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pg_collation.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pg_collation.c
4  * routines to support manipulation of the pg_collation relation
5  *
6  * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/catalog/pg_collation.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 #include "postgres.h"
16 
17 #include "access/genam.h"
18 #include "access/htup_details.h"
19 #include "access/sysattr.h"
20 #include "access/table.h"
21 #include "catalog/catalog.h"
22 #include "catalog/dependency.h"
23 #include "catalog/indexing.h"
24 #include "catalog/objectaccess.h"
25 #include "catalog/pg_collation.h"
26 #include "catalog/pg_namespace.h"
27 #include "mb/pg_wchar.h"
28 #include "utils/builtins.h"
29 #include "utils/fmgroids.h"
30 #include "utils/pg_locale.h"
31 #include "utils/rel.h"
32 #include "utils/syscache.h"
33 
34 
35 /*
36  * CollationCreate
37  *
38  * Add a new tuple to pg_collation.
39  *
40  * if_not_exists: if true, don't fail on duplicate name, just print a notice
41  * and return InvalidOid.
42  * quiet: if true, don't fail on duplicate name, just silently return
43  * InvalidOid (overrides if_not_exists).
44  */
45 Oid
46 CollationCreate(const char *collname, Oid collnamespace,
47  Oid collowner,
48  char collprovider,
49  bool collisdeterministic,
50  int32 collencoding,
51  const char *collcollate, const char *collctype,
52  const char *collversion,
53  bool if_not_exists,
54  bool quiet)
55 {
56  Relation rel;
57  TupleDesc tupDesc;
58  HeapTuple tup;
59  Datum values[Natts_pg_collation];
60  bool nulls[Natts_pg_collation];
61  NameData name_name,
62  name_collate,
63  name_ctype;
64  Oid oid;
65  ObjectAddress myself,
66  referenced;
67 
68  AssertArg(collname);
69  AssertArg(collnamespace);
70  AssertArg(collowner);
71  AssertArg(collcollate);
72  AssertArg(collctype);
73 
74  /*
75  * Make sure there is no existing collation of same name & encoding.
76  *
77  * This would be caught by the unique index anyway; we're just giving a
78  * friendlier error message. The unique index provides a backstop against
79  * race conditions.
80  */
82  PointerGetDatum(collname),
83  Int32GetDatum(collencoding),
84  ObjectIdGetDatum(collnamespace)))
85  {
86  if (quiet)
87  return InvalidOid;
88  else if (if_not_exists)
89  {
92  collencoding == -1
93  ? errmsg("collation \"%s\" already exists, skipping",
94  collname)
95  : errmsg("collation \"%s\" for encoding \"%s\" already exists, skipping",
96  collname, pg_encoding_to_char(collencoding))));
97  return InvalidOid;
98  }
99  else
100  ereport(ERROR,
102  collencoding == -1
103  ? errmsg("collation \"%s\" already exists",
104  collname)
105  : errmsg("collation \"%s\" for encoding \"%s\" already exists",
106  collname, pg_encoding_to_char(collencoding))));
107  }
108 
109  /* open pg_collation; see below about the lock level */
110  rel = table_open(CollationRelationId, ShareRowExclusiveLock);
111 
112  /*
113  * Also forbid a specific-encoding collation shadowing an any-encoding
114  * collation, or an any-encoding collation being shadowed (see
115  * get_collation_name()). This test is not backed up by the unique index,
116  * so we take a ShareRowExclusiveLock earlier, to protect against
117  * concurrent changes fooling this check.
118  */
119  if ((collencoding == -1 &&
121  PointerGetDatum(collname),
123  ObjectIdGetDatum(collnamespace))) ||
124  (collencoding != -1 &&
126  PointerGetDatum(collname),
127  Int32GetDatum(-1),
128  ObjectIdGetDatum(collnamespace))))
129  {
130  if (quiet)
131  {
132  table_close(rel, NoLock);
133  return InvalidOid;
134  }
135  else if (if_not_exists)
136  {
137  table_close(rel, NoLock);
138  ereport(NOTICE,
140  errmsg("collation \"%s\" already exists, skipping",
141  collname)));
142  return InvalidOid;
143  }
144  else
145  ereport(ERROR,
147  errmsg("collation \"%s\" already exists",
148  collname)));
149  }
150 
151  tupDesc = RelationGetDescr(rel);
152 
153  /* form a tuple */
154  memset(nulls, 0, sizeof(nulls));
155 
156  namestrcpy(&name_name, collname);
158  Anum_pg_collation_oid);
159  values[Anum_pg_collation_oid - 1] = ObjectIdGetDatum(oid);
160  values[Anum_pg_collation_collname - 1] = NameGetDatum(&name_name);
161  values[Anum_pg_collation_collnamespace - 1] = ObjectIdGetDatum(collnamespace);
162  values[Anum_pg_collation_collowner - 1] = ObjectIdGetDatum(collowner);
163  values[Anum_pg_collation_collprovider - 1] = CharGetDatum(collprovider);
164  values[Anum_pg_collation_collisdeterministic - 1] = BoolGetDatum(collisdeterministic);
165  values[Anum_pg_collation_collencoding - 1] = Int32GetDatum(collencoding);
166  namestrcpy(&name_collate, collcollate);
167  values[Anum_pg_collation_collcollate - 1] = NameGetDatum(&name_collate);
168  namestrcpy(&name_ctype, collctype);
169  values[Anum_pg_collation_collctype - 1] = NameGetDatum(&name_ctype);
170  if (collversion)
171  values[Anum_pg_collation_collversion - 1] = CStringGetTextDatum(collversion);
172  else
173  nulls[Anum_pg_collation_collversion - 1] = true;
174 
175  tup = heap_form_tuple(tupDesc, values, nulls);
176 
177  /* insert a new tuple */
178  CatalogTupleInsert(rel, tup);
179  Assert(OidIsValid(oid));
180 
181  /* set up dependencies for the new collation */
182  myself.classId = CollationRelationId;
183  myself.objectId = oid;
184  myself.objectSubId = 0;
185 
186  /* create dependency on namespace */
187  referenced.classId = NamespaceRelationId;
188  referenced.objectId = collnamespace;
189  referenced.objectSubId = 0;
190  recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
191 
192  /* create dependency on owner */
193  recordDependencyOnOwner(CollationRelationId, oid, collowner);
194 
195  /* dependency on extension */
196  recordDependencyOnCurrentExtension(&myself, false);
197 
198  /* Post creation hook for new collation */
199  InvokeObjectPostCreateHook(CollationRelationId, oid, 0);
200 
201  heap_freetuple(tup);
202  table_close(rel, NoLock);
203 
204  return oid;
205 }
206 
207 /*
208  * RemoveCollationById
209  *
210  * Remove a tuple from pg_collation by Oid. This function is solely
211  * called inside catalog/dependency.c
212  */
213 void
215 {
216  Relation rel;
217  ScanKeyData scanKeyData;
218  SysScanDesc scandesc;
219  HeapTuple tuple;
220 
221  rel = table_open(CollationRelationId, RowExclusiveLock);
222 
223  ScanKeyInit(&scanKeyData,
224  Anum_pg_collation_oid,
225  BTEqualStrategyNumber, F_OIDEQ,
226  ObjectIdGetDatum(collationOid));
227 
228  scandesc = systable_beginscan(rel, CollationOidIndexId, true,
229  NULL, 1, &scanKeyData);
230 
231  tuple = systable_getnext(scandesc);
232 
233  if (HeapTupleIsValid(tuple))
234  CatalogTupleDelete(rel, &tuple->t_self);
235  else
236  elog(ERROR, "could not find tuple for collation %u", collationOid);
237 
238  systable_endscan(scandesc);
239 
241 }
Oid GetNewOidWithIndex(Relation relation, Oid indexId, AttrNumber oidcolumn)
Definition: catalog.c:322
#define NameGetDatum(X)
Definition: postgres.h:595
#define CollationOidIndexId
Definition: indexing.h:123
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:133
void systable_endscan(SysScanDesc sysscan)
Definition: genam.c:525
#define InvokeObjectPostCreateHook(classId, objectId, subId)
Definition: objectaccess.h:151
#define RelationGetDescr(relation)
Definition: rel.h:448
#define PointerGetDatum(X)
Definition: postgres.h:556
int errcode(int sqlerrcode)
Definition: elog.c:608
void CatalogTupleDelete(Relation heapRel, ItemPointer tid)
Definition: indexing.c:269
void recordDependencyOn(const ObjectAddress *depender, const ObjectAddress *referenced, DependencyType behavior)
Definition: pg_depend.c:43
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, Datum *values, bool *isnull)
Definition: heaptuple.c:1020
void recordDependencyOnOwner(Oid classId, Oid objectId, Oid owner)
Definition: pg_shdepend.c:164
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
unsigned int Oid
Definition: postgres_ext.h:31
int namestrcpy(Name name, const char *str)
Definition: name.c:250
#define OidIsValid(objectId)
Definition: c.h:645
void RemoveCollationById(Oid collationOid)
Definition: pg_collation.c:214
SysScanDesc systable_beginscan(Relation heapRelation, Oid indexId, bool indexOK, Snapshot snapshot, int nkeys, ScanKey key)
Definition: genam.c:352
signed int int32
Definition: c.h:347
HeapTuple systable_getnext(SysScanDesc sysscan)
Definition: genam.c:444
#define ObjectIdGetDatum(X)
Definition: postgres.h:507
#define ERROR
Definition: elog.h:43
#define SearchSysCacheExists3(cacheId, key1, key2, key3)
Definition: syscache.h:187
ItemPointerData t_self
Definition: htup.h:65
Definition: c.h:610
#define NoLock
Definition: lockdefs.h:34
#define RowExclusiveLock
Definition: lockdefs.h:38
#define ereport(elevel, rest)
Definition: elog.h:141
#define AssertArg(condition)
Definition: c.h:741
uintptr_t Datum
Definition: postgres.h:367
int GetDatabaseEncoding(void)
Definition: mbutils.c:1046
#define BoolGetDatum(X)
Definition: postgres.h:402
#define InvalidOid
Definition: postgres_ext.h:36
#define NOTICE
Definition: elog.h:37
const char * pg_encoding_to_char(int encoding)
Definition: encnames.c:607
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
#define Assert(condition)
Definition: c.h:739
#define ShareRowExclusiveLock
Definition: lockdefs.h:42
void recordDependencyOnCurrentExtension(const ObjectAddress *object, bool isReplace)
Definition: pg_depend.c:138
Oid CollationCreate(const char *collname, Oid collnamespace, Oid collowner, char collprovider, bool collisdeterministic, int32 collencoding, const char *collcollate, const char *collctype, const char *collversion, bool if_not_exists, bool quiet)
Definition: pg_collation.c:46
#define CharGetDatum(X)
Definition: postgres.h:416
static Datum values[MAXATTR]
Definition: bootstrap.c:167
#define Int32GetDatum(X)
Definition: postgres.h:479
int errmsg(const char *fmt,...)
Definition: elog.c:822
#define elog(elevel,...)
Definition: elog.h:228
void ScanKeyInit(ScanKey entry, AttrNumber attributeNumber, StrategyNumber strategy, RegProcedure procedure, Datum argument)
Definition: scankey.c:76
#define CStringGetTextDatum(s)
Definition: builtins.h:83
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:39
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:31
void CatalogTupleInsert(Relation heapRel, HeapTuple tup)
Definition: indexing.c:183
#define BTEqualStrategyNumber
Definition: stratnum.h:31