src/backend/catalog/pg_collation.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pg_collation.c
   4  *        routines to support manipulation of the pg_collation relation
   5  *
   6  * Portions Copyright (c) 1996-2024, 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/htup_details.h"
  18 #include "access/table.h"
  19 #include "catalog/catalog.h"
  20 #include "catalog/dependency.h"
  21 #include "catalog/indexing.h"
  22 #include "catalog/objectaccess.h"
  23 #include "catalog/pg_collation.h"
  24 #include "catalog/pg_namespace.h"
  25 #include "mb/pg_wchar.h"
  26 #include "utils/builtins.h"
  27 #include "utils/rel.h"
  28 #include "utils/syscache.h"
  29
  30
  31 /*
  32  * CollationCreate
  33  *
  34  * Add a new tuple to pg_collation.
  35  *
  36  * if_not_exists: if true, don't fail on duplicate name, just print a notice
  37  * and return InvalidOid.
  38  * quiet: if true, don't fail on duplicate name, just silently return
  39  * InvalidOid (overrides if_not_exists).
  40  */
  41 Oid
  42 CollationCreate(const char *collname, Oid collnamespace,
  43                                 Oid collowner,
  44                                 char collprovider,
  45                                 bool collisdeterministic,
  46                                 int32 collencoding,
  47                                 const char *collcollate, const char *collctype,
  48                                 const char *colllocale,
  49                                 const char *collicurules,
  50                                 const char *collversion,
  51                                 bool if_not_exists,
  52                                 bool quiet)
  53 {
  54         Relation        rel;
  55         TupleDesc       tupDesc;
  56         HeapTuple       tup;
  57         Datum           values[Natts_pg_collation];
  58         bool            nulls[Natts_pg_collation];
  59         NameData        name_name;
  60         Oid                     oid;
  61         ObjectAddress myself,
  62                                 referenced;
  63
  64         Assert(collname);
  65         Assert(collnamespace);
  66         Assert(collowner);
  67         Assert((collprovider == COLLPROVIDER_LIBC &&
  68                         collcollate && collctype && !colllocale) ||
  69                    (collprovider != COLLPROVIDER_LIBC &&
  70                         !collcollate && !collctype && colllocale));
  71
  72         /*
  73          * Make sure there is no existing collation of same name & encoding.
  74          *
  75          * This would be caught by the unique index anyway; we're just giving a
  76          * friendlier error message.  The unique index provides a backstop against
  77          * race conditions.
  78          */
  79         oid = GetSysCacheOid3(COLLNAMEENCNSP,
  80                                                   Anum_pg_collation_oid,
  81                                                   PointerGetDatum(collname),
  82                                                   Int32GetDatum(collencoding),
  83                                                   ObjectIdGetDatum(collnamespace));
  84         if (OidIsValid(oid))
  85         {
  86                 if (quiet)
  87                         return InvalidOid;
  88                 else if (if_not_exists)
  89                 {
  90                         /*
  91                          * If we are in an extension script, insist that the pre-existing
  92                          * object be a member of the extension, to avoid security risks.
  93                          */
  94                         ObjectAddressSet(myself, CollationRelationId, oid);
  95                         checkMembershipInCurrentExtension(&myself);
  96
  97                         /* OK to skip */
  98                         ereport(NOTICE,
  99                                         (errcode(ERRCODE_DUPLICATE_OBJECT),
 100                                          collencoding == -1
 101                                          ? errmsg("collation \"%s\" already exists, skipping",
 102                                                           collname)
 103                                          : errmsg("collation \"%s\" for encoding \"%s\" already exists, skipping",
 104                                                           collname, pg_encoding_to_char(collencoding))));
 105                         return InvalidOid;
 106                 }
 107                 else
 108                         ereport(ERROR,
 109                                         (errcode(ERRCODE_DUPLICATE_OBJECT),
 110                                          collencoding == -1
 111                                          ? errmsg("collation \"%s\" already exists",
 112                                                           collname)
 113                                          : errmsg("collation \"%s\" for encoding \"%s\" already exists",
 114                                                           collname, pg_encoding_to_char(collencoding))));
 115         }
 116
 117         /* open pg_collation; see below about the lock level */
 118         rel = table_open(CollationRelationId, ShareRowExclusiveLock);
 119
 120         /*
 121          * Also forbid a specific-encoding collation shadowing an any-encoding
 122          * collation, or an any-encoding collation being shadowed (see
 123          * get_collation_name()).  This test is not backed up by the unique index,
 124          * so we take a ShareRowExclusiveLock earlier, to protect against
 125          * concurrent changes fooling this check.
 126          */
 127         if (collencoding == -1)
 128                 oid = GetSysCacheOid3(COLLNAMEENCNSP,
 129                                                           Anum_pg_collation_oid,
 130                                                           PointerGetDatum(collname),
 131                                                           Int32GetDatum(GetDatabaseEncoding()),
 132                                                           ObjectIdGetDatum(collnamespace));
 133         else
 134                 oid = GetSysCacheOid3(COLLNAMEENCNSP,
 135                                                           Anum_pg_collation_oid,
 136                                                           PointerGetDatum(collname),
 137                                                           Int32GetDatum(-1),
 138                                                           ObjectIdGetDatum(collnamespace));
 139         if (OidIsValid(oid))
 140         {
 141                 if (quiet)
 142                 {
 143                         table_close(rel, NoLock);
 144                         return InvalidOid;
 145                 }
 146                 else if (if_not_exists)
 147                 {
 148                         /*
 149                          * If we are in an extension script, insist that the pre-existing
 150                          * object be a member of the extension, to avoid security risks.
 151                          */
 152                         ObjectAddressSet(myself, CollationRelationId, oid);
 153                         checkMembershipInCurrentExtension(&myself);
 154
 155                         /* OK to skip */
 156                         table_close(rel, NoLock);
 157                         ereport(NOTICE,
 158                                         (errcode(ERRCODE_DUPLICATE_OBJECT),
 159                                          errmsg("collation \"%s\" already exists, skipping",
 160                                                         collname)));
 161                         return InvalidOid;
 162                 }
 163                 else
 164                         ereport(ERROR,
 165                                         (errcode(ERRCODE_DUPLICATE_OBJECT),
 166                                          errmsg("collation \"%s\" already exists",
 167                                                         collname)));
 168         }
 169
 170         tupDesc = RelationGetDescr(rel);
 171
 172         /* form a tuple */
 173         memset(nulls, 0, sizeof(nulls));
 174
 175         namestrcpy(&name_name, collname);
 176         oid = GetNewOidWithIndex(rel, CollationOidIndexId,
 177                                                          Anum_pg_collation_oid);
 178         values[Anum_pg_collation_oid - 1] = ObjectIdGetDatum(oid);
 179         values[Anum_pg_collation_collname - 1] = NameGetDatum(&name_name);
 180         values[Anum_pg_collation_collnamespace - 1] = ObjectIdGetDatum(collnamespace);
 181         values[Anum_pg_collation_collowner - 1] = ObjectIdGetDatum(collowner);
 182         values[Anum_pg_collation_collprovider - 1] = CharGetDatum(collprovider);
 183         values[Anum_pg_collation_collisdeterministic - 1] = BoolGetDatum(collisdeterministic);
 184         values[Anum_pg_collation_collencoding - 1] = Int32GetDatum(collencoding);
 185         if (collcollate)
 186                 values[Anum_pg_collation_collcollate - 1] = CStringGetTextDatum(collcollate);
 187         else
 188                 nulls[Anum_pg_collation_collcollate - 1] = true;
 189         if (collctype)
 190                 values[Anum_pg_collation_collctype - 1] = CStringGetTextDatum(collctype);
 191         else
 192                 nulls[Anum_pg_collation_collctype - 1] = true;
 193         if (colllocale)
 194                 values[Anum_pg_collation_colllocale - 1] = CStringGetTextDatum(colllocale);
 195         else
 196                 nulls[Anum_pg_collation_colllocale - 1] = true;
 197         if (collicurules)
 198                 values[Anum_pg_collation_collicurules - 1] = CStringGetTextDatum(collicurules);
 199         else
 200                 nulls[Anum_pg_collation_collicurules - 1] = true;
 201         if (collversion)
 202                 values[Anum_pg_collation_collversion - 1] = CStringGetTextDatum(collversion);
 203         else
 204                 nulls[Anum_pg_collation_collversion - 1] = true;
 205
 206         tup = heap_form_tuple(tupDesc, values, nulls);
 207
 208         /* insert a new tuple */
 209         CatalogTupleInsert(rel, tup);
 210         Assert(OidIsValid(oid));
 211
 212         /* set up dependencies for the new collation */
 213         myself.classId = CollationRelationId;
 214         myself.objectId = oid;
 215         myself.objectSubId = 0;
 216
 217         /* create dependency on namespace */
 218         referenced.classId = NamespaceRelationId;
 219         referenced.objectId = collnamespace;
 220         referenced.objectSubId = 0;
 221         recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
 222
 223         /* create dependency on owner */
 224         recordDependencyOnOwner(CollationRelationId, oid, collowner);
 225
 226         /* dependency on extension */
 227         recordDependencyOnCurrentExtension(&myself, false);
 228
 229         /* Post creation hook for new collation */
 230         InvokeObjectPostCreateHook(CollationRelationId, oid, 0);
 231
 232         heap_freetuple(tup);
 233         table_close(rel, NoLock);
 234
 235         return oid;
 236 }