contrib/hstore/hstore_gin.c

   1 #include "hstore.h"
   2
   3 #include "access/gin.h"
   4
   5 #define KEYFLAG         'K'
   6 #define VALFLAG         'V'
   7 #define NULLFLAG        'N'
   8
   9 PG_FUNCTION_INFO_V1(gin_extract_hstore);
  10 Datum           gin_extract_hstore(PG_FUNCTION_ARGS);
  11
  12 static text *
  13 makeitem(char *str, int len)
  14 {
  15         text       *item;
  16
  17         item = (text *) palloc(VARHDRSZ + len + 1);
  18         SET_VARSIZE(item, VARHDRSZ + len + 1);
  19
  20         if (str && len > 0)
  21                 memcpy(VARDATA(item) + 1, str, len);
  22
  23         return item;
  24 }
  25
  26 Datum
  27 gin_extract_hstore(PG_FUNCTION_ARGS)
  28 {
  29         HStore     *hs = PG_GETARG_HS(0);
  30         int32      *nentries = (int32 *) PG_GETARG_POINTER(1);
  31         Datum      *entries = NULL;
  32
  33         *nentries = 2 * hs->size;
  34
  35         if (hs->size > 0)
  36         {
  37                 HEntry     *ptr = ARRPTR(hs);
  38                 char       *words = STRPTR(hs);
  39                 int                     i = 0;
  40
  41                 entries = (Datum *) palloc(sizeof(Datum) * 2 * hs->size);
  42
  43                 while (ptr - ARRPTR(hs) < hs->size)
  44                 {
  45                         text       *item;
  46
  47                         item = makeitem(words + ptr->pos, ptr->keylen);
  48                         *VARDATA(item) = KEYFLAG;
  49                         entries[i++] = PointerGetDatum(item);
  50
  51                         if (ptr->valisnull)
  52                         {
  53                                 item = makeitem(NULL, 0);
  54                                 *VARDATA(item) = NULLFLAG;
  55
  56                         }
  57                         else
  58                         {
  59                                 item = makeitem(words + ptr->pos + ptr->keylen, ptr->vallen);
  60                                 *VARDATA(item) = VALFLAG;
  61                         }
  62                         entries[i++] = PointerGetDatum(item);
  63
  64                         ptr++;
  65                 }
  66         }
  67
  68         PG_FREE_IF_COPY(hs, 0);
  69         PG_RETURN_POINTER(entries);
  70 }
  71
  72 PG_FUNCTION_INFO_V1(gin_extract_hstore_query);
  73 Datum           gin_extract_hstore_query(PG_FUNCTION_ARGS);
  74
  75 Datum
  76 gin_extract_hstore_query(PG_FUNCTION_ARGS)
  77 {
  78         StrategyNumber strategy = PG_GETARG_UINT16(2);
  79
  80         if (strategy == HStoreContainsStrategyNumber)
  81         {
  82                 PG_RETURN_DATUM(DirectFunctionCall2(
  83                                                                                         gin_extract_hstore,
  84                                                                                         PG_GETARG_DATUM(0),
  85                                                                                         PG_GETARG_DATUM(1)
  86                                                                                         ));
  87         }
  88         else if (strategy == HStoreExistsStrategyNumber)
  89         {
  90                 text       *item,
  91                                    *q = PG_GETARG_TEXT_P(0);
  92                 int32      *nentries = (int32 *) PG_GETARG_POINTER(1);
  93                 Datum      *entries = NULL;
  94
  95                 *nentries = 1;
  96                 entries = (Datum *) palloc(sizeof(Datum));
  97
  98                 item = makeitem(VARDATA(q), VARSIZE(q) - VARHDRSZ);
  99                 *VARDATA(item) = KEYFLAG;
 100                 entries[0] = PointerGetDatum(item);
 101
 102                 PG_RETURN_POINTER(entries);
 103         }
 104         else
 105                 elog(ERROR, "Unsupported strategy number: %d", strategy);
 106
 107         PG_RETURN_POINTER(NULL);
 108 }
 109
 110 PG_FUNCTION_INFO_V1(gin_consistent_hstore);
 111 Datum           gin_consistent_hstore(PG_FUNCTION_ARGS);
 112
 113 Datum
 114 gin_consistent_hstore(PG_FUNCTION_ARGS)
 115 {
 116         StrategyNumber strategy = PG_GETARG_UINT16(1);
 117         bool            res = true;
 118
 119         if (strategy == HStoreContainsStrategyNumber)
 120         {
 121                 bool       *check = (bool *) PG_GETARG_POINTER(0);
 122                 HStore     *query = PG_GETARG_HS(2);
 123                 int                     i;
 124
 125                 for (i = 0; res && i < 2 * query->size; i++)
 126                         if (check[i] == false)
 127                                 res = false;
 128         }
 129         else if (strategy == HStoreExistsStrategyNumber)
 130                 res = true;
 131         else
 132                 elog(ERROR, "Unsupported strategy number: %d", strategy);
 133
 134         PG_RETURN_BOOL(res);
 135 }