X-Git-Url: https://git.heureux-cyclage.org/?a=blobdiff_plain;f=includes%2FSearchEngine.php;h=72e0635c6e082534da95411fb33f1f5f1ef75f58;hb=f9da6c460b6f4cfd457b0ebf1a6e7a347755706b;hp=c3b38519a7f3e1085fe52df29a13c8ce57a39e75;hpb=ba78b052b03dfe8fb23aeae9d9d423f078f59d6c;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/SearchEngine.php b/includes/SearchEngine.php
index c3b38519a7..72e0635c6e 100644
--- a/includes/SearchEngine.php
+++ b/includes/SearchEngine.php
@@ -1,12 +1,14 @@
 <?php
 /**
- * Contain a class for special pages
- * @package MediaWiki
- * @subpackage Search
+ * @defgroup Search Search
+ *
+ * @file
+ * @ingroup Search
  */
 
 /**
- * @package MediaWiki
+ * Contain a class for special pages
+ * @ingroup Search
  */
 class SearchEngine {
 	var $limit = 10;
@@ -40,78 +42,75 @@ class SearchEngine {
 	function searchTitle( $term ) {
 		return null;
 	}
-
+	
 	/**
 	 * If an exact title match can be find, or a very slightly close match,
 	 * return the title. If no match, returns NULL.
 	 *
-	 * @static
 	 * @param string $term
 	 * @return Title
-	 * @private
 	 */
-	function getNearMatch( $term ) {
-		# Exact match? No need to look further.
-		$title = Title::newFromText( $term );
-		if (is_null($title))
-			return NULL;
+	public static function getNearMatch( $searchterm ) {
+		global $wgContLang;
 
-		if ( $title->getNamespace() == NS_SPECIAL || $title->exists() ) {
-			return $title;
-		}
+		$allSearchTerms = array($searchterm);
 
-		# Now try all lower case (i.e. first letter capitalized)
-		#
-		$title = Title::newFromText( strtolower( $term ) );
-		if ( $title->exists() ) {
-			return $title;
+		if($wgContLang->hasVariants()){
+			$allSearchTerms = array_merge($allSearchTerms,$wgContLang->convertLinkToAllVariants($searchterm));
 		}
 
-		# Now try capitalized string
-		#
-		$title = Title::newFromText( ucwords( strtolower( $term ) ) );
-		if ( $title->exists() ) {
-			return $title;
-		}
+		foreach($allSearchTerms as $term){
 
-		# Now try all upper case
-		#
-		$title = Title::newFromText( strtoupper( $term ) );
-		if ( $title->exists() ) {
-			return $title;
-		}
+			# Exact match? No need to look further.
+			$title = Title::newFromText( $term );
+			if (is_null($title))
+				return NULL;
 
-		# Now try Word-Caps-Breaking-At-Word-Breaks, for hyphenated names etc
-		$title = Title::newFromText( preg_replace_callback(
-			'/\b([\w\x80-\xff]+)\b/',
-			create_function( '$matches', '
-				global $wgContLang;
-				return $wgContLang->ucfirst($matches[1]);
-				' ),
-			$term ) );
-		if ( $title->exists() ) {
-			return $title;
-		}
+			if ( $title->getNamespace() == NS_SPECIAL || $title->isExternal() 
+			     || $title->exists() ) {
+				return $title;
+			}
 
-		global $wgCapitalLinks, $wgContLang;
-		if( !$wgCapitalLinks ) {
-			// Catch differs-by-first-letter-case-only
-			$title = Title::newFromText( $wgContLang->ucfirst( $term ) );
-			if ( $title->exists() ) {
+			# Now try all lower case (i.e. first letter capitalized)
+			#
+			$title = Title::newFromText( $wgContLang->lc( $term ) );
+			if ( $title && $title->exists() ) {
 				return $title;
 			}
-			$title = Title::newFromText( $wgContLang->lcfirst( $term ) );
-			if ( $title->exists() ) {
+
+			# Now try capitalized string
+			#
+			$title = Title::newFromText( $wgContLang->ucwords( $term ) );
+			if ( $title && $title->exists() ) {
+				return $title;
+			}
+
+			# Now try all upper case
+			#
+			$title = Title::newFromText( $wgContLang->uc( $term ) );
+			if ( $title && $title->exists() ) {
+				return $title;
+			}
+
+			# Now try Word-Caps-Breaking-At-Word-Breaks, for hyphenated names etc
+			$title = Title::newFromText( $wgContLang->ucwordbreaks($term) );
+			if ( $title && $title->exists() ) {
+				return $title;
+			}
+
+			// Give hooks a chance at better match variants
+			$title = null;
+			if( !wfRunHooks( 'SearchGetNearMatch', array( $term, &$title ) ) ) {
 				return $title;
 			}
 		}
 
-		$title = Title::newFromText( $term );
+		$title = Title::newFromText( $searchterm );
 
 		# Entering an IP address goes to the contributions page
 		if ( ( $title->getNamespace() == NS_USER && User::isIP($title->getText() ) )
-			|| User::isIP( trim( $term ) ) ) {
-			return Title::makeTitle( NS_SPECIAL, "Contributions/" . $title->getDbkey() );
+			|| User::isIP( trim( $searchterm ) ) ) {
+			return SpecialPage::getTitleFor( 'Contributions', $title->getDBkey() );
 		}
 
 
@@ -120,15 +119,32 @@ class SearchEngine {
 			return $title;
 		}
 
+		# Go to images that exist even if there's no local page.
+		# There may have been a funny upload, or it may be on a shared
+		# file repository such as Wikimedia Commons.
+		if( $title->getNamespace() == NS_IMAGE ) {
+			$image = wfFindFile( $title );
+			if( $image ) {
+				return $title;
+			}
+		}
+
+		# MediaWiki namespace? Page may be "implied" if not customized.
+		# Just return it, with caps forced as the message system likes it.
+		if( $title->getNamespace() == NS_MEDIAWIKI ) {
+			return Title::makeTitle( NS_MEDIAWIKI, $wgContLang->ucfirst( $title->getText() ) );
+		}
+
 		# Quoted term? Try without the quotes...
-		if( preg_match( '/^"([^"]+)"$/', $term, $matches ) ) {
+		$matches = array();
+		if( preg_match( '/^"([^"]+)"$/', $searchterm, $matches ) ) {
 			return SearchEngine::getNearMatch( $matches[1] );
 		}
 
 		return NULL;
 	}
 
-	function legalSearchChars() {
+	public static function legalSearchChars() {
 		return "A-Za-z_'0-9\\x80-\\xFF\\-";
 	}
 
@@ -156,12 +172,42 @@ class SearchEngine {
 		$this->namespaces = $namespaces;
 	}
 
+	/**
+	 * Parse some common prefixes: all (search everything)
+	 * or namespace names
+	 *
+	 * @param string $query
+	 */
+	function replacePrefixes( $query ){
+		global $wgContLang;
+
+		if( strpos($query,':') === false )
+			return $query; // nothing to do
+
+		$parsed = $query;
+		$allkeyword = wfMsgForContent('searchall').":";
+		if( strncmp($query, $allkeyword, strlen($allkeyword)) == 0 ){
+			$this->namespaces = null;
+			$parsed = substr($query,strlen($allkeyword));
+		} else if( strpos($query,':') !== false ) {
+			$prefix = substr($query,0,strpos($query,':'));
+			$index = $wgContLang->getNsIndex($prefix);
+			if($index !== false){
+				$this->namespaces = array($index);
+				$parsed = substr($query,strlen($prefix)+1);
+			}
+		}
+		if(trim($parsed) == '')
+			return $query; // prefix was the whole query
+
+		return $parsed;
+	}
+
 	/**
 	 * Make a list of searchable namespaces and their canonical names.
 	 * @return array
-	 * @access public
 	 */
-	function searchableNamespaces() {
+	public static function searchableNamespaces() {
 		global $wgContLang;
 		$arr = array();
 		foreach( $wgContLang->getNamespaces() as $ns => $name ) {
@@ -171,6 +217,51 @@ class SearchEngine {
 		}
 		return $arr;
 	}
+	
+	/**
+	 * Extract default namespaces to search from the given user's
+	 * settings, returning a list of index numbers.
+	 *
+	 * @param User $user
+	 * @return array
+	 * @static 
+	 */
+	public static function userNamespaces( &$user ) {
+		$arr = array();
+		foreach( SearchEngine::searchableNamespaces() as $ns => $name ) {
+			if( $user->getOption( 'searchNs' . $ns ) ) {
+				$arr[] = $ns;
+			}
+		}
+		return $arr;
+	}
+	
+	/**
+	 * Find snippet highlight settings for a given user
+	 *
+	 * @param User $user
+	 * @return array contextlines, contextchars 
+	 * @static
+	 */
+	public static function userHighlightPrefs( &$user ){
+		//$contextlines = $user->getOption( 'contextlines',  5 );
+		//$contextchars = $user->getOption( 'contextchars', 50 );
+		$contextlines = 2; // Hardcode this. Old defaults sucked. :)
+		$contextchars = 75; // same as above.... :P
+		return array($contextlines, $contextchars);
+	}
+	
+	/**
+	 * An array of namespaces indexes to be searched by default
+	 * 
+	 * @return array 
+	 * @static
+	 */
+	public static function defaultNamespaces(){
+		global $wgNamespacesToBeSearchedDefault;
+		
+		return array_keys($wgNamespacesToBeSearchedDefault, true);
+	}
 
 	/**
 	 * Return a 'cleaned up' search string
@@ -187,20 +278,16 @@ class SearchEngine {
 	 * active database backend, and return a configured instance.
 	 *
 	 * @return SearchEngine
-	 * @private
 	 */
-	function create() {
-		global $wgDBtype, $wgSearchType;
+	public static function create() {
+		global $wgSearchType;
+		$dbr = wfGetDB( DB_SLAVE );
 		if( $wgSearchType ) {
 			$class = $wgSearchType;
-		} elseif( $wgDBtype == 'mysql' ) {
-			$class = 'SearchMySQL4';
-		} else if ( $wgDBtype == 'postgres' ) {
-			$class = 'SearchPostgres';
 		} else {
-			$class = 'SearchEngineDummy';
+			$class = $dbr->getSearchEngine();
 		}
-		$search = new $class( wfGetDB( DB_SLAVE ) );
+		$search = new $class( $dbr );
 		$search->setLimitOffset(0,0);
 		return $search;
 	}
@@ -226,12 +313,45 @@ class SearchEngine {
 	 * @param string $title
 	 * @abstract
 	 */
-    function updateTitle( $id, $title ) {
+	function updateTitle( $id, $title ) {
 		// no-op
-    }
+	}
+	
+	/**
+	 * Get OpenSearch suggestion template
+	 * 
+	 * @return string
+	 * @static 
+	 */
+	public static function getOpenSearchTemplate() {
+		global $wgOpenSearchTemplate, $wgServer, $wgScriptPath;
+		if($wgOpenSearchTemplate)		
+			return $wgOpenSearchTemplate;
+		else{ 
+			$ns = implode(',',SearchEngine::defaultNamespaces());
+			if(!$ns) $ns = "0";
+			return $wgServer . $wgScriptPath . '/api.php?action=opensearch&search={searchTerms}&namespace='.$ns;
+		}
+	}
+	
+	/**
+	 * Get internal MediaWiki Suggest template 
+	 * 
+	 * @return string
+	 * @static
+	 */
+	public static function getMWSuggestTemplate() {
+		global $wgMWSuggestTemplate, $wgServer, $wgScriptPath;
+		if($wgMWSuggestTemplate)		
+			return $wgMWSuggestTemplate;
+		else 
+			return $wgServer . $wgScriptPath . '/api.php?action=opensearch&search={searchTerms}&namespace={namespaces}';
+	}
 }
 
-/** @package MediaWiki */
+/**
+ * @ingroup Search
+ */
 class SearchResultSet {
 	/**
 	 * Fetch an array of regular expression fragments for matching
@@ -285,15 +405,47 @@ class SearchResultSet {
 	}
 
 	/**
-	 * Some search modes return a suggested alternate term if there are
-	 * no exact hits. Check hasSuggestion() first.
+	 * @return string suggested query, null if none
+	 */
+	function getSuggestionQuery(){
+		return null;
+	}
+
+	/**
+	 * @return string highlighted suggested query, '' if none
+	 */
+	function getSuggestionSnippet(){
+		return '';
+	}
+	
+	/**
+	 * Return information about how and from where the results were fetched,
+	 * should be useful for diagnostics and debugging 
 	 *
 	 * @return string
-	 * @access public
 	 */
-	function getSuggestion() {
-		return '';
+	function getInfo() {
+		return null;
+	}
+	
+	/**
+	 * Return a result set of hits on other (multiple) wikis associated with this one
+	 *
+	 * @return SearchResultSet
+	 */
+	function getInterwikiResults() {
+		return null;
+	}
+	
+	/**
+	 * Check if there are results on other wikis
+	 *
+	 * @return boolean
+	 */
+	function hasInterwikiResults() {
+		return $this->getInterwikiResults() != null;
 	}
+	
 
 	/**
 	 * Fetches next search result, or false.
@@ -304,12 +456,62 @@ class SearchResultSet {
 	function next() {
 		return false;
 	}
+
+	/**
+	 * Frees the result set, if applicable.
+	 * @ access public
+	 */
+	function free() {
+		// ...
+	}
+}
+
+
+/**
+ * @ingroup Search
+ */
+class SearchResultTooMany {
+	## Some search engines may bail out if too many matches are found
 }
 
-/** @package MediaWiki */
+
+/**
+ * @fixme This class is horribly factored. It would probably be better to have
+ * a useful base class to which you pass some standard information, then let
+ * the fancy self-highlighters extend that.
+ * @ingroup Search
+ */
 class SearchResult {
+	var $mRevision = null;
+
 	function SearchResult( $row ) {
 		$this->mTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
+		if( !is_null($this->mTitle) )
+			$this->mRevision = Revision::newFromTitle( $this->mTitle );
+	}
+	
+	/**
+	 * Check if this is result points to an invalid title
+	 *
+	 * @return boolean
+	 * @access public
+	 */
+	function isBrokenTitle(){
+		if( is_null($this->mTitle) )
+			return true;
+		return false;
+	}
+	
+	/**
+	 * Check if target page is missing, happens when index is out of date
+	 * 
+	 * @return boolean
+	 * @access public
+	 */
+	function isMissingRevision(){
+		if( !$this->mRevision )
+			return true;
+		return false;
 	}
 
 	/**
@@ -326,20 +528,607 @@ class SearchResult {
 	function getScore() {
 		return null;
 	}
+
+	/**
+	 * Lazy initialization of article text from DB
+	 */
+	protected function initText(){
+		if( !isset($this->mText) ){
+			$this->mText = $this->mRevision->getText();
+		}
+	}
+	
+	/**
+	 * @param array $terms terms to highlight
+	 * @return string highlighted text snippet, null (and not '') if not supported 
+	 */
+	function getTextSnippet($terms){
+		global $wgUser, $wgAdvancedSearchHighlighting;
+		$this->initText();
+		list($contextlines,$contextchars) = SearchEngine::userHighlightPrefs($wgUser);
+		$h = new SearchHighlighter();
+		if( $wgAdvancedSearchHighlighting )
+			return $h->highlightText( $this->mText, $terms, $contextlines, $contextchars );
+		else
+			return $h->highlightSimple( $this->mText, $terms, $contextlines, $contextchars );
+	}
+	
+	/**
+	 * @param array $terms terms to highlight
+	 * @return string highlighted title, '' if not supported
+	 */
+	function getTitleSnippet($terms){
+		return '';
+	}
+
+	/**
+	 * @param array $terms terms to highlight
+	 * @return string highlighted redirect name (redirect to this page), '' if none or not supported
+	 */
+	function getRedirectSnippet($terms){
+		return '';
+	}
+
+	/**
+	 * @return Title object for the redirect to this page, null if none or not supported
+	 */
+	function getRedirectTitle(){
+		return null;
+	}
+
+	/**
+	 * @return string highlighted relevant section name, null if none or not supported
+	 */
+	function getSectionSnippet(){
+		return '';
+	}
+
+	/**
+	 * @return Title object (pagename+fragment) for the section, null if none or not supported
+	 */
+	function getSectionTitle(){
+		return null;
+	}
+
+	/**
+	 * @return string timestamp
+	 */
+	function getTimestamp(){
+		return $this->mRevision->getTimestamp();
+	}
+
+	/**
+	 * @return int number of words
+	 */
+	function getWordCount(){
+		$this->initText();
+		return str_word_count( $this->mText );
+	}
+
+	/**
+	 * @return int size in bytes
+	 */
+	function getByteSize(){
+		$this->initText();
+		return strlen( $this->mText );
+	}
+	
+	/**
+	 * @return boolean if hit has related articles
+	 */
+	function hasRelated(){
+		return false;
+	}
+	
+	/**
+	 * @return interwiki prefix of the title (return iw even if title is broken)
+	 */
+	function getInterwikiPrefix(){
+		return '';
+	}
 }
 
 /**
- * @package MediaWiki
+ * Highlight bits of wikitext
+ * 
+ * @ingroup Search
  */
-class SearchEngineDummy {
-	function search( $term ) {
-		return null;
+class SearchHighlighter {	
+	var $mCleanWikitext = true;
+	
+	function SearchHighlighter($cleanupWikitext = true){
+		$this->mCleanWikitext = $cleanupWikitext;
+	}
+	
+	/**
+	 * Default implementation of wikitext highlighting
+	 *
+	 * @param string $text
+	 * @param array $terms Terms to highlight (unescaped)
+	 * @param int $contextlines
+	 * @param int $contextchars
+	 * @return string
+	 */
+	public function highlightText( $text, $terms, $contextlines, $contextchars ) {
+		global $wgLang, $wgContLang;
+		global $wgSearchHighlightBoundaries;
+		$fname = __METHOD__;
+		
+		if($text == '')
+			return '';
+				
+		// spli text into text + templates/links/tables
+		$spat = "/(\\{\\{)|(\\[\\[[^\\]:]+:)|(\n\\{\\|)";
+		// first capture group is for detecting nested templates/links/tables/references
+		$endPatterns = array(
+			1 => '/(\{\{)|(\}\})/', // template
+			2 => '/(\[\[)|(\]\])/', // image
+			3 => "/(\n\\{\\|)|(\n\\|\\})/"); // table
+			 
+		// FIXME: this should prolly be a hook or something
+		if(function_exists('wfCite')){
+			$spat .= '|(<ref>)'; // references via cite extension
+			$endPatterns[4] = '/(<ref>)|(<\/ref>)/';
+		}
+		$spat .= '/';
+		$textExt = array(); // text extracts
+		$otherExt = array();  // other extracts
+		wfProfileIn( "$fname-split" );
+		$start = 0;
+		$textLen = strlen($text);
+		$count = 0; // sequence number to maintain ordering
+		while( $start < $textLen ){
+			// find start of template/image/table
+			if( preg_match( $spat, $text, $matches, PREG_OFFSET_CAPTURE, $start ) ){
+				$epat = '';	
+				foreach($matches as $key => $val){
+					if($key > 0 && $val[1] != -1){
+						if($key == 2){
+							// see if this is an image link
+							$ns = substr($val[0],2,-1);
+							if( $wgContLang->getNsIndex($ns) != NS_IMAGE )
+								break;
+							
+						}
+						$epat = $endPatterns[$key];
+						$this->splitAndAdd( $textExt, $count, substr( $text, $start, $val[1] - $start ) );						
+						$start = $val[1];
+						break;
+					}
+				}
+				if( $epat ){
+					// find end (and detect any nested elements)
+					$level = 0; 
+					$offset = $start + 1;
+					$found = false;
+					while( preg_match( $epat, $text, $endMatches, PREG_OFFSET_CAPTURE, $offset ) ){
+						if( array_key_exists(2,$endMatches) ){
+							// found end
+							if($level == 0){
+								$len = strlen($endMatches[2][0]);
+								$off = $endMatches[2][1];
+								$this->splitAndAdd( $otherExt, $count, 
+									substr( $text, $start, $off + $len  - $start ) );
+								$start = $off + $len;
+								$found = true;
+								break;
+							} else{
+								// end of nested element
+								$level -= 1;
+							}
+						} else{
+							// nested
+							$level += 1;
+						}
+						$offset = $endMatches[0][1] + strlen($endMatches[0][0]);
+					}
+					if( ! $found ){
+						// couldn't find appropriate closing tag, skip
+						$this->splitAndAdd( $textExt, $count, substr( $text, $start, strlen($matches[0][0]) ) );
+						$start += strlen($matches[0][0]);
+					}
+					continue;
+				}
+			}
+			// else: add as text extract
+			$this->splitAndAdd( $textExt, $count, substr($text,$start) );
+			break;
+		}
+		
+		$all = $textExt + $otherExt; // these have disjunct key sets
+		
+		wfProfileOut( "$fname-split" );
+		
+		// prepare regexps
+		foreach( $terms as $index => $term ) {
+			$terms[$index] = preg_quote( $term, '/' );			
+			// manually do upper/lowercase stuff for utf-8 since PHP won't do it
+			if(preg_match('/[\x80-\xff]/', $term) ){
+				$terms[$index] = preg_replace_callback('/./us',array($this,'caseCallback'),$terms[$index]);
+			}
+			
+			
+		}
+		$anyterm = implode( '|', $terms );
+		$phrase = implode("$wgSearchHighlightBoundaries+", $terms );
+
+		// FIXME: a hack to scale contextchars, a correct solution
+		// would be to have contextchars actually be char and not byte
+		// length, and do proper utf-8 substrings and lengths everywhere,
+		// but PHP is making that very hard and unclean to implement :(
+		$scale = strlen($anyterm) / mb_strlen($anyterm);
+		$contextchars = intval( $contextchars * $scale );
+		
+		$patPre = "(^|$wgSearchHighlightBoundaries)";
+		$patPost = "($wgSearchHighlightBoundaries|$)"; 
+		
+		$pat1 = "/(".$phrase.")/ui";
+		$pat2 = "/$patPre(".$anyterm.")$patPost/ui";
+		
+		wfProfileIn( "$fname-extract" );
+		
+		$left = $contextlines;
+
+		$snippets = array();
+		$offsets = array();		
+		
+		// show beginning only if it contains all words
+		$first = 0;
+		$firstText = '';
+		foreach($textExt as $index => $line){
+			if(strlen($line)>0 && $line[0] != ';' && $line[0] != ':'){
+				$firstText = $this->extract( $line, 0, $contextchars * $contextlines );
+				$first = $index;
+				break;
+			}
+		}
+		if( $firstText ){
+			$succ = true;
+			// check if first text contains all terms
+			foreach($terms as $term){
+				if( ! preg_match("/$patPre".$term."$patPost/ui", $firstText) ){
+					$succ = false;
+					break;
+				}
+			}
+			if( $succ ){
+				$snippets[$first] = $firstText;
+				$offsets[$first] = 0; 
+			}
+		}
+		if( ! $snippets ) {		
+			// match whole query on text 
+			$this->process($pat1, $textExt, $left, $contextchars, $snippets, $offsets);
+			// match whole query on templates/tables/images
+			$this->process($pat1, $otherExt, $left, $contextchars, $snippets, $offsets);
+			// match any words on text
+			$this->process($pat2, $textExt, $left, $contextchars, $snippets, $offsets);
+			// match any words on templates/tables/images
+			$this->process($pat2, $otherExt, $left, $contextchars, $snippets, $offsets);
+			
+			ksort($snippets);
+		}
+		
+		// add extra chars to each snippet to make snippets constant size
+		$extended = array();						
+		if( count( $snippets ) == 0){
+			// couldn't find the target words, just show beginning of article
+			$targetchars = $contextchars * $contextlines;
+			$snippets[$first] = '';
+			$offsets[$first] = 0;
+		} else{
+			// if begin of the article contains the whole phrase, show only that !!	
+			if( array_key_exists($first,$snippets) && preg_match($pat1,$snippets[$first]) 
+			    && $offsets[$first] < $contextchars * 2 ){
+				$snippets = array ($first => $snippets[$first]);
+			}
+			
+			// calc by how much to extend existing snippets
+			$targetchars = intval( ($contextchars * $contextlines) / count ( $snippets ) );
+		}  
+
+		foreach($snippets as $index => $line){
+			$extended[$index] = $line;
+			$len = strlen($line);
+			if( $len < $targetchars - 20 ){
+				// complete this line
+				if($len < strlen( $all[$index] )){
+					$extended[$index] = $this->extract( $all[$index], $offsets[$index], $offsets[$index]+$targetchars, $offsets[$index]);
+					$len = strlen( $extended[$index] );
+				}
+				
+				// add more lines
+				$add = $index + 1;
+				while( $len < $targetchars - 20 
+				       && array_key_exists($add,$all) 
+				       && !array_key_exists($add,$snippets) ){
+				    $offsets[$add] = 0;
+				    $tt = "\n".$this->extract( $all[$add], 0, $targetchars - $len, $offsets[$add] );
+					$extended[$add] = $tt;
+					$len += strlen( $tt );
+					$add++; 					
+				}
+			} 
+		}
+		
+		//$snippets = array_map('htmlspecialchars', $extended);
+		$snippets = $extended;
+		$last = -1;
+		$extract = '';
+		foreach($snippets as $index => $line){
+			if($last == -1) 
+				$extract .= $line; // first line
+			elseif($last+1 == $index && $offsets[$last]+strlen($snippets[$last]) >= strlen($all[$last]))
+				$extract .= " ".$line; // continous lines
+			else
+				$extract .= '<b> ... </b>' . $line;
+
+			$last = $index;
+		}
+		if( $extract )
+			$extract .= '<b> ... </b>';
+		
+		$processed = array();
+		foreach($terms as $term){
+			if( ! isset($processed[$term]) ){
+				$pat3 = "/$patPre(".$term.")$patPost/ui"; // highlight word  
+				$extract = preg_replace( $pat3,
+			  		"\\1<span class='searchmatch'>\\2</span>\\3", $extract );
+				$processed[$term] = true;
+			}
+		}
+		
+		wfProfileOut( "$fname-extract" );
+		
+		return $extract;
+	}
+	
+	/**
+	 * Split text into lines and add it to extracts array
+	 *
+	 * @param array $extracts index -> $line
+	 * @param int $count
+	 * @param string $text
+	 */
+	function splitAndAdd(&$extracts, &$count, $text){
+		$split = explode( "\n", $this->mCleanWikitext? $this->removeWiki($text) : $text );
+		foreach($split as $line){
+			$tt = trim($line);
+			if( $tt )
+				$extracts[$count++] = $tt;
+		}
+	}
+	
+	/**
+	 * Do manual case conversion for non-ascii chars
+	 *
+	 * @param unknown_type $matches
+	 */
+	function caseCallback($matches){
+		global $wgContLang;
+		if( strlen($matches[0]) > 1 ){
+			return '['.$wgContLang->lc($matches[0]).$wgContLang->uc($matches[0]).']';
+		} else
+			return $matches[0];
+	}
+	
+	/**
+	 * Extract part of the text from start to end, but by
+	 * not chopping up words
+	 * @param string $text
+	 * @param int $start
+	 * @param int $end
+	 * @param int $posStart (out) actual start position
+	 * @param int $posEnd (out) actual end position
+	 * @return string  
+	 */
+	function extract($text, $start, $end, &$posStart = null, &$posEnd = null ){
+		global $wgContLang;		
+		
+		if( $start != 0)
+			$start = $this->position( $text, $start, 1 );
+		if( $end >= strlen($text) )
+			$end = strlen($text);
+		else
+			$end = $this->position( $text, $end );
+			
+		if(!is_null($posStart))
+			$posStart = $start;
+		if(!is_null($posEnd))
+			$posEnd = $end;
+		
+		if($end > $start)
+			return substr($text, $start, $end-$start);
+		else
+			return '';
+	} 
+	
+	/**
+	 * Find a nonletter near a point (index) in the text
+	 *
+	 * @param string $text
+	 * @param int $point
+	 * @param int $offset to found index
+	 * @return int nearest nonletter index, or beginning of utf8 char if none
+	 */
+	function position($text, $point, $offset=0 ){
+		$tolerance = 10;
+		$s = max( 0, $point - $tolerance );
+		$l = min( strlen($text), $point + $tolerance ) - $s;
+		$m = array();
+		if( preg_match('/[ ,.!?~!@#$%^&*\(\)+=\-\\\|\[\]"\'<>]/', substr($text,$s,$l), $m, PREG_OFFSET_CAPTURE ) ){
+			return $m[0][1] + $s + $offset;
+		} else{
+			// check if point is on a valid first UTF8 char
+			$char = ord( $text[$point] );
+			while( $char >= 0x80 && $char < 0xc0 ) {
+				// skip trailing bytes
+				$point++;
+				if($point >= strlen($text))
+					return strlen($text);
+				$char = ord( $text[$point] );
+			}
+			return $point;
+			
+		}
+	}
+	
+	/**
+	 * Search extracts for a pattern, and return snippets
+	 *
+	 * @param string $pattern regexp for matching lines
+	 * @param array $extracts extracts to search   
+	 * @param int $linesleft number of extracts to make
+	 * @param int $contextchars length of snippet
+	 * @param array $out map for highlighted snippets
+	 * @param array $offsets map of starting points of snippets
+	 * @protected
+	 */
+	function process( $pattern, $extracts, &$linesleft, &$contextchars, &$out, &$offsets ){
+		if($linesleft == 0)
+			return; // nothing to do
+		foreach($extracts as $index => $line){			
+			if( array_key_exists($index,$out) )
+				continue; // this line already highlighted
+				
+			$m = array();
+			if ( !preg_match( $pattern, $line, $m, PREG_OFFSET_CAPTURE ) )
+				continue;
+				
+			$offset = $m[0][1];
+			$len = strlen($m[0][0]);
+			if($offset + $len < $contextchars)
+				$begin = 0; 
+			elseif( $len > $contextchars)
+				$begin = $offset;
+			else
+				$begin = $offset + intval( ($len - $contextchars) / 2 );
+			
+			$end = $begin + $contextchars;
+			
+			$posBegin = $begin;
+			// basic snippet from this line
+			$out[$index] = $this->extract($line,$begin,$end,$posBegin);
+			$offsets[$index] = $posBegin;
+			$linesleft--;			
+			if($linesleft == 0)
+				return;
+		}
+	}
+	
+	/** 
+	 * Basic wikitext removal
+	 * @protected
+	 */
+	function removeWiki($text) {
+		$fname = __METHOD__;
+		wfProfileIn( $fname );
+		
+		//$text = preg_replace("/'{2,5}/", "", $text);
+		//$text = preg_replace("/\[[a-z]+:\/\/[^ ]+ ([^]]+)\]/", "\\2", $text);
+		//$text = preg_replace("/\[\[([^]|]+)\]\]/", "\\1", $text);
+		//$text = preg_replace("/\[\[([^]]+\|)?([^|]]+)\]\]/", "\\2", $text);
+		//$text = preg_replace("/\\{\\|(.*?)\\|\\}/", "", $text);
+		//$text = preg_replace("/\\[\\[[A-Za-z_-]+:([^|]+?)\\]\\]/", "", $text);
+		$text = preg_replace("/\\{\\{([^|]+?)\\}\\}/", "", $text);
+		$text = preg_replace("/\\{\\{([^|]+\\|)(.*?)\\}\\}/", "\\2", $text);
+		$text = preg_replace("/\\[\\[([^|]+?)\\]\\]/", "\\1", $text);		
+		$text = preg_replace_callback("/\\[\\[([^|]+\\|)(.*?)\\]\\]/", array($this,'linkReplace'), $text);
+		//$text = preg_replace("/\\[\\[([^|]+\\|)(.*?)\\]\\]/", "\\2", $text);
+		$text = preg_replace("/<\/?[^>]+>/", "", $text);
+		$text = preg_replace("/'''''/", "", $text);
+		$text = preg_replace("/('''|<\/?[iIuUbB]>)/", "", $text);
+		$text = preg_replace("/''/", "", $text);
+		
+		wfProfileOut( $fname );
+		return $text;
 	}
-	function setLimitOffset($l, $o) {}
-	function legalSearchChars() {}
-	function update() {}
-	function setnamespaces() {}
-	function searchtitle() {}
-	function searchtext() {}
+	
+	/**
+	 * callback to replace [[target|caption]] kind of links, if
+	 * the target is category or image, leave it
+	 *
+	 * @param array $matches
+	 */
+	function linkReplace($matches){
+		$colon = strpos( $matches[1], ':' ); 
+		if( $colon === false )
+			return $matches[2]; // replace with caption
+		global $wgContLang;
+		$ns = substr( $matches[1], 0, $colon );
+		$index = $wgContLang->getNsIndex($ns);
+		if( $index !== false && ($index == NS_IMAGE || $index == NS_CATEGORY) )
+			return $matches[0]; // return the whole thing 
+		else
+			return $matches[2];
+		
+	}
+
+	/**
+     * Simple & fast snippet extraction, but gives completely unrelevant
+     * snippets
+     *
+     * @param string $text
+     * @param array $terms
+     * @param int $contextlines
+     * @param int $contextchars
+     * @return string
+     */
+    public function highlightSimple( $text, $terms, $contextlines, $contextchars ) {
+        global $wgLang, $wgContLang;
+        $fname = __METHOD__;
+    
+        $lines = explode( "\n", $text );
+        
+        $terms = implode( '|', $terms );
+        $terms = str_replace( '/', "\\/", $terms);
+        $max = intval( $contextchars ) + 1;
+        $pat1 = "/(.*)($terms)(.{0,$max})/i";
+
+        $lineno = 0;
+
+        $extract = "";
+        wfProfileIn( "$fname-extract" );
+        foreach ( $lines as $line ) {
+            if ( 0 == $contextlines ) {
+                break;
+            }
+            ++$lineno;
+            $m = array();
+            if ( ! preg_match( $pat1, $line, $m ) ) {
+                continue;
+            }
+            --$contextlines;
+            $pre = $wgContLang->truncate( $m[1], -$contextchars, ' ... ' );
+
+            if ( count( $m ) < 3 ) {
+                $post = '';
+            } else {
+                $post = $wgContLang->truncate( $m[3], $contextchars, ' ... ' );
+            }
+
+            $found = $m[2];
+
+            $line = htmlspecialchars( $pre . $found . $post );
+            $pat2 = '/(' . $terms . ")/i";
+            $line = preg_replace( $pat2,
+              "<span class='searchmatch'>\\1</span>", $line );
+
+            $extract .= "${line}\n";
+        }
+        wfProfileOut( "$fname-extract" );
+        
+        return $extract;
+    }
+	
+}
+
+/**
+ * Dummy class to be used when non-supported Database engine is present.
+ * @fixme Dummy class should probably try something at least mildly useful,
+ * such as a LIKE search through titles.
+ * @ingroup Search
+ */
+class SearchEngineDummy extends SearchEngine {
+	// no-op
 }
-?>