Files
postgresql/src/include/utils/typcache.h
Tom Lane ec646dbc65 Create a 'type cache' that keeps track of the data needed for any particular
datatype by array_eq and array_cmp; use this to solve problems with memory
leaks in array indexing support.  The parser's equality_oper and ordering_oper
routines also use the cache.  Change the operator search algorithms to look
for appropriate btree or hash index opclasses, instead of assuming operators
named '<' or '=' have the right semantics.  (ORDER BY ASC/DESC now also look
at opclasses, instead of assuming '<' and '>' are the right things.)  Add
several more index opclasses so that there is no regression in functionality
for base datatypes.  initdb forced due to catalog additions.
2003-08-17 19:58:06 +00:00

67 lines
2.1 KiB
C

/*-------------------------------------------------------------------------
*
* typcache.h
* Type cache definitions.
*
* The type cache exists to speed lookup of certain information about data
* types that is not directly available from a type's pg_type row.
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: typcache.h,v 1.1 2003/08/17 19:58:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef TYPCACHE_H
#define TYPCACHE_H
#include "fmgr.h"
typedef struct TypeCacheEntry
{
/* typeId is the hash lookup key and MUST BE FIRST */
Oid type_id; /* OID of the data type */
/* some subsidiary information copied from the pg_type row */
int16 typlen;
bool typbyval;
char typalign;
/*
* Information obtained from opclass entries
*
* These will be InvalidOid if no match could be found, or if the
* information hasn't yet been requested.
*/
Oid btree_opc; /* OID of the default btree opclass */
Oid hash_opc; /* OID of the default hash opclass */
Oid eq_opr; /* OID of the equality operator */
Oid lt_opr; /* OID of the less-than operator */
Oid gt_opr; /* OID of the greater-than operator */
Oid cmp_proc; /* OID of the btree comparison function */
/*
* Pre-set-up fmgr call info for the equality operator and the btree
* comparison function. These are kept in the type cache to avoid
* problems with memory leaks in repeated calls to array_eq and array_cmp.
* There is not currently a need to maintain call info for the lt_opr
* or gt_opr.
*/
FmgrInfo eq_opr_finfo;
FmgrInfo cmp_proc_finfo;
} TypeCacheEntry;
/* Bit flags to indicate which fields a given caller needs to have set */
#define TYPECACHE_EQ_OPR 0x0001
#define TYPECACHE_LT_OPR 0x0002
#define TYPECACHE_GT_OPR 0x0004
#define TYPECACHE_CMP_PROC 0x0008
#define TYPECACHE_EQ_OPR_FINFO 0x0010
#define TYPECACHE_CMP_PROC_FINFO 0x0020
extern TypeCacheEntry *lookup_type_cache(Oid type_id, int flags);
#endif /* TYPCACHE_H */