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99 lines
3.7 KiB
C
99 lines
3.7 KiB
C
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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/* Written by Sergei A. Golubchik, who has a shared copyright to this code */
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/* some definitions for full-text indices */
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#include "fulltext.h"
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#include <m_ctype.h>
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#include <my_tree.h>
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#define MIN_WORD_LEN 4
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#define HYPHEN_IS_DELIM
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#define HYPHEN_IS_CONCAT /* not used for now */
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#define COMPILE_STOPWORDS_IN
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/* Most of the formulae were shamelessly stolen from SMART distribution
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ftp://ftp.cs.cornell.edu/pub/smart/smart.11.0.tar.Z
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NORM_PIVOT was taken from the article
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A.Singhal, C.Buckley, M.Mitra, "Pivoted Document Length Normalization",
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ACM SIGIR'96, 21-29, 1996
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*/
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#define LWS_FOR_QUERY LWS_TF
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#define LWS_IN_USE LWS_LOG
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#define PRENORM_IN_USE PRENORM_AVG
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#define NORM_IN_USE NORM_PIVOT
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#define GWS_IN_USE GWS_PROB
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/*==============================================================*/
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#define LWS_TF (count)
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#define LWS_BINARY (count>0)
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#define LWS_SQUARE (count*count)
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#define LWS_LOG (count?(log(count)+1):0)
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/*--------------------------------------------------------------*/
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#define PRENORM_NONE (p->weight)
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#define PRENORM_MAX (p->weight/docstat.max)
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#define PRENORM_AUG (0.4+0.6*p->weight/docstat.max)
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#define PRENORM_AVG (p->weight/docstat.sum*docstat.uniq)
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#define PRENORM_AVGLOG ((1+log(p->weight))/(1+log(docstat.sum/docstat.uniq)))
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/*--------------------------------------------------------------*/
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#define NORM_NONE (1)
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#define NORM_SUM (docstat.nsum)
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#define NORM_COS (sqrt(docstat.nsum2))
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#ifdef EVAL_RUN
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/*
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extern ulong collstat;
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#define PIVOT_STAT (docstat.uniq)
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#define PIVOT_SLOPE (0.69)
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#define PIVOT_PIVOT ((double)collstat/(info->state->records+1))
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#define NORM_PIVOT ((1-PIVOT_SLOPE)*PIVOT_PIVOT+PIVOT_SLOPE*docstat.uniq)
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*/
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#endif /* EVAL_RUN */
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#define PIVOT_VAL (0.0115)
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#define NORM_PIVOT (1+PIVOT_VAL*docstat.uniq)
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/*---------------------------------------------------------------*/
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#define GWS_NORM (1/sqrt(sum2))
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#define GWS_GFIDF (sum/doc_cnt)
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/* Mysterious, but w/o (double) GWS_IDF performs better :-o */
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#define GWS_IDF log(aio->info->state->records/doc_cnt)
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#define GWS_IDF1 log((double)aio->info->state->records/doc_cnt)
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#define GWS_PROB log(((double)(aio->info->state->records-doc_cnt))/doc_cnt)
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#define GWS_FREQ (1.0/doc_cnt)
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#define GWS_SQUARED pow(log((double)aio->info->state->records/doc_cnt),2)
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#define GWS_CUBIC pow(log((double)aio->info->state->records/doc_cnt),3)
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#define GWS_ENTROPY (1-(suml/sum-log(sum))/log(aio->info->state->records))
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/*=================================================================*/
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typedef struct st_ft_word {
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byte * pos;
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uint len;
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double weight;
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#ifdef EVAL_RUN
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byte cnt;
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#endif /* EVAL_RUN */
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} FT_WORD;
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int is_stopword(char *word, uint len);
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uint _ft_make_key(MI_INFO *, uint , byte *, FT_WORD *, my_off_t);
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TREE * ft_parse(TREE *, byte *, int);
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FT_WORD * ft_linearize(MI_INFO *, uint, byte *, TREE *);
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