Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * pg_subscription.c
4 : * replication subscriptions
5 : *
6 : * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : * IDENTIFICATION
10 : * src/backend/catalog/pg_subscription.c
11 : *
12 : *-------------------------------------------------------------------------
13 : */
14 :
15 : #include "postgres.h"
16 :
17 : #include "access/genam.h"
18 : #include "access/heapam.h"
19 : #include "access/htup_details.h"
20 : #include "access/tableam.h"
21 : #include "access/xact.h"
22 : #include "catalog/indexing.h"
23 : #include "catalog/pg_subscription.h"
24 : #include "catalog/pg_subscription_rel.h"
25 : #include "catalog/pg_type.h"
26 : #include "miscadmin.h"
27 : #include "nodes/makefuncs.h"
28 : #include "storage/lmgr.h"
29 : #include "utils/array.h"
30 : #include "utils/builtins.h"
31 : #include "utils/fmgroids.h"
32 : #include "utils/lsyscache.h"
33 : #include "utils/pg_lsn.h"
34 : #include "utils/rel.h"
35 : #include "utils/syscache.h"
36 :
37 : static List *textarray_to_stringlist(ArrayType *textarray);
38 :
39 : /*
40 : * Fetch the subscription from the syscache.
41 : */
42 : Subscription *
43 1130 : GetSubscription(Oid subid, bool missing_ok)
44 : {
45 : HeapTuple tup;
46 : Subscription *sub;
47 : Form_pg_subscription subform;
48 : Datum datum;
49 : bool isnull;
50 :
51 1130 : tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
52 :
53 1130 : if (!HeapTupleIsValid(tup))
54 : {
55 0 : if (missing_ok)
56 0 : return NULL;
57 :
58 0 : elog(ERROR, "cache lookup failed for subscription %u", subid);
59 : }
60 :
61 1130 : subform = (Form_pg_subscription) GETSTRUCT(tup);
62 :
63 1130 : sub = (Subscription *) palloc(sizeof(Subscription));
64 1130 : sub->oid = subid;
65 1130 : sub->dbid = subform->subdbid;
66 1130 : sub->skiplsn = subform->subskiplsn;
67 1130 : sub->name = pstrdup(NameStr(subform->subname));
68 1130 : sub->owner = subform->subowner;
69 1130 : sub->enabled = subform->subenabled;
70 1130 : sub->binary = subform->subbinary;
71 1130 : sub->stream = subform->substream;
72 1130 : sub->twophasestate = subform->subtwophasestate;
73 1130 : sub->disableonerr = subform->subdisableonerr;
74 1130 : sub->passwordrequired = subform->subpasswordrequired;
75 1130 : sub->runasowner = subform->subrunasowner;
76 :
77 : /* Get conninfo */
78 1130 : datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
79 : tup,
80 : Anum_pg_subscription_subconninfo);
81 1130 : sub->conninfo = TextDatumGetCString(datum);
82 :
83 : /* Get slotname */
84 1130 : datum = SysCacheGetAttr(SUBSCRIPTIONOID,
85 : tup,
86 : Anum_pg_subscription_subslotname,
87 : &isnull);
88 1130 : if (!isnull)
89 1064 : sub->slotname = pstrdup(NameStr(*DatumGetName(datum)));
90 : else
91 66 : sub->slotname = NULL;
92 :
93 : /* Get synccommit */
94 1130 : datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
95 : tup,
96 : Anum_pg_subscription_subsynccommit);
97 1130 : sub->synccommit = TextDatumGetCString(datum);
98 :
99 : /* Get publications */
100 1130 : datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
101 : tup,
102 : Anum_pg_subscription_subpublications);
103 1130 : sub->publications = textarray_to_stringlist(DatumGetArrayTypeP(datum));
104 :
105 : /* Get origin */
106 1130 : datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID,
107 : tup,
108 : Anum_pg_subscription_suborigin);
109 1130 : sub->origin = TextDatumGetCString(datum);
110 :
111 1130 : ReleaseSysCache(tup);
112 :
113 1130 : return sub;
114 : }
115 :
116 : /*
117 : * Return number of subscriptions defined in given database.
118 : * Used by dropdb() to check if database can indeed be dropped.
119 : */
120 : int
121 40 : CountDBSubscriptions(Oid dbid)
122 : {
123 40 : int nsubs = 0;
124 : Relation rel;
125 : ScanKeyData scankey;
126 : SysScanDesc scan;
127 : HeapTuple tup;
128 :
129 40 : rel = table_open(SubscriptionRelationId, RowExclusiveLock);
130 :
131 40 : ScanKeyInit(&scankey,
132 : Anum_pg_subscription_subdbid,
133 : BTEqualStrategyNumber, F_OIDEQ,
134 : ObjectIdGetDatum(dbid));
135 :
136 40 : scan = systable_beginscan(rel, InvalidOid, false,
137 : NULL, 1, &scankey);
138 :
139 40 : while (HeapTupleIsValid(tup = systable_getnext(scan)))
140 0 : nsubs++;
141 :
142 40 : systable_endscan(scan);
143 :
144 40 : table_close(rel, NoLock);
145 :
146 40 : return nsubs;
147 : }
148 :
149 : /*
150 : * Free memory allocated by subscription struct.
151 : */
152 : void
153 48 : FreeSubscription(Subscription *sub)
154 : {
155 48 : pfree(sub->name);
156 48 : pfree(sub->conninfo);
157 48 : if (sub->slotname)
158 48 : pfree(sub->slotname);
159 48 : list_free_deep(sub->publications);
160 48 : pfree(sub);
161 48 : }
162 :
163 : /*
164 : * Disable the given subscription.
165 : */
166 : void
167 8 : DisableSubscription(Oid subid)
168 : {
169 : Relation rel;
170 : bool nulls[Natts_pg_subscription];
171 : bool replaces[Natts_pg_subscription];
172 : Datum values[Natts_pg_subscription];
173 : HeapTuple tup;
174 :
175 : /* Look up the subscription in the catalog */
176 8 : rel = table_open(SubscriptionRelationId, RowExclusiveLock);
177 8 : tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
178 :
179 8 : if (!HeapTupleIsValid(tup))
180 0 : elog(ERROR, "cache lookup failed for subscription %u", subid);
181 :
182 8 : LockSharedObject(SubscriptionRelationId, subid, 0, AccessShareLock);
183 :
184 : /* Form a new tuple. */
185 8 : memset(values, 0, sizeof(values));
186 8 : memset(nulls, false, sizeof(nulls));
187 8 : memset(replaces, false, sizeof(replaces));
188 :
189 : /* Set the subscription to disabled. */
190 8 : values[Anum_pg_subscription_subenabled - 1] = BoolGetDatum(false);
191 8 : replaces[Anum_pg_subscription_subenabled - 1] = true;
192 :
193 : /* Update the catalog */
194 8 : tup = heap_modify_tuple(tup, RelationGetDescr(rel), values, nulls,
195 : replaces);
196 8 : CatalogTupleUpdate(rel, &tup->t_self, tup);
197 8 : heap_freetuple(tup);
198 :
199 8 : table_close(rel, NoLock);
200 8 : }
201 :
202 : /*
203 : * Convert text array to list of strings.
204 : *
205 : * Note: the resulting list of strings is pallocated here.
206 : */
207 : static List *
208 1130 : textarray_to_stringlist(ArrayType *textarray)
209 : {
210 : Datum *elems;
211 : int nelems,
212 : i;
213 1130 : List *res = NIL;
214 :
215 1130 : deconstruct_array_builtin(textarray, TEXTOID, &elems, NULL, &nelems);
216 :
217 1130 : if (nelems == 0)
218 0 : return NIL;
219 :
220 2920 : for (i = 0; i < nelems; i++)
221 1790 : res = lappend(res, makeString(TextDatumGetCString(elems[i])));
222 :
223 1130 : return res;
224 : }
225 :
226 : /*
227 : * Add new state record for a subscription table.
228 : */
229 : void
230 316 : AddSubscriptionRelState(Oid subid, Oid relid, char state,
231 : XLogRecPtr sublsn)
232 : {
233 : Relation rel;
234 : HeapTuple tup;
235 : bool nulls[Natts_pg_subscription_rel];
236 : Datum values[Natts_pg_subscription_rel];
237 :
238 316 : LockSharedObject(SubscriptionRelationId, subid, 0, AccessShareLock);
239 :
240 316 : rel = table_open(SubscriptionRelRelationId, RowExclusiveLock);
241 :
242 : /* Try finding existing mapping. */
243 316 : tup = SearchSysCacheCopy2(SUBSCRIPTIONRELMAP,
244 : ObjectIdGetDatum(relid),
245 : ObjectIdGetDatum(subid));
246 316 : if (HeapTupleIsValid(tup))
247 0 : elog(ERROR, "subscription table %u in subscription %u already exists",
248 : relid, subid);
249 :
250 : /* Form the tuple. */
251 316 : memset(values, 0, sizeof(values));
252 316 : memset(nulls, false, sizeof(nulls));
253 316 : values[Anum_pg_subscription_rel_srsubid - 1] = ObjectIdGetDatum(subid);
254 316 : values[Anum_pg_subscription_rel_srrelid - 1] = ObjectIdGetDatum(relid);
255 316 : values[Anum_pg_subscription_rel_srsubstate - 1] = CharGetDatum(state);
256 316 : if (sublsn != InvalidXLogRecPtr)
257 0 : values[Anum_pg_subscription_rel_srsublsn - 1] = LSNGetDatum(sublsn);
258 : else
259 316 : nulls[Anum_pg_subscription_rel_srsublsn - 1] = true;
260 :
261 316 : tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
262 :
263 : /* Insert tuple into catalog. */
264 316 : CatalogTupleInsert(rel, tup);
265 :
266 316 : heap_freetuple(tup);
267 :
268 : /* Cleanup. */
269 316 : table_close(rel, NoLock);
270 316 : }
271 :
272 : /*
273 : * Update the state of a subscription table.
274 : */
275 : void
276 1196 : UpdateSubscriptionRelState(Oid subid, Oid relid, char state,
277 : XLogRecPtr sublsn)
278 : {
279 : Relation rel;
280 : HeapTuple tup;
281 : bool nulls[Natts_pg_subscription_rel];
282 : Datum values[Natts_pg_subscription_rel];
283 : bool replaces[Natts_pg_subscription_rel];
284 :
285 1196 : LockSharedObject(SubscriptionRelationId, subid, 0, AccessShareLock);
286 :
287 1196 : rel = table_open(SubscriptionRelRelationId, RowExclusiveLock);
288 :
289 : /* Try finding existing mapping. */
290 1196 : tup = SearchSysCacheCopy2(SUBSCRIPTIONRELMAP,
291 : ObjectIdGetDatum(relid),
292 : ObjectIdGetDatum(subid));
293 1196 : if (!HeapTupleIsValid(tup))
294 0 : elog(ERROR, "subscription table %u in subscription %u does not exist",
295 : relid, subid);
296 :
297 : /* Update the tuple. */
298 1196 : memset(values, 0, sizeof(values));
299 1196 : memset(nulls, false, sizeof(nulls));
300 1196 : memset(replaces, false, sizeof(replaces));
301 :
302 1196 : replaces[Anum_pg_subscription_rel_srsubstate - 1] = true;
303 1196 : values[Anum_pg_subscription_rel_srsubstate - 1] = CharGetDatum(state);
304 :
305 1196 : replaces[Anum_pg_subscription_rel_srsublsn - 1] = true;
306 1196 : if (sublsn != InvalidXLogRecPtr)
307 588 : values[Anum_pg_subscription_rel_srsublsn - 1] = LSNGetDatum(sublsn);
308 : else
309 608 : nulls[Anum_pg_subscription_rel_srsublsn - 1] = true;
310 :
311 1196 : tup = heap_modify_tuple(tup, RelationGetDescr(rel), values, nulls,
312 : replaces);
313 :
314 : /* Update the catalog. */
315 1196 : CatalogTupleUpdate(rel, &tup->t_self, tup);
316 :
317 : /* Cleanup. */
318 1196 : table_close(rel, NoLock);
319 1196 : }
320 :
321 : /*
322 : * Get state of subscription table.
323 : *
324 : * Returns SUBREL_STATE_UNKNOWN when the table is not in the subscription.
325 : */
326 : char
327 1904 : GetSubscriptionRelState(Oid subid, Oid relid, XLogRecPtr *sublsn)
328 : {
329 : HeapTuple tup;
330 : char substate;
331 : bool isnull;
332 : Datum d;
333 : Relation rel;
334 :
335 : /*
336 : * This is to avoid the race condition with AlterSubscription which tries
337 : * to remove this relstate.
338 : */
339 1904 : rel = table_open(SubscriptionRelRelationId, AccessShareLock);
340 :
341 : /* Try finding the mapping. */
342 1904 : tup = SearchSysCache2(SUBSCRIPTIONRELMAP,
343 : ObjectIdGetDatum(relid),
344 : ObjectIdGetDatum(subid));
345 :
346 1904 : if (!HeapTupleIsValid(tup))
347 : {
348 52 : table_close(rel, AccessShareLock);
349 52 : *sublsn = InvalidXLogRecPtr;
350 52 : return SUBREL_STATE_UNKNOWN;
351 : }
352 :
353 : /* Get the state. */
354 1852 : substate = ((Form_pg_subscription_rel) GETSTRUCT(tup))->srsubstate;
355 :
356 : /* Get the LSN */
357 1852 : d = SysCacheGetAttr(SUBSCRIPTIONRELMAP, tup,
358 : Anum_pg_subscription_rel_srsublsn, &isnull);
359 1852 : if (isnull)
360 966 : *sublsn = InvalidXLogRecPtr;
361 : else
362 886 : *sublsn = DatumGetLSN(d);
363 :
364 : /* Cleanup */
365 1852 : ReleaseSysCache(tup);
366 :
367 1852 : table_close(rel, AccessShareLock);
368 :
369 1852 : return substate;
370 : }
371 :
372 : /*
373 : * Drop subscription relation mapping. These can be for a particular
374 : * subscription, or for a particular relation, or both.
375 : */
376 : void
377 38496 : RemoveSubscriptionRel(Oid subid, Oid relid)
378 : {
379 : Relation rel;
380 : TableScanDesc scan;
381 : ScanKeyData skey[2];
382 : HeapTuple tup;
383 38496 : int nkeys = 0;
384 :
385 38496 : rel = table_open(SubscriptionRelRelationId, RowExclusiveLock);
386 :
387 38496 : if (OidIsValid(subid))
388 : {
389 200 : ScanKeyInit(&skey[nkeys++],
390 : Anum_pg_subscription_rel_srsubid,
391 : BTEqualStrategyNumber,
392 : F_OIDEQ,
393 : ObjectIdGetDatum(subid));
394 : }
395 :
396 38496 : if (OidIsValid(relid))
397 : {
398 38356 : ScanKeyInit(&skey[nkeys++],
399 : Anum_pg_subscription_rel_srrelid,
400 : BTEqualStrategyNumber,
401 : F_OIDEQ,
402 : ObjectIdGetDatum(relid));
403 : }
404 :
405 : /* Do the search and delete what we found. */
406 38496 : scan = table_beginscan_catalog(rel, nkeys, skey);
407 38658 : while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
408 : {
409 : Form_pg_subscription_rel subrel;
410 :
411 162 : subrel = (Form_pg_subscription_rel) GETSTRUCT(tup);
412 :
413 : /*
414 : * We don't allow to drop the relation mapping when the table
415 : * synchronization is in progress unless the caller updates the
416 : * corresponding subscription as well. This is to ensure that we don't
417 : * leave tablesync slots or origins in the system when the
418 : * corresponding table is dropped.
419 : */
420 162 : if (!OidIsValid(subid) && subrel->srsubstate != SUBREL_STATE_READY)
421 : {
422 0 : ereport(ERROR,
423 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
424 : errmsg("could not drop relation mapping for subscription \"%s\"",
425 : get_subscription_name(subrel->srsubid, false)),
426 : errdetail("Table synchronization for relation \"%s\" is in progress and is in state \"%c\".",
427 : get_rel_name(relid), subrel->srsubstate),
428 :
429 : /*
430 : * translator: first %s is a SQL ALTER command and second %s is a
431 : * SQL DROP command
432 : */
433 : errhint("Use %s to enable subscription if not already enabled or use %s to drop the subscription.",
434 : "ALTER SUBSCRIPTION ... ENABLE",
435 : "DROP SUBSCRIPTION ...")));
436 : }
437 :
438 162 : CatalogTupleDelete(rel, &tup->t_self);
439 : }
440 38496 : table_endscan(scan);
441 :
442 38496 : table_close(rel, RowExclusiveLock);
443 38496 : }
444 :
445 : /*
446 : * Does the subscription have any relations?
447 : *
448 : * Use this function only to know true/false, and when you have no need for the
449 : * List returned by GetSubscriptionRelations.
450 : */
451 : bool
452 342 : HasSubscriptionRelations(Oid subid)
453 : {
454 : Relation rel;
455 : ScanKeyData skey[1];
456 : SysScanDesc scan;
457 : bool has_subrels;
458 :
459 342 : rel = table_open(SubscriptionRelRelationId, AccessShareLock);
460 :
461 342 : ScanKeyInit(&skey[0],
462 : Anum_pg_subscription_rel_srsubid,
463 : BTEqualStrategyNumber, F_OIDEQ,
464 : ObjectIdGetDatum(subid));
465 :
466 342 : scan = systable_beginscan(rel, InvalidOid, false,
467 : NULL, 1, skey);
468 :
469 : /* If even a single tuple exists then the subscription has tables. */
470 342 : has_subrels = HeapTupleIsValid(systable_getnext(scan));
471 :
472 : /* Cleanup */
473 342 : systable_endscan(scan);
474 342 : table_close(rel, AccessShareLock);
475 :
476 342 : return has_subrels;
477 : }
478 :
479 : /*
480 : * Get the relations for the subscription.
481 : *
482 : * If not_ready is true, return only the relations that are not in a ready
483 : * state, otherwise return all the relations of the subscription. The
484 : * returned list is palloc'ed in the current memory context.
485 : */
486 : List *
487 1586 : GetSubscriptionRelations(Oid subid, bool not_ready)
488 : {
489 1586 : List *res = NIL;
490 : Relation rel;
491 : HeapTuple tup;
492 1586 : int nkeys = 0;
493 : ScanKeyData skey[2];
494 : SysScanDesc scan;
495 :
496 1586 : rel = table_open(SubscriptionRelRelationId, AccessShareLock);
497 :
498 1586 : ScanKeyInit(&skey[nkeys++],
499 : Anum_pg_subscription_rel_srsubid,
500 : BTEqualStrategyNumber, F_OIDEQ,
501 : ObjectIdGetDatum(subid));
502 :
503 1586 : if (not_ready)
504 1510 : ScanKeyInit(&skey[nkeys++],
505 : Anum_pg_subscription_rel_srsubstate,
506 : BTEqualStrategyNumber, F_CHARNE,
507 : CharGetDatum(SUBREL_STATE_READY));
508 :
509 1586 : scan = systable_beginscan(rel, InvalidOid, false,
510 : NULL, nkeys, skey);
511 :
512 4168 : while (HeapTupleIsValid(tup = systable_getnext(scan)))
513 : {
514 : Form_pg_subscription_rel subrel;
515 : SubscriptionRelState *relstate;
516 : Datum d;
517 : bool isnull;
518 :
519 2582 : subrel = (Form_pg_subscription_rel) GETSTRUCT(tup);
520 :
521 2582 : relstate = (SubscriptionRelState *) palloc(sizeof(SubscriptionRelState));
522 2582 : relstate->relid = subrel->srrelid;
523 2582 : relstate->state = subrel->srsubstate;
524 2582 : d = SysCacheGetAttr(SUBSCRIPTIONRELMAP, tup,
525 : Anum_pg_subscription_rel_srsublsn, &isnull);
526 2582 : if (isnull)
527 2106 : relstate->lsn = InvalidXLogRecPtr;
528 : else
529 476 : relstate->lsn = DatumGetLSN(d);
530 :
531 2582 : res = lappend(res, relstate);
532 : }
533 :
534 : /* Cleanup */
535 1586 : systable_endscan(scan);
536 1586 : table_close(rel, AccessShareLock);
537 :
538 1586 : return res;
539 : }
|
