postgresql/src/backend/access/table/table.c

149 lines
3.4 KiB
C

/*-------------------------------------------------------------------------
*
* table.c
* Generic routines for table related code.
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/access/table/table.c
*
*
* NOTES
* This file contains table_ routines that implement access to tables (in
* contrast to other relation types like indexes) that are independent of
* individual table access methods.
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/relation.h"
#include "access/table.h"
#include "storage/lmgr.h"
static inline void validate_relation_kind(Relation r);
/* ----------------
* table_open - open a table relation by relation OID
*
* This is essentially relation_open plus check that the relation
* is not an index nor a composite type. (The caller should also
* check that it's not a view or foreign table before assuming it has
* storage.)
* ----------------
*/
Relation
table_open(Oid relationId, LOCKMODE lockmode)
{
Relation r;
r = relation_open(relationId, lockmode);
validate_relation_kind(r);
return r;
}
/* ----------------
* try_table_open - open a table relation by relation OID
*
* Same as table_open, except return NULL instead of failing
* if the relation does not exist.
* ----------------
*/
Relation
try_table_open(Oid relationId, LOCKMODE lockmode)
{
Relation r;
r = try_relation_open(relationId, lockmode);
/* leave if table does not exist */
if (!r)
return NULL;
validate_relation_kind(r);
return r;
}
/* ----------------
* table_openrv - open a table relation specified
* by a RangeVar node
*
* As above, but relation is specified by a RangeVar.
* ----------------
*/
Relation
table_openrv(const RangeVar *relation, LOCKMODE lockmode)
{
Relation r;
r = relation_openrv(relation, lockmode);
validate_relation_kind(r);
return r;
}
/* ----------------
* table_openrv_extended - open a table relation specified
* by a RangeVar node
*
* As above, but optionally return NULL instead of failing for
* relation-not-found.
* ----------------
*/
Relation
table_openrv_extended(const RangeVar *relation, LOCKMODE lockmode,
bool missing_ok)
{
Relation r;
r = relation_openrv_extended(relation, lockmode, missing_ok);
if (r)
validate_relation_kind(r);
return r;
}
/* ----------------
* table_close - close a table
*
* If lockmode is not "NoLock", we then release the specified lock.
*
* Note that it is often sensible to hold a lock beyond relation_close;
* in that case, the lock is released automatically at xact end.
* ----------------
*/
void
table_close(Relation relation, LOCKMODE lockmode)
{
relation_close(relation, lockmode);
}
/* ----------------
* validate_relation_kind - check the relation's kind
*
* Make sure relkind is not index or composite type
* ----------------
*/
static inline void
validate_relation_kind(Relation r)
{
if (r->rd_rel->relkind == RELKIND_INDEX ||
r->rd_rel->relkind == RELKIND_PARTITIONED_INDEX ||
r->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot open relation \"%s\"",
RelationGetRelationName(r)),
errdetail_relkind_not_supported(r->rd_rel->relkind)));
}