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 1.3 2000/10/21 15:55:21 momjian Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15 #include "postgres.h"
  16
  17 #include "access/genam.h"
  18 #include "access/heapam.h"
  19 #include "catalog/catname.h"
  20 #include "catalog/indexing.h"
  21 #include "catalog/pg_largeobject.h"
  22 #include "miscadmin.h"
  23 #include "utils/fmgroids.h"
  24
  25 bytea *_byteain(const char *data, int32 size);
  26
  27 bytea *_byteain(const char *data, int32 size) {
  28         bytea   *result;
  29
  30         result = (bytea *)palloc(size + VARHDRSZ);
  31         result->vl_len = size + VARHDRSZ;
  32         if (size > 0)
  33                 memcpy(result->vl_dat, data, size);
  34
  35         return result;
  36 }
  37
  38 Oid LargeobjectCreate(Oid loid) {
  39         Oid             retval;
  40         Relation                pg_largeobject;
  41         HeapTuple       ntup = (HeapTuple) palloc(sizeof(HeapTupleData));
  42         Relation                idescs[Num_pg_largeobject_indices];
  43         Datum           values[Natts_pg_largeobject];
  44         char            nulls[Natts_pg_largeobject];
  45         int             i;
  46
  47         for (i=0; i<Natts_pg_largeobject; i++) {
  48                 nulls[i] = ' ';
  49                 values[i] = (Datum)NULL;
  50         }
  51
  52         i = 0;
  53         values[i++] = ObjectIdGetDatum(loid);
  54         values[i++] = Int32GetDatum(0);
  55         values[i++] = (Datum) _byteain(NULL, 0);
  56
  57         pg_largeobject = heap_openr(LargeobjectRelationName, RowExclusiveLock);
  58         ntup = heap_formtuple(pg_largeobject->rd_att, values, nulls);
  59         retval = heap_insert(pg_largeobject, ntup);
  60
  61         if (!IsIgnoringSystemIndexes()) {
  62                 CatalogOpenIndices(Num_pg_largeobject_indices, Name_pg_largeobject_indices, idescs);
  63                 CatalogIndexInsert(idescs, Num_pg_largeobject_indices, pg_largeobject, ntup);
  64                 CatalogCloseIndices(Num_pg_largeobject_indices, idescs);
  65         }
  66
  67         heap_close(pg_largeobject, RowExclusiveLock);
  68         heap_freetuple(ntup);
  69
  70         CommandCounterIncrement();
  71
  72         return retval;
  73 }
  74
  75 void LargeobjectDrop(Oid loid) {
  76         Relation        pg_largeobject;
  77         Relation        pg_lo_id;
  78         ScanKeyData     skey;
  79         IndexScanDesc   sd = (IndexScanDesc) NULL;
  80         RetrieveIndexResult     indexRes;
  81         int     found = 0;
  82
  83         ScanKeyEntryInitialize(&skey,
  84                                             (bits16) 0x0,
  85                                             (AttrNumber) 1,
  86                                             (RegProcedure) F_OIDEQ,
  87                                             ObjectIdGetDatum(loid));
  88
  89         pg_largeobject = heap_openr(LargeobjectRelationName, RowShareLock);
  90         pg_lo_id = index_openr(LargeobjectLOIdIndex);
  91
  92         sd = index_beginscan(pg_lo_id, false, 1, &skey);
  93
  94         while((indexRes = index_getnext(sd, ForwardScanDirection))) {
  95                 found++;
  96                 heap_delete(pg_largeobject, &indexRes->heap_iptr, NULL);
  97                 pfree(indexRes);
  98         }
  99
 100         index_endscan(sd);
 101
 102         index_close(pg_lo_id);
 103         heap_close(pg_largeobject, RowShareLock);
 104         if (found == 0)
 105                 elog(ERROR, "LargeobjectDrop: large object %d not found", loid);
 106 }
 107
 108 int LargeobjectFind(Oid loid) {
 109         int     retval = 0;
 110         Relation        pg_lo_id;
 111         ScanKeyData     skey;
 112         IndexScanDesc   sd = (IndexScanDesc) NULL;
 113         RetrieveIndexResult     indexRes;
 114
 115         ScanKeyEntryInitialize(&skey,
 116                                             (bits16) 0x0,
 117                                             (AttrNumber) 1,
 118                                             (RegProcedure) F_OIDEQ,
 119                                             ObjectIdGetDatum(loid));
 120
 121         pg_lo_id = index_openr(LargeobjectLOIdIndex);
 122
 123         sd = index_beginscan(pg_lo_id, false, 1, &skey);
 124
 125         if ((indexRes = index_getnext(sd, ForwardScanDirection))) {
 126                 retval = 1;
 127                 pfree(indexRes);
 128         }
 129
 130         index_endscan(sd);
 131
 132         index_close(pg_lo_id);
 133         return retval;
 134 }
 135