src/include/access/heapam.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * heapam.h
   4  *        POSTGRES heap access method 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/heapam.h,v 1.101 2005/06/06 17:01:24 tgl Exp $
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef HEAPAM_H
  15 #define HEAPAM_H
  16
  17 #include "access/htup.h"
  18 #include "access/relscan.h"
  19 #include "access/sdir.h"
  20 #include "access/tupmacs.h"
  21 #include "access/xlogutils.h"
  22 #include "nodes/primnodes.h"
  23 #include "storage/block.h"
  24 #include "storage/lmgr.h"
  25 #include "utils/rel.h"
  26 #include "utils/tqual.h"
  27
  28 /* ----------------
  29  *              fastgetattr
  30  *
  31  *              Fetch a user attribute's value as a Datum (might be either a
  32  *              value, or a pointer into the data area of the tuple).
  33  *
  34  *              This must not be used when a system attribute might be requested.
  35  *              Furthermore, the passed attnum MUST be valid.  Use heap_getattr()
  36  *              instead, if in doubt.
  37  *
  38  *              This gets called many times, so we macro the cacheable and NULL
  39  *              lookups, and call nocachegetattr() for the rest.
  40  * ----------------
  41  */
  42
  43 #if !defined(DISABLE_COMPLEX_MACRO)
  44
  45 #define fastgetattr(tup, attnum, tupleDesc, isnull)                                     \
  46 (                                                                                                                                       \
  47         AssertMacro((attnum) > 0),                                                                              \
  48         ((isnull) ? (*(isnull) = false) : (dummyret)NULL),                              \
  49         HeapTupleNoNulls(tup) ?                                                                                 \
  50         (                                                                                                                               \
  51                 (tupleDesc)->attrs[(attnum)-1]->attcacheoff >= 0 ?                      \
  52                 (                                                                                                                       \
  53                         fetchatt((tupleDesc)->attrs[(attnum)-1],                                \
  54                                 (char *) (tup)->t_data + (tup)->t_data->t_hoff +        \
  55                                         (tupleDesc)->attrs[(attnum)-1]->attcacheoff)    \
  56                 )                                                                                                                       \
  57                 :                                                                                                                       \
  58                         nocachegetattr((tup), (attnum), (tupleDesc), (isnull))  \
  59         )                                                                                                                               \
  60         :                                                                                                                               \
  61         (                                                                                                                               \
  62                 att_isnull((attnum)-1, (tup)->t_data->t_bits) ?                         \
  63                 (                                                                                                                       \
  64                         ((isnull) ? (*(isnull) = true) : (dummyret)NULL),               \
  65                         (Datum)NULL                                                                                             \
  66                 )                                                                                                                       \
  67                 :                                                                                                                       \
  68                 (                                                                                                                       \
  69                         nocachegetattr((tup), (attnum), (tupleDesc), (isnull))  \
  70                 )                                                                                                                       \
  71         )                                                                                                                               \
  72 )
  73
  74 #else                                                   /* defined(DISABLE_COMPLEX_MACRO) */
  75
  76 extern Datum fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
  77                         bool *isnull);
  78 #endif   /* defined(DISABLE_COMPLEX_MACRO) */
  79
  80
  81 /* ----------------
  82  *              heap_getattr
  83  *
  84  *              Extract an attribute of a heap tuple and return it as a Datum.
  85  *              This works for either system or user attributes.  The given attnum
  86  *              is properly range-checked.
  87  *
  88  *              If the field in question has a NULL value, we return a zero Datum
  89  *              and set *isnull == true.  Otherwise, we set *isnull == false.
  90  *
  91  *              <tup> is the pointer to the heap tuple.  <attnum> is the attribute
  92  *              number of the column (field) caller wants.      <tupleDesc> is a
  93  *              pointer to the structure describing the row and all its fields.
  94  * ----------------
  95  */
  96 #define heap_getattr(tup, attnum, tupleDesc, isnull) \
  97 ( \
  98         AssertMacro((tup) != NULL), \
  99         ( \
 100                 ((attnum) > 0) ? \
 101                 ( \
 102                         ((attnum) > (int) (tup)->t_data->t_natts) ? \
 103                         ( \
 104                                 ((isnull) ? (*(isnull) = true) : (dummyret)NULL), \
 105                                 (Datum)NULL \
 106                         ) \
 107                         : \
 108                                 fastgetattr((tup), (attnum), (tupleDesc), (isnull)) \
 109                 ) \
 110                 : \
 111                         heap_getsysattr((tup), (attnum), (tupleDesc), (isnull)) \
 112         ) \
 113 )
 114
 115
 116 /* ----------------
 117  *              function prototypes for heap access method
 118  *
 119  * heap_create, heap_create_with_catalog, and heap_drop_with_catalog
 120  * are declared in catalog/heap.h
 121  * ----------------
 122  */
 123
 124 /* heapam.c */
 125
 126 typedef enum
 127 {
 128         LockTupleShared,
 129         LockTupleExclusive
 130 } LockTupleMode;
 131
 132 extern Relation relation_open(Oid relationId, LOCKMODE lockmode);
 133 extern Relation conditional_relation_open(Oid relationId, LOCKMODE lockmode, bool nowait);
 134 extern Relation relation_openrv(const RangeVar *relation, LOCKMODE lockmode);
 135 extern void relation_close(Relation relation, LOCKMODE lockmode);
 136
 137 extern Relation heap_open(Oid relationId, LOCKMODE lockmode);
 138 extern Relation heap_openrv(const RangeVar *relation, LOCKMODE lockmode);
 139
 140 #define heap_close(r,l)  relation_close(r,l)
 141
 142 extern HeapScanDesc heap_beginscan(Relation relation, Snapshot snapshot,
 143                            int nkeys, ScanKey key);
 144 extern void heap_rescan(HeapScanDesc scan, ScanKey key);
 145 extern void heap_endscan(HeapScanDesc scan);
 146 extern HeapTuple heap_getnext(HeapScanDesc scan, ScanDirection direction);
 147
 148 extern bool heap_fetch(Relation relation, Snapshot snapshot,
 149                    HeapTuple tuple, Buffer *userbuf, bool keep_buf,
 150                    PgStat_Info *pgstat_info);
 151 extern bool heap_release_fetch(Relation relation, Snapshot snapshot,
 152                                    HeapTuple tuple, Buffer *userbuf, bool keep_buf,
 153                                    PgStat_Info *pgstat_info);
 154
 155 extern ItemPointer heap_get_latest_tid(Relation relation, Snapshot snapshot,
 156                                         ItemPointer tid);
 157 extern void setLastTid(const ItemPointer tid);
 158
 159 extern Oid      heap_insert(Relation relation, HeapTuple tup, CommandId cid);
 160 extern HTSU_Result heap_delete(Relation relation, ItemPointer tid, ItemPointer ctid,
 161                         CommandId cid, Snapshot crosscheck, bool wait);
 162 extern HTSU_Result heap_update(Relation relation, ItemPointer otid, HeapTuple tup,
 163                 ItemPointer ctid, CommandId cid, Snapshot crosscheck, bool wait);
 164 extern HTSU_Result heap_lock_tuple(Relation relation, HeapTuple tup,
 165                                  Buffer *userbuf, CommandId cid, LockTupleMode mode);
 166
 167 extern Oid      simple_heap_insert(Relation relation, HeapTuple tup);
 168 extern void simple_heap_delete(Relation relation, ItemPointer tid);
 169 extern void simple_heap_update(Relation relation, ItemPointer otid,
 170                                    HeapTuple tup);
 171
 172 extern void heap_markpos(HeapScanDesc scan);
 173 extern void heap_restrpos(HeapScanDesc scan);
 174
 175 extern void heap_redo(XLogRecPtr lsn, XLogRecord *rptr);
 176 extern void heap_desc(char *buf, uint8 xl_info, char *rec);
 177 extern XLogRecPtr log_heap_clean(Relation reln, Buffer buffer,
 178                            OffsetNumber *unused, int uncnt);
 179 extern XLogRecPtr log_heap_move(Relation reln, Buffer oldbuf,
 180                           ItemPointerData from,
 181                           Buffer newbuf, HeapTuple newtup);
 182
 183 /* in common/heaptuple.c */
 184 extern Size heap_compute_data_size(TupleDesc tupleDesc,
 185                                                                    Datum *values, bool *isnull);
 186 extern void heap_fill_tuple(TupleDesc tupleDesc,
 187                                                         Datum *values, bool *isnull,
 188                                                         char *data, uint16 *infomask, bits8 *bit);
 189 extern bool heap_attisnull(HeapTuple tup, int attnum);
 190 extern Datum nocachegetattr(HeapTuple tup, int attnum,
 191                            TupleDesc att, bool *isnull);
 192 extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
 193                                 bool *isnull);
 194 extern HeapTuple heap_copytuple(HeapTuple tuple);
 195 extern void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest);
 196 extern HeapTuple heap_form_tuple(TupleDesc tupleDescriptor,
 197                            Datum *values, bool *isnull);
 198 extern HeapTuple heap_formtuple(TupleDesc tupleDescriptor,
 199                            Datum *values, char *nulls);
 200 extern HeapTuple heap_modify_tuple(HeapTuple tuple,
 201                                  TupleDesc tupleDesc,
 202                                  Datum *replValues,
 203                                  bool *replIsnull,
 204                                  bool *doReplace);
 205 extern HeapTuple heap_modifytuple(HeapTuple tuple,
 206                                  TupleDesc tupleDesc,
 207                                  Datum *replValues,
 208                                  char *replNulls,
 209                                  char *replActions);
 210 extern void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
 211                                  Datum *values, bool *isnull);
 212 extern void heap_deformtuple(HeapTuple tuple, TupleDesc tupleDesc,
 213                                  Datum *values, char *nulls);
 214 extern void heap_freetuple(HeapTuple tuple);
 215 extern HeapTuple heap_addheader(int natts, bool withoid,
 216                                                                 Size structlen, void *structure);
 217
 218 #endif   /* HEAPAM_H */