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Viewing changes to contrib/pg_trgm/trgm_gin.c

  • Committer: Bazaar Package Importer
  • Author(s): Martin Pitt
  • Date: 2009-03-20 12:00:13 UTC
  • Revision ID: james.westby@ubuntu.com-20090320120013-hogj7egc5mjncc5g
Tags: upstream-8.4~0cvs20090328
Import upstream version 8.4~0cvs20090328

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