diff options
Diffstat (limited to 'myisam/ft_nlq_search.c')
| -rw-r--r-- | myisam/ft_nlq_search.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/myisam/ft_nlq_search.c b/myisam/ft_nlq_search.c new file mode 100644 index 00000000000..3b4937ca4d9 --- /dev/null +++ b/myisam/ft_nlq_search.c @@ -0,0 +1,191 @@ +/* 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 */ + +#include "ftdefs.h" + +/* search with natural language queries */ + +typedef struct st_all_in_one { + MI_INFO *info; + uint keynr; + 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(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 + + 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); + + while(!r) + { + if (_mi_compare_text(default_charset_info, + 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) 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))) 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; + } + + return 0; +} + +static int walk_and_copy(FT_SUPERDOC *from, + uint32 count __attribute__((unused)), FT_DOC **to) +{ + from->doc.weight+=from->tmp_weight*from->word_ptr->weight; + (*to)->dpos=from->doc.dpos; + (*to)->weight=from->doc.weight; + (*to)++; + return 0; +} + +FT_DOCLIST *ft_nlq_search(MI_INFO *info, uint keynr, byte *query, + uint query_len) +{ + TREE *wtree, allocated_wtree; + ALL_IN_ONE aio; + FT_DOC *dptr; + FT_DOCLIST *dlist=NULL; + + aio.info=info; + aio.keynr=keynr; + aio.keybuff=aio.info->lastkey+aio.info->s->base.max_key_length; + aio.keyinfo=aio.info->s->keyinfo+keynr; + aio.key_root=aio.info->s->state.key_root[keynr]; + + bzero(&allocated_wtree,sizeof(allocated_wtree)); + + init_tree(&aio.dtree,0,sizeof(FT_SUPERDOC),(qsort_cmp)&FT_SUPERDOC_cmp,0, + NULL); + + if(!(wtree=ft_parse(&allocated_wtree,query,query_len))) + return NULL; + + if(tree_walk(wtree, (tree_walk_action)&walk_and_match, &aio, + left_root_right)) + goto err; + + dlist=(FT_DOCLIST *)my_malloc(sizeof(FT_DOCLIST)+sizeof(FT_DOC)*(aio.dtree.elements_in_tree-1),MYF(0)); + if(!dlist) + goto err; + + 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); + +err: + delete_tree(wtree); + delete_tree(&aio.dtree); + return dlist; +} + |