src/include/access/heapam.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * heapam.h
   4  *        POSTGRES heap access method definitions.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * $Id: heapam.h,v 1.78 2002/07/20 05:16:59 momjian 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  *                              leftover cruft from old statistics code
  30  * ----------------------------------------------------------------
  31  */
  32
  33 #define IncrHeapAccessStat(x)   ((void) 0)
  34
  35 /* ----------------
  36  *              fastgetattr
  37  *
  38  *              Fetch a user attribute's value as a Datum (might be either a
  39  *              value, or a pointer into the data area of the tuple).
  40  *
  41  *              This must not be used when a system attribute might be requested.
  42  *              Furthermore, the passed attnum MUST be valid.  Use heap_getattr()
  43  *              instead, if in doubt.
  44  *
  45  *              This gets called many times, so we macro the cacheable and NULL
  46  *              lookups, and call nocachegetattr() for the rest.
  47  * ----------------
  48  */
  49
  50 extern Datum nocachegetattr(HeapTuple tup, int attnum,
  51                            TupleDesc att, bool *isnull);
  52
  53 #if !defined(DISABLE_COMPLEX_MACRO)
  54
  55 #define fastgetattr(tup, attnum, tupleDesc, isnull)                                     \
  56 (                                                                                                                                       \
  57         AssertMacro((attnum) > 0),                                                                              \
  58         ((isnull) ? (*(isnull) = false) : (dummyret)NULL),                              \
  59         HeapTupleNoNulls(tup) ?                                                                                 \
  60         (                                                                                                                               \
  61                 (tupleDesc)->attrs[(attnum)-1]->attcacheoff >= 0 ?                      \
  62                 (                                                                                                                       \
  63                         fetchatt((tupleDesc)->attrs[(attnum)-1],                                \
  64                                 (char *) (tup)->t_data + (tup)->t_data->t_hoff +        \
  65                                         (tupleDesc)->attrs[(attnum)-1]->attcacheoff)    \
  66                 )                                                                                                                       \
  67                 :                                                                                                                       \
  68                         nocachegetattr((tup), (attnum), (tupleDesc), (isnull))  \
  69         )                                                                                                                               \
  70         :                                                                                                                               \
  71         (                                                                                                                               \
  72                 att_isnull((attnum)-1, (tup)->t_data->t_bits) ?                         \
  73                 (                                                                                                                       \
  74                         ((isnull) ? (*(isnull) = true) : (dummyret)NULL),               \
  75                         (Datum)NULL                                                                                             \
  76                 )                                                                                                                       \
  77                 :                                                                                                                       \
  78                 (                                                                                                                       \
  79                         nocachegetattr((tup), (attnum), (tupleDesc), (isnull))  \
  80                 )                                                                                                                       \
  81         )                                                                                                                               \
  82 )
  83
  84 #else                                                   /* defined(DISABLE_COMPLEX_MACRO) */
  85
  86 extern Datum fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
  87                         bool *isnull);
  88 #endif   /* defined(DISABLE_COMPLEX_MACRO) */
  89
  90
  91 /* ----------------
  92  *              heap_getattr
  93  *
  94  *              Extract an attribute of a heap tuple and return it as a Datum.
  95  *              This works for either system or user attributes.  The given attnum
  96  *              is properly range-checked.
  97  *
  98  *              If the field in question has a NULL value, we return a zero Datum
  99  *              and set *isnull == true.  Otherwise, we set *isnull == false.
 100  *
 101  *              <tup> is the pointer to the heap tuple.  <attnum> is the attribute
 102  *              number of the column (field) caller wants.      <tupleDesc> is a
 103  *              pointer to the structure describing the row and all its fields.
 104  * ----------------
 105  */
 106 #define heap_getattr(tup, attnum, tupleDesc, isnull) \
 107 ( \
 108         AssertMacro((tup) != NULL), \
 109         ( \
 110                 ((attnum) > 0) ? \
 111                 ( \
 112                         ((attnum) > (int) (tup)->t_data->t_natts) ? \
 113                         ( \
 114                                 ((isnull) ? (*(isnull) = true) : (dummyret)NULL), \
 115                                 (Datum)NULL \
 116                         ) \
 117                         : \
 118                                 fastgetattr((tup), (attnum), (tupleDesc), (isnull)) \
 119                 ) \
 120                 : \
 121                         heap_getsysattr((tup), (attnum), (isnull)) \
 122         ) \
 123 )
 124
 125 extern Datum heap_getsysattr(HeapTuple tup, int attnum, bool *isnull);
 126
 127
 128 /* ----------------
 129  *              function prototypes for heap access method
 130  *
 131  * heap_create, heap_create_with_catalog, and heap_drop_with_catalog
 132  * are declared in catalog/heap.h
 133  * ----------------
 134  */
 135
 136 /* heapam.c */
 137
 138 extern Relation relation_open(Oid relationId, LOCKMODE lockmode);
 139 extern Relation relation_openrv(const RangeVar *relation, LOCKMODE lockmode);
 140 extern Relation relation_openr(const char *sysRelationName, LOCKMODE lockmode);
 141 extern void relation_close(Relation relation, LOCKMODE lockmode);
 142
 143 extern Relation heap_open(Oid relationId, LOCKMODE lockmode);
 144 extern Relation heap_openrv(const RangeVar *relation, LOCKMODE lockmode);
 145 extern Relation heap_openr(const char *sysRelationName, LOCKMODE lockmode);
 146
 147 #define heap_close(r,l)  relation_close(r,l)
 148
 149 extern HeapScanDesc heap_beginscan(Relation relation, Snapshot snapshot,
 150                                                                    int nkeys, ScanKey key);
 151 extern void heap_rescan(HeapScanDesc scan, ScanKey key);
 152 extern void heap_endscan(HeapScanDesc scan);
 153 extern HeapTuple heap_getnext(HeapScanDesc scan, ScanDirection direction);
 154
 155 extern bool heap_fetch(Relation relation, Snapshot snapshot,
 156                                            HeapTuple tuple, Buffer *userbuf, bool keep_buf,
 157                                            PgStat_Info *pgstat_info);
 158
 159 extern ItemPointer heap_get_latest_tid(Relation relation, Snapshot snapshot,
 160                                                                            ItemPointer tid);
 161 extern void setLastTid(const ItemPointer tid);
 162
 163 extern Oid      heap_insert(Relation relation, HeapTuple tup, CommandId cid);
 164 extern int      heap_delete(Relation relation, ItemPointer tid, ItemPointer ctid,
 165                                                 CommandId cid);
 166 extern int heap_update(Relation relation, ItemPointer otid, HeapTuple tup,
 167                                            ItemPointer ctid, CommandId cid);
 168 extern int      heap_mark4update(Relation relation, HeapTuple tup,
 169                                                          Buffer *userbuf, CommandId cid);
 170
 171 extern Oid      simple_heap_insert(Relation relation, HeapTuple tup);
 172 extern void simple_heap_delete(Relation relation, ItemPointer tid);
 173 extern void simple_heap_update(Relation relation, ItemPointer otid,
 174                                    HeapTuple tup);
 175
 176 extern void heap_markpos(HeapScanDesc scan);
 177 extern void heap_restrpos(HeapScanDesc scan);
 178
 179 extern void heap_redo(XLogRecPtr lsn, XLogRecord *rptr);
 180 extern void heap_undo(XLogRecPtr lsn, XLogRecord *rptr);
 181 extern void heap_desc(char *buf, uint8 xl_info, char *rec);
 182 extern XLogRecPtr log_heap_clean(Relation reln, Buffer buffer,
 183                            char *unused, int unlen);
 184 extern XLogRecPtr log_heap_move(Relation reln, Buffer oldbuf,
 185                           ItemPointerData from,
 186                           Buffer newbuf, HeapTuple newtup);
 187
 188 /* in common/heaptuple.c */
 189 extern Size ComputeDataSize(TupleDesc tupleDesc, Datum *value, char *nulls);
 190 extern void DataFill(char *data, TupleDesc tupleDesc,
 191                  Datum *value, char *nulls, uint16 *infomask,
 192                  bits8 *bit);
 193 extern int      heap_attisnull(HeapTuple tup, int attnum);
 194 extern Datum nocachegetattr(HeapTuple tup, int attnum,
 195                            TupleDesc att, bool *isnull);
 196 extern HeapTuple heap_copytuple(HeapTuple tuple);
 197 extern void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest);
 198 extern HeapTuple heap_formtuple(TupleDesc tupleDescriptor,
 199                            Datum *value, char *nulls);
 200 extern HeapTuple heap_modifytuple(HeapTuple tuple,
 201                 Relation relation, Datum *replValue, char *replNull, char *repl);
 202 extern void heap_freetuple(HeapTuple tuple);
 203 extern HeapTuple heap_addheader(int natts, bool withoid, Size structlen, void *structure);
 204
 205 #endif   /* HEAPAM_H */