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Functions
comment.h File Reference
#include "catalog/objectaddress.h"
#include "nodes/parsenodes.h"
Include dependency graph for comment.h:
This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Functions

ObjectAddress CommentObject (CommentStmt *stmt)
 
void DeleteComments (Oid oid, Oid classoid, int32 subid)
 
void CreateComments (Oid oid, Oid classoid, int32 subid, const char *comment)
 
void DeleteSharedComments (Oid oid, Oid classoid)
 
void CreateSharedComments (Oid oid, Oid classoid, const char *comment)
 
char * GetComment (Oid oid, Oid classoid, int32 subid)
 

Function Documentation

◆ CommentObject()

ObjectAddress CommentObject ( CommentStmt *  stmt)
extern

Definition at line 40 of file comment.c.

41{
42 Relation relation;
43 ObjectAddress address = InvalidObjectAddress;
44 bool missing_ok;
45
46 /*
47 * When loading a dump, we may see a COMMENT ON DATABASE for the old name
48 * of the database. Erroring out would prevent pg_restore from completing
49 * (which is really pg_restore's fault, but for now we will work around
50 * the problem here). Consensus is that the best fix is to treat wrong
51 * database name as a WARNING not an ERROR; hence, the following special
52 * case.
53 */
54 if (stmt->objtype == OBJECT_DATABASE)
55 {
56 char *database = strVal(stmt->object);
57
58 if (!OidIsValid(get_database_oid(database, true)))
59 {
60 ereport(WARNING,
61 (errcode(ERRCODE_UNDEFINED_DATABASE),
62 errmsg("database \"%s\" does not exist", database)));
63 return address;
64 }
65 }
66
67 /*
68 * During binary upgrade, allow nonexistent large objects so that we don't
69 * have to create them during schema restoration. pg_upgrade will
70 * transfer the contents of pg_largeobject_metadata via COPY or by
71 * copying/linking its files from the old cluster later on.
72 */
73 missing_ok = IsBinaryUpgrade && stmt->objtype == OBJECT_LARGEOBJECT;
74
75 /*
76 * Translate the parser representation that identifies this object into an
77 * ObjectAddress. get_object_address() will throw an error if the object
78 * does not exist, and will also acquire a lock on the target to guard
79 * against concurrent DROP operations.
80 */
81 address = get_object_address(stmt->objtype, stmt->object,
82 &relation, ShareUpdateExclusiveLock,
83 missing_ok);
84
85 /* Require ownership of the target object. */
86 check_object_ownership(GetUserId(), stmt->objtype, address,
87 stmt->object, relation);
88
89 /* Perform other integrity checks as needed. */
90 switch (stmt->objtype)
91 {
92 case OBJECT_COLUMN:
93
94 /*
95 * Allow comments only on columns of tables, views, materialized
96 * views, composite types, and foreign tables (which are the only
97 * relkinds for which pg_dump will dump per-column comments). In
98 * particular we wish to disallow comments on index columns,
99 * because the naming of an index's columns may change across PG
100 * versions, so dumping per-column comments could create reload
101 * failures.
102 */
103 if (relation->rd_rel->relkind != RELKIND_RELATION &&
104 relation->rd_rel->relkind != RELKIND_VIEW &&
105 relation->rd_rel->relkind != RELKIND_MATVIEW &&
106 relation->rd_rel->relkind != RELKIND_COMPOSITE_TYPE &&
107 relation->rd_rel->relkind != RELKIND_FOREIGN_TABLE &&
108 relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
109 ereport(ERROR,
110 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
111 errmsg("cannot set comment on relation \"%s\"",
112 RelationGetRelationName(relation)),
113 errdetail_relkind_not_supported(relation->rd_rel->relkind)));
114 break;
115 default:
116 break;
117 }
118
119 /*
120 * Databases, tablespaces, and roles are cluster-wide objects, so any
121 * comments on those objects are recorded in the shared pg_shdescription
122 * catalog. Comments on all other objects are recorded in pg_description.
123 */
124 if (stmt->objtype == OBJECT_DATABASE || stmt->objtype == OBJECT_TABLESPACE
125 || stmt->objtype == OBJECT_ROLE)
126 CreateSharedComments(address.objectId, address.classId, stmt->comment);
127 else
128 CreateComments(address.objectId, address.classId, address.objectSubId,
129 stmt->comment);
130
131 /*
132 * If get_object_address() opened the relation for us, we close it to keep
133 * the reference count correct - but we retain any locks acquired by
134 * get_object_address() until commit time, to guard against concurrent
135 * activity.
136 */
137 if (relation != NULL)
138 relation_close(relation, NoLock);
139
140 return address;
141}
OidIsValid
#define OidIsValid(objectId)
Definition c.h:800
CreateSharedComments
void CreateSharedComments(Oid oid, Oid classoid, const char *comment)
Definition comment.c:248
CreateComments
void CreateComments(Oid oid, Oid classoid, int32 subid, const char *comment)
Definition comment.c:153
get_database_oid
Oid get_database_oid(const char *dbname, bool missing_ok)
Definition dbcommands.c:3181
errcode
int errcode(int sqlerrcode)
Definition elog.c:874
errmsg
int errmsg(const char *fmt,...)
Definition elog.c:1093
WARNING
#define WARNING
Definition elog.h:36
ERROR
#define ERROR
Definition elog.h:39
ereport
#define ereport(elevel,...)
Definition elog.h:150
IsBinaryUpgrade
bool IsBinaryUpgrade
Definition globals.c:121
stmt
#define stmt
Definition indent_codes.h:59
NoLock
#define NoLock
Definition lockdefs.h:34
ShareUpdateExclusiveLock
#define ShareUpdateExclusiveLock
Definition lockdefs.h:39
GetUserId
Oid GetUserId(void)
Definition miscinit.c:469
check_object_ownership
void check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address, Node *object, Relation relation)
Definition objectaddress.c:2391
InvalidObjectAddress
const ObjectAddress InvalidObjectAddress
Definition objectaddress.c:837
get_object_address
ObjectAddress get_object_address(ObjectType objtype, Node *object, Relation *relp, LOCKMODE lockmode, bool missing_ok)
Definition objectaddress.c:923
OBJECT_COLUMN
@ OBJECT_COLUMN
Definition parsenodes.h:2360
OBJECT_TABLESPACE
@ OBJECT_TABLESPACE
Definition parsenodes.h:2396
OBJECT_ROLE
@ OBJECT_ROLE
Definition parsenodes.h:2387
OBJECT_LARGEOBJECT
@ OBJECT_LARGEOBJECT
Definition parsenodes.h:2376
OBJECT_DATABASE
@ OBJECT_DATABASE
Definition parsenodes.h:2363
errdetail_relkind_not_supported
int errdetail_relkind_not_supported(char relkind)
Definition pg_class.c:24
fb
static int fb(int x)
Definition preproc-init.c:92
RelationGetRelationName
#define RelationGetRelationName(relation)
Definition rel.h:548
relation_close
void relation_close(Relation relation, LOCKMODE lockmode)
Definition relation.c:205
RelationData::rd_rel
Form_pg_class rd_rel
Definition rel.h:111
strVal
#define strVal(v)
Definition value.h:82

References check_object_ownership(), ObjectAddress::classId, CreateComments(), CreateSharedComments(), ereport, errcode(), errdetail_relkind_not_supported(), errmsg(), ERROR, fb(), get_database_oid(), get_object_address(), GetUserId(), InvalidObjectAddress, IsBinaryUpgrade, NoLock, OBJECT_COLUMN, OBJECT_DATABASE, OBJECT_LARGEOBJECT, OBJECT_ROLE, OBJECT_TABLESPACE, ObjectAddress::objectId, ObjectAddress::objectSubId, OidIsValid, RelationData::rd_rel, relation_close(), RelationGetRelationName, ShareUpdateExclusiveLock, stmt, strVal, and WARNING.

Referenced by ATExecCmd(), ProcessUtilitySlow(), and standard_ProcessUtility().

◆ CreateComments()

void CreateComments ( Oid  oid,
Oid  classoid,
int32  subid,
const char *  comment 
)
extern

Definition at line 153 of file comment.c.

154{
155 Relation description;
156 ScanKeyData skey[3];
157 SysScanDesc sd;
158 HeapTuple oldtuple;
159 HeapTuple newtuple = NULL;
160 Datum values[Natts_pg_description];
161 bool nulls[Natts_pg_description];
162 bool replaces[Natts_pg_description];
163 int i;
164
165 /* Reduce empty-string to NULL case */
166 if (comment != NULL && strlen(comment) == 0)
167 comment = NULL;
168
169 /* Prepare to form or update a tuple, if necessary */
170 if (comment != NULL)
171 {
172 for (i = 0; i < Natts_pg_description; i++)
173 {
174 nulls[i] = false;
175 replaces[i] = true;
176 }
177 values[Anum_pg_description_objoid - 1] = ObjectIdGetDatum(oid);
178 values[Anum_pg_description_classoid - 1] = ObjectIdGetDatum(classoid);
179 values[Anum_pg_description_objsubid - 1] = Int32GetDatum(subid);
180 values[Anum_pg_description_description - 1] = CStringGetTextDatum(comment);
181 }
182
183 /* Use the index to search for a matching old tuple */
184
185 ScanKeyInit(&skey[0],
186 Anum_pg_description_objoid,
187 BTEqualStrategyNumber, F_OIDEQ,
188 ObjectIdGetDatum(oid));
189 ScanKeyInit(&skey[1],
190 Anum_pg_description_classoid,
191 BTEqualStrategyNumber, F_OIDEQ,
192 ObjectIdGetDatum(classoid));
193 ScanKeyInit(&skey[2],
194 Anum_pg_description_objsubid,
195 BTEqualStrategyNumber, F_INT4EQ,
196 Int32GetDatum(subid));
197
198 description = table_open(DescriptionRelationId, RowExclusiveLock);
199
200 sd = systable_beginscan(description, DescriptionObjIndexId, true,
201 NULL, 3, skey);
202
203 while ((oldtuple = systable_getnext(sd)) != NULL)
204 {
205 /* Found the old tuple, so delete or update it */
206
207 if (comment == NULL)
208 CatalogTupleDelete(description, &oldtuple->t_self);
209 else
210 {
211 newtuple = heap_modify_tuple(oldtuple, RelationGetDescr(description), values,
212 nulls, replaces);
213 CatalogTupleUpdate(description, &oldtuple->t_self, newtuple);
214 }
215
216 break; /* Assume there can be only one match */
217 }
218
219 systable_endscan(sd);
220
221 /* If we didn't find an old tuple, insert a new one */
222
223 if (newtuple == NULL && comment != NULL)
224 {
225 newtuple = heap_form_tuple(RelationGetDescr(description),
226 values, nulls);
227 CatalogTupleInsert(description, newtuple);
228 }
229
230 if (newtuple != NULL)
231 heap_freetuple(newtuple);
232
233 /* Done */
234
235 table_close(description, NoLock);
236}
values
static Datum values[MAXATTR]
Definition bootstrap.c:147
CStringGetTextDatum
#define CStringGetTextDatum(s)
Definition builtins.h:98
systable_endscan
void systable_endscan(SysScanDesc sysscan)
Definition genam.c:603
systable_getnext
HeapTuple systable_getnext(SysScanDesc sysscan)
Definition genam.c:514
systable_beginscan
SysScanDesc systable_beginscan(Relation heapRelation, Oid indexId, bool indexOK, Snapshot snapshot, int nkeys, ScanKey key)
Definition genam.c:388
heap_modify_tuple
HeapTuple heap_modify_tuple(HeapTuple tuple, TupleDesc tupleDesc, const Datum *replValues, const bool *replIsnull, const bool *doReplace)
Definition heaptuple.c:1210
heap_form_tuple
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
Definition heaptuple.c:1117
heap_freetuple
void heap_freetuple(HeapTuple htup)
Definition heaptuple.c:1435
comment
#define comment
Definition indent_codes.h:49
CatalogTupleUpdate
void CatalogTupleUpdate(Relation heapRel, const ItemPointerData *otid, HeapTuple tup)
Definition indexing.c:313
CatalogTupleInsert
void CatalogTupleInsert(Relation heapRel, HeapTuple tup)
Definition indexing.c:233
CatalogTupleDelete
void CatalogTupleDelete(Relation heapRel, const ItemPointerData *tid)
Definition indexing.c:365
i
int i
Definition isn.c:77
RowExclusiveLock
#define RowExclusiveLock
Definition lockdefs.h:38
ObjectIdGetDatum
static Datum ObjectIdGetDatum(Oid X)
Definition postgres.h:262
Datum
uint64_t Datum
Definition postgres.h:70
Int32GetDatum
static Datum Int32GetDatum(int32 X)
Definition postgres.h:222
RelationGetDescr
#define RelationGetDescr(relation)
Definition rel.h:540
ScanKeyInit
void ScanKeyInit(ScanKey entry, AttrNumber attributeNumber, StrategyNumber strategy, RegProcedure procedure, Datum argument)
Definition scankey.c:76
BTEqualStrategyNumber
#define BTEqualStrategyNumber
Definition stratnum.h:31
HeapTupleData::t_self
ItemPointerData t_self
Definition htup.h:65
table_close
void table_close(Relation relation, LOCKMODE lockmode)
Definition table.c:126
table_open
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition table.c:40
description
const char * description
Definition wait_event_funcs.c:29

References BTEqualStrategyNumber, CatalogTupleDelete(), CatalogTupleInsert(), CatalogTupleUpdate(), comment, CStringGetTextDatum, description, fb(), heap_form_tuple(), heap_freetuple(), heap_modify_tuple(), i, Int32GetDatum(), NoLock, ObjectIdGetDatum(), RelationGetDescr, RowExclusiveLock, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), HeapTupleData::t_self, table_close(), table_open(), and values.

Referenced by CommentObject(), CreateExtensionInternal(), CreateStatistics(), DefineIndex(), and pg_import_system_collations().

◆ CreateSharedComments()

void CreateSharedComments ( Oid  oid,
Oid  classoid,
const char *  comment 
)
extern

Definition at line 248 of file comment.c.

249{
250 Relation shdescription;
251 ScanKeyData skey[2];
252 SysScanDesc sd;
253 HeapTuple oldtuple;
254 HeapTuple newtuple = NULL;
255 Datum values[Natts_pg_shdescription];
256 bool nulls[Natts_pg_shdescription];
257 bool replaces[Natts_pg_shdescription];
258 int i;
259
260 /* Reduce empty-string to NULL case */
261 if (comment != NULL && strlen(comment) == 0)
262 comment = NULL;
263
264 /* Prepare to form or update a tuple, if necessary */
265 if (comment != NULL)
266 {
267 for (i = 0; i < Natts_pg_shdescription; i++)
268 {
269 nulls[i] = false;
270 replaces[i] = true;
271 }
272 values[Anum_pg_shdescription_objoid - 1] = ObjectIdGetDatum(oid);
273 values[Anum_pg_shdescription_classoid - 1] = ObjectIdGetDatum(classoid);
274 values[Anum_pg_shdescription_description - 1] = CStringGetTextDatum(comment);
275 }
276
277 /* Use the index to search for a matching old tuple */
278
279 ScanKeyInit(&skey[0],
280 Anum_pg_shdescription_objoid,
281 BTEqualStrategyNumber, F_OIDEQ,
282 ObjectIdGetDatum(oid));
283 ScanKeyInit(&skey[1],
284 Anum_pg_shdescription_classoid,
285 BTEqualStrategyNumber, F_OIDEQ,
286 ObjectIdGetDatum(classoid));
287
288 shdescription = table_open(SharedDescriptionRelationId, RowExclusiveLock);
289
290 sd = systable_beginscan(shdescription, SharedDescriptionObjIndexId, true,
291 NULL, 2, skey);
292
293 while ((oldtuple = systable_getnext(sd)) != NULL)
294 {
295 /* Found the old tuple, so delete or update it */
296
297 if (comment == NULL)
298 CatalogTupleDelete(shdescription, &oldtuple->t_self);
299 else
300 {
301 newtuple = heap_modify_tuple(oldtuple, RelationGetDescr(shdescription),
302 values, nulls, replaces);
303 CatalogTupleUpdate(shdescription, &oldtuple->t_self, newtuple);
304 }
305
306 break; /* Assume there can be only one match */
307 }
308
309 systable_endscan(sd);
310
311 /* If we didn't find an old tuple, insert a new one */
312
313 if (newtuple == NULL && comment != NULL)
314 {
315 newtuple = heap_form_tuple(RelationGetDescr(shdescription),
316 values, nulls);
317 CatalogTupleInsert(shdescription, newtuple);
318 }
319
320 if (newtuple != NULL)
321 heap_freetuple(newtuple);
322
323 /* Done */
324
325 table_close(shdescription, NoLock);
326}

References BTEqualStrategyNumber, CatalogTupleDelete(), CatalogTupleInsert(), CatalogTupleUpdate(), comment, CStringGetTextDatum, fb(), heap_form_tuple(), heap_freetuple(), heap_modify_tuple(), i, NoLock, ObjectIdGetDatum(), RelationGetDescr, RowExclusiveLock, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), HeapTupleData::t_self, table_close(), table_open(), and values.

Referenced by CommentObject().

◆ DeleteComments()

void DeleteComments ( Oid  oid,
Oid  classoid,
int32  subid 
)
extern

Definition at line 336 of file comment.c.

337{
338 Relation description;
339 ScanKeyData skey[3];
340 int nkeys;
341 SysScanDesc sd;
342 HeapTuple oldtuple;
343
344 /* Use the index to search for all matching old tuples */
345
346 ScanKeyInit(&skey[0],
347 Anum_pg_description_objoid,
348 BTEqualStrategyNumber, F_OIDEQ,
349 ObjectIdGetDatum(oid));
350 ScanKeyInit(&skey[1],
351 Anum_pg_description_classoid,
352 BTEqualStrategyNumber, F_OIDEQ,
353 ObjectIdGetDatum(classoid));
354
355 if (subid != 0)
356 {
357 ScanKeyInit(&skey[2],
358 Anum_pg_description_objsubid,
359 BTEqualStrategyNumber, F_INT4EQ,
360 Int32GetDatum(subid));
361 nkeys = 3;
362 }
363 else
364 nkeys = 2;
365
366 description = table_open(DescriptionRelationId, RowExclusiveLock);
367
368 sd = systable_beginscan(description, DescriptionObjIndexId, true,
369 NULL, nkeys, skey);
370
371 while ((oldtuple = systable_getnext(sd)) != NULL)
372 CatalogTupleDelete(description, &oldtuple->t_self);
373
374 /* Done */
375
376 systable_endscan(sd);
377 table_close(description, RowExclusiveLock);
378}

References BTEqualStrategyNumber, CatalogTupleDelete(), description, fb(), Int32GetDatum(), ObjectIdGetDatum(), RowExclusiveLock, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), HeapTupleData::t_self, table_close(), and table_open().

Referenced by deleteOneObject().

◆ DeleteSharedComments()

void DeleteSharedComments ( Oid  oid,
Oid  classoid 
)
extern

Definition at line 384 of file comment.c.

385{
386 Relation shdescription;
387 ScanKeyData skey[2];
388 SysScanDesc sd;
389 HeapTuple oldtuple;
390
391 /* Use the index to search for all matching old tuples */
392
393 ScanKeyInit(&skey[0],
394 Anum_pg_shdescription_objoid,
395 BTEqualStrategyNumber, F_OIDEQ,
396 ObjectIdGetDatum(oid));
397 ScanKeyInit(&skey[1],
398 Anum_pg_shdescription_classoid,
399 BTEqualStrategyNumber, F_OIDEQ,
400 ObjectIdGetDatum(classoid));
401
402 shdescription = table_open(SharedDescriptionRelationId, RowExclusiveLock);
403
404 sd = systable_beginscan(shdescription, SharedDescriptionObjIndexId, true,
405 NULL, 2, skey);
406
407 while ((oldtuple = systable_getnext(sd)) != NULL)
408 CatalogTupleDelete(shdescription, &oldtuple->t_self);
409
410 /* Done */
411
412 systable_endscan(sd);
413 table_close(shdescription, RowExclusiveLock);
414}

References BTEqualStrategyNumber, CatalogTupleDelete(), fb(), ObjectIdGetDatum(), RowExclusiveLock, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), HeapTupleData::t_self, table_close(), and table_open().

Referenced by dropdb(), DropRole(), and DropTableSpace().

◆ GetComment()

char * GetComment ( Oid  oid,
Oid  classoid,
int32  subid 
)
extern

Definition at line 420 of file comment.c.

421{
422 Relation description;
423 ScanKeyData skey[3];
424 SysScanDesc sd;
425 TupleDesc tupdesc;
426 HeapTuple tuple;
427 char *comment;
428
429 /* Use the index to search for a matching old tuple */
430
431 ScanKeyInit(&skey[0],
432 Anum_pg_description_objoid,
433 BTEqualStrategyNumber, F_OIDEQ,
434 ObjectIdGetDatum(oid));
435 ScanKeyInit(&skey[1],
436 Anum_pg_description_classoid,
437 BTEqualStrategyNumber, F_OIDEQ,
438 ObjectIdGetDatum(classoid));
439 ScanKeyInit(&skey[2],
440 Anum_pg_description_objsubid,
441 BTEqualStrategyNumber, F_INT4EQ,
442 Int32GetDatum(subid));
443
444 description = table_open(DescriptionRelationId, AccessShareLock);
445 tupdesc = RelationGetDescr(description);
446
447 sd = systable_beginscan(description, DescriptionObjIndexId, true,
448 NULL, 3, skey);
449
450 comment = NULL;
451 while ((tuple = systable_getnext(sd)) != NULL)
452 {
453 Datum value;
454 bool isnull;
455
456 /* Found the tuple, get description field */
457 value = heap_getattr(tuple, Anum_pg_description_description, tupdesc, &isnull);
458 if (!isnull)
459 comment = TextDatumGetCString(value);
460 break; /* Assume there can be only one match */
461 }
462
463 systable_endscan(sd);
464
465 /* Done */
466 table_close(description, AccessShareLock);
467
468 return comment;
469}
TextDatumGetCString
#define TextDatumGetCString(d)
Definition builtins.h:99
heap_getattr
static Datum heap_getattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
Definition htup_details.h:890
value
static struct @174 value
AccessShareLock
#define AccessShareLock
Definition lockdefs.h:36

References AccessShareLock, BTEqualStrategyNumber, comment, description, fb(), heap_getattr(), Int32GetDatum(), ObjectIdGetDatum(), RelationGetDescr, ScanKeyInit(), systable_beginscan(), systable_endscan(), systable_getnext(), table_close(), table_open(), TextDatumGetCString, and value.

Referenced by ATPostAlterTypeParse(), expandTableLikeClause(), RebuildConstraintComment(), and transformTableLikeClause().