postgresql/src/include/catalog/pg_cast.h

107 lines
3.1 KiB
C

/*-------------------------------------------------------------------------
*
* pg_cast.h
* definition of the "type casts" system catalog (pg_cast)
*
* As of Postgres 8.0, pg_cast describes not only type coercion functions
* but also length coercion functions.
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/catalog/pg_cast.h
*
* NOTES
* The Catalog.pm module reads this file and derives schema
* information.
*
*-------------------------------------------------------------------------
*/
#ifndef PG_CAST_H
#define PG_CAST_H
#include "catalog/dependency.h"
#include "catalog/genbki.h"
#include "catalog/pg_cast_d.h"
/* ----------------
* pg_cast definition. cpp turns this into
* typedef struct FormData_pg_cast
* ----------------
*/
CATALOG(pg_cast,2605,CastRelationId)
{
Oid oid; /* oid */
/* source datatype for cast */
Oid castsource BKI_LOOKUP(pg_type);
/* destination datatype for cast */
Oid casttarget BKI_LOOKUP(pg_type);
/* cast function; 0 = binary coercible */
Oid castfunc BKI_LOOKUP_OPT(pg_proc);
/* contexts in which cast can be used */
char castcontext;
/* cast method */
char castmethod;
} FormData_pg_cast;
/* ----------------
* Form_pg_cast corresponds to a pointer to a tuple with
* the format of pg_cast relation.
* ----------------
*/
typedef FormData_pg_cast *Form_pg_cast;
DECLARE_UNIQUE_INDEX_PKEY(pg_cast_oid_index, 2660, CastOidIndexId, pg_cast, btree(oid oid_ops));
DECLARE_UNIQUE_INDEX(pg_cast_source_target_index, 2661, CastSourceTargetIndexId, pg_cast, btree(castsource oid_ops, casttarget oid_ops));
MAKE_SYSCACHE(CASTSOURCETARGET, pg_cast_source_target_index, 256);
#ifdef EXPOSE_TO_CLIENT_CODE
/*
* The allowable values for pg_cast.castcontext are specified by this enum.
* Since castcontext is stored as a "char", we use ASCII codes for human
* convenience in reading the table. Note that internally to the backend,
* these values are converted to the CoercionContext enum (see primnodes.h),
* which is defined to sort in a convenient order; the ASCII codes don't
* have to sort in any special order.
*/
typedef enum CoercionCodes
{
COERCION_CODE_IMPLICIT = 'i', /* coercion in context of expression */
COERCION_CODE_ASSIGNMENT = 'a', /* coercion in context of assignment */
COERCION_CODE_EXPLICIT = 'e', /* explicit cast operation */
} CoercionCodes;
/*
* The allowable values for pg_cast.castmethod are specified by this enum.
* Since castmethod is stored as a "char", we use ASCII codes for human
* convenience in reading the table.
*/
typedef enum CoercionMethod
{
COERCION_METHOD_FUNCTION = 'f', /* use a function */
COERCION_METHOD_BINARY = 'b', /* types are binary-compatible */
COERCION_METHOD_INOUT = 'i', /* use input/output functions */
} CoercionMethod;
#endif /* EXPOSE_TO_CLIENT_CODE */
extern ObjectAddress CastCreate(Oid sourcetypeid,
Oid targettypeid,
Oid funcid,
Oid incastid,
Oid outcastid,
char castcontext,
char castmethod,
DependencyType behavior);
#endif /* PG_CAST_H */