includes/SearchEngine.php

   1 <?php
   2 # See search.doc
   3
   4 define( "MW_SEARCH_OK", true );
   5 define( "MW_SEARCH_BAD_QUERY", false );
   6
   7 class SearchEngine {
   8         /* private */ var $rawText, $filteredText, $searchTerms;
   9         /* private */ var $titleCond, $textCond;
  10
  11         var $doSearchRedirects = true;
  12         var $addToQuery = array();
  13         var $namespacesToSearch = array();
  14         var $alternateTitle;
  15         var $allTitles = false;
  16
  17         function SearchEngine( $text ) {
  18                 $this->rawText = trim( $text );
  19
  20                 # We display the query, so let's strip it for safety
  21                 #
  22                 global $wgDBmysql4;
  23                 $lc = SearchEngine::legalSearchChars() . "()";
  24                 if( $wgDBmysql4 ) {
  25                         $lc .= "\"~<>*+-";
  26                 }
  27                 $this->filteredText = trim( preg_replace( "/[^{$lc}]/", " ", $text ) );
  28                 $this->searchTerms = array();
  29                 $this->strictMatching = true; # Google-style, add '+' on all terms
  30
  31                 $this->db =& wfGetDB( DB_SLAVE );
  32         }
  33
  34         # Return a partial WHERE clause to limit the search to the given namespaces
  35         function queryNamespaces() {
  36                 $namespaces = implode( ",", $this->namespacesToSearch );
  37                 if ($namespaces == "") {
  38                         $namespaces = "0";
  39                 }
  40                 return "AND cur_namespace IN (" . $namespaces . ")";
  41         }
  42
  43         # Return a partial WHERE clause to include or exclude redirects from results
  44         function searchRedirects() {
  45                 if ( $this->doSearchRedirects ) {
  46                         return "";
  47                 } else {
  48                         return "AND cur_is_redirect=0 ";
  49                 }
  50         }
  51
  52         /* private */ function initNamespaceCheckbox( $i )
  53         {
  54                 global $wgUser, $wgNamespacesToBeSearchedDefault;
  55
  56                 if ($wgUser->getID()) {
  57                         // User is logged in so we retrieve his default namespaces
  58                         return $wgUser->getOption( "searchNs".$i );
  59                 } else {
  60                         // User is not logged in so we give him the global default namespaces
  61                         return !empty($wgNamespacesToBeSearchedDefault[ $i ]);
  62                 }
  63         }
  64
  65         # Display the "power search" footer. Does not actually perform the search,
  66         # that is done by showResults()
  67         function powersearch() {
  68                 global $wgUser, $wgOut, $wgLang, $wgTitle, $wgRequest;
  69                 $sk =& $wgUser->getSkin();
  70
  71                 $search                 = $this->rawText;
  72                 $searchx                = $wgRequest->getVal( 'searchx' );
  73                 $listredirs             = $wgRequest->getVal( 'redirs' );
  74
  75                 $ret = wfMsg("powersearchtext"); # Text to be returned
  76                 $tempText = ""; # Temporary text, for substitution into $ret
  77
  78                 if( isset( $_REQUEST["searchx"] ) ) {
  79                         $this->addToQuery["searchx"] = "1";
  80                 }
  81
  82                 # Do namespace checkboxes
  83                 $namespaces = $wgLang->getNamespaces();
  84                 foreach ( $namespaces as $i => $namespace ) {
  85                         # Skip virtual namespaces
  86                         if ( $i < 0 ) {
  87                                 continue;
  88                         }
  89
  90                         $formVar = "ns$i";
  91
  92                         # Initialise checkboxValues, either from defaults or from
  93                         # a previous invocation
  94                         if ( !isset( $searchx ) ) {
  95                                 $checkboxValue = $this->initNamespaceCheckbox( $i );
  96                         } else {
  97                                 $checkboxValue = $wgRequest->getVal( $formVar );
  98                         }
  99
 100                         $checked = "";
 101                         if ( $checkboxValue == 1 ) {
 102                                 $checked = " checked='checked'";
 103                                 $this->addToQuery["ns{$i}"] = 1;
 104                                 array_push( $this->namespacesToSearch, $i );
 105                         }
 106                         $name = str_replace( "_", " ", $namespaces[$i] );
 107                         if ( "" == $name ) {
 108                                 $name = wfMsg( "blanknamespace" );
 109                         }
 110
 111                         if ( $tempText !== "" ) {
 112                                 $tempText .= " ";
 113                         }
 114                         $tempText .= "<input type='checkbox' value=\"1\" name=\"" .
 115                           "ns{$i}\"{$checked} />{$name}\n";
 116                 }
 117                 $ret = str_replace ( "$1", $tempText, $ret );
 118
 119                 # List redirects checkbox
 120
 121                 $checked = "";
 122                 if ( $listredirs == 1 ) {
 123                         $this->addToQuery["redirs"] = 1;
 124                         $checked = " checked='checked'";
 125                 }
 126                 $tempText = "<input type='checkbox' value='1' name=\"redirs\"{$checked} />\n";
 127                 $ret = str_replace( "$2", $tempText, $ret );
 128
 129                 # Search field
 130
 131                 $tempText = "<input type='text' name=\"search\" value=\"" .
 132                         htmlspecialchars( $search ) ."\" width='80' />\n";
 133         $ret = str_replace( "$3", $tempText, $ret );
 134
 135                 # Searchx button
 136
 137                 $tempText = "<input type='submit' name=\"searchx\" value=\"" .
 138                   wfMsg("powersearch") . "\" />\n";
 139                 $ret = str_replace( "$9", $tempText, $ret );
 140
 141                 $action = $sk->escapeSearchLink();
 142                 $ret = "<br /><br />\n<form id=\"powersearch\" method=\"get\" " .
 143                   "action=\"$action\">\n{$ret}\n</form>\n";
 144
 145                 if ( isset ( $searchx ) ) {
 146                         if ( ! $listredirs ) {
 147                                 $this->doSearchRedirects = false;
 148                         }
 149                 }
 150                 return $ret;
 151         }
 152
 153         function setupPage() {
 154                 global $wgOut;
 155                 $wgOut->setPageTitle( wfMsg( "searchresults" ) );
 156                 $wgOut->setSubtitle( wfMsg( "searchquery", htmlspecialchars( $this->rawText ) ) );
 157                 $wgOut->setArticleRelated( false );
 158                 $wgOut->setRobotpolicy( "noindex,nofollow" );
 159         }
 160
 161         # Perform the search and construct the results page
 162         function showResults() {
 163                 global $wgUser, $wgTitle, $wgOut, $wgLang;
 164                 global $wgDisableTextSearch, $wgInputEncoding;
 165                 $fname = "SearchEngine::showResults";
 166
 167                 $search = $this->rawText;
 168
 169                 $powersearch = $this->powersearch(); /* Need side-effects here? */
 170
 171                 $this->setupPage();
 172
 173                 $sk = $wgUser->getSkin();
 174                 $wgOut->addWikiText( wfMsg( "searchresulttext" ) );
 175
 176                 if ( !$this->parseQuery() ) {
 177                         $wgOut->addWikiText(
 178                                 "==" . wfMsg( "badquery" ) . "==\n" .
 179                                 wfMsg( "badquerytext" ) );
 180                         return;
 181                 }
 182                 list( $limit, $offset ) = wfCheckLimits( 20, "searchlimit" );
 183
 184                 if ( $wgDisableTextSearch ) {
 185                         $wgOut->addHTML( wfMsg( "searchdisabled" ) );
 186                         $wgOut->addHTML( wfMsg( "googlesearch",
 187                                 htmlspecialchars( $this->rawText ),
 188                                 htmlspecialchars( $wgInputEncoding ) ) );
 189                         return;
 190                 }
 191
 192                 $titleMatches = $this->getMatches( $this->titleCond, $limit, $offset );
 193                 $textMatches = $this->getMatches( $this->textCond, $limit, $offset );
 194
 195                 $sk = $wgUser->getSkin();
 196
 197                 $num = count( $titleMatches ) + count( $textMatches );
 198                 if ( $num >= $limit ) {
 199                         $top = wfShowingResults( $offset, $limit );
 200                 } else {
 201                         $top = wfShowingResultsNum( $offset, $limit, $num );
 202                 }
 203                 $wgOut->addHTML( "<p>{$top}</p>\n" );
 204
 205                 # For powersearch
 206                 $a2l = "";
 207                 $akk = array_keys( $this->addToQuery );
 208                 foreach ( $akk AS $ak ) {
 209                         $a2l .= "&{$ak}={$this->addToQuery[$ak]}" ;
 210                 }
 211
 212                 $prevnext = wfViewPrevNext( $offset, $limit, "",
 213                   "search=" . wfUrlencode( $this->filteredText ) . $a2l );
 214                 $wgOut->addHTML( "<br />{$prevnext}\n" );
 215
 216                 $foundsome = $this->showMatches( $titleMatches, $offset, "notitlematches", "titlematches" )
 217                                   || $this->showMatches( $textMatches,  $offset, "notextmatches",  "textmatches"  );
 218
 219                 if ( !$foundsome ) {
 220                         $wgOut->addWikiText( wfMsg( "nonefound" ) );
 221                 }
 222                 $wgOut->addHTML( "<p>{$prevnext}</p>\n" );
 223                 $wgOut->addHTML( $powersearch );
 224         }
 225
 226         function legalSearchChars() {
 227                 $lc = "A-Za-z_'0-9\\x80-\\xFF\\-";
 228                 return $lc;
 229         }
 230
 231         function parseQuery() {
 232                 global $wgDBmysql4;
 233                 if( $wgDBmysql4 ) {
 234                         # Use cleaner boolean search if available
 235                         return $this->parseQuery4();
 236                 } else {
 237                         # Fall back to ugly hack with multiple search clauses
 238                         return $this->parseQuery3();
 239                 }
 240         }
 241
 242         function parseQuery3() {
 243                 global $wgDBminWordLen, $wgLang;
 244
 245                 # on non mysql4 database: get list of words we don't want to search for
 246                 require_once( "FulltextStoplist.php" );
 247
 248                 $lc = SearchEngine::legalSearchChars() . "()";
 249                 $q = preg_replace( "/([()])/", " \\1 ", $this->filteredText );
 250                 $q = preg_replace( "/\\s+/", " ", $q );
 251                 $w = explode( " ", trim( $q ) );
 252
 253                 $last = $cond = "";
 254                 foreach ( $w as $word ) {
 255                         $word = $wgLang->stripForSearch( $word );
 256                         if ( "and" == $word || "or" == $word || "not" == $word
 257                           || "(" == $word || ")" == $word ) {
 258                                 $cond .= " " . strtoupper( $word );
 259                                 $last = "";
 260                         } else if ( strlen( $word ) < $wgDBminWordLen ) {
 261                                 continue;
 262                         } else if ( FulltextStoplist::inList( $word ) ) {
 263                                 continue;
 264                         } else {
 265                                 if ( "" != $last ) { $cond .= " AND"; }
 266                                 $cond .= " (MATCH (##field##) AGAINST ('" .
 267                                   $this->db->strencode( $word ). "'))";
 268                                 $last = $word;
 269                                 array_push( $this->searchTerms, "\\b" . $word . "\\b" );
 270                         }
 271                 }
 272                 if ( 0 == count( $this->searchTerms ) ) {
 273                         return MW_SEARCH_BAD_QUERY;
 274                 }
 275
 276                 $this->titleCond = "(" . str_replace( "##field##",
 277                   "si_title", $cond ) . " )";
 278
 279                 $this->textCond = "(" . str_replace( "##field##",
 280                   "si_text", $cond ) . " AND (cur_is_redirect=0) )";
 281
 282                 return MW_SEARCH_OK;
 283         }
 284
 285         function parseQuery4() {
 286                 global $wgLang;
 287                 $lc = SearchEngine::legalSearchChars();
 288                 $searchon = "";
 289                 $this->searchTerms = array();
 290
 291                 # FIXME: This doesn't handle parenthetical expressions.
 292                 if( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
 293                           $this->filteredText, $m, PREG_SET_ORDER ) ) {
 294                         foreach( $m as $terms ) {
 295                                 if( $searchon !== "" ) $searchon .= " ";
 296                                 if( $this->strictMatching && ($terms[1] == "") ) {
 297                                         $terms[1] = "+";
 298                                 }
 299                                 $searchon .= $terms[1] . $wgLang->stripForSearch( $terms[2] );
 300                                 if( $terms[3] ) {
 301                                         $regexp = preg_quote( $terms[3] );
 302                                         if( $terms[4] ) $regexp .= "[0-9A-Za-z_]+";
 303                                 } else {
 304                                         $regexp = preg_quote( str_replace( '"', '', $terms[2] ) );
 305                                 }
 306                                 $this->searchTerms[] = $regexp;
 307                         }
 308                         wfDebug( "Would search with '$searchon'\n" );
 309                         wfDebug( "Match with /\b" . implode( '\b|\b', $this->searchTerms ) . "\b/\n" );
 310                 } else {
 311                         wfDebug( "Can't understand search query '{$this->filteredText}'\n" );
 312                 }
 313
 314                 $searchon = $this->db->strencode( $searchon );
 315                 $this->titleCond = " MATCH(si_title) AGAINST('$searchon' IN BOOLEAN MODE)";
 316                 $this->textCond = " (MATCH(si_text) AGAINST('$searchon' IN BOOLEAN MODE) AND cur_is_redirect=0)";
 317                 return MW_SEARCH_OK;
 318         }
 319
 320         function &getMatches( $cond, $limit, $offset = 0 ) {
 321                 $searchindex = $this->db->tableName( 'searchindex' );
 322                 $cur = $this->db->tableName( 'cur' );
 323                 $searchnamespaces = $this->queryNamespaces();
 324                 $redircond = $this->searchRedirects();
 325
 326                 $sql = "SELECT cur_id,cur_namespace,cur_title," .
 327                   "cur_text FROM $cur,$searchindex " .
 328                   "WHERE cur_id=si_page AND {$cond} " .
 329                   "{$searchnamespaces} {$redircond} " .
 330                   $this->db->limitResult( $limit, $offset );
 331
 332                 $res = $this->db->query( $sql, "SearchEngine::getMatches" );
 333                 $matches = array();
 334                 while ( $row = $this->db->fetchObject( $res ) ) {
 335                         $matches[] = $row;
 336                 }
 337                 $this->db->freeResult( $res );
 338
 339                 return $matches;
 340         }
 341
 342         function showMatches( &$matches, $offset, $msgEmpty, $msgFound ) {
 343                 global $wgOut;
 344                 if ( 0 == count( $matches ) ) {
 345                         $wgOut->addHTML( "<h2>" . wfMsg( $msgEmpty ) .
 346                           "</h2>\n" );
 347                         return false;
 348                 } else {
 349                         $off = $offset + 1;
 350                         $wgOut->addHTML( "<h2>" . wfMsg( $msgFound ) .
 351                           "</h2>\n<ol start='{$off}'>" );
 352
 353                         foreach( $matches as $row ) {
 354                                 $this->showHit( $row );
 355                         }
 356                         $wgOut->addHTML( "</ol>\n" );
 357                         return true;
 358                 }
 359         }
 360
 361         function showHit( $row ) {
 362                 global $wgUser, $wgOut, $wgLang;
 363
 364                 $t = Title::makeName( $row->cur_namespace, $row->cur_title );
 365                 if( is_null( $t ) ) {
 366                         $wgOut->addHTML( "<!-- Broken link in search result -->\n" );
 367                         return;
 368                 }
 369                 $sk = $wgUser->getSkin();
 370
 371                 $contextlines = $wgUser->getOption( "contextlines" );
 372                 if ( "" == $contextlines ) { $contextlines = 5; }
 373                 $contextchars = $wgUser->getOption( "contextchars" );
 374                 if ( "" == $contextchars ) { $contextchars = 50; }
 375
 376                 $link = $sk->makeKnownLink( $t, "" );
 377                 $size = wfMsg( "nbytes", strlen( $row->cur_text ) );
 378                 $wgOut->addHTML( "<li>{$link} ({$size})" );
 379
 380                 $lines = explode( "\n", $row->cur_text );
 381                 $pat1 = "/(.*)(" . implode( "|", $this->searchTerms ) . ")(.*)/i";
 382                 $lineno = 0;
 383
 384                 foreach ( $lines as $line ) {
 385                         if ( 0 == $contextlines ) {
 386                                 break;
 387                         }
 388                         --$contextlines;
 389                         ++$lineno;
 390                         if ( ! preg_match( $pat1, $line, $m ) ) {
 391                                 continue;
 392                         }
 393
 394                         $pre = $wgLang->truncate( $m[1], -$contextchars, "..." );
 395
 396                         if ( count( $m ) < 3 ) {
 397                                 $post = "";
 398                         } else {
 399                                 $post = $wgLang->truncate( $m[3], $contextchars, "..." );
 400                         }
 401
 402                         $found = $m[2];
 403
 404                         $line = htmlspecialchars( $pre . $found . $post );
 405                         $pat2 = "/(" . implode( "|", $this->searchTerms ) . ")/i";
 406                         $line = preg_replace( $pat2,
 407                           "<span class='searchmatch'>\\1</span>", $line );
 408
 409                         $wgOut->addHTML( "<br /><small>{$lineno}: {$line}</small>\n" );
 410                 }
 411                 $wgOut->addHTML( "</li>\n" );
 412         }
 413
 414         function getNearMatch() {
 415                 # Exact match? No need to look further.
 416                 $title = Title::newFromText( $this->rawText );
 417                 if ( $title->getNamespace() == NS_SPECIAL || 0 != $title->getArticleID() ) {
 418                         return $title;
 419                 }
 420
 421                 # Now try all lower case (i.e. first letter capitalized)
 422                 #
 423                 $title = Title::newFromText( strtolower( $this->rawText ) );
 424                 if ( 0 != $title->getArticleID() ) {
 425                         return $title;
 426                 }
 427
 428                 # Now try capitalized string
 429                 #
 430                 $title = Title::newFromText( ucwords( strtolower( $this->rawText ) ) );
 431                 if ( 0 != $title->getArticleID() ) {
 432                         return $title;
 433                 }
 434
 435                 # Now try all upper case
 436                 #
 437                 $title = Title::newFromText( strtoupper( $this->rawText ) );
 438                 if ( 0 != $title->getArticleID() ) {
 439                         return $title;
 440                 }
 441
 442                 # Entering an IP address goes to the contributions page
 443                 if ( preg_match( '/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/', $this->rawText ) ) {
 444                         $title = Title::makeTitle( NS_SPECIAL, "Contributions/" . $this->rawText );
 445                         return $title;
 446                 }
 447
 448                 return NULL;
 449         }
 450
 451         function goResult() {
 452                 global $wgOut, $wgGoToEdit;
 453                 global $wgDisableTextSearch;
 454                 $fname = "SearchEngine::goResult";
 455
 456                 # Try to go to page as entered.
 457                 #
 458                 $t = Title::newFromText( $this->rawText );
 459
 460                 # If the string cannot be used to create a title
 461                 if( is_null( $t ) ){
 462                         $this->showResults();
 463                         return;
 464                 }
 465
 466                 # If there's an exact or very near match, jump right there.
 467                 $t = $this->getNearMatch();
 468                 if( !is_null( $t ) ) {
 469                         $wgOut->redirect( $t->getFullURL() );
 470                         return;
 471                 }
 472
 473                 # No match, generate an edit URL
 474                 $t = Title::newFromText( $this->rawText );
 475
 476                 # If the feature is enabled, go straight to the edit page
 477                 if ( $wgGoToEdit ) {
 478                         $wgOut->redirect( $t->getFullURL( "action=edit" ) );
 479                         return;
 480                 }
 481
 482                 if( $t ) {
 483                         $editurl = $t->escapeLocalURL( "action=edit" );
 484                 } else {
 485                         $editurl = ""; # ??
 486                 }
 487                 $wgOut->addHTML( "<p>" . wfMsg("nogomatch", $editurl ) . "</p>\n" );
 488
 489                 # Try a fuzzy title search
 490                 $anyhit = false;
 491                 global $wgDisableFuzzySearch;
 492                 if(! $wgDisableFuzzySearch ){
 493                         foreach( array(NS_MAIN, NS_WP, NS_USER, NS_IMAGE, NS_MEDIAWIKI) as $namespace){
 494                                 $anyhit |= SearchEngine::doFuzzyTitleSearch( $this->rawText, $namespace );
 495                         }
 496                 }
 497
 498                 if( ! $anyhit ){
 499                         return $this->showResults();
 500                 }
 501         }
 502
 503         /* static */ function doFuzzyTitleSearch( $search, $namespace ){
 504                 global $wgLang, $wgOut;
 505
 506                 $this->setupPage();
 507
 508                 $sstr = ucfirst($search);
 509                 $sstr = str_replace(" ", "_", $sstr);
 510                 $fuzzymatches = SearchEngine::fuzzyTitles( $sstr, $namespace );
 511                 $fuzzymatches = array_slice($fuzzymatches, 0, 10);
 512                 $slen = strlen( $search );
 513                 $wikitext = "";
 514                 foreach($fuzzymatches as $res){
 515                         $t = str_replace("_", " ", $res[1]);
 516                         $tfull = $wgLang->getNsText( $namespace ) . ":$t|$t";
 517                         if( $namespace == NS_MAIN )
 518                                 $tfull = "$t";
 519                         $distance = $res[0];
 520                         $closeness = (strlen( $search ) - $distance) / strlen( $search );
 521                         $percent = intval( $closeness * 100 ) . "%";
 522                         $stars = str_repeat("*", ceil(5 * $closeness) );
 523                         $wikitext .= "* [[$tfull]] $percent ($stars)\n";
 524                 }
 525                 if( $wikitext ){
 526                         if( $namespace != NS_MAIN )
 527                                 $wikitext = "=== " . $wgLang->getNsText( $namespace ) . " ===\n" . $wikitext;
 528                         $wgOut->addWikiText( $wikitext );
 529                         return true;
 530                 }
 531                 return false;
 532         }
 533
 534         /* static */ function fuzzyTitles( $sstr, $namespace = NS_MAIN ){
 535                 $span = 0.10; // weed on title length before doing levenshtein.
 536                 $tolerance = 0.35; // allowed percentage of erronous characters
 537                 $slen = strlen($sstr);
 538                 $tolerance_count = ceil($tolerance * $slen);
 539                 $spanabs = ceil($slen * (1 + $span)) - $slen;
 540                 # print "Word: $sstr, len = $slen, range = [$min, $max], tolerance_count = $tolerance_count<BR>\n";
 541                 $result = array();
 542                 $cnt = 0;
 543                 for( $i=0; $i <= $spanabs; $i++ ){
 544                         $titles = SearchEngine::getTitlesByLength( $slen + $i, $namespace );
 545                         if( $i != 0) {
 546                                 $titles = array_merge($titles, SearchEngine::getTitlesByLength( $slen - $i, $namespace ) );
 547                         }
 548                         foreach($titles as $t){
 549                                 $d = levenshtein($sstr, $t);
 550                                 if($d < $tolerance_count)
 551                                         $result[] = array($d, $t);
 552                                 $cnt++;
 553                         }
 554                 }
 555                 usort($result, "SearchEngine_pcmp");
 556                 return $result;
 557         }
 558
 559         /* static */ function getTitlesByLength($aLength, $aNamespace = 0){
 560                 global $wgMemc, $wgDBname;
 561                 $fname = 'SearchEngin::getTitlesByLength';
 562
 563                 // to avoid multiple costly SELECTs in case of no memcached
 564                 if( $this->allTitles ){
 565                         if( isset( $this->allTitles[$aLength][$aNamespace] ) ){
 566                                 return $this->allTitles[$aLength][$aNamespace];
 567                         } else {
 568                                 return array();
 569                         }
 570                 }
 571
 572                 $mkey = "$wgDBname:titlesbylength:$aLength:$aNamespace";
 573                 $mkeyts = "$wgDBname:titlesbylength:createtime";
 574                 $ts = $wgMemc->get( $mkeyts );
 575                 $result = $wgMemc->get( $mkey );
 576
 577                 if( time() - $ts < 3600 ){
 578                         // note: in case of insufficient memcached space, we return
 579                         // an empty list instead of starting to hit the DB.
 580                         return is_array( $result ) ? $result : array();
 581                 }
 582
 583                 $wgMemc->set( $mkeyts, time() );
 584
 585                 $res = $this->db->select( 'cur', array( 'cur_title', 'cur_namespace' ), false, $fname );
 586                 $titles = array(); // length, ns, [titles]
 587                 while( $obj = $this->db->fetchObject( $res ) ){
 588                         $title = $obj->cur_title;
 589                         $ns = $obj->cur_namespace;
 590                         $len = strlen( $title );
 591                         $titles[$len][$ns][] = $title;
 592                 }
 593                 foreach($titles as $length => $length_arr){
 594                         foreach($length_arr as $ns => $title_arr){
 595                                 $mkey = "$wgDBname:titlesbylength:$length:$ns";
 596                                 $wgMemc->set( $mkey, $title_arr, 3600 * 24 );
 597                         }
 598                 }
 599                 $this->allTitles = $titles;
 600                 if( isset( $titles[$aLength][$aNamespace] ) )
 601                         return $titles[$aLength][$aNamespace];
 602                 else
 603                         return array();
 604         }
 605 }
 606
 607 /* private static */ function SearchEngine_pcmp($a, $b){ return $a[0] - $b[0]; }
 608
 609 ?>