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-rw-r--r--myisam/ft_nlq_search.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/myisam/ft_nlq_search.c b/myisam/ft_nlq_search.c
new file mode 100644
index 00000000000..ac9fa5a9a8c
--- /dev/null
+++ b/myisam/ft_nlq_search.c
@@ -0,0 +1,290 @@
+/* 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;
+ 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
+
+ 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;
+}
+
+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;
+
+/* black magic ON */
+ if ((int) (keynr = _mi_check_index(info,keynr)) < 0)
+ return NULL;
+ if (_mi_readinfo(info,F_RDLCK,1))
+ return NULL;
+/* black magic OFF */
+
+ aio.info=info;
+ aio.keynr=keynr;
+ aio.keybuff=info->lastkey+info->s->base.max_key_length;
+ aio.keyinfo=info->s->keyinfo+keynr;
+ 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);
+
+ 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;
+ 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;
+}
+
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