postgresql/contrib/pg_trgm/trgm_gin.c
2009-06-11 14:49:15 +00:00

98 lines
2.1 KiB
C

/*
* $PostgreSQL: pgsql/contrib/pg_trgm/trgm_gin.c,v 1.8 2009/06/11 14:48:51 momjian Exp $
*/
#include "trgm.h"
#include "access/gin.h"
#include "access/itup.h"
#include "access/tuptoaster.h"
#include "storage/bufpage.h"
#include "utils/array.h"
#include "utils/builtins.h"
PG_FUNCTION_INFO_V1(gin_extract_trgm);
Datum gin_extract_trgm(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(gin_trgm_consistent);
Datum gin_trgm_consistent(PG_FUNCTION_ARGS);
Datum
gin_extract_trgm(PG_FUNCTION_ARGS)
{
text *val = (text *) PG_GETARG_TEXT_P(0);
int32 *nentries = (int32 *) PG_GETARG_POINTER(1);
Datum *entries = NULL;
TRGM *trg;
int4 trglen;
*nentries = 0;
trg = generate_trgm(VARDATA(val), VARSIZE(val) - VARHDRSZ);
trglen = ARRNELEM(trg);
if (trglen > 0)
{
trgm *ptr;
int4 i = 0,
item;
*nentries = (int32) trglen;
entries = (Datum *) palloc(sizeof(Datum) * trglen);
ptr = GETARR(trg);
while (ptr - GETARR(trg) < ARRNELEM(trg))
{
item = trgm2int(ptr);
entries[i++] = Int32GetDatum(item);
ptr++;
}
if (PG_NARGS() > 4)
{
/*
* Function called from query extracting
*/
Pointer **extra_data = (Pointer **) PG_GETARG_POINTER(4);
*extra_data = (Pointer *) palloc0(sizeof(Pointer) * (*nentries));
*(int32 *) (*extra_data) = trglen;
}
}
PG_RETURN_POINTER(entries);
}
Datum
gin_trgm_consistent(PG_FUNCTION_ARGS)
{
bool *check = (bool *) PG_GETARG_POINTER(0);
/* StrategyNumber strategy = PG_GETARG_UINT16(1); */
/* text *query = PG_GETARG_TEXT_P(2); */
/* int32 nkeys = PG_GETARG_INT32(3); */
Pointer *extra_data = (Pointer *) PG_GETARG_POINTER(4);
bool *recheck = (bool *) PG_GETARG_POINTER(5);
bool res = FALSE;
int4 i,
trglen,
ntrue = 0;
/* All cases served by this function are inexact */
*recheck = true;
trglen = *(int32 *) extra_data;
for (i = 0; i < trglen; i++)
if (check[i])
ntrue++;
#ifdef DIVUNION
res = (trglen == ntrue) ? true : ((((((float4) ntrue) / ((float4) (trglen - ntrue)))) >= trgm_limit) ? true : false);
#else
res = (trglen == 0) ? false : ((((((float4) ntrue) / ((float4) trglen))) >= trgm_limit) ? true : false);
#endif
PG_RETURN_BOOL(res);
}