : LoadOutputPlugin(&ctx->callbacks, NameStr(slot->data.plugin));
174 : :
175 : : /*
176 : : * Now that the slot's xmin has been set, we can announce ourselves as a
177 : : * logical decoding backend which doesn't need to be checked individually
178 : : * when computing the xmin horizon because the xmin is enforced via
179 : : * replication slots.
180 : : *
181 : : * We can only do so if we're outside of a transaction (i.e. the case when
182 : : * streaming changes via walsender), otherwise an already setup
183 : : * snapshot/xid would end up being ignored. That's not a particularly
184 : : * bothersome restriction since the SQL interface can't be used for
185 : : * streaming anyway.
186 : : */
187 [ # # ]: 0 : if (!IsTransactionOrTransactionBlock())
188 : : {
189 : 0 : LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
190 : 0 : MyProc->statusFlags |= PROC_IN_LOGICAL_DECODING;
191 : 0 : ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags;
192 : 0 : LWLockRelease(ProcArrayLock);
193 : 0 : }
194 : :
195 : 0 : ctx->slot = slot;
196 : :
197 : 0 : ctx->reader = XLogReaderAllocate(wal_segment_size, NULL, xl_routine, ctx);
198 [ # # ]: 0 : if (!ctx->reader)
199 [ # # # # ]: 0 : ereport(ERROR,
200 : : (errcode(ERRCODE_OUT_OF_MEMORY),
201 : : errmsg("out of memory"),
202 : : errdetail("Failed while allocating a WAL reading processor.")));
203 : :
204 : 0 : ctx->reorder = ReorderBufferAllocate();
205 : 0 : ctx->snapshot_builder =
206 : 0 : AllocateSnapshotBuilder(ctx->reorder, xmin_horizon, start_lsn,
207 : 0 : need_full_snapshot, in_create, slot->data.two_phase_at);
208 : :
209 : 0 : ctx->reorder->private_data = ctx;
210 : :
211 : : /* wrap output plugin callbacks, so we can add error context information */
212 : 0 : ctx->reorder->begin = begin_cb_wrapper;
213 : 0 : ctx->reorder->apply_change = change_cb_wrapper;
214 : 0 : ctx->reorder->apply_truncate = truncate_cb_wrapper;
215 : 0 : ctx->reorder->commit = commit_cb_wrapper;
216 : 0 : ctx->reorder->message = message_cb_wrapper;
217 : :
218 : : /*
219 : : * To support streaming, we require start/stop/abort/commit/change
220 : : * callbacks. The message and truncate callbacks are optional, similar to
221 : : * regular output plugins. We however enable streaming when at least one
222 : : * of the methods is enabled so that we can easily identify missing
223 : : * methods.
224 : : *
225 : : * We decide it here, but only check it later in the wrappers.
226 : : */
227 [ # # ]: 0 : ctx->streaming = (ctx->callbacks.stream_start_cb != NULL) ||
228 [ # # ]: 0 : (ctx->callbacks.stream_stop_cb != NULL) ||
229 [ # # ]: 0 : (ctx->callbacks.stream_abort_cb != NULL) ||
230 [ # # ]: 0 : (ctx->callbacks.stream_commit_cb != NULL) ||
231 [ # # ]: 0 : (ctx->callbacks.stream_change_cb != NULL) ||
232 [ # # ]: 0 : (ctx->callbacks.stream_message_cb != NULL) ||
233 : 0 : (ctx->callbacks.stream_truncate_cb != NULL);
234 : :
235 : : /*
236 : : * streaming callbacks
237 : : *
238 : : * stream_message and stream_truncate callbacks are optional, so we do not
239 : : * fail with ERROR when missing, but the wrappers simply do nothing. We
240 : : * must set the ReorderBuffer callbacks to something, otherwise the calls
241 : : * from there will crash (we don't want to move the checks there).
242 : : */
243 : 0 : ctx->reorder->stream_start = stream_start_cb_wrapper;
244 : 0 : ctx->reorder->stream_stop = stream_stop_cb_wrapper;
245 : 0 : ctx->reorder->stream_abort = stream_abort_cb_wrapper;
246 : 0 : ctx->reorder->stream_prepare = stream_prepare_cb_wrapper;
247 : 0 : ctx->reorder->stream_commit = stream_commit_cb_wrapper;
248 : 0 : ctx->reorder->stream_change = stream_change_cb_wrapper;
249 : 0 : ctx->reorder->stream_message = stream_message_cb_wrapper;
250 : 0 : ctx->reorder->stream_truncate = stream_truncate_cb_wrapper;
251 : :
252 : :
253 : : /*
254 : : * To support two-phase logical decoding, we require
255 : : * begin_prepare/prepare/commit-prepare/abort-prepare callbacks. The
256 : : * filter_prepare callback is optional. We however enable two-phase
257 : : * logical decoding when at least one of the methods is enabled so that we
258 : : * can easily identify missing methods.
259 : : *
260 : : * We decide it here, but only check it later in the wrappers.
261 : : */
262 [ # # ]: 0 : ctx->twophase = (ctx->callbacks.begin_prepare_cb != NULL) ||
263 [ # # ]: 0 : (ctx->callbacks.prepare_cb != NULL) ||
264 [ # # ]: 0 : (ctx->callbacks.commit_prepared_cb != NULL) ||
265 [ # # ]: 0 : (ctx->callbacks.rollback_prepared_cb != NULL) ||
266 [ # # ]: 0 : (ctx->callbacks.stream_prepare_cb != NULL) ||
267 : 0 : (ctx->callbacks.filter_prepare_cb != NULL);
268 : :
269 : : /*
270 : : * Callback to support decoding at prepare time.
271 : : */
272 : 0 : ctx->reorder->begin_prepare = begin_prepare_cb_wrapper;
273 : 0 : ctx->reorder->prepare = prepare_cb_wrapper;
274 : 0 : ctx->reorder->commit_prepared = commit_prepared_cb_wrapper;
275 : 0 : ctx->reorder->rollback_prepared = rollback_prepared_cb_wrapper;
276 : :
277 : : /*
278 : : * Callback to support updating progress during sending data of a
279 : : * transaction (and its subtransactions) to the output plugin.
280 : : */
281 : 0 : ctx->reorder->update_progress_txn = update_progress_txn_cb_wrapper;
282 : :
283 : 0 : ctx->out = makeStringInfo();
284 : 0 : ctx->prepare_write = prepare_write;
285 : 0 : ctx->write = do_write;
286 : 0 : ctx->update_progress = update_progress;
287 : :
288 : 0 : ctx->output_plugin_options = output_plugin_options;
289 : :
290 : 0 : ctx->fast_forward = fast_forward;
291 : :
292 : 0 : MemoryContextSwitchTo(old_context);
293 : :
294 : 0 : return ctx;
295 : 0 : }
296 : :
297 : : /*
298 : : * Create a new decoding context, for a new logical slot.
299 : : *
300 : : * plugin -- contains the name of the output plugin
301 : : * output_plugin_options -- contains options passed to the output plugin
302 : : * need_full_snapshot -- if true, must obtain a snapshot able to read all
303 : : * tables; if false, one that can read only catalogs is acceptable.
304 : : * restart_lsn -- if given as invalid, it's this routine's responsibility to
305 : : * mark WAL as reserved by setting a convenient restart_lsn for the slot.
306 : : * Otherwise, we set for decoding to start from the given LSN without
307 : : * marking WAL reserved beforehand. In that scenario, it's up to the
308 : : * caller to guarantee that WAL remains available.
309 : : * xl_routine -- XLogReaderRoutine for underlying XLogReader
310 : : * prepare_write, do_write, update_progress --
311 : : * callbacks that perform the use-case dependent, actual, work.
312 : : *
313 : : * Needs to be called while in a memory context that's at least as long lived
314 : : * as the decoding context because further memory contexts will be created
315 : : * inside it.
316 : : *
317 : : * Returns an initialized decoding context after calling the output plugin's
318 : : * startup function.
319 : : */
320 : : LogicalDecodingContext *
321 : 0 : CreateInitDecodingContext(const char *plugin,
322 : : List *output_plugin_options,
323 : : bool need_full_snapshot,
324 : : XLogRecPtr restart_lsn,
325 : : XLogReaderRoutine *xl_routine,
326 : : LogicalOutputPluginWriterPrepareWrite prepare_write,
327 : : LogicalOutputPluginWriterWrite do_write,
328 : : LogicalOutputPluginWriterUpdateProgress update_progress)
329 : : {
330 : 0 : TransactionId xmin_horizon = InvalidTransactionId;
331 : 0 : ReplicationSlot *slot;
332 : 0 : NameData plugin_name;
333 : 0 : LogicalDecodingContext *ctx;
334 : 0 : MemoryContext old_context;
335 : :
336 : : /*
337 : : * On a standby, this check is also required while creating the slot.
338 : : * Check the comments in the function.
339 : : */
340 : 0 : CheckLogicalDecodingRequirements();
341 : :
342 : : /* shorter lines... */
343 : 0 : slot = MyReplicationSlot;
344 : :
345 : : /* first some sanity checks that are unlikely to be violated */
346 [ # # ]: 0 : if (slot == NULL)
347 [ # # # # ]: 0 : elog(ERROR, "cannot perform logical decoding without an acquired slot");
348 : :
349 [ # # ]: 0 : if (plugin == NULL)
350 [ # # # # ]: 0 : elog(ERROR, "cannot initialize logical decoding without a specified plugin");
351 : :
352 : : /* Make sure the passed slot is suitable. These are user facing errors. */
353 [ # # ]: 0 : if (SlotIsPhysical(slot))
354 [ # # # # ]: 0 : ereport(ERROR,
355 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
356 : : errmsg("cannot use physical replication slot for logical decoding")));
357 : :
358 [ # # ]: 0 : if (slot->data.database != MyDatabaseId)
359 [ # # # # ]: 0 : ereport(ERROR,
360 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
361 : : errmsg("replication slot \"%s\" was not created in this database",
362 : : NameStr(slot->data.name))));
363 : :
364 [ # # # # ]: 0 : if (IsTransactionState() &&
365 : 0 : GetTopTransactionIdIfAny() != InvalidTransactionId)
366 [ # # # # ]: 0 : ereport(ERROR,
367 : : (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
368 : : errmsg("cannot create logical replication slot in transaction that has performed writes")));
369 : :
370 : : /*
371 : : * Register output plugin name with slot. We need the mutex to avoid
372 : : * concurrent reading of a partially copied string. But we don't want any
373 : : * complicated code while holding a spinlock, so do namestrcpy() outside.
374 : : */
375 : 0 : namestrcpy(&plugin_name, plugin);
376 [ # # ]: 0 : SpinLockAcquire(&slot->mutex);
377 : 0 : slot->data.plugin = plugin_name;
378 : 0 : SpinLockRelease(&slot->mutex);
379 : :
380 [ # # ]: 0 : if (!XLogRecPtrIsValid(restart_lsn))
381 : 0 : ReplicationSlotReserveWal();
382 : : else
383 : : {
384 [ # # ]: 0 : SpinLockAcquire(&slot->mutex);
385 : 0 : slot->data.restart_lsn = restart_lsn;
386 : 0 : SpinLockRelease(&slot->mutex);
387 : : }
388 : :
389 : : /* ----
390 : : * This is a bit tricky: We need to determine a safe xmin horizon to start
391 : : * decoding from, to avoid starting from a running xacts record referring
392 : : * to xids whose rows have been vacuumed or pruned
393 : : * already. GetOldestSafeDecodingTransactionId() returns such a value, but
394 : : * without further interlock its return value might immediately be out of
395 : : * date.
396 : : *
397 : : * So we have to acquire both the ReplicationSlotControlLock and the
398 : : * ProcArrayLock to prevent concurrent computation and update of new xmin
399 : : * horizons by other backends, get the safe decoding xid, and inform the
400 : : * slot machinery about the new limit. Once that's done both locks can be
401 : : * released as the slot machinery now is protecting against vacuum.
402 : : *
403 : : * Note that, temporarily, the data, not just the catalog, xmin has to be
404 : : * reserved if a data snapshot is to be exported. Otherwise the initial
405 : : * data snapshot created here is not guaranteed to be valid. After that
406 : : * the data xmin doesn't need to be managed anymore and the global xmin
407 : : * should be recomputed. As we are fine with losing the pegged data xmin
408 : : * after crash - no chance a snapshot would get exported anymore - we can
409 : : * get away with just setting the slot's
410 : : * effective_xmin. ReplicationSlotRelease will reset it again.
411 : : *
412 : : * ----
413 : : */
414 : 0 : LWLockAcquire(ReplicationSlotControlLock, LW_EXCLUSIVE);
415 : 0 : LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
416 : :
417 : 0 : xmin_horizon = GetOldestSafeDecodingTransactionId(!need_full_snapshot);
418 : :
419 [ # # ]: 0 : SpinLockAcquire(&slot->mutex);
420 : 0 : slot->effective_catalog_xmin = xmin_horizon;
421 : 0 : slot->data.catalog_xmin = xmin_horizon;
422 [ # # ]: 0 : if (need_full_snapshot)
423 : 0 : slot->effective_xmin = xmin_horizon;
424 : 0 : SpinLockRelease(&slot->mutex);
425 : :
426 : 0 : ReplicationSlotsComputeRequiredXmin(true);
427 : :
428 : 0 : LWLockRelease(ProcArrayLock);
429 : 0 : LWLockRelease(ReplicationSlotControlLock);
430 : :
431 : 0 : ReplicationSlotMarkDirty();
432 : 0 : ReplicationSlotSave();
433 : :
434 : 0 : ctx = StartupDecodingContext(NIL, restart_lsn, xmin_horizon,
435 : 0 : need_full_snapshot, false, true,
436 : 0 : xl_routine, prepare_write, do_write,
437 : 0 : update_progress);
438 : :
439 : : /* call output plugin initialization callback */
440 : 0 : old_context = MemoryContextSwitchTo(ctx->context);
441 [ # # ]: 0 : if (ctx->callbacks.startup_cb != NULL)
442 : 0 : startup_cb_wrapper(ctx, &ctx->options, true);
443 : 0 : MemoryContextSwitchTo(old_context);
444 : :
445 : : /*
446 : : * We allow decoding of prepared transactions when the two_phase is
447 : : * enabled at the time of slot creation, or when the two_phase option is
448 : : * given at the streaming start, provided the plugin supports all the
449 : : * callbacks for two-phase.
450 : : */
451 : 0 : ctx->twophase &= slot->data.two_phase;
452 : :
453 : 0 : ctx->reorder->output_rewrites = ctx->options.receive_rewrites;
454 : :
455 : 0 : return ctx;
456 : 0 : }
457 : :
458 : : /*
459 : : * Create a new decoding context, for a logical slot that has previously been
460 : : * used already.
461 : : *
462 : : * start_lsn
463 : : * The LSN at which to start decoding. If InvalidXLogRecPtr, restart
464 : : * from the slot's confirmed_flush; otherwise, start from the specified
465 : : * location (but move it forwards to confirmed_flush if it's older than
466 : : * that, see below).
467 : : *
468 : : * output_plugin_options
469 : : * options passed to the output plugin.
470 : : *
471 : : * fast_forward
472 : : * bypass the generation of logical changes.
473 : : *
474 : : * xl_routine
475 : : * XLogReaderRoutine used by underlying xlogreader
476 : : *
477 : : * prepare_write, do_write, update_progress
478 : : * callbacks that have to be filled to perform the use-case dependent,
479 : : * actual work.
480 : : *
481 : : * Needs to be called while in a memory context that's at least as long lived
482 : : * as the decoding context because further memory contexts will be created
483 : : * inside it.
484 : : *
485 : : * Returns an initialized decoding context after calling the output plugin's
486 : : * startup function.
487 : : */
488 : : LogicalDecodingContext *
489 : 0 : CreateDecodingContext(XLogRecPtr start_lsn,
490 : : List *output_plugin_options,
491 : : bool fast_forward,
492 : : XLogReaderRoutine *xl_routine,
493 : : LogicalOutputPluginWriterPrepareWrite prepare_write,
494 : : LogicalOutputPluginWriterWrite do_write,
495 : : LogicalOutputPluginWriterUpdateProgress update_progress)
496 : : {
497 : 0 : LogicalDecodingContext *ctx;
498 : 0 : ReplicationSlot *slot;
499 : 0 : MemoryContext old_context;
500 : :
501 : : /* shorter lines... */
502 : 0 : slot = MyReplicationSlot;
503 : :
504 : : /* first some sanity checks that are unlikely to be violated */
505 [ # # ]: 0 : if (slot == NULL)
506 [ # # # # ]: 0 : elog(ERROR, "cannot perform logical decoding without an acquired slot");
507 : :
508 : : /* make sure the passed slot is suitable, these are user facing errors */
509 [ # # ]: 0 : if (SlotIsPhysical(slot))
510 [ # # # # ]: 0 : ereport(ERROR,
511 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
512 : : errmsg("cannot use physical replication slot for logical decoding")));
513 : :
514 : : /*
515 : : * We need to access the system tables during decoding to build the
516 : : * logical changes unless we are in fast_forward mode where no changes are
517 : : * generated.
518 : : */
519 [ # # # # ]: 0 : if (slot->data.database != MyDatabaseId && !fast_forward)
520 [ # # # # ]: 0 : ereport(ERROR,
521 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
522 : : errmsg("replication slot \"%s\" was not created in this database",
523 : : NameStr(slot->data.name))));
524 : :
525 : : /*
526 : : * The slots being synced from the primary can't be used for decoding as
527 : : * they are used after failover. However, we do allow advancing the LSNs
528 : : * during the synchronization of slots. See update_local_synced_slot.
529 : : */
530 [ # # # # : 0 : if (RecoveryInProgress() && slot->data.synced && !IsSyncingReplicationSlots())
# # ]
531 [ # # # # ]: 0 : ereport(ERROR,
532 : : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
533 : : errmsg("cannot use replication slot \"%s\" for logical decoding",
534 : : NameStr(slot->data.name)),
535 : : errdetail("This replication slot is being synchronized from the primary server."),
536 : : errhint("Specify another replication slot."));
537 : :
538 : : /* slot must be valid to allow decoding */
539 [ # # ]: 0 : Assert(slot->data.invalidated == RS_INVAL_NONE);
540 [ # # ]: 0 : Assert(XLogRecPtrIsValid(slot->data.restart_lsn));
541 : :
542 [ # # ]: 0 : if (!XLogRecPtrIsValid(start_lsn))
543 : : {
544 : : /* continue from last position */
545 : 0 : start_lsn = slot->data.confirmed_flush;
546 : 0 : }
547 [ # # ]: 0 : else if (start_lsn < slot->data.confirmed_flush)
548 : : {
549 : : /*
550 : : * It might seem like we should error out in this case, but it's
551 : : * pretty common for a client to acknowledge a LSN it doesn't have to
552 : : * do anything for, and thus didn't store persistently, because the
553 : : * xlog records didn't result in anything relevant for logical
554 : : * decoding. Clients have to be able to do that to support synchronous
555 : : * replication.
556 : : *
557 : : * Starting at a different LSN than requested might not catch certain
558 : : * kinds of client errors; so the client may wish to check that
559 : : * confirmed_flush_lsn matches its expectations.
560 : : */
561 [ # # # # ]: 0 : elog(LOG, "%X/%08X has been already streamed, forwarding to %X/%08X",
562 : : LSN_FORMAT_ARGS(start_lsn),
563 : : LSN_FORMAT_ARGS(slot->data.confirmed_flush));
564 : :
565 : 0 : start_lsn = slot->data.confirmed_flush;
566 : 0 : }
567 : :
568 : 0 : ctx = StartupDecodingContext(output_plugin_options,
569 : 0 : start_lsn, InvalidTransactionId, false,
570 : 0 : fast_forward, false, xl_routine, prepare_write,
571 : 0 : do_write, update_progress);
572 : :
573 : : /* call output plugin initialization callback */
574 : 0 : old_context = MemoryContextSwitchTo(ctx->context);
575 [ # # ]: 0 : if (ctx->callbacks.startup_cb != NULL)
576 : 0 : startup_cb_wrapper(ctx, &ctx->options, false);
577 : 0 : MemoryContextSwitchTo(old_context);
578 : :
579 : : /*
580 : : * We allow decoding of prepared transactions when the two_phase is
581 : : * enabled at the time of slot creation, or when the two_phase option is
582 : : * given at the streaming start, provided the plugin supports all the
583 : : * callbacks for two-phase.
584 : : */
585 [ # # ]: 0 : ctx->twophase &= (slot->data.two_phase || ctx->twophase_opt_given);
586 : :
587 : : /* Mark slot to allow two_phase decoding if not already marked */
588 [ # # # # ]: 0 : if (ctx->twophase && !slot->data.two_phase)
589 : : {
590 [ # # ]: 0 : SpinLockAcquire(&slot->mutex);
591 : 0 : slot->data.two_phase = true;
592 : 0 : slot->data.two_phase_at = start_lsn;
593 : 0 : SpinLockRelease(&slot->mutex);
594 : 0 : ReplicationSlotMarkDirty();
595 : 0 : ReplicationSlotSave();
596 : 0 : SnapBuildSetTwoPhaseAt(ctx->snapshot_builder, start_lsn);
597 : 0 : }
598 : :
599 : 0 : ctx->reorder->output_rewrites = ctx->options.receive_rewrites;
600 : :
601 [ # # # # ]: 0 : ereport(LOG,
602 : : (errmsg("starting logical decoding for slot \"%s\"",
603 : : NameStr(slot->data.name)),
604 : : errdetail("Streaming transactions committing after %X/%08X, reading WAL from %X/%08X.",
605 : : LSN_FORMAT_ARGS(slot->data.confirmed_flush),
606 : : LSN_FORMAT_ARGS(slot->data.restart_lsn))));
607 : :
608 : 0 : return ctx;
609 : 0 : }
610 : :
611 : : /*
612 : : * Returns true if a consistent initial decoding snapshot has been built.
613 : : */
614 : : bool
615 : 0 : DecodingContextReady(LogicalDecodingContext *ctx)
616 : : {
617 : 0 : return SnapBuildCurrentState(ctx->snapshot_builder) == SNAPBUILD_CONSISTENT;
618 : : }
619 : :
620 : : /*
621 : : * Read from the decoding slot, until it is ready to start extracting changes.
622 : : */
623 : : void
624 : 0 : DecodingContextFindStartpoint(LogicalDecodingContext *ctx)
625 : : {
626 : 0 : ReplicationSlot *slot = ctx->slot;
627 : :
628 : : /* Initialize from where to start reading WAL. */
629 : 0 : XLogBeginRead(ctx->reader, slot->data.restart_lsn);
630 : :
631 [ # # # # ]: 0 : elog(DEBUG1, "searching for logical decoding starting point, starting at %X/%08X",
632 : : LSN_FORMAT_ARGS(slot->data.restart_lsn));
633 : :
634 : : /* Wait for a consistent starting point */
635 : 0 : for (;;)
636 : : {
637 : 0 : XLogRecord *record;
638 : 0 : char *err = NULL;
639 : :
640 : : /* the read_page callback waits for new WAL */
641 : 0 : record = XLogReadRecord(ctx->reader, &err);
642 [ # # ]: 0 : if (err)
643 [ # # # # ]: 0 : elog(ERROR, "could not find logical decoding starting point: %s", err);
644 [ # # ]: 0 : if (!record)
645 [ # # # # ]: 0 : elog(ERROR, "could not find logical decoding starting point");
646 : :
647 : 0 : LogicalDecodingProcessRecord(ctx, ctx->reader);
648 : :
649 : : /* only continue till we found a consistent spot */
650 [ # # ]: 0 : if (DecodingContextReady(ctx))
651 : 0 : break;
652 : :
653 [ # # ]: 0 : CHECK_FOR_INTERRUPTS();
654 [ # # # ]: 0 : }
655 : :
656 [ # # ]: 0 : SpinLockAcquire(&slot->mutex);
657 : 0 : slot->data.confirmed_flush = ctx->reader->EndRecPtr;
658 [ # # ]: 0 : if (slot->data.two_phase)
659 : 0 : slot->data.two_phase_at = ctx->reader->EndRecPtr;
660 : 0 : SpinLockRelease(&slot->mutex);
661 : 0 : }
662 : :
663 : : /*
664 : : * Free a previously allocated decoding context, invoking the shutdown
665 : : * callback if necessary.
666 : : */
667 : : void
668 : 0 : FreeDecodingContext(LogicalDecodingContext *ctx)
669 : : {
670 [ # # ]: 0 : if (ctx->callbacks.shutdown_cb != NULL)
671 : 0 : shutdown_cb_wrapper(ctx);
672 : :
673 : 0 : ReorderBufferFree(ctx->reorder);
674 : 0 : FreeSnapshotBuilder(ctx->snapshot_builder);
675 : 0 : XLogReaderFree(ctx->reader);
676 : 0 : MemoryContextDelete(ctx->context);
677 : 0 : }
678 : :
679 : : /*
680 : : * Prepare a write using the context's output routine.
681 : : */
682 : : void
683 : 0 : OutputPluginPrepareWrite(struct LogicalDecodingContext *ctx, bool last_write)
684 : : {
685 [ # # ]: 0 : if (!ctx->accept_writes)
686 [ # # # # ]: 0 : elog(ERROR, "writes are only accepted in commit, begin and change callbacks");
687 : :
688 : 0 : ctx->prepare_write(ctx, ctx->write_location, ctx->write_xid, last_write);
689 : 0 : ctx->prepared_write = true;
690 : 0 : }
691 : :
692 : : /*
693 : : * Perform a write using the context's output routine.
694 : : */
695 : : void
696 : 0 : OutputPluginWrite(struct LogicalDecodingContext *ctx, bool last_write)
697 : : {
698 [ # # ]: 0 : if (!ctx->prepared_write)
699 [ # # # # ]: 0 : elog(ERROR, "OutputPluginPrepareWrite needs to be called before OutputPluginWrite");
700 : :
701 : 0 : ctx->write(ctx, ctx->write_location, ctx->write_xid, last_write);
702 : 0 : ctx->prepared_write = false;
703 : 0 : }
704 : :
705 : : /*
706 : : * Update progress tracking (if supported).
707 : : */
708 : : void
709 : 0 : OutputPluginUpdateProgress(struct LogicalDecodingContext *ctx,
710 : : bool skipped_xact)
711 : : {
712 [ # # ]: 0 : if (!ctx->update_progress)
713 : 0 : return;
714 : :
715 : 0 : ctx->update_progress(ctx, ctx->write_location, ctx->write_xid,
716 : 0 : skipped_xact);
717 : 0 : }
718 : :
719 : : /*
720 : : * Load the output plugin, lookup its output plugin init function, and check
721 : : * that it provides the required callbacks.
722 : : */
723 : : static void
724 : 0 : LoadOutputPlugin(OutputPluginCallbacks *callbacks, const char *plugin)
725 : : {
726 : 0 : LogicalOutputPluginInit plugin_init;
727 : :
728 : 0 : plugin_init = (LogicalOutputPluginInit)
729 : 0 : load_external_function(plugin, "_PG_output_plugin_init", false, NULL);
730 : :
731 [ # # ]: 0 : if (plugin_init == NULL)
732 [ # # # # ]: 0 : elog(ERROR, "output plugins have to declare the _PG_output_plugin_init symbol");
733 : :
734 : : /* ask the output plugin to fill the callback struct */
735 : 0 : plugin_init(callbacks);
736 : :
737 [ # # ]: 0 : if (callbacks->begin_cb == NULL)
738 [ # # # # ]: 0 : elog(ERROR, "output plugins have to register a begin callback");
739 [ # # ]: 0 : if (callbacks->change_cb == NULL)
740 [ # # # # ]: 0 : elog(ERROR, "output plugins have to register a change callback");
741 [ # # ]: 0 : if (callbacks->commit_cb == NULL)
742 [ # # # # ]: 0 : elog(ERROR, "output plugins have to register a commit callback");
743 : 0 : }
744 : :
745 : : static void
746 : 0 : output_plugin_error_callback(void *arg)
747 : : {
748 : 0 : LogicalErrorCallbackState *state = (LogicalErrorCallbackState *) arg;
749 : :
750 : : /* not all callbacks have an associated LSN */
751 [ # # ]: 0 : if (XLogRecPtrIsValid(state->report_location))
752 : 0 : errcontext("slot \"%s\", output plugin \"%s\", in the %s callback, associated LSN %X/%08X",
753 : 0 : NameStr(state->ctx->slot->data.name),
754 : 0 : NameStr(state->ctx->slot->data.plugin),
755 : 0 : state->callback_name,
756 : 0 : LSN_FORMAT_ARGS(state->report_location));
757 : : else
758 : 0 : errcontext("slot \"%s\", output plugin \"%s\", in the %s callback",
759 : 0 : NameStr(state->ctx->slot->data.name),
760 : 0 : NameStr(state->ctx->slot->data.plugin),
761 : 0 : state->callback_name);
762 : 0 : }
763 : :
764 : : static void
765 : 0 : startup_cb_wrapper(LogicalDecodingContext *ctx, OutputPluginOptions *opt, bool is_init)
766 : : {
767 : 0 : LogicalErrorCallbackState state;
768 : 0 : ErrorContextCallback errcallback;
769 : :
770 [ # # ]: 0 : Assert(!ctx->fast_forward);
771 : :
772 : : /* Push callback + info on the error context stack */
773 : 0 : state.ctx = ctx;
774 : 0 : state.callback_name = "startup";
775 : 0 : state.report_location = InvalidXLogRecPtr;
776 : 0 : errcallback.callback = output_plugin_error_callback;
777 : 0 : errcallback.arg = &state;
778 : 0 : errcallback.previous = error_context_stack;
779 : 0 : error_context_stack = &errcallback;
780 : :
781 : : /* set output state */
782 : 0 : ctx->accept_writes = false;
783 : 0 : ctx->end_xact = false;
784 : :
785 : : /* do the actual work: call callback */
786 : 0 : ctx->callbacks.startup_cb(ctx, opt, is_init);
787 : :
788 : : /* Pop the error context stack */
789 : 0 : error_context_stack = errcallback.previous;
790 : 0 : }
791 : :
792 : : static void
793 : 0 : shutdown_cb_wrapper(LogicalDecodingContext *ctx)
794 : : {
795 : 0 : LogicalErrorCallbackState state;
796 : 0 : ErrorContextCallback errcallback;
797 : :
798 [ # # ]: 0 : Assert(!ctx->fast_forward);
799 : :
800 : : /* Push callback + info on the error context stack */
801 : 0 : state.ctx = ctx;
802 : 0 : state.callback_name = "shutdown";
803 : 0 : state.report_location = InvalidXLogRecPtr;
804 : 0 : errcallback.callback = output_plugin_error_callback;
805 : 0 : errcallback.arg = &state;
806 : 0 : errcallback.previous = error_context_stack;
807 : 0 : error_context_stack = &errcallback;
808 : :
809 : : /* set output state */
810 : 0 : ctx->accept_writes = false;
811 : 0 : ctx->end_xact = false;
812 : :
813 : : /* do the actual work: call callback */
814 : 0 : ctx->callbacks.shutdown_cb(ctx);
815 : :
816 : : /* Pop the error context stack */
817 : 0 : error_context_stack = errcallback.previous;
818 : 0 : }
819 : :
820 : :
821 : : /*
822 : : * Callbacks for ReorderBuffer which add in some more information and then call
823 : : * output_plugin.h plugins.
824 : : */
825 : : static void
826 : 0 : begin_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn)
827 : : {
828 : 0 : LogicalDecodingContext *ctx = cache->private_data;
829 : 0 : LogicalErrorCallbackState state;
830 : 0 : ErrorContextCallback errcallback;
831 : :
832 [ # # ]: 0 : Assert(!ctx->fast_forward);
833 : :
834 : : /* Push callback + info on the error context stack */
835 : 0 : state.ctx = ctx;
836 : 0 : state.callback_name = "begin";
837 : 0 : state.report_location = txn->first_lsn;
838 : 0 : errcallback.callback = output_plugin_error_callback;
839 : 0 : errcallback.arg = &state;
840 : 0 : errcallback.previous = error_context_stack;
841 : 0 : error_context_stack = &errcallback;
842 : :
843 : : /* set output state */
844 : 0 : ctx->accept_writes = true;
845 : 0 : ctx->write_xid = txn->xid;
846 : 0 : ctx->write_location = txn->first_lsn;
847 : 0 : ctx->end_xact = false;
848 : :
849 : : /* do the actual work: call callback */
850 : 0 : ctx->callbacks.begin_cb(ctx, txn);
851 : :
852 : : /* Pop the error context stack */
853 : 0 : error_context_stack = errcallback.previous;
854 : 0 : }
855 : :
856 : : static void
857 : 0 : commit_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
858 : : XLogRecPtr commit_lsn)
859 : : {
860 : 0 : LogicalDecodingContext *ctx = cache->private_data;
861 : 0 : LogicalErrorCallbackState state;
862 : 0 : ErrorContextCallback errcallback;
863 : :
864 [ # # ]: 0 : Assert(!ctx->fast_forward);
865 : :
866 : : /* Push callback + info on the error context stack */
867 : 0 : state.ctx = ctx;
868 : 0 : state.callback_name = "commit";
869 : 0 : state.report_location = txn->final_lsn; /* beginning of commit record */
870 : 0 : errcallback.callback = output_plugin_error_callback;
871 : 0 : errcallback.arg = &state;
872 : 0 : errcallback.previous = error_context_stack;
873 : 0 : error_context_stack = &errcallback;
874 : :
875 : : /* set output state */
876 : 0 : ctx->accept_writes = true;
877 : 0 : ctx->write_xid = txn->xid;
878 : 0 : ctx->write_location = txn->end_lsn; /* points to the end of the record */
879 : 0 : ctx->end_xact = true;
880 : :
881 : : /* do the actual work: call callback */
882 : 0 : ctx->callbacks.commit_cb(ctx, txn, commit_lsn);
883 : :
884 : : /* Pop the error context stack */
885 : 0 : error_context_stack = errcallback.previous;
886 : 0 : }
887 : :
888 : : /*
889 : : * The functionality of begin_prepare is quite similar to begin with the
890 : : * exception that this will have gid (global transaction id) information which
891 : : * can be used by plugin. Now, we thought about extending the existing begin
892 : : * but that would break the replication protocol and additionally this looks
893 : : * cleaner.
894 : : */
895 : : static void
896 : 0 : begin_prepare_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn)
897 : : {
898 : 0 : LogicalDecodingContext *ctx = cache->private_data;
899 : 0 : LogicalErrorCallbackState state;
900 : 0 : ErrorContextCallback errcallback;
901 : :
902 [ # # ]: 0 : Assert(!ctx->fast_forward);
903 : :
904 : : /* We're only supposed to call this when two-phase commits are supported */
905 [ # # ]: 0 : Assert(ctx->twophase);
906 : :
907 : : /* Push callback + info on the error context stack */
908 : 0 : state.ctx = ctx;
909 : 0 : state.callback_name = "begin_prepare";
910 : 0 : state.report_location = txn->first_lsn;
911 : 0 : errcallback.callback = output_plugin_error_callback;
912 : 0 : errcallback.arg = &state;
913 : 0 : errcallback.previous = error_context_stack;
914 : 0 : error_context_stack = &errcallback;
915 : :
916 : : /* set output state */
917 : 0 : ctx->accept_writes = true;
918 : 0 : ctx->write_xid = txn->xid;
919 : 0 : ctx->write_location = txn->first_lsn;
920 : 0 : ctx->end_xact = false;
921 : :
922 : : /*
923 : : * If the plugin supports two-phase commits then begin prepare callback is
924 : : * mandatory
925 : : */
926 [ # # ]: 0 : if (ctx->callbacks.begin_prepare_cb == NULL)
927 [ # # # # ]: 0 : ereport(ERROR,
928 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
929 : : errmsg("logical replication at prepare time requires a %s callback",
930 : : "begin_prepare_cb")));
931 : :
932 : : /* do the actual work: call callback */
933 : 0 : ctx->callbacks.begin_prepare_cb(ctx, txn);
934 : :
935 : : /* Pop the error context stack */
936 : 0 : error_context_stack = errcallback.previous;
937 : 0 : }
938 : :
939 : : static void
940 : 0 : prepare_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
941 : : XLogRecPtr prepare_lsn)
942 : : {
943 : 0 : LogicalDecodingContext *ctx = cache->private_data;
944 : 0 : LogicalErrorCallbackState state;
945 : 0 : ErrorContextCallback errcallback;
946 : :
947 [ # # ]: 0 : Assert(!ctx->fast_forward);
948 : :
949 : : /* We're only supposed to call this when two-phase commits are supported */
950 [ # # ]: 0 : Assert(ctx->twophase);
951 : :
952 : : /* Push callback + info on the error context stack */
953 : 0 : state.ctx = ctx;
954 : 0 : state.callback_name = "prepare";
955 : 0 : state.report_location = txn->final_lsn; /* beginning of prepare record */
956 : 0 : errcallback.callback = output_plugin_error_callback;
957 : 0 : errcallback.arg = &state;
958 : 0 : errcallback.previous = error_context_stack;
959 : 0 : error_context_stack = &errcallback;
960 : :
961 : : /* set output state */
962 : 0 : ctx->accept_writes = true;
963 : 0 : ctx->write_xid = txn->xid;
964 : 0 : ctx->write_location = txn->end_lsn; /* points to the end of the record */
965 : 0 : ctx->end_xact = true;
966 : :
967 : : /*
968 : : * If the plugin supports two-phase commits then prepare callback is
969 : : * mandatory
970 : : */
971 [ # # ]: 0 : if (ctx->callbacks.prepare_cb == NULL)
972 [ # # # # ]: 0 : ereport(ERROR,
973 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
974 : : errmsg("logical replication at prepare time requires a %s callback",
975 : : "prepare_cb")));
976 : :
977 : : /* do the actual work: call callback */
978 : 0 : ctx->callbacks.prepare_cb(ctx, txn, prepare_lsn);
979 : :
980 : : /* Pop the error context stack */
981 : 0 : error_context_stack = errcallback.previous;
982 : 0 : }
983 : :
984 : : static void
985 : 0 : commit_prepared_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
986 : : XLogRecPtr commit_lsn)
987 : : {
988 : 0 : LogicalDecodingContext *ctx = cache->private_data;
989 : 0 : LogicalErrorCallbackState state;
990 : 0 : ErrorContextCallback errcallback;
991 : :
992 [ # # ]: 0 : Assert(!ctx->fast_forward);
993 : :
994 : : /* We're only supposed to call this when two-phase commits are supported */
995 [ # # ]: 0 : Assert(ctx->twophase);
996 : :
997 : : /* Push callback + info on the error context stack */
998 : 0 : state.ctx = ctx;
999 : 0 : state.callback_name = "commit_prepared";
1000 : 0 : state.report_location = txn->final_lsn; /* beginning of commit record */
1001 : 0 : errcallback.callback = output_plugin_error_callback;
1002 : 0 : errcallback.arg = &state;
1003 : 0 : errcallback.previous = error_context_stack;
1004 : 0 : error_context_stack = &errcallback;
1005 : :
1006 : : /* set output state */
1007 : 0 : ctx->accept_writes = true;
1008 : 0 : ctx->write_xid = txn->xid;
1009 : 0 : ctx->write_location = txn->end_lsn; /* points to the end of the record */
1010 : 0 : ctx->end_xact = true;
1011 : :
1012 : : /*
1013 : : * If the plugin support two-phase commits then commit prepared callback
1014 : : * is mandatory
1015 : : */
1016 [ # # ]: 0 : if (ctx->callbacks.commit_prepared_cb == NULL)
1017 [ # # # # ]: 0 : ereport(ERROR,
1018 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1019 : : errmsg("logical replication at prepare time requires a %s callback",
1020 : : "commit_prepared_cb")));
1021 : :
1022 : : /* do the actual work: call callback */
1023 : 0 : ctx->callbacks.commit_prepared_cb(ctx, txn, commit_lsn);
1024 : :
1025 : : /* Pop the error context stack */
1026 : 0 : error_context_stack = errcallback.previous;
1027 : 0 : }
1028 : :
1029 : : static void
1030 : 0 : rollback_prepared_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1031 : : XLogRecPtr prepare_end_lsn,
1032 : : TimestampTz prepare_time)
1033 : : {
1034 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1035 : 0 : LogicalErrorCallbackState state;
1036 : 0 : ErrorContextCallback errcallback;
1037 : :
1038 [ # # ]: 0 : Assert(!ctx->fast_forward);
1039 : :
1040 : : /* We're only supposed to call this when two-phase commits are supported */
1041 [ # # ]: 0 : Assert(ctx->twophase);
1042 : :
1043 : : /* Push callback + info on the error context stack */
1044 : 0 : state.ctx = ctx;
1045 : 0 : state.callback_name = "rollback_prepared";
1046 : 0 : state.report_location = txn->final_lsn; /* beginning of commit record */
1047 : 0 : errcallback.callback = output_plugin_error_callback;
1048 : 0 : errcallback.arg = &state;
1049 : 0 : errcallback.previous = error_context_stack;
1050 : 0 : error_context_stack = &errcallback;
1051 : :
1052 : : /* set output state */
1053 : 0 : ctx->accept_writes = true;
1054 : 0 : ctx->write_xid = txn->xid;
1055 : 0 : ctx->write_location = txn->end_lsn; /* points to the end of the record */
1056 : 0 : ctx->end_xact = true;
1057 : :
1058 : : /*
1059 : : * If the plugin support two-phase commits then rollback prepared callback
1060 : : * is mandatory
1061 : : */
1062 [ # # ]: 0 : if (ctx->callbacks.rollback_prepared_cb == NULL)
1063 [ # # # # ]: 0 : ereport(ERROR,
1064 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1065 : : errmsg("logical replication at prepare time requires a %s callback",
1066 : : "rollback_prepared_cb")));
1067 : :
1068 : : /* do the actual work: call callback */
1069 : 0 : ctx->callbacks.rollback_prepared_cb(ctx, txn, prepare_end_lsn,
1070 : 0 : prepare_time);
1071 : :
1072 : : /* Pop the error context stack */
1073 : 0 : error_context_stack = errcallback.previous;
1074 : 0 : }
1075 : :
1076 : : static void
1077 : 0 : change_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1078 : : Relation relation, ReorderBufferChange *change)
1079 : : {
1080 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1081 : 0 : LogicalErrorCallbackState state;
1082 : 0 : ErrorContextCallback errcallback;
1083 : :
1084 [ # # ]: 0 : Assert(!ctx->fast_forward);
1085 : :
1086 : : /* Push callback + info on the error context stack */
1087 : 0 : state.ctx = ctx;
1088 : 0 : state.callback_name = "change";
1089 : 0 : state.report_location = change->lsn;
1090 : 0 : errcallback.callback = output_plugin_error_callback;
1091 : 0 : errcallback.arg = &state;
1092 : 0 : errcallback.previous = error_context_stack;
1093 : 0 : error_context_stack = &errcallback;
1094 : :
1095 : : /* set output state */
1096 : 0 : ctx->accept_writes = true;
1097 : 0 : ctx->write_xid = txn->xid;
1098 : :
1099 : : /*
1100 : : * Report this change's lsn so replies from clients can give an up-to-date
1101 : : * answer. This won't ever be enough (and shouldn't be!) to confirm
1102 : : * receipt of this transaction, but it might allow another transaction's
1103 : : * commit to be confirmed with one message.
1104 : : */
1105 : 0 : ctx->write_location = change->lsn;
1106 : :
1107 : 0 : ctx->end_xact = false;
1108 : :
1109 : 0 : ctx->callbacks.change_cb(ctx, txn, relation, change);
1110 : :
1111 : : /* Pop the error context stack */
1112 : 0 : error_context_stack = errcallback.previous;
1113 : 0 : }
1114 : :
1115 : : static void
1116 : 0 : truncate_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1117 : : int nrelations, Relation relations[], ReorderBufferChange *change)
1118 : : {
1119 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1120 : 0 : LogicalErrorCallbackState state;
1121 : 0 : ErrorContextCallback errcallback;
1122 : :
1123 [ # # ]: 0 : Assert(!ctx->fast_forward);
1124 : :
1125 [ # # ]: 0 : if (!ctx->callbacks.truncate_cb)
1126 : 0 : return;
1127 : :
1128 : : /* Push callback + info on the error context stack */
1129 : 0 : state.ctx = ctx;
1130 : 0 : state.callback_name = "truncate";
1131 : 0 : state.report_location = change->lsn;
1132 : 0 : errcallback.callback = output_plugin_error_callback;
1133 : 0 : errcallback.arg = &state;
1134 : 0 : errcallback.previous = error_context_stack;
1135 : 0 : error_context_stack = &errcallback;
1136 : :
1137 : : /* set output state */
1138 : 0 : ctx->accept_writes = true;
1139 : 0 : ctx->write_xid = txn->xid;
1140 : :
1141 : : /*
1142 : : * Report this change's lsn so replies from clients can give an up-to-date
1143 : : * answer. This won't ever be enough (and shouldn't be!) to confirm
1144 : : * receipt of this transaction, but it might allow another transaction's
1145 : : * commit to be confirmed with one message.
1146 : : */
1147 : 0 : ctx->write_location = change->lsn;
1148 : :
1149 : 0 : ctx->end_xact = false;
1150 : :
1151 : 0 : ctx->callbacks.truncate_cb(ctx, txn, nrelations, relations, change);
1152 : :
1153 : : /* Pop the error context stack */
1154 : 0 : error_context_stack = errcallback.previous;
1155 [ # # ]: 0 : }
1156 : :
1157 : : bool
1158 : 0 : filter_prepare_cb_wrapper(LogicalDecodingContext *ctx, TransactionId xid,
1159 : : const char *gid)
1160 : : {
1161 : 0 : LogicalErrorCallbackState state;
1162 : 0 : ErrorContextCallback errcallback;
1163 : 0 : bool ret;
1164 : :
1165 [ # # ]: 0 : Assert(!ctx->fast_forward);
1166 : :
1167 : : /* Push callback + info on the error context stack */
1168 : 0 : state.ctx = ctx;
1169 : 0 : state.callback_name = "filter_prepare";
1170 : 0 : state.report_location = InvalidXLogRecPtr;
1171 : 0 : errcallback.callback = output_plugin_error_callback;
1172 : 0 : errcallback.arg = &state;
1173 : 0 : errcallback.previous = error_context_stack;
1174 : 0 : error_context_stack = &errcallback;
1175 : :
1176 : : /* set output state */
1177 : 0 : ctx->accept_writes = false;
1178 : 0 : ctx->end_xact = false;
1179 : :
1180 : : /* do the actual work: call callback */
1181 : 0 : ret = ctx->callbacks.filter_prepare_cb(ctx, xid, gid);
1182 : :
1183 : : /* Pop the error context stack */
1184 : 0 : error_context_stack = errcallback.previous;
1185 : :
1186 : 0 : return ret;
1187 : 0 : }
1188 : :
1189 : : bool
1190 : 0 : filter_by_origin_cb_wrapper(LogicalDecodingContext *ctx, RepOriginId origin_id)
1191 : : {
1192 : 0 : LogicalErrorCallbackState state;
1193 : 0 : ErrorContextCallback errcallback;
1194 : 0 : bool ret;
1195 : :
1196 [ # # ]: 0 : Assert(!ctx->fast_forward);
1197 : :
1198 : : /* Push callback + info on the error context stack */
1199 : 0 : state.ctx = ctx;
1200 : 0 : state.callback_name = "filter_by_origin";
1201 : 0 : state.report_location = InvalidXLogRecPtr;
1202 : 0 : errcallback.callback = output_plugin_error_callback;
1203 : 0 : errcallback.arg = &state;
1204 : 0 : errcallback.previous = error_context_stack;
1205 : 0 : error_context_stack = &errcallback;
1206 : :
1207 : : /* set output state */
1208 : 0 : ctx->accept_writes = false;
1209 : 0 : ctx->end_xact = false;
1210 : :
1211 : : /* do the actual work: call callback */
1212 : 0 : ret = ctx->callbacks.filter_by_origin_cb(ctx, origin_id);
1213 : :
1214 : : /* Pop the error context stack */
1215 : 0 : error_context_stack = errcallback.previous;
1216 : :
1217 : 0 : return ret;
1218 : 0 : }
1219 : :
1220 : : static void
1221 : 0 : message_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1222 : : XLogRecPtr message_lsn, bool transactional,
1223 : : const char *prefix, Size message_size, const char *message)
1224 : : {
1225 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1226 : 0 : LogicalErrorCallbackState state;
1227 : 0 : ErrorContextCallback errcallback;
1228 : :
1229 [ # # ]: 0 : Assert(!ctx->fast_forward);
1230 : :
1231 [ # # ]: 0 : if (ctx->callbacks.message_cb == NULL)
1232 : 0 : return;
1233 : :
1234 : : /* Push callback + info on the error context stack */
1235 : 0 : state.ctx = ctx;
1236 : 0 : state.callback_name = "message";
1237 : 0 : state.report_location = message_lsn;
1238 : 0 : errcallback.callback = output_plugin_error_callback;
1239 : 0 : errcallback.arg = &state;
1240 : 0 : errcallback.previous = error_context_stack;
1241 : 0 : error_context_stack = &errcallback;
1242 : :
1243 : : /* set output state */
1244 : 0 : ctx->accept_writes = true;
1245 [ # # ]: 0 : ctx->write_xid = txn != NULL ? txn->xid : InvalidTransactionId;
1246 : 0 : ctx->write_location = message_lsn;
1247 : 0 : ctx->end_xact = false;
1248 : :
1249 : : /* do the actual work: call callback */
1250 : 0 : ctx->callbacks.message_cb(ctx, txn, message_lsn, transactional, prefix,
1251 : 0 : message_size, message);
1252 : :
1253 : : /* Pop the error context stack */
1254 : 0 : error_context_stack = errcallback.previous;
1255 [ # # ]: 0 : }
1256 : :
1257 : : static void
1258 : 0 : stream_start_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1259 : : XLogRecPtr first_lsn)
1260 : : {
1261 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1262 : 0 : LogicalErrorCallbackState state;
1263 : 0 : ErrorContextCallback errcallback;
1264 : :
1265 [ # # ]: 0 : Assert(!ctx->fast_forward);
1266 : :
1267 : : /* We're only supposed to call this when streaming is supported. */
1268 [ # # ]: 0 : Assert(ctx->streaming);
1269 : :
1270 : : /* Push callback + info on the error context stack */
1271 : 0 : state.ctx = ctx;
1272 : 0 : state.callback_name = "stream_start";
1273 : 0 : state.report_location = first_lsn;
1274 : 0 : errcallback.callback = output_plugin_error_callback;
1275 : 0 : errcallback.arg = &state;
1276 : 0 : errcallback.previous = error_context_stack;
1277 : 0 : error_context_stack = &errcallback;
1278 : :
1279 : : /* set output state */
1280 : 0 : ctx->accept_writes = true;
1281 : 0 : ctx->write_xid = txn->xid;
1282 : :
1283 : : /*
1284 : : * Report this message's lsn so replies from clients can give an
1285 : : * up-to-date answer. This won't ever be enough (and shouldn't be!) to
1286 : : * confirm receipt of this transaction, but it might allow another
1287 : : * transaction's commit to be confirmed with one message.
1288 : : */
1289 : 0 : ctx->write_location = first_lsn;
1290 : :
1291 : 0 : ctx->end_xact = false;
1292 : :
1293 : : /* in streaming mode, stream_start_cb is required */
1294 [ # # ]: 0 : if (ctx->callbacks.stream_start_cb == NULL)
1295 [ # # # # ]: 0 : ereport(ERROR,
1296 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1297 : : errmsg("logical streaming requires a %s callback",
1298 : : "stream_start_cb")));
1299 : :
1300 : 0 : ctx->callbacks.stream_start_cb(ctx, txn);
1301 : :
1302 : : /* Pop the error context stack */
1303 : 0 : error_context_stack = errcallback.previous;
1304 : 0 : }
1305 : :
1306 : : static void
1307 : 0 : stream_stop_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1308 : : XLogRecPtr last_lsn)
1309 : : {
1310 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1311 : 0 : LogicalErrorCallbackState state;
1312 : 0 : ErrorContextCallback errcallback;
1313 : :
1314 [ # # ]: 0 : Assert(!ctx->fast_forward);
1315 : :
1316 : : /* We're only supposed to call this when streaming is supported. */
1317 [ # # ]: 0 : Assert(ctx->streaming);
1318 : :
1319 : : /* Push callback + info on the error context stack */
1320 : 0 : state.ctx = ctx;
1321 : 0 : state.callback_name = "stream_stop";
1322 : 0 : state.report_location = last_lsn;
1323 : 0 : errcallback.callback = output_plugin_error_callback;
1324 : 0 : errcallback.arg = &state;
1325 : 0 : errcallback.previous = error_context_stack;
1326 : 0 : error_context_stack = &errcallback;
1327 : :
1328 : : /* set output state */
1329 : 0 : ctx->accept_writes = true;
1330 : 0 : ctx->write_xid = txn->xid;
1331 : :
1332 : : /*
1333 : : * Report this message's lsn so replies from clients can give an
1334 : : * up-to-date answer. This won't ever be enough (and shouldn't be!) to
1335 : : * confirm receipt of this transaction, but it might allow another
1336 : : * transaction's commit to be confirmed with one message.
1337 : : */
1338 : 0 : ctx->write_location = last_lsn;
1339 : :
1340 : 0 : ctx->end_xact = false;
1341 : :
1342 : : /* in streaming mode, stream_stop_cb is required */
1343 [ # # ]: 0 : if (ctx->callbacks.stream_stop_cb == NULL)
1344 [ # # # # ]: 0 : ereport(ERROR,
1345 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1346 : : errmsg("logical streaming requires a %s callback",
1347 : : "stream_stop_cb")));
1348 : :
1349 : 0 : ctx->callbacks.stream_stop_cb(ctx, txn);
1350 : :
1351 : : /* Pop the error context stack */
1352 : 0 : error_context_stack = errcallback.previous;
1353 : 0 : }
1354 : :
1355 : : static void
1356 : 0 : stream_abort_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1357 : : XLogRecPtr abort_lsn)
1358 : : {
1359 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1360 : 0 : LogicalErrorCallbackState state;
1361 : 0 : ErrorContextCallback errcallback;
1362 : :
1363 [ # # ]: 0 : Assert(!ctx->fast_forward);
1364 : :
1365 : : /* We're only supposed to call this when streaming is supported. */
1366 [ # # ]: 0 : Assert(ctx->streaming);
1367 : :
1368 : : /* Push callback + info on the error context stack */
1369 : 0 : state.ctx = ctx;
1370 : 0 : state.callback_name = "stream_abort";
1371 : 0 : state.report_location = abort_lsn;
1372 : 0 : errcallback.callback = output_plugin_error_callback;
1373 : 0 : errcallback.arg = &state;
1374 : 0 : errcallback.previous = error_context_stack;
1375 : 0 : error_context_stack = &errcallback;
1376 : :
1377 : : /* set output state */
1378 : 0 : ctx->accept_writes = true;
1379 : 0 : ctx->write_xid = txn->xid;
1380 : 0 : ctx->write_location = abort_lsn;
1381 : 0 : ctx->end_xact = true;
1382 : :
1383 : : /* in streaming mode, stream_abort_cb is required */
1384 [ # # ]: 0 : if (ctx->callbacks.stream_abort_cb == NULL)
1385 [ # # # # ]: 0 : ereport(ERROR,
1386 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1387 : : errmsg("logical streaming requires a %s callback",
1388 : : "stream_abort_cb")));
1389 : :
1390 : 0 : ctx->callbacks.stream_abort_cb(ctx, txn, abort_lsn);
1391 : :
1392 : : /* Pop the error context stack */
1393 : 0 : error_context_stack = errcallback.previous;
1394 : 0 : }
1395 : :
1396 : : static void
1397 : 0 : stream_prepare_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1398 : : XLogRecPtr prepare_lsn)
1399 : : {
1400 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1401 : 0 : LogicalErrorCallbackState state;
1402 : 0 : ErrorContextCallback errcallback;
1403 : :
1404 [ # # ]: 0 : Assert(!ctx->fast_forward);
1405 : :
1406 : : /*
1407 : : * We're only supposed to call this when streaming and two-phase commits
1408 : : * are supported.
1409 : : */
1410 [ # # ]: 0 : Assert(ctx->streaming);
1411 [ # # ]: 0 : Assert(ctx->twophase);
1412 : :
1413 : : /* Push callback + info on the error context stack */
1414 : 0 : state.ctx = ctx;
1415 : 0 : state.callback_name = "stream_prepare";
1416 : 0 : state.report_location = txn->final_lsn;
1417 : 0 : errcallback.callback = output_plugin_error_callback;
1418 : 0 : errcallback.arg = &state;
1419 : 0 : errcallback.previous = error_context_stack;
1420 : 0 : error_context_stack = &errcallback;
1421 : :
1422 : : /* set output state */
1423 : 0 : ctx->accept_writes = true;
1424 : 0 : ctx->write_xid = txn->xid;
1425 : 0 : ctx->write_location = txn->end_lsn;
1426 : 0 : ctx->end_xact = true;
1427 : :
1428 : : /* in streaming mode with two-phase commits, stream_prepare_cb is required */
1429 [ # # ]: 0 : if (ctx->callbacks.stream_prepare_cb == NULL)
1430 [ # # # # ]: 0 : ereport(ERROR,
1431 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1432 : : errmsg("logical streaming at prepare time requires a %s callback",
1433 : : "stream_prepare_cb")));
1434 : :
1435 : 0 : ctx->callbacks.stream_prepare_cb(ctx, txn, prepare_lsn);
1436 : :
1437 : : /* Pop the error context stack */
1438 : 0 : error_context_stack = errcallback.previous;
1439 : 0 : }
1440 : :
1441 : : static void
1442 : 0 : stream_commit_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1443 : : XLogRecPtr commit_lsn)
1444 : : {
1445 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1446 : 0 : LogicalErrorCallbackState state;
1447 : 0 : ErrorContextCallback errcallback;
1448 : :
1449 [ # # ]: 0 : Assert(!ctx->fast_forward);
1450 : :
1451 : : /* We're only supposed to call this when streaming is supported. */
1452 [ # # ]: 0 : Assert(ctx->streaming);
1453 : :
1454 : : /* Push callback + info on the error context stack */
1455 : 0 : state.ctx = ctx;
1456 : 0 : state.callback_name = "stream_commit";
1457 : 0 : state.report_location = txn->final_lsn;
1458 : 0 : errcallback.callback = output_plugin_error_callback;
1459 : 0 : errcallback.arg = &state;
1460 : 0 : errcallback.previous = error_context_stack;
1461 : 0 : error_context_stack = &errcallback;
1462 : :
1463 : : /* set output state */
1464 : 0 : ctx->accept_writes = true;
1465 : 0 : ctx->write_xid = txn->xid;
1466 : 0 : ctx->write_location = txn->end_lsn;
1467 : 0 : ctx->end_xact = true;
1468 : :
1469 : : /* in streaming mode, stream_commit_cb is required */
1470 [ # # ]: 0 : if (ctx->callbacks.stream_commit_cb == NULL)
1471 [ # # # # ]: 0 : ereport(ERROR,
1472 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1473 : : errmsg("logical streaming requires a %s callback",
1474 : : "stream_commit_cb")));
1475 : :
1476 : 0 : ctx->callbacks.stream_commit_cb(ctx, txn, commit_lsn);
1477 : :
1478 : : /* Pop the error context stack */
1479 : 0 : error_context_stack = errcallback.previous;
1480 : 0 : }
1481 : :
1482 : : static void
1483 : 0 : stream_change_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1484 : : Relation relation, ReorderBufferChange *change)
1485 : : {
1486 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1487 : 0 : LogicalErrorCallbackState state;
1488 : 0 : ErrorContextCallback errcallback;
1489 : :
1490 [ # # ]: 0 : Assert(!ctx->fast_forward);
1491 : :
1492 : : /* We're only supposed to call this when streaming is supported. */
1493 [ # # ]: 0 : Assert(ctx->streaming);
1494 : :
1495 : : /* Push callback + info on the error context stack */
1496 : 0 : state.ctx = ctx;
1497 : 0 : state.callback_name = "stream_change";
1498 : 0 : state.report_location = change->lsn;
1499 : 0 : errcallback.callback = output_plugin_error_callback;
1500 : 0 : errcallback.arg = &state;
1501 : 0 : errcallback.previous = error_context_stack;
1502 : 0 : error_context_stack = &errcallback;
1503 : :
1504 : : /* set output state */
1505 : 0 : ctx->accept_writes = true;
1506 : 0 : ctx->write_xid = txn->xid;
1507 : :
1508 : : /*
1509 : : * Report this change's lsn so replies from clients can give an up-to-date
1510 : : * answer. This won't ever be enough (and shouldn't be!) to confirm
1511 : : * receipt of this transaction, but it might allow another transaction's
1512 : : * commit to be confirmed with one message.
1513 : : */
1514 : 0 : ctx->write_location = change->lsn;
1515 : :
1516 : 0 : ctx->end_xact = false;
1517 : :
1518 : : /* in streaming mode, stream_change_cb is required */
1519 [ # # ]: 0 : if (ctx->callbacks.stream_change_cb == NULL)
1520 [ # # # # ]: 0 : ereport(ERROR,
1521 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1522 : : errmsg("logical streaming requires a %s callback",
1523 : : "stream_change_cb")));
1524 : :
1525 : 0 : ctx->callbacks.stream_change_cb(ctx, txn, relation, change);
1526 : :
1527 : : /* Pop the error context stack */
1528 : 0 : error_context_stack = errcallback.previous;
1529 : 0 : }
1530 : :
1531 : : static void
1532 : 0 : stream_message_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1533 : : XLogRecPtr message_lsn, bool transactional,
1534 : : const char *prefix, Size message_size, const char *message)
1535 : : {
1536 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1537 : 0 : LogicalErrorCallbackState state;
1538 : 0 : ErrorContextCallback errcallback;
1539 : :
1540 [ # # ]: 0 : Assert(!ctx->fast_forward);
1541 : :
1542 : : /* We're only supposed to call this when streaming is supported. */
1543 [ # # ]: 0 : Assert(ctx->streaming);
1544 : :
1545 : : /* this callback is optional */
1546 [ # # ]: 0 : if (ctx->callbacks.stream_message_cb == NULL)
1547 : 0 : return;
1548 : :
1549 : : /* Push callback + info on the error context stack */
1550 : 0 : state.ctx = ctx;
1551 : 0 : state.callback_name = "stream_message";
1552 : 0 : state.report_location = message_lsn;
1553 : 0 : errcallback.callback = output_plugin_error_callback;
1554 : 0 : errcallback.arg = &state;
1555 : 0 : errcallback.previous = error_context_stack;
1556 : 0 : error_context_stack = &errcallback;
1557 : :
1558 : : /* set output state */
1559 : 0 : ctx->accept_writes = true;
1560 [ # # ]: 0 : ctx->write_xid = txn != NULL ? txn->xid : InvalidTransactionId;
1561 : 0 : ctx->write_location = message_lsn;
1562 : 0 : ctx->end_xact = false;
1563 : :
1564 : : /* do the actual work: call callback */
1565 : 0 : ctx->callbacks.stream_message_cb(ctx, txn, message_lsn, transactional, prefix,
1566 : 0 : message_size, message);
1567 : :
1568 : : /* Pop the error context stack */
1569 : 0 : error_context_stack = errcallback.previous;
1570 [ # # ]: 0 : }
1571 : :
1572 : : static void
1573 : 0 : stream_truncate_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1574 : : int nrelations, Relation relations[],
1575 : : ReorderBufferChange *change)
1576 : : {
1577 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1578 : 0 : LogicalErrorCallbackState state;
1579 : 0 : ErrorContextCallback errcallback;
1580 : :
1581 [ # # ]: 0 : Assert(!ctx->fast_forward);
1582 : :
1583 : : /* We're only supposed to call this when streaming is supported. */
1584 [ # # ]: 0 : Assert(ctx->streaming);
1585 : :
1586 : : /* this callback is optional */
1587 [ # # ]: 0 : if (!ctx->callbacks.stream_truncate_cb)
1588 : 0 : return;
1589 : :
1590 : : /* Push callback + info on the error context stack */
1591 : 0 : state.ctx = ctx;
1592 : 0 : state.callback_name = "stream_truncate";
1593 : 0 : state.report_location = change->lsn;
1594 : 0 : errcallback.callback = output_plugin_error_callback;
1595 : 0 : errcallback.arg = &state;
1596 : 0 : errcallback.previous = error_context_stack;
1597 : 0 : error_context_stack = &errcallback;
1598 : :
1599 : : /* set output state */
1600 : 0 : ctx->accept_writes = true;
1601 : 0 : ctx->write_xid = txn->xid;
1602 : :
1603 : : /*
1604 : : * Report this change's lsn so replies from clients can give an up-to-date
1605 : : * answer. This won't ever be enough (and shouldn't be!) to confirm
1606 : : * receipt of this transaction, but it might allow another transaction's
1607 : : * commit to be confirmed with one message.
1608 : : */
1609 : 0 : ctx->write_location = change->lsn;
1610 : :
1611 : 0 : ctx->end_xact = false;
1612 : :
1613 : 0 : ctx->callbacks.stream_truncate_cb(ctx, txn, nrelations, relations, change);
1614 : :
1615 : : /* Pop the error context stack */
1616 : 0 : error_context_stack = errcallback.previous;
1617 [ # # ]: 0 : }
1618 : :
1619 : : static void
1620 : 0 : update_progress_txn_cb_wrapper(ReorderBuffer *cache, ReorderBufferTXN *txn,
1621 : : XLogRecPtr lsn)
1622 : : {
1623 : 0 : LogicalDecodingContext *ctx = cache->private_data;
1624 : 0 : LogicalErrorCallbackState state;
1625 : 0 : ErrorContextCallback errcallback;
1626 : :
1627 [ # # ]: 0 : Assert(!ctx->fast_forward);
1628 : :
1629 : : /* Push callback + info on the error context stack */
1630 : 0 : state.ctx = ctx;
1631 : 0 : state.callback_name = "update_progress_txn";
1632 : 0 : state.report_location = lsn;
1633 : 0 : errcallback.callback = output_plugin_error_callback;
1634 : 0 : errcallback.arg = &state;
1635 : 0 : errcallback.previous = error_context_stack;
1636 : 0 : error_context_stack = &errcallback;
1637 : :
1638 : : /* set output state */
1639 : 0 : ctx->accept_writes = false;
1640 : 0 : ctx->write_xid = txn->xid;
1641 : :
1642 : : /*
1643 : : * Report this change's lsn so replies from clients can give an up-to-date
1644 : : * answer. This won't ever be enough (and shouldn't be!) to confirm
1645 : : * receipt of this transaction, but it might allow another transaction's
1646 : : * commit to be confirmed with one message.
1647 : : */
1648 : 0 : ctx->write_location = lsn;
1649 : :
1650 : 0 : ctx->end_xact = false;
1651 : :
1652 : 0 : OutputPluginUpdateProgress(ctx, false);
1653 : :
1654 : : /* Pop the error context stack */
1655 : 0 : error_context_stack = errcallback.previous;
1656 : 0 : }
1657 : :
1658 : : /*
1659 : : * Set the required catalog xmin horizon for historic snapshots in the current
1660 : : * replication slot.
1661 : : *
1662 : : * Note that in the most cases, we won't be able to immediately use the xmin
1663 : : * to increase the xmin horizon: we need to wait till the client has confirmed
1664 : : * receiving current_lsn with LogicalConfirmReceivedLocation().
1665 : : */
1666 : : void
1667 : 0 : LogicalIncreaseXminForSlot(XLogRecPtr current_lsn, TransactionId xmin)
1668 : : {
1669 : 0 : bool updated_xmin = false;
1670 : 0 : ReplicationSlot *slot;
1671 : 0 : bool got_new_xmin = false;
1672 : :
1673 : 0 : slot = MyReplicationSlot;
1674 : :
1675 [ # # ]: 0 : Assert(slot != NULL);
1676 : :
1677 [ # # ]: 0 : SpinLockAcquire(&slot->mutex);
1678 : :
1679 : : /*
1680 : : * don't overwrite if we already have a newer xmin. This can happen if we
1681 : : * restart decoding in a slot.
1682 : : */
1683 [ # # ]: 0 : if (TransactionIdPrecedesOrEquals(xmin, slot->data.catalog_xmin))
1684 : : {
1685 : 0 : }
1686 : :
1687 : : /*
1688 : : * If the client has already confirmed up to this lsn, we directly can
1689 : : * mark this as accepted. This can happen if we restart decoding in a
1690 : : * slot.
1691 : : */
1692 [ # # ]: 0 : else if (current_lsn <= slot->data.confirmed_flush)
1693 : : {
1694 : 0 : slot->candidate_catalog_xmin = xmin;
1695 : 0 : slot->candidate_xmin_lsn = current_lsn;
1696 : :
1697 : : /* our candidate can directly be used */
1698 : 0 : updated_xmin = true;
1699 : 0 : }
1700 : :
1701 : : /*
1702 : : * Only increase if the previous values have been applied, otherwise we
1703 : : * might never end up updating if the receiver acks too slowly.
1704 : : */
1705 [ # # ]: 0 : else if (!XLogRecPtrIsValid(slot->candidate_xmin_lsn))
1706 : : {
1707 : 0 : slot->candidate_catalog_xmin = xmin;
1708 : 0 : slot->candidate_xmin_lsn = current_lsn;
1709 : :
1710 : : /*
1711 : : * Log new xmin at an appropriate log level after releasing the
1712 : : * spinlock.
1713 : : */
1714 : 0 : got_new_xmin = true;
1715 : 0 : }
1716 : 0 : SpinLockRelease(&slot->mutex);
1717 : :
1718 [ # # ]: 0 : if (got_new_xmin)
1719 [ # # # # ]: 0 : elog(DEBUG1, "got new catalog xmin %u at %X/%08X", xmin,
1720 : : LSN_FORMAT_ARGS(current_lsn));
1721 : :
1722 : : /* candidate already valid with the current flush position, apply */
1723 [ # # ]: 0 : if (updated_xmin)
1724 : 0 : LogicalConfirmReceivedLocation(slot->data.confirmed_flush);
1725 : 0 : }
1726 : :
1727 : : /*
1728 : : * Mark the minimal LSN (restart_lsn) we need to read to replay all
1729 : : * transactions that have not yet committed at current_lsn.
1730 : : *
1731 : : * Just like LogicalIncreaseXminForSlot this only takes effect when the
1732 : : * client has confirmed to have received current_lsn.
1733 : : */
1734 : : void
1735 : 0 : LogicalIncreaseRestartDecodingForSlot(XLogRecPtr current_lsn, XLogRecPtr restart_lsn)
1736 : : {
1737 : 0 : bool updated_lsn = false;
1738 : 0 : ReplicationSlot *slot;
1739 : :
1740 : 0 : slot = MyReplicationSlot;
1741 : :
1742 [ # # ]: 0 : Assert(slot != NULL);
1743 [ # # ]: 0 : Assert(XLogRecPtrIsValid(restart_lsn));
1744 [ # # ]: 0 : Assert(XLogRecPtrIsValid(current_lsn));
1745 : :
1746 [ # # ]: 0 : SpinLockAcquire(&slot->mutex);
1747 : :
1748 : : /* don't overwrite if have a newer restart lsn */
1749 [ # # ]: 0 : if (restart_lsn <= slot->data.restart_lsn)
1750 : : {
1751 : 0 : SpinLockRelease(&slot->mutex);
1752 : 0 : }
1753 : :
1754 : : /*
1755 : : * We might have already flushed far enough to directly accept this lsn,
1756 : : * in this case there is no need to check for existing candidate LSNs
1757 : : */
1758 [ # # ]: 0 : else if (current_lsn <= slot->data.confirmed_flush)
1759 : : {
1760 : 0 : slot->candidate_restart_valid = current_lsn;
1761 : 0 : slot->candidate_restart_lsn = restart_lsn;
1762 : 0 : SpinLockRelease(&slot->mutex);
1763 : :
1764 : : /* our candidate can directly be used */
1765 : 0 : updated_lsn = true;
1766 : 0 : }
1767 : :
1768 : : /*
1769 : : * Only increase if the previous values have been applied, otherwise we
1770 : : * might never end up updating if the receiver acks too slowly. A missed
1771 : : * value here will just cause some extra effort after reconnecting.
1772 : : */
1773 [ # # ]: 0 : else if (!XLogRecPtrIsValid(slot->candidate_restart_valid))
1774 : : {
1775 : 0 : slot->candidate_restart_valid = current_lsn;
1776 : 0 : slot->candidate_restart_lsn = restart_lsn;
1777 : 0 : SpinLockRelease(&slot->mutex);
1778 : :
1779 [ # # # # ]: 0 : elog(DEBUG1, "got new restart lsn %X/%08X at %X/%08X",
1780 : : LSN_FORMAT_ARGS(restart_lsn),
1781 : : LSN_FORMAT_ARGS(current_lsn));
1782 : 0 : }
1783 : : else
1784 : : {
1785 : 0 : XLogRecPtr candidate_restart_lsn;
1786 : 0 : XLogRecPtr candidate_restart_valid;
1787 : 0 : XLogRecPtr confirmed_flush;
1788 : :
1789 : 0 : candidate_restart_lsn = slot->candidate_restart_lsn;
1790 : 0 : candidate_restart_valid = slot->candidate_restart_valid;
1791 : 0 : confirmed_flush = slot->data.confirmed_flush;
1792 : 0 : SpinLockRelease(&slot->mutex);
1793 : :
1794 [ # # # # ]: 0 : elog(DEBUG1, "failed to increase restart lsn: proposed %X/%08X, after %X/%08X, current candidate %X/%08X, current after %X/%08X, flushed up to %X/%08X",
1795 : : LSN_FORMAT_ARGS(restart_lsn),
1796 : : LSN_FORMAT_ARGS(current_lsn),
1797 : : LSN_FORMAT_ARGS(candidate_restart_lsn),
1798 : : LSN_FORMAT_ARGS(candidate_restart_valid),
1799 : : LSN_FORMAT_ARGS(confirmed_flush));
1800 : 0 : }
1801 : :
1802 : : /* candidates are already valid with the current flush position, apply */
1803 [ # # ]: 0 : if (updated_lsn)
1804 : 0 : LogicalConfirmReceivedLocation(slot->data.confirmed_flush);
1805 : 0 : }
1806 : :
1807 : : /*
1808 : : * Handle a consumer's confirmation having received all changes up to lsn.
1809 : : */
1810 : : void
1811 : 0 : LogicalConfirmReceivedLocation(XLogRecPtr lsn)
1812 : : {
1813 [ # # ]: 0 : Assert(XLogRecPtrIsValid(lsn));
1814 : :
1815 : : /* Do an unlocked check for candidate_lsn first. */
1816 [ # # # # ]: 0 : if (XLogRecPtrIsValid(MyReplicationSlot->candidate_xmin_lsn) ||
1817 : 0 : XLogRecPtrIsValid(MyReplicationSlot->candidate_restart_valid))
1818 : : {
1819 : 0 : bool updated_xmin = false;
1820 : 0 : bool updated_restart = false;
1821 : 0 : XLogRecPtr restart_lsn pg_attribute_unused();
1822 : :
1823 [ # # ]: 0 : SpinLockAcquire(&MyReplicationSlot->mutex);
1824 : :
1825 : : /* remember the old restart lsn */
1826 : 0 : restart_lsn = MyReplicationSlot->data.restart_lsn;
1827 : :
1828 : : /*
1829 : : * Prevent moving the confirmed_flush backwards, as this could lead to
1830 : : * data duplication issues caused by replicating already replicated
1831 : : * changes.
1832 : : *
1833 : : * This can happen when a client acknowledges an LSN it doesn't have
1834 : : * to do anything for, and thus didn't store persistently. After a
1835 : : * restart, the client can send the prior LSN that it stored
1836 : : * persistently as an acknowledgement, but we need to ignore such an
1837 : : * LSN. See similar case handling in CreateDecodingContext.
1838 : : */
1839 [ # # ]: 0 : if (lsn > MyReplicationSlot->data.confirmed_flush)
1840 : 0 : MyReplicationSlot->data.confirmed_flush = lsn;
1841 : :
1842 : : /* if we're past the location required for bumping xmin, do so */
1843 [ # # # # ]: 0 : if (XLogRecPtrIsValid(MyReplicationSlot->candidate_xmin_lsn) &&
1844 : 0 : MyReplicationSlot->candidate_xmin_lsn <= lsn)
1845 : : {
1846 : : /*
1847 : : * We have to write the changed xmin to disk *before* we change
1848 : : * the in-memory value, otherwise after a crash we wouldn't know
1849 : : * that some catalog tuples might have been removed already.
1850 : : *
1851 : : * Ensure that by first writing to ->xmin and only update
1852 : : * ->effective_xmin once the new state is synced to disk. After a
1853 : : * crash ->effective_xmin is set to ->xmin.
1854 : : */
1855 [ # # # # ]: 0 : if (TransactionIdIsValid(MyReplicationSlot->candidate_catalog_xmin) &&
1856 : 0 : MyReplicationSlot->data.catalog_xmin != MyReplicationSlot->candidate_catalog_xmin)
1857 : : {
1858 : 0 : MyReplicationSlot->data.catalog_xmin = MyReplicationSlot->candidate_catalog_xmin;
1859 : 0 : MyReplicationSlot->candidate_catalog_xmin = InvalidTransactionId;
1860 : 0 : MyReplicationSlot->candidate_xmin_lsn = InvalidXLogRecPtr;
1861 : 0 : updated_xmin = true;
1862 : 0 : }
1863 : 0 : }
1864 : :
1865 [ # # # # ]: 0 : if (XLogRecPtrIsValid(MyReplicationSlot->candidate_restart_valid) &&
1866 : 0 : MyReplicationSlot->candidate_restart_valid <= lsn)
1867 : : {
1868 [ # # ]: 0 : Assert(XLogRecPtrIsValid(MyReplicationSlot->candidate_restart_lsn));
1869 : :
1870 : 0 : MyReplicationSlot->data.restart_lsn = MyReplicationSlot->candidate_restart_lsn;
1871 : 0 : MyReplicationSlot->candidate_restart_lsn = InvalidXLogRecPtr;
1872 : 0 : MyReplicationSlot->candidate_restart_valid = InvalidXLogRecPtr;
1873 : 0 : updated_restart = true;
1874 : 0 : }
1875 : :
1876 : 0 : SpinLockRelease(&MyReplicationSlot->mutex);
1877 : :
1878 : : /* first write new xmin to disk, so we know what's up after a crash */
1879 [ # # # # ]: 0 : if (updated_xmin || updated_restart)
1880 : : {
1881 : : #ifdef USE_INJECTION_POINTS
1882 : : XLogSegNo seg1,
1883 : : seg2;
1884 : :
1885 : : XLByteToSeg(restart_lsn, seg1, wal_segment_size);
1886 : : XLByteToSeg(MyReplicationSlot->data.restart_lsn, seg2, wal_segment_size);
1887 : :
1888 : : /* trigger injection point, but only if segment changes */
1889 : : if (seg1 != seg2)
1890 : : INJECTION_POINT("logical-replication-slot-advance-segment", NULL);
1891 : : #endif
1892 : :
1893 : 0 : ReplicationSlotMarkDirty();
1894 : 0 : ReplicationSlotSave();
1895 [ # # # # ]: 0 : elog(DEBUG1, "updated xmin: %u restart: %u", updated_xmin, updated_restart);
1896 : 0 : }
1897 : :
1898 : : /*
1899 : : * Now the new xmin is safely on disk, we can let the global value
1900 : : * advance. We do not take ProcArrayLock or similar since we only
1901 : : * advance xmin here and there's not much harm done by a concurrent
1902 : : * computation missing that.
1903 : : */
1904 [ # # ]: 0 : if (updated_xmin)
1905 : : {
1906 [ # # ]: 0 : SpinLockAcquire(&MyReplicationSlot->mutex);
1907 : 0 : MyReplicationSlot->effective_catalog_xmin = MyReplicationSlot->data.catalog_xmin;
1908 : 0 : SpinLockRelease(&MyReplicationSlot->mutex);
1909 : :
1910 : 0 : ReplicationSlotsComputeRequiredXmin(false);
1911 : 0 : ReplicationSlotsComputeRequiredLSN();
1912 : 0 : }
1913 : 0 : }
1914 : : else
1915 : : {
1916 [ # # ]: 0 : SpinLockAcquire(&MyReplicationSlot->mutex);
1917 : :
1918 : : /*
1919 : : * Prevent moving the confirmed_flush backwards. See comments above
1920 : : * for the details.
1921 : : */
1922 [ # # ]: 0 : if (lsn > MyReplicationSlot->data.confirmed_flush)
1923 : 0 : MyReplicationSlot->data.confirmed_flush = lsn;
1924 : :
1925 : 0 : SpinLockRelease(&MyReplicationSlot->mutex);
1926 : : }
1927 : 0 : }
1928 : :
1929 : : /*
1930 : : * Clear logical streaming state during (sub)transaction abort.
1931 : : */
1932 : : void
1933 : 8199 : ResetLogicalStreamingState(void)
1934 : : {
1935 : 8199 : CheckXidAlive = InvalidTransactionId;
1936 : 8199 : bsysscan = false;
1937 : 8199 : }
1938 : :
1939 : : /*
1940 : : * Report stats for a slot.
1941 : : */
1942 : : void
1943 : 0 : UpdateDecodingStats(LogicalDecodingContext *ctx)
1944 : : {
1945 : 0 : ReorderBuffer *rb = ctx->reorder;
1946 : 0 : PgStat_StatReplSlotEntry repSlotStat;
1947 : :
1948 : : /* Nothing to do if we don't have any replication stats to be sent. */
1949 [ # # # # : 0 : if (rb->spillBytes <= 0 && rb->streamBytes <= 0 && rb->totalBytes <= 0 &&
# # # # ]
1950 : 0 : rb->memExceededCount <= 0)
1951 : 0 : return;
1952 : :
1953 [ # # # # ]: 0 : elog(DEBUG2, "UpdateDecodingStats: updating stats %p %" PRId64 " %" PRId64 " %" PRId64 " %" PRId64 " %" PRId64 " %" PRId64 " %" PRId64 " %" PRId64 " %" PRId64,
1954 : : rb,
1955 : : rb->spillTxns,
1956 : : rb->spillCount,
1957 : : rb->spillBytes,
1958 : : rb->streamTxns,
1959 : : rb->streamCount,
1960 : : rb->streamBytes,
1961 : : rb->memExceededCount,
1962 : : rb->totalTxns,
1963 : : rb->totalBytes);
1964 : :
1965 : 0 : repSlotStat.spill_txns = rb->spillTxns;
1966 : 0 : repSlotStat.spill_count = rb->spillCount;
1967 : 0 : repSlotStat.spill_bytes = rb->spillBytes;
1968 : 0 : repSlotStat.stream_txns = rb->streamTxns;
1969 : 0 : repSlotStat.stream_count = rb->streamCount;
1970 : 0 : repSlotStat.stream_bytes = rb->streamBytes;
1971 : 0 : repSlotStat.mem_exceeded_count = rb->memExceededCount;
1972 : 0 : repSlotStat.total_txns = rb->totalTxns;
1973 : 0 : repSlotStat.total_bytes = rb->totalBytes;
1974 : :
1975 : 0 : pgstat_report_replslot(ctx->slot, &repSlotStat);
1976 : :
1977 : 0 : rb->spillTxns = 0;
1978 : 0 : rb->spillCount = 0;
1979 : 0 : rb->spillBytes = 0;
1980 : 0 : rb->streamTxns = 0;
1981 : 0 : rb->streamCount = 0;
1982 : 0 : rb->streamBytes = 0;
1983 : 0 : rb->memExceededCount = 0;
1984 : 0 : rb->totalTxns = 0;
1985 : 0 : rb->totalBytes = 0;
1986 [ # # ]: 0 : }
1987 : :
1988 : : /*
1989 : : * Read up to the end of WAL starting from the decoding slot's restart_lsn.
1990 : : * Return true if any meaningful/decodable WAL records are encountered,
1991 : : * otherwise false.
1992 : : */
1993 : : bool
1994 : 0 : LogicalReplicationSlotHasPendingWal(XLogRecPtr end_of_wal)
1995 : : {
1996 : 0 : bool has_pending_wal = false;
1997 : :
1998 [ # # ]: 0 : Assert(MyReplicationSlot);
1999 : :
2000 [ # # ]: 0 : PG_TRY();
2001 : : {
2002 : 0 : LogicalDecodingContext *ctx;
2003 : :
2004 : : /*
2005 : : * Create our decoding context in fast_forward mode, passing start_lsn
2006 : : * as InvalidXLogRecPtr, so that we start processing from the slot's
2007 : : * confirmed_flush.
2008 : : */
2009 : 0 : ctx = CreateDecodingContext(InvalidXLogRecPtr,
2010 : : NIL,
2011 : : true, /* fast_forward */
2012 : 0 : XL_ROUTINE(.page_read = read_local_xlog_page,
2013 : : .segment_open = wal_segment_open,
2014 : : .segment_close = wal_segment_close),
2015 : : NULL, NULL, NULL);
2016 : :
2017 : : /*
2018 : : * Start reading at the slot's restart_lsn, which we know points to a
2019 : : * valid record.
2020 : : */
2021 : 0 : XLogBeginRead(ctx->reader, MyReplicationSlot->data.restart_lsn);
2022 : :
2023 : : /* Invalidate non-timetravel entries */
2024 : 0 : InvalidateSystemCaches();
2025 : :
2026 : : /* Loop until the end of WAL or some changes are processed */
2027 [ # # # # ]: 0 : while (!has_pending_wal && ctx->reader->EndRecPtr < end_of_wal)
2028 : : {
2029 : 0 : XLogRecord *record;
2030 : 0 : char *errm = NULL;
2031 : :
2032 : 0 : record = XLogReadRecord(ctx->reader, &errm);
2033 : :
2034 [ # # ]: 0 : if (errm)
2035 [ # # # # ]: 0 : elog(ERROR, "could not find record for logical decoding: %s", errm);
2036 : :
2037 [ # # ]: 0 : if (record != NULL)
2038 : 0 : LogicalDecodingProcessRecord(ctx, ctx->reader);
2039 : :
2040 : 0 : has_pending_wal = ctx->processing_required;
2041 : :
2042 [ # # ]: 0 : CHECK_FOR_INTERRUPTS();
2043 : 0 : }
2044 : :
2045 : : /* Clean up */
2046 : 0 : FreeDecodingContext(ctx);
2047 : 0 : InvalidateSystemCaches();
2048 : 0 : }
2049 : 0 : PG_CATCH();
2050 : : {
2051 : : /* clear all timetravel entries */
2052 : 0 : InvalidateSystemCaches();
2053 : :
2054 : 0 : PG_RE_THROW();
2055 : : }
2056 [ # # ]: 0 : PG_END_TRY();
2057 : :
2058 : 0 : return has_pending_wal;
2059 : 0 : }
2060 : :
2061 : : /*
2062 : : * Helper function for advancing our logical replication slot forward.
2063 : : *
2064 : : * The slot's restart_lsn is used as start point for reading records, while
2065 : : * confirmed_flush is used as base point for the decoding context.
2066 : : *
2067 : : * We cannot just do LogicalConfirmReceivedLocation to update confirmed_flush,
2068 : : * because we need to digest WAL to advance restart_lsn allowing to recycle
2069 : : * WAL and removal of old catalog tuples. As decoding is done in fast_forward
2070 : : * mode, no changes are generated anyway.
2071 : : *
2072 : : * *found_consistent_snapshot will be true if the initial decoding snapshot has
2073 : : * been built; Otherwise, it will be false.
2074 : : */
2075 : : XLogRecPtr
2076 : 0 : LogicalSlotAdvanceAndCheckSnapState(XLogRecPtr moveto,
2077 : : bool *found_consistent_snapshot)
2078 : : {
2079 : 0 : LogicalDecodingContext *ctx;
2080 : 0 : ResourceOwner old_resowner PG_USED_FOR_ASSERTS_ONLY = CurrentResourceOwner;
2081 : 0 : XLogRecPtr retlsn;
2082 : :
2083 [ # # ]: 0 : Assert(XLogRecPtrIsValid(moveto));
2084 : :
2085 [ # # ]: 0 : if (found_consistent_snapshot)
2086 : 0 : *found_consistent_snapshot = false;
2087 : :
2088 [ # # ]: 0 : PG_TRY();
2089 : : {
2090 : : /*
2091 : : * Create our decoding context in fast_forward mode, passing start_lsn
2092 : : * as InvalidXLogRecPtr, so that we start processing from my slot's
2093 : : * confirmed_flush.
2094 : : */
2095 : 0 : ctx = CreateDecodingContext(InvalidXLogRecPtr,
2096 : : NIL,
2097 : : true, /* fast_forward */
2098 : 0 : XL_ROUTINE(.page_read = read_local_xlog_page,
2099 : : .segment_open = wal_segment_open,
2100 : : .segment_close = wal_segment_close),
2101 : : NULL, NULL, NULL);
2102 : :
2103 : : /*
2104 : : * Wait for specified streaming replication standby servers (if any)
2105 : : * to confirm receipt of WAL up to moveto lsn.
2106 : : */
2107 : 0 : WaitForStandbyConfirmation(moveto);
2108 : :
2109 : : /*
2110 : : * Start reading at the slot's restart_lsn, which we know to point to
2111 : : * a valid record.
2112 : : */
2113 : 0 : XLogBeginRead(ctx->reader, MyReplicationSlot->data.restart_lsn);
2114 : :
2115 : : /* invalidate non-timetravel entries */
2116 : 0 : InvalidateSystemCaches();
2117 : :
2118 : : /* Decode records until we reach the requested target */
2119 [ # # ]: 0 : while (ctx->reader->EndRecPtr < moveto)
2120 : : {
2121 : 0 : char *errm = NULL;
2122 : 0 : XLogRecord *record;
2123 : :
2124 : : /*
2125 : : * Read records. No changes are generated in fast_forward mode,
2126 : : * but snapbuilder/slot statuses are updated properly.
2127 : : */
2128 : 0 : record = XLogReadRecord(ctx->reader, &errm);
2129 [ # # ]: 0 : if (errm)
2130 [ # # # # ]: 0 : elog(ERROR, "could not find record while advancing replication slot: %s",
2131 : : errm);
2132 : :
2133 : : /*
2134 : : * Process the record. Storage-level changes are ignored in
2135 : : * fast_forward mode, but other modules (such as snapbuilder)
2136 : : * might still have critical updates to do.
2137 : : */
2138 [ # # ]: 0 : if (record)
2139 : : {
2140 : 0 : LogicalDecodingProcessRecord(ctx, ctx->reader);
2141 : :
2142 : : /*
2143 : : * We used to have bugs where logical decoding would fail to
2144 : : * preserve the resource owner. That's important here, so
2145 : : * verify that that doesn't happen anymore. XXX this could be
2146 : : * removed once it's been battle-tested.
2147 : : */
2148 [ # # ]: 0 : Assert(CurrentResourceOwner == old_resowner);
2149 : 0 : }
2150 : :
2151 [ # # ]: 0 : CHECK_FOR_INTERRUPTS();
2152 : 0 : }
2153 : :
2154 [ # # # # ]: 0 : if (found_consistent_snapshot && DecodingContextReady(ctx))
2155 : 0 : *found_consistent_snapshot = true;
2156 : :
2157 [ # # ]: 0 : if (XLogRecPtrIsValid(ctx->reader->EndRecPtr))
2158 : : {
2159 : 0 : LogicalConfirmReceivedLocation(moveto);
2160 : :
2161 : : /*
2162 : : * If only the confirmed_flush LSN has changed the slot won't get
2163 : : * marked as dirty by the above. Callers on the walsender
2164 : : * interface are expected to keep track of their own progress and
2165 : : * don't need it written out. But SQL-interface users cannot
2166 : : * specify their own start positions and it's harder for them to
2167 : : * keep track of their progress, so we should make more of an
2168 : : * effort to save it for them.
2169 : : *
2170 : : * Dirty the slot so it is written out at the next checkpoint. The
2171 : : * LSN position advanced to may still be lost on a crash but this
2172 : : * makes the data consistent after a clean shutdown.
2173 : : */
2174 : 0 : ReplicationSlotMarkDirty();
2175 : 0 : }
2176 : :
2177 : 0 : retlsn = MyReplicationSlot->data.confirmed_flush;
2178 : :
2179 : : /* free context, call shutdown callback */
2180 : 0 : FreeDecodingContext(ctx);
2181 : :
2182 : 0 : InvalidateSystemCaches();
2183 : : }
2184 : 0 : PG_CATCH();
2185 : : {
2186 : : /* clear all timetravel entries */
2187 : 0 : InvalidateSystemCaches();
2188 : :
2189 : 0 : PG_RE_THROW();
2190 : : }
2191 [ # # ]: 0 : PG_END_TRY();
2192 : :
2193 : 0 : return retlsn;
2194 : 0 : }
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