xref: /dokuwiki/inc/fulltext.php (revision ece9fa7a2e2237ae9c68cc8c39521de00ac91739) 
1<?php
2/**
3 * DokuWiki fulltextsearch functions using the index
4 *
5 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
6 * @author     Andreas Gohr <andi@splitbrain.org>
7 */
8
9  if(!defined('DOKU_INC')) define('DOKU_INC',realpath(dirname(__FILE__).'/../').'/');
10  require_once(DOKU_INC.'inc/indexer.php');
11
12
13/**
14 * Wrapper around preg_quote adding the default delimiter
15 */
16function ft_preg_quote_cb($string){
17    return preg_quote($string,'/');
18}
19
20/**
21 * The fulltext search
22 *
23 * Returns a list of matching documents for the given query
24 *
25 */
26function ft_pageSearch($query,&$poswords){
27    $q = ft_queryParser($query);
28    // use this for higlighting later:
29    $poswords = str_replace('*','',join(' ',$q['and']));
30
31    // lookup all words found in the query
32    $words  = array_merge($q['and'],$q['not']);
33    if(!count($words)) return array();
34    $result = idx_lookup($words);
35
36    // merge search results with query
37    foreach($q['and'] as $pos => $w){
38        $q['and'][$pos] = $result[$w];
39    }
40    // create a list of unwanted docs
41    $not = array();
42    foreach($q['not'] as $pos => $w){
43        $not = array_merge($not,array_keys($result[$w]));
44    }
45
46    // combine and-words
47    if(count($q['and']) > 1){
48        $docs = ft_resultCombine($q['and']);
49    }else{
50        $docs = $q['and'][0];
51    }
52    if(!count($docs)) return array();
53
54    // create a list of hidden pages in the result
55    $hidden = array();
56    $hidden = array_filter(array_keys($docs),'isHiddenPage');
57    $not = array_merge($not,$hidden);
58
59    // filter unmatched namespaces
60    if(!empty($q['ns'])) {
61        $pattern = implode('|^',$q['ns']);
62        foreach($docs as $key => $val) {
63            if(!preg_match('/^'.$pattern.'/',$key)) {
64                unset($docs[$key]);
65            }
66        }
67    }
68
69    // remove negative matches
70    foreach($not as $n){
71        unset($docs[$n]);
72    }
73
74    if(!count($docs)) return array();
75    // handle phrases
76    if(count($q['phrases'])){
77        //build a regexp
78        $q['phrases'] = array_map('utf8_strtolower',$q['phrases']);
79        $q['phrases'] = array_map('ft_preg_quote_cb',$q['phrases']);
80        $regex = '('.join('|',$q['phrases']).')';
81        // check the source of all documents for the exact phrases
82        foreach(array_keys($docs) as $id){
83            $text  = utf8_strtolower(rawWiki($id));
84            if(!preg_match('/'.$regex.'/usi',$text)){
85                unset($docs[$id]); // no hit - remove
86            }
87        }
88    }
89
90    if(!count($docs)) return array();
91
92    // check ACL permissions
93    foreach(array_keys($docs) as $doc){
94        if(auth_quickaclcheck($doc) < AUTH_READ){
95            unset($docs[$doc]);
96        }
97    }
98
99    if(!count($docs)) return array();
100
101    // if there are any hits left, sort them by count
102    arsort($docs);
103
104    return $docs;
105}
106
107/**
108 * Returns the backlinks for a given page
109 *
110 * Does a quick lookup with the fulltext index, then
111 * evaluates the instructions of the found pages
112 */
113function ft_backlinks($id){
114    global $conf;
115    $swfile   = DOKU_INC.'inc/lang/'.$conf['lang'].'/stopwords.txt';
116    $stopwords = @file_exists($swfile) ? file($swfile) : array();
117
118    $result = array();
119
120    // quick lookup of the pagename
121    $page    = noNS($id);
122    $matches = idx_lookup(idx_tokenizer($page,$stopwords));  // pagename may contain specials (_ or .)
123    $docs    = array_keys(ft_resultCombine(array_values($matches)));
124    $docs    = array_filter($docs,'isVisiblePage'); // discard hidden pages
125    if(!count($docs)) return $result;
126    require_once(DOKU_INC.'inc/parserutils.php');
127
128    // check metadata for matching links
129    foreach($docs as $match){
130        // metadata relation reference links are already resolved
131        $links = p_get_metadata($match,'relation references');
132        if (isset($links[$id])) $result[] = $match;
133    }
134
135    if(!count($result)) return $result;
136
137    // check ACL permissions
138    foreach(array_keys($result) as $idx){
139        if(auth_quickaclcheck($result[$idx]) < AUTH_READ){
140            unset($result[$idx]);
141        }
142    }
143
144    sort($result);
145    return $result;
146}
147
148/**
149 * Quicksearch for pagenames
150 *
151 * By default it only matches the pagename and ignores the
152 * namespace. This can be changed with the second parameter
153 *
154 * @author Andreas Gohr <andi@splitbrain.org>
155 */
156function ft_pageLookup($id,$pageonly=true){
157    global $conf;
158    $id    = preg_quote($id,'/');
159    $pages = file($conf['indexdir'].'/page.idx');
160    if($id) $pages = array_values(preg_grep('/'.$id.'/',$pages));
161
162    $cnt = count($pages);
163    for($i=0; $i<$cnt; $i++){
164        if($pageonly){
165            if(!preg_match('/'.$id.'/',noNS($pages[$i]))){
166                unset($pages[$i]);
167                continue;
168            }
169        }
170        if(!@file_exists(wikiFN($pages[$i]))){
171            unset($pages[$i]);
172            continue;
173        }
174    }
175
176    $pages = array_filter($pages,'isVisiblePage'); // discard hidden pages
177    if(!count($pages)) return array();
178
179    // check ACL permissions
180    foreach(array_keys($pages) as $idx){
181        if(auth_quickaclcheck($pages[$idx]) < AUTH_READ){
182            unset($pages[$idx]);
183        }
184    }
185
186    $pages = array_map('trim',$pages);
187    sort($pages);
188    return $pages;
189}
190
191/**
192 * Creates a snippet extract
193 *
194 * @author Andreas Gohr <andi@splitbrain.org>
195 */
196function ft_snippet($id,$poswords){
197    $poswords = preg_quote($poswords,'#');
198    $re       = '('.str_replace(' ','|',$poswords).')';
199    $text     = rawWiki($id);
200
201    $match = array();
202    $snippets = array();
203    $utf8_offset = $offset = $end = 0;
204    $len = utf8_strlen($text);
205
206    for ($cnt=3; $cnt--;) {
207      if (!preg_match('#'.$re.'#iu',$text,$match,PREG_OFFSET_CAPTURE,$offset)) break;
208
209      list($str,$idx) = $match[0];
210
211      // convert $idx (a byte offset) into a utf8 character offset
212      $utf8_idx = utf8_strlen(substr($text,0,$idx));
213      $utf8_len = utf8_strlen($str);
214
215      // establish context, 100 bytes surrounding the match string
216      // first look to see if we can go 100 either side,
217      // then drop to 50 adding any excess if the other side can't go to 50,
218      $pre = min($utf8_idx-$utf8_offset,100);
219      $post = min($len-$utf8_idx-$utf8_len,100);
220
221      if ($pre>50 && $post>50) {
222        $pre = $post = 50;
223      } else if ($pre>50) {
224        $pre = min($pre,100-$post);
225      } else if ($post>50) {
226        $post = min($post, 100-$pre);
227      } else {
228        // both are less than 50, means the context is the whole string
229        // make it so and break out of this loop - there is no need for the
230        // complex snippet calculations
231        $snippets = array($text);
232        break;
233      }
234
235      // establish context start and end points, try to append to previous
236      // context if possible
237      $start = $utf8_idx - $pre;
238      $append = ($start < $end) ? $end : false;  // still the end of the previous context snippet
239      $end = $utf8_idx + $utf8_len + $post;      // now set it to the end of this context
240
241      if ($append) {
242        $snippets[count($snippets)-1] .= utf8_substr($text,$append,$end-$append);
243      } else {
244        $snippets[] = utf8_substr($text,$start,$end-$start);
245      }
246
247      // set $offset for next match attempt
248      //   substract strlen to avoid splitting a potential search success,
249      //   this is an approximation as the search pattern may match strings
250      //   of varying length and it will fail if the context snippet
251      //   boundary breaks a matching string longer than the current match
252      $utf8_offset = $utf8_idx + $post;
253      $offset = $idx + strlen(utf8_substr($text,$utf8_idx,$post));
254      $offset = utf8_correctIdx($text,$offset);
255    }
256
257    $m = "\1";
258    $snippets = preg_replace('#'.$re.'#iu',$m.'$1'.$m,$snippets);
259    $snippet = preg_replace('#'.$m.'([^'.$m.']*?)'.$m.'#iu','<span class="search_hit">$1</span>',hsc(join('... ',$snippets)));
260
261    return $snippet;
262}
263
264/**
265 * Combine found documents and sum up their scores
266 *
267 * This function is used to combine searched words with a logical
268 * AND. Only documents available in all arrays are returned.
269 *
270 * based upon PEAR's PHP_Compat function for array_intersect_key()
271 *
272 * @param array $args An array of page arrays
273 */
274function ft_resultCombine($args){
275    $array_count = count($args);
276    if($array_count == 1){
277        return $args[0];
278    }
279
280    $result = array();
281    foreach ($args[0] as $key1 => $value1) {
282        for ($i = 1; $i !== $array_count; $i++) {
283            foreach ($args[$i] as $key2 => $value2) {
284                if ((string) $key1 === (string) $key2) {
285                    if(!isset($result[$key1])) $result[$key1] = $value1;
286                    $result[$key1] += $value2;
287                }
288            }
289        }
290    }
291    return $result;
292}
293
294/**
295 * Builds an array of search words from a query
296 *
297 * @todo support OR and parenthesises?
298 */
299function ft_queryParser($query){
300    global $conf;
301    $swfile   = DOKU_INC.'inc/lang/'.$conf['lang'].'/stopwords.txt';
302    if(@file_exists($swfile)){
303        $stopwords = file($swfile);
304    }else{
305        $stopwords = array();
306    }
307
308    $q = array();
309    $q['query']   = $query;
310    $q['ns']      = array();
311    $q['phrases'] = array();
312    $q['and']     = array();
313    $q['not']     = array();
314
315    // strip namespace from query
316    if(preg_match('/([^@]*)@(.*)/',$query,$match))  {
317        $query = $match[1];
318        $q['ns'] = explode('@',preg_replace("/ /",'',$match[2]));
319    }
320
321    // handle phrase searches
322    while(preg_match('/"(.*?)"/',$query,$match)){
323        $q['phrases'][] = $match[1];
324        $q['and'] = array_merge(idx_tokenizer($match[0],$stopwords));
325        $query = preg_replace('/"(.*?)"/','',$query,1);
326    }
327
328    $words = explode(' ',$query);
329    foreach($words as $w){
330        if($w{0} == '-'){
331            $token = idx_tokenizer($w,$stopwords,true);
332            if(count($token)) $q['not'] = array_merge($q['not'],$token);
333        }else{
334            // asian "words" need to be searched as phrases
335            if(@preg_match_all('/('.IDX_ASIAN.'+)/u',$w,$matches)){
336                $q['phrases'] = array_merge($q['phrases'],$matches[1]);
337
338            }
339            $token = idx_tokenizer($w,$stopwords,true);
340            if(count($token)) $q['and'] = array_merge($q['and'],$token);
341        }
342    }
343
344    return $q;
345}
346
347//Setup VIM: ex: et ts=4 enc=utf-8 :
348