granicus.if.org Git - postgresql/blob - src/backend/catalog/pg_largeobject.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pg_largeobject.c
   4  *        routines to support manipulation of the pg_largeobject relation
   5  *
   6  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $Header: /cvsroot/pgsql/src/backend/catalog/pg_largeobject.c,v 1.1 2000/10/08 03:18:53 momjian Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #include "postgres.h"
  16
  17 #include "access/genam.h"
  18 #include "access/heapam.h"
  19 #include "access/itup.h"
  20 #include "catalog/catname.h"
  21 #include "catalog/indexing.h"
  22 #include "catalog/pg_largeobject.h"
  23 #include "miscadmin.h"
  24 #include "parser/parse_func.h"
  25 #include "utils/builtins.h"
  26 #include "utils/syscache.h"
  27
  28 bytea *_byteain(const char *data, int32 size);
  29
  30 bytea *_byteain(const char *data, int32 size) {
  31         bytea   *result;
  32
  33         result = (bytea *)palloc(size + VARHDRSZ);
  34         result->vl_len = size + VARHDRSZ;
  35         if (size > 0)
  36                 memcpy(result->vl_dat, data, size);
  37
  38         return result;
  39 }
  40
  41 Oid LargeobjectCreate(Oid loid) {
  42         Oid             retval;
  43         Relation                pg_largeobject;
  44         HeapTuple       ntup = (HeapTuple) palloc(sizeof(HeapTupleData));
  45         Relation                idescs[Num_pg_largeobject_indices];
  46         Datum           values[Natts_pg_largeobject];
  47         char            nulls[Natts_pg_largeobject];
  48         int             i;
  49
  50         for (i=0; i<Natts_pg_largeobject; i++) {
  51                 nulls[i] = ' ';
  52                 values[i] = (Datum)NULL;
  53         }
  54
  55         i = 0;
  56         values[i++] = ObjectIdGetDatum(loid);
  57         values[i++] = Int32GetDatum(0);
  58         values[i++] = (Datum) _byteain(NULL, 0);
  59
  60         pg_largeobject = heap_openr(LargeobjectRelationName, RowExclusiveLock);
  61         ntup = heap_formtuple(pg_largeobject->rd_att, values, nulls);
  62         retval = heap_insert(pg_largeobject, ntup);
  63
  64         if (!IsIgnoringSystemIndexes()) {
  65                 CatalogOpenIndices(Num_pg_largeobject_indices, Name_pg_largeobject_indices, idescs);
  66                 CatalogIndexInsert(idescs, Num_pg_largeobject_indices, pg_largeobject, ntup);
  67                 CatalogCloseIndices(Num_pg_largeobject_indices, idescs);
  68         }
  69
  70         heap_close(pg_largeobject, RowExclusiveLock);
  71         heap_freetuple(ntup);
  72
  73         CommandCounterIncrement();
  74
  75         return retval;
  76 }
  77
  78 void LargeobjectDrop(Oid loid) {
  79         Relation        pg_largeobject;
  80         Relation        pg_lo_id;
  81         ScanKeyData     skey;
  82         IndexScanDesc   sd = (IndexScanDesc) NULL;
  83         RetrieveIndexResult     indexRes;
  84         int     found = 0;
  85
  86         ScanKeyEntryInitialize(&skey,
  87                                             (bits16) 0x0,
  88                                             (AttrNumber) 1,
  89                                             (RegProcedure) F_OIDEQ,
  90                                             ObjectIdGetDatum(loid));
  91
  92         pg_largeobject = heap_openr(LargeobjectRelationName, RowShareLock);
  93         pg_lo_id = index_openr(LargeobjectLOIdIndex);
  94
  95         sd = index_beginscan(pg_lo_id, false, 1, &skey);
  96
  97         while((indexRes = index_getnext(sd, ForwardScanDirection))) {
  98                 found++;
  99                 heap_delete(pg_largeobject, &indexRes->heap_iptr, NULL);
 100                 pfree(indexRes);
 101         }
 102
 103         index_endscan(sd);
 104
 105         index_close(pg_lo_id);
 106         heap_close(pg_largeobject, RowShareLock);
 107         if (found == 0)
 108                 elog(ERROR, "LargeobjectDrop: large object %d not found", loid);
 109 }
 110
 111 int LargeobjectFind(Oid loid) {
 112         int     retval = 0;
 113         Relation        pg_lo_id;
 114         ScanKeyData     skey;
 115         IndexScanDesc   sd = (IndexScanDesc) NULL;
 116         RetrieveIndexResult     indexRes;
 117
 118         ScanKeyEntryInitialize(&skey,
 119                                             (bits16) 0x0,
 120                                             (AttrNumber) 1,
 121                                             (RegProcedure) F_OIDEQ,
 122                                             ObjectIdGetDatum(loid));
 123
 124         pg_lo_id = index_openr(LargeobjectLOIdIndex);
 125
 126         sd = index_beginscan(pg_lo_id, false, 1, &skey);
 127
 128         if ((indexRes = index_getnext(sd, ForwardScanDirection))) {
 129                 retval = 1;
 130                 pfree(indexRes);
 131         }
 132
 133         index_endscan(sd);
 134
 135         index_close(pg_lo_id);
 136         return retval;
 137 }
 138