/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* Written by Sergei A. Golubchik, who has a shared copyright to this code */ #define FT_CORE #include "ftdefs.h" /* search with natural language queries */ typedef struct ft_doc_rec { my_off_t dpos; double weight; } FT_DOC; struct st_ft_info { struct _ft_vft *please; MI_INFO *info; int ndocs; int curdoc; FT_DOC doc[1]; }; typedef struct st_all_in_one { MI_INFO *info; uint keynr; CHARSET_INFO *charset; uchar *keybuff; MI_KEYDEF *keyinfo; my_off_t key_root; TREE dtree; } ALL_IN_ONE; typedef struct st_ft_superdoc { FT_DOC doc; FT_WORD *word_ptr; double tmp_weight; } FT_SUPERDOC; static int FT_SUPERDOC_cmp(void* cmp_arg __attribute__((unused)), FT_SUPERDOC *p1, FT_SUPERDOC *p2) { if (p1->doc.dpos < p2->doc.dpos) return -1; if (p1->doc.dpos == p2->doc.dpos) return 0; return 1; } static int walk_and_match(FT_WORD *word, uint32 count, ALL_IN_ONE *aio) { uint keylen, r, doc_cnt; #ifdef EVAL_RUN uint cnt; double sum, sum2, suml; #endif /* EVAL_RUN */ FT_SUPERDOC sdoc, *sptr; TREE_ELEMENT *selem; #if HA_FT_WTYPE == HA_KEYTYPE_FLOAT float tmp_weight; #else #error #endif DBUG_ENTER("walk_and_match"); word->weight=LWS_FOR_QUERY; keylen=_ft_make_key(aio->info,aio->keynr,(char*) aio->keybuff,word,0); #ifdef EVAL_RUN keylen-=1+HA_FT_WLEN; #else /* EVAL_RUN */ keylen-=HA_FT_WLEN; #endif /* EVAL_RUN */ #ifdef EVAL_RUN sum=sum2=suml= #endif /* EVAL_RUN */ doc_cnt=0; r=_mi_search(aio->info, aio->keyinfo, aio->keybuff, keylen, SEARCH_FIND | SEARCH_PREFIX, aio->key_root); aio->info->update|= HA_STATE_AKTIV; /* for _mi_test_if_changed() */ while (!r) { if (_mi_compare_text(aio->charset, aio->info->lastkey,keylen, aio->keybuff,keylen,0)) break; #if HA_FT_WTYPE == HA_KEYTYPE_FLOAT #ifdef EVAL_RUN mi_float4get(tmp_weight,aio->info->lastkey+keylen+1); #else /* EVAL_RUN */ mi_float4get(tmp_weight,aio->info->lastkey+keylen); #endif /* EVAL_RUN */ #else #error #endif if(tmp_weight==0) DBUG_RETURN(doc_cnt); /* stopword, doc_cnt should be 0 */ #ifdef EVAL_RUN cnt=*(byte *)(aio->info->lastkey+keylen); #endif /* EVAL_RUN */ sdoc.doc.dpos=aio->info->lastpos; /* saving document matched into dtree */ if (!(selem=tree_insert(&aio->dtree, &sdoc, 0))) DBUG_RETURN(1); sptr=(FT_SUPERDOC *)ELEMENT_KEY((&aio->dtree), selem); if (selem->count==1) /* document's first match */ sptr->doc.weight=0; else sptr->doc.weight+=sptr->tmp_weight*sptr->word_ptr->weight; sptr->word_ptr=word; sptr->tmp_weight=tmp_weight; doc_cnt++; #ifdef EVAL_RUN sum +=cnt; sum2+=cnt*cnt; suml+=cnt*log(cnt); #endif /* EVAL_RUN */ if (_mi_test_if_changed(aio->info) == 0) r=_mi_search_next(aio->info, aio->keyinfo, aio->info->lastkey, aio->info->lastkey_length, SEARCH_BIGGER, aio->key_root); else r=_mi_search(aio->info, aio->keyinfo, aio->info->lastkey, aio->info->lastkey_length, SEARCH_BIGGER, aio->key_root); } if (doc_cnt) { word->weight*=GWS_IN_USE; if (word->weight < 0) word->weight=0; } DBUG_RETURN(0); } static int walk_and_copy(FT_SUPERDOC *from, uint32 count __attribute__((unused)), FT_DOC **to) { DBUG_ENTER("walk_and_copy"); from->doc.weight+=from->tmp_weight*from->word_ptr->weight; (*to)->dpos=from->doc.dpos; (*to)->weight=from->doc.weight; (*to)++; DBUG_RETURN(0); } static int FT_DOC_cmp(FT_DOC *a, FT_DOC *b) { return sgn(b->weight - a->weight); } FT_INFO *ft_init_nlq_search(MI_INFO *info, uint keynr, byte *query, uint query_len, my_bool presort) { TREE allocated_wtree, *wtree=&allocated_wtree; ALL_IN_ONE aio; FT_DOC *dptr; FT_INFO *dlist=NULL; my_off_t saved_lastpos=info->lastpos; DBUG_ENTER("ft_init_nlq_search"); /* black magic ON */ if ((int) (keynr = _mi_check_index(info,keynr)) < 0) DBUG_RETURN(NULL); if (_mi_readinfo(info,F_RDLCK,1)) DBUG_RETURN(NULL); /* black magic OFF */ aio.info=info; aio.keynr=keynr; aio.keyinfo=info->s->keyinfo+keynr; aio.charset=aio.keyinfo->seg->charset; aio.keybuff=info->lastkey+info->s->base.max_key_length; aio.key_root=info->s->state.key_root[keynr]; bzero(&allocated_wtree,sizeof(allocated_wtree)); init_tree(&aio.dtree,0,0,sizeof(FT_SUPERDOC),(qsort_cmp2)&FT_SUPERDOC_cmp,0, NULL, NULL); ft_parse_init(&allocated_wtree, aio.charset); if (ft_parse(&allocated_wtree,query,query_len)) goto err; if (tree_walk(wtree, (tree_walk_action)&walk_and_match, &aio, left_root_right)) goto err2; dlist=(FT_INFO *)my_malloc(sizeof(FT_INFO)+ sizeof(FT_DOC)*(aio.dtree.elements_in_tree-1), MYF(0)); if(!dlist) goto err2; dlist->please= (struct _ft_vft *) & _ft_vft_nlq; dlist->ndocs=aio.dtree.elements_in_tree; dlist->curdoc=-1; dlist->info=aio.info; dptr=dlist->doc; tree_walk(&aio.dtree, (tree_walk_action) &walk_and_copy, &dptr, left_root_right); if (presort) qsort(dlist->doc, dlist->ndocs, sizeof(FT_DOC), (qsort_cmp)&FT_DOC_cmp); err2: delete_tree(wtree); delete_tree(&aio.dtree); err: info->lastpos=saved_lastpos; DBUG_RETURN(dlist); } int ft_nlq_read_next(FT_INFO *handler, char *record) { MI_INFO *info= (MI_INFO *) handler->info; if (++handler->curdoc >= handler->ndocs) { --handler->curdoc; return HA_ERR_END_OF_FILE; } info->update&= (HA_STATE_CHANGED | HA_STATE_ROW_CHANGED); info->lastpos=handler->doc[handler->curdoc].dpos; if (!(*info->read_record)(info,info->lastpos,record)) { info->update|= HA_STATE_AKTIV; /* Record is read */ return 0; } return my_errno; } float ft_nlq_find_relevance(FT_INFO *handler, byte *record __attribute__((unused)), uint length __attribute__((unused))) { int a,b,c; FT_DOC *docs=handler->doc; my_off_t docid=handler->info->lastpos; if (docid == HA_POS_ERROR) return -5.0; /* Assuming docs[] is sorted by dpos... */ for (a=0, b=handler->ndocs, c=(a+b)/2; b-a>1; c=(a+b)/2) { if (docs[c].dpos > docid) b=c; else a=c; } if (docs[a].dpos == docid) return (float) docs[a].weight; else return 0.0; } void ft_nlq_close_search(FT_INFO *handler) { my_free((gptr)handler,MYF(0)); } float ft_nlq_get_relevance(FT_INFO *handler) { return (float) handler->doc[handler->curdoc].weight; } void ft_nlq_reinit_search(FT_INFO *handler) { handler->curdoc=-1; }