PostgreSQL Source Code: src/backend/catalog/pg_cast.c Source File

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pg_cast.c
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1/*-------------------------------------------------------------------------
2 *
3 * pg_cast.c
4 * routines to support manipulation of the pg_cast relation
5 *
6 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 *
10 * IDENTIFICATION
11 * src/backend/catalog/pg_cast.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_cast.h"
24#include "catalog/pg_proc.h"
25#include "catalog/pg_type.h"
26#include "utils/builtins.h"
27#include "utils/rel.h"
28#include "utils/syscache.h"
29
30/*
31 * ----------------------------------------------------------------
32 * CastCreate
33 *
34 * Forms and inserts catalog tuples for a new cast being created.
35 * Caller must have already checked privileges, and done consistency
36 * checks on the given datatypes and cast function (if applicable).
37 *
38 * Since we allow binary coercibility of the datatypes to the cast
39 * function's input and result, there could be one or two WITHOUT FUNCTION
40 * casts that this one depends on. We don't record that explicitly
41 * in pg_cast, but we still need to make dependencies on those casts.
42 *
43 * 'behavior' indicates the types of the dependencies that the new
44 * cast will have on its input and output types, the cast function,
45 * and the other casts if any.
46 * ----------------------------------------------------------------
47 */
48ObjectAddress
49 CastCreate(Oid sourcetypeid, Oid targettypeid,
50 Oid funcid, Oid incastid, Oid outcastid,
51 char castcontext, char castmethod, DependencyType behavior)
52{
53 Relation relation;
54 HeapTuple tuple;
55 Oid castid;
56 Datum values[Natts_pg_cast];
57 bool nulls[Natts_pg_cast] = {0};
58 ObjectAddress myself,
59 referenced;
60 ObjectAddresses *addrs;
61
62 relation = table_open(CastRelationId, RowExclusiveLock);
63
64 /*
65 * Check for duplicate. This is just to give a friendly error message,
66 * the unique index would catch it anyway (so no need to sweat about race
67 * conditions).
68 */
69 tuple = SearchSysCache2(CASTSOURCETARGET,
70 ObjectIdGetDatum(sourcetypeid),
71 ObjectIdGetDatum(targettypeid));
72 if (HeapTupleIsValid(tuple))
73 ereport(ERROR,
74 (errcode(ERRCODE_DUPLICATE_OBJECT),
75 errmsg("cast from type %s to type %s already exists",
76 format_type_be(sourcetypeid),
77 format_type_be(targettypeid))));
78
79 /* ready to go */
80 castid = GetNewOidWithIndex(relation, CastOidIndexId, Anum_pg_cast_oid);
81 values[Anum_pg_cast_oid - 1] = ObjectIdGetDatum(castid);
82 values[Anum_pg_cast_castsource - 1] = ObjectIdGetDatum(sourcetypeid);
83 values[Anum_pg_cast_casttarget - 1] = ObjectIdGetDatum(targettypeid);
84 values[Anum_pg_cast_castfunc - 1] = ObjectIdGetDatum(funcid);
85 values[Anum_pg_cast_castcontext - 1] = CharGetDatum(castcontext);
86 values[Anum_pg_cast_castmethod - 1] = CharGetDatum(castmethod);
87
88 tuple = heap_form_tuple(RelationGetDescr(relation), values, nulls);
89
90 CatalogTupleInsert(relation, tuple);
91
92 addrs = new_object_addresses();
93
94 /* make dependency entries */
95 ObjectAddressSet(myself, CastRelationId, castid);
96
97 /* dependency on source type */
98 ObjectAddressSet(referenced, TypeRelationId, sourcetypeid);
99 add_exact_object_address(&referenced, addrs);
100
101 /* dependency on target type */
102 ObjectAddressSet(referenced, TypeRelationId, targettypeid);
103 add_exact_object_address(&referenced, addrs);
104
105 /* dependency on function */
106 if (OidIsValid(funcid))
107 {
108 ObjectAddressSet(referenced, ProcedureRelationId, funcid);
109 add_exact_object_address(&referenced, addrs);
110 }
111
112 /* dependencies on casts required for function */
113 if (OidIsValid(incastid))
114 {
115 ObjectAddressSet(referenced, CastRelationId, incastid);
116 add_exact_object_address(&referenced, addrs);
117 }
118 if (OidIsValid(outcastid))
119 {
120 ObjectAddressSet(referenced, CastRelationId, outcastid);
121 add_exact_object_address(&referenced, addrs);
122 }
123
124 record_object_address_dependencies(&myself, addrs, behavior);
125 free_object_addresses(addrs);
126
127 /* dependency on extension */
128 recordDependencyOnCurrentExtension(&myself, false);
129
130 /* Post creation hook for new cast */
131 InvokeObjectPostCreateHook(CastRelationId, castid, 0);
132
133 heap_freetuple(tuple);
134
135 table_close(relation, RowExclusiveLock);
136
137 return myself;
138}
static Datum values[MAXATTR]
Definition: bootstrap.c:153
#define OidIsValid(objectId)
Definition: c.h:774
Oid GetNewOidWithIndex(Relation relation, Oid indexId, AttrNumber oidcolumn)
Definition: catalog.c:448
void record_object_address_dependencies(const ObjectAddress *depender, ObjectAddresses *referenced, DependencyType behavior)
Definition: dependency.c:2768
void add_exact_object_address(const ObjectAddress *object, ObjectAddresses *addrs)
Definition: dependency.c:2559
ObjectAddresses * new_object_addresses(void)
Definition: dependency.c:2513
void free_object_addresses(ObjectAddresses *addrs)
Definition: dependency.c:2799
DependencyType
Definition: dependency.h:32
int errcode(int sqlerrcode)
Definition: elog.c:854
int errmsg(const char *fmt,...)
Definition: elog.c:1071
#define ERROR
Definition: elog.h:39
#define ereport(elevel,...)
Definition: elog.h:150
char * format_type_be(Oid type_oid)
Definition: format_type.c:343
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
Definition: heaptuple.c:1117
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1435
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
void CatalogTupleInsert(Relation heapRel, HeapTuple tup)
Definition: indexing.c:233
#define RowExclusiveLock
Definition: lockdefs.h:38
#define InvokeObjectPostCreateHook(classId, objectId, subId)
Definition: objectaccess.h:173
#define ObjectAddressSet(addr, class_id, object_id)
Definition: objectaddress.h:40
ObjectAddress CastCreate(Oid sourcetypeid, Oid targettypeid, Oid funcid, Oid incastid, Oid outcastid, char castcontext, char castmethod, DependencyType behavior)
Definition: pg_cast.c:49
void recordDependencyOnCurrentExtension(const ObjectAddress *object, bool isReplace)
Definition: pg_depend.c:193
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:262
uint64_t Datum
Definition: postgres.h:70
static Datum CharGetDatum(char X)
Definition: postgres.h:132
unsigned int Oid
Definition: postgres_ext.h:32
#define RelationGetDescr(relation)
Definition: rel.h:540
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:30
Definition: rel.h:56
HeapTuple SearchSysCache2(int cacheId, Datum key1, Datum key2)
Definition: syscache.c:230
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:126
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:40

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