some DBUG_ENTER/RETURN macro added

safer GWS_PROB, avoid log(0)


myisam/ft_nlq_search.c:
  some DBUG_ENTER/RETURN macro added
myisam/ft_parser.c:
  some DBUG_ENTER/RETURN macro added
myisam/ftdefs.h:
  safer GWS_PROB, avoid log(0).
sql/item_func.cc:
  some DBUG_ENTER/RETURN macro added

3 files changed, 22 insertions, 14 deletions

diff --git a/myisam/ft_nlq_search.c b/myisam/ft_nlq_search.c
index 5670edde7c0..6df9fd235fa 100644
--- a/myisam/ft_nlq_search.c
+++ b/myisam/ft_nlq_search.c
@@ -79,6 +79,8 @@ static int walk_and_match(FT_WORD *word, uint32 count, ALL_IN_ONE *aio)
 #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);
@@ -111,7 +113,7 @@ static int walk_and_match(FT_WORD *word, uint32 count, ALL_IN_ONE *aio)
 #else
 #error
 #endif
-    if(tmp_weight==0) return doc_cnt; /* stopword, doc_cnt should be 0 */
+    if(tmp_weight==0) DBUG_RETURN(doc_cnt); /* stopword, doc_cnt should be 0 */
 
 #ifdef EVAL_RUN
     cnt=*(byte *)(aio->info->lastkey+keylen);
@@ -121,7 +123,7 @@ static int walk_and_match(FT_WORD *word, uint32 count, ALL_IN_ONE *aio)
 
     /* saving document matched into dtree */
     if (!(selem=tree_insert(&aio->dtree, &sdoc, 0)))
-      return 1;
+      DBUG_RETURN(1);
 
     sptr=(FT_SUPERDOC *)ELEMENT_KEY((&aio->dtree), selem);
 
@@ -152,21 +154,22 @@ static int walk_and_match(FT_WORD *word, uint32 count, ALL_IN_ONE *aio)
   if (doc_cnt)
   {
     word->weight*=GWS_IN_USE;
-    if (word->weight < 0)
-      word->weight=0;
+    if (word->weight < 0) word->weight=0;
+
   }
-  return 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)++;
-  return 0;
+  DBUG_RETURN(0);
 }
 
 
@@ -184,12 +187,13 @@ FT_INFO *ft_init_nlq_search(MI_INFO *info, uint keynr, byte *query,
   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)
-    return NULL;
+    DBUG_RETURN(NULL);
   if (_mi_readinfo(info,F_RDLCK,1))
-    return NULL;
+    DBUG_RETURN(NULL);
 /* black magic OFF */
 
   aio.info=info;
@@ -236,7 +240,7 @@ err2:
 
 err:
   info->lastpos=saved_lastpos;
-  return dlist;
+  DBUG_RETURN(dlist);
 }
 
 
diff --git a/myisam/ft_parser.c b/myisam/ft_parser.c
index 283216762e1..c25ed6022a0 100644
--- a/myisam/ft_parser.c
+++ b/myisam/ft_parser.c
@@ -186,6 +186,7 @@ byte ft_simple_get_word(byte **start, byte *end, FT_WORD *word)
 {
   byte *doc=*start;
   int mwc;
+  DBUG_ENTER("ft_simple_get_word");
 
   while (doc<end)
   {
@@ -207,32 +208,35 @@ byte ft_simple_get_word(byte **start, byte *end, FT_WORD *word)
         !is_stopword(word->pos, word->len))
     {
       *start=doc;
-      return 1;
+      DBUG_RETURN(1);
     }
   }
-  return 0;
+  DBUG_RETURN(0);
 }
 
 void ft_parse_init(TREE *wtree, CHARSET_INFO *cs)
 {
+  DBUG_ENTER("ft_parse_init");
   if (!is_tree_inited(wtree))
     init_tree(wtree,0,0,sizeof(FT_WORD),(qsort_cmp2)&FT_WORD_cmp,0,NULL, cs);
+  DBUG_VOID_RETURN;
 }
 
 int ft_parse(TREE *wtree, byte *doc, int doclen)
 {
   byte   *end=doc+doclen;
   FT_WORD w;
+  DBUG_ENTER("ft_parse");
 
   while (ft_simple_get_word(&doc,end,&w))
   {
     if (!tree_insert(wtree, &w, 0))
       goto err;
   }
-  return 0;
+  DBUG_RETURN(0);
 
 err:
   delete_tree(wtree);
-  return 1;
+  DBUG_RETURN(1);
 }
 
diff --git a/myisam/ftdefs.h b/myisam/ftdefs.h
index a1352a13150..62fa4362e19 100644
--- a/myisam/ftdefs.h
+++ b/myisam/ftdefs.h
@@ -78,7 +78,7 @@ extern ulong collstat;
 /* Mysterious, but w/o (double) GWS_IDF performs better :-o */
 #define GWS_IDF		   log(aio->info->state->records/doc_cnt)
 #define GWS_IDF1	   log((double)aio->info->state->records/doc_cnt)
-#define GWS_PROB log(((double)(aio->info->state->records-doc_cnt))/doc_cnt)
+#define GWS_PROB ((aio->info->state->records > doc_cnt) ? log(((double)(aio->info->state->records-doc_cnt))/doc_cnt) : 0 )
 #define GWS_FREQ					(1.0/doc_cnt)
 #define GWS_SQUARED pow(log((double)aio->info->state->records/doc_cnt),2)
 #define GWS_CUBIC   pow(log((double)aio->info->state->records/doc_cnt),3)