Add prefix support for synonym dictionary

diff --git a/doc/src/sgml/textsearch.sgml b/doc/src/sgml/textsearch.sgml
index 547c0153ac8be831491f799155702f55d7c4f400..ed78c1d10a0baab3f63ab38c7ce5d8ffe0c4dd0d 100644 (file)
--- a/doc/src/sgml/textsearch.sgml
+++ b/doc/src/sgml/textsearch.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/textsearch.sgml,v 1.52 2009/06/17 21:58:49 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/textsearch.sgml,v 1.53 2009/08/14 14:53:20 teodor Exp $ -->
 
 <chapter id="textsearch">
  <title id="textsearch-title">Full Text Search</title>
@@ -2288,6 +2288,63 @@ SELECT * FROM ts_debug('english', 'Paris');
  asciiword | Word, all ASCII | Paris | {my_synonym,english_stem} | my_synonym | {paris}
 </programlisting>
    </para>
+   
+   <para>
+    An asterisk (<literal>*</literal>) at the end of definition word indicates 
+    that definition word is a prefix, and <function>to_tsquery()</function> 
+    function will transform that definition to the prefix search format (see 
+    <xref linkend="textsearch-parsing-queries">). 
+    Notice that it is ignored in <function>to_tsvector()</function>.
+   </para>
+
+   <para>
+    Contents of <filename>$SHAREDIR/tsearch_data/synonym_sample.syn</>:
+   </para>
+<programlisting>
+postgres        pgsql
+postgresql      pgsql
+postgre pgsql
+gogle   googl
+indices index*
+</programlisting>
+
+   <para>
+    Results:
+   </para>
+<programlisting>
+=# create text search dictionary syn( template=synonym,synonyms='synonym_sample');
+=# select ts_lexize('syn','indices');
+ ts_lexize
+-----------
+ {index}
+(1 row)
+
+=# create text search configuration tst ( copy=simple);
+=# alter text search configuration tst alter mapping for asciiword with syn;
+=# select to_tsquery('tst','indices');
+ to_tsquery
+------------
+ 'index':*
+(1 row)
+
+=# select 'indexes are very useful'::tsvector;
+            tsvector             
+---------------------------------
+ 'are' 'indexes' 'useful' 'very'
+(1 row)
+
+=# select 'indexes are very useful'::tsvector @@ to_tsquery('tst','indices');
+ ?column?
+----------
+ t
+(1 row)
+
+=# select to_tsvector('tst','indices');
+ to_tsvector
+-------------
+ 'index':1
+(1 row)
+</programlisting>
 
    <para>
     The only parameter required by the <literal>synonym</> template is

diff --git a/src/backend/tsearch/dict_synonym.c b/src/backend/tsearch/dict_synonym.c
index a9d094880def285b44d9b5428c0d33bf0ff27135..13ecfd0eed2594d069d3d6647625d8a8593090f4 100644 (file)
--- a/src/backend/tsearch/dict_synonym.c
+++ b/src/backend/tsearch/dict_synonym.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/tsearch/dict_synonym.c,v 1.10 2009/01/01 17:23:48 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/tsearch/dict_synonym.c,v 1.11 2009/08/14 14:53:20 teodor Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,6 +23,8 @@ typedef struct
 {
        char       *in;
        char       *out;
+       int                     outlen;
+       uint16          flags;
 } Syn;
 
 typedef struct
@@ -36,11 +38,14 @@ typedef struct
  * Finds the next whitespace-delimited word within the 'in' string.
  * Returns a pointer to the first character of the word, and a pointer
  * to the next byte after the last character in the word (in *end).
+ * Character '*' at the end of word will not be threated as word
+ * charater if flags is not null.
  */
 static char *
-findwrd(char *in, char **end)
+findwrd(char *in, char **end, uint16 *flags)
 {
        char       *start;
+       char       *lastchar;
 
        /* Skip leading spaces */
        while (*in && t_isspace(in))
@@ -53,13 +58,27 @@ findwrd(char *in, char **end)
                return NULL;
        }
 
-       start = in;
+       lastchar = start = in;
 
        /* Find end of word */
        while (*in && !t_isspace(in))
+       {
+               lastchar = in;
                in += pg_mblen(in);
+       }
+
+       if ( in - lastchar == 1 && t_iseq(lastchar, '*') && flags )
+       {
+               *flags = TSL_PREFIX;
+               *end = lastchar;
+       }
+       else
+       {
+               if (flags)
+                               *flags = 0;
+               *end = in;
+       }
 
-       *end = in;
        return start;
 }
 
@@ -84,6 +103,7 @@ dsynonym_init(PG_FUNCTION_ARGS)
                           *end = NULL;
        int                     cur = 0;
        char       *line = NULL;
+       uint16          flags = 0;
 
        foreach(l, dictoptions)
        {
@@ -117,7 +137,7 @@ dsynonym_init(PG_FUNCTION_ARGS)
 
        while ((line = tsearch_readline(&trst)) != NULL)
        {
-               starti = findwrd(line, &end);
+               starti = findwrd(line, &end, NULL);
                if (!starti)
                {
                        /* Empty line */
@@ -130,7 +150,7 @@ dsynonym_init(PG_FUNCTION_ARGS)
                }
                *end = '\0';
 
-               starto = findwrd(end + 1, &end);
+               starto = findwrd(end + 1, &end, &flags);
                if (!starto)
                {
                        /* A line with only one word (+whitespace). Ignore silently. */
@@ -168,6 +188,9 @@ dsynonym_init(PG_FUNCTION_ARGS)
                        d->syn[cur].out = lowerstr(starto);
                }
 
+               d->syn[cur].outlen = strlen(starto);
+               d->syn[cur].flags = flags; 
+
                cur++;
 
 skipline:
@@ -212,7 +235,8 @@ dsynonym_lexize(PG_FUNCTION_ARGS)
                PG_RETURN_POINTER(NULL);
 
        res = palloc0(sizeof(TSLexeme) * 2);
-       res[0].lexeme = pstrdup(found->out);
+       res[0].lexeme = pnstrdup(found->out, found->outlen);
+       res[0].flags = found->flags;
 
        PG_RETURN_POINTER(res);
 }

diff --git a/src/backend/tsearch/synonym_sample.syn b/src/backend/tsearch/synonym_sample.syn
index 4e2eaeec0c1ac0d7fa3b5f66500d1a55829e7bd0..3ecbcf901cbb69e1ba649515371ba8d1d865de8c 100644 (file)
--- a/src/backend/tsearch/synonym_sample.syn
+++ b/src/backend/tsearch/synonym_sample.syn
@@ -2,3 +2,4 @@ postgres        pgsql
 postgresql     pgsql
 postgre        pgsql
 gogle  googl
+indices        index*

diff --git a/src/test/regress/expected/tsdicts.out b/src/test/regress/expected/tsdicts.out
index 3ae6a671dad4dd63deda69b4a41436ba92543aed..aba67fcab79cd6e18ce9b61de720c413dd36933b 100644 (file)
--- a/src/test/regress/expected/tsdicts.out
+++ b/src/test/regress/expected/tsdicts.out
@@ -208,6 +208,12 @@ SELECT ts_lexize('synonym', 'Gogle');
  {googl}
 (1 row)
 
+SELECT ts_lexize('synonym', 'indices');
+ ts_lexize 
+-----------
+ {index}
+(1 row)
+
 -- Create and simple test thesaurus dictionary
 -- More tests in configuration checks because ts_lexize()
 -- cannot pass more than one word to thesaurus.
@@ -290,6 +296,18 @@ SELECT to_tsvector('synonym_tst', 'Most common mistake is to write Gogle instead
  'common':2 'googl':7,10 'instead':8 'mistak':3 'write':6
 (1 row)
 
+SELECT to_tsvector('synonym_tst', 'Indexes or indices - Which is right plural form of index?');
+                 to_tsvector                  
+----------------------------------------------
+ 'form':8 'index':1,3,10 'plural':7 'right':6
+(1 row)
+
+SELECT to_tsquery('synonym_tst', 'Index & indices');
+     to_tsquery      
+---------------------
+ 'index' & 'index':*
+(1 row)
+
 -- test thesaurus in configuration
 -- see thesaurus_sample.ths to understand 'odd' resulting tsvector
 CREATE TEXT SEARCH CONFIGURATION thesaurus_tst (

diff --git a/src/test/regress/sql/tsdicts.sql b/src/test/regress/sql/tsdicts.sql
index f36e63a31107ef024328b8ea9b43e9bfe31fde45..000f6eb2e7b9e99ebd0e5f92665c39655b83c6a2 100644 (file)
--- a/src/test/regress/sql/tsdicts.sql
+++ b/src/test/regress/sql/tsdicts.sql
@@ -56,6 +56,7 @@ CREATE TEXT SEARCH DICTIONARY synonym (
 
 SELECT ts_lexize('synonym', 'PoStGrEs');
 SELECT ts_lexize('synonym', 'Gogle');
+SELECT ts_lexize('synonym', 'indices');
 
 -- Create and simple test thesaurus dictionary
 -- More tests in configuration checks because ts_lexize()
@@ -104,6 +105,8 @@ ALTER TEXT SEARCH CONFIGURATION synonym_tst ALTER MAPPING FOR
 
 SELECT to_tsvector('synonym_tst', 'Postgresql is often called as postgres or pgsql and pronounced as postgre');
 SELECT to_tsvector('synonym_tst', 'Most common mistake is to write Gogle instead of Google');
+SELECT to_tsvector('synonym_tst', 'Indexes or indices - Which is right plural form of index?');
+SELECT to_tsquery('synonym_tst', 'Index & indices');
 
 -- test thesaurus in configuration
 -- see thesaurus_sample.ths to understand 'odd' resulting tsvector