src/include/access/valid.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * valid.h
   4  *        POSTGRES tuple qualification validity definitions.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $PostgreSQL: pgsql/src/include/access/valid.h,v 1.36 2004/12/31 22:03:21 pgsql Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef VALID_H
  15 #define VALID_H
  16
  17 /*
  18  *              HeapKeyTest
  19  *
  20  *              Test a heap tuple to see if it satisfies a scan key.
  21  */
  22 #define HeapKeyTest(tuple, \
  23                                         tupdesc, \
  24                                         nkeys, \
  25                                         keys, \
  26                                         result) \
  27 do \
  28 { \
  29         /* Use underscores to protect the variables passed in as parameters */ \
  30         int                     __cur_nkeys = (nkeys); \
  31         ScanKey         __cur_keys = (keys); \
  32  \
  33         (result) = true; /* may change */ \
  34         for (; __cur_nkeys--; __cur_keys++) \
  35         { \
  36                 Datum   __atp; \
  37                 bool    __isnull; \
  38                 Datum   __test; \
  39  \
  40                 if (__cur_keys->sk_flags & SK_ISNULL) \
  41                 { \
  42                         (result) = false; \
  43                         break; \
  44                 } \
  45  \
  46                 __atp = heap_getattr((tuple), \
  47                                                          __cur_keys->sk_attno, \
  48                                                          (tupdesc), \
  49                                                          &__isnull); \
  50  \
  51                 if (__isnull) \
  52                 { \
  53                         (result) = false; \
  54                         break; \
  55                 } \
  56  \
  57                 __test = FunctionCall2(&__cur_keys->sk_func, \
  58                                                            __atp, __cur_keys->sk_argument); \
  59  \
  60                 if (!DatumGetBool(__test)) \
  61                 { \
  62                         (result) = false; \
  63                         break; \
  64                 } \
  65         } \
  66 } while (0)
  67
  68 /*
  69  *              HeapTupleSatisfies
  70  *
  71  *      res is set TRUE if the HeapTuple satisfies the timequal and keytest,
  72  *      otherwise it is set FALSE.      Note that the hint bits in the HeapTuple's
  73  *      t_infomask may be updated as a side effect.
  74  *
  75  *      on 8/21/92 mao says:  i rearranged the tests here to do keytest before
  76  *      SatisfiesTimeQual.      profiling indicated that even for vacuumed relations,
  77  *      time qual checking was more expensive than key testing.  time qual is
  78  *      least likely to fail, too.      we should really add the time qual test to
  79  *      the restriction and optimize it in the normal way.      this has interactions
  80  *      with joey's expensive function work.
  81  */
  82 #define HeapTupleSatisfies(tuple, \
  83                                                    relation, \
  84                                                    buffer, \
  85                                                    disk_page, \
  86                                                    snapshot, \
  87                                                    nKeys, \
  88                                                    key, \
  89                                                    res) \
  90 do \
  91 { \
  92         if ((key) != NULL) \
  93                 HeapKeyTest(tuple, RelationGetDescr(relation), nKeys, key, res); \
  94         else \
  95                 (res) = true; \
  96  \
  97         if ((res) && (relation)->rd_rel->relkind != RELKIND_UNCATALOGED) \
  98                 (res) = HeapTupleSatisfiesVisibility(tuple, snapshot, buffer); \
  99 } while (0)
 100
 101 #endif   /* VALID_H */