src/include/utils/typcache.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * typcache.h
   4  *        Type cache definitions.
   5  *
   6  * The type cache exists to speed lookup of certain information about data
   7  * types that is not directly available from a type's pg_type row.
   8  *
   9  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  10  * Portions Copyright (c) 1994, Regents of the University of California
  11  *
  12  * $PostgreSQL$
  13  *
  14  *-------------------------------------------------------------------------
  15  */
  16 #ifndef TYPCACHE_H
  17 #define TYPCACHE_H
  18
  19 #include "access/tupdesc.h"
  20 #include "fmgr.h"
  21
  22
  23 typedef struct TypeCacheEntry
  24 {
  25         /* typeId is the hash lookup key and MUST BE FIRST */
  26         Oid                     type_id;                /* OID of the data type */
  27
  28         /* some subsidiary information copied from the pg_type row */
  29         int16           typlen;
  30         bool            typbyval;
  31         char            typalign;
  32         char            typtype;
  33         Oid                     typrelid;
  34
  35         /*
  36          * Information obtained from opfamily entries
  37          *
  38          * These will be InvalidOid if no match could be found, or if the
  39          * information hasn't yet been requested.
  40          */
  41         Oid                     btree_opf;              /* the default btree opclass' family */
  42         Oid                     btree_opintype; /* the default btree opclass' opcintype */
  43         Oid                     hash_opf;               /* the default hash opclass' family */
  44         Oid                     hash_opintype;  /* the default hash opclass' opcintype */
  45         Oid                     eq_opr;                 /* the equality operator */
  46         Oid                     lt_opr;                 /* the less-than operator */
  47         Oid                     gt_opr;                 /* the greater-than operator */
  48         Oid                     cmp_proc;               /* the btree comparison function */
  49
  50         /*
  51          * Pre-set-up fmgr call info for the equality operator and the btree
  52          * comparison function.  These are kept in the type cache to avoid
  53          * problems with memory leaks in repeated calls to array_eq and array_cmp.
  54          * There is not currently a need to maintain call info for the lt_opr or
  55          * gt_opr.
  56          */
  57         FmgrInfo        eq_opr_finfo;
  58         FmgrInfo        cmp_proc_finfo;
  59
  60         /*
  61          * Tuple descriptor if it's a composite type (row type).  NULL if not
  62          * composite or information hasn't yet been requested.  (NOTE: this is a
  63          * reference-counted tupledesc.)
  64          */
  65         TupleDesc       tupDesc;
  66 } TypeCacheEntry;
  67
  68 /* Bit flags to indicate which fields a given caller needs to have set */
  69 #define TYPECACHE_EQ_OPR                        0x0001
  70 #define TYPECACHE_LT_OPR                        0x0002
  71 #define TYPECACHE_GT_OPR                        0x0004
  72 #define TYPECACHE_CMP_PROC                      0x0008
  73 #define TYPECACHE_EQ_OPR_FINFO          0x0010
  74 #define TYPECACHE_CMP_PROC_FINFO        0x0020
  75 #define TYPECACHE_TUPDESC                       0x0040
  76 #define TYPECACHE_BTREE_OPFAMILY        0x0080
  77
  78 extern TypeCacheEntry *lookup_type_cache(Oid type_id, int flags);
  79
  80 extern TupleDesc lookup_rowtype_tupdesc(Oid type_id, int32 typmod);
  81
  82 extern TupleDesc lookup_rowtype_tupdesc_noerror(Oid type_id, int32 typmod,
  83                                                            bool noError);
  84
  85 extern TupleDesc lookup_rowtype_tupdesc_copy(Oid type_id, int32 typmod);
  86
  87 extern void assign_record_type_typmod(TupleDesc tupDesc);
  88
  89 extern void flush_rowtype_cache(Oid type_id);
  90
  91 #endif   /* TYPCACHE_H */