includes/SearchEngine.php

   1 <?php
   2 /**
   3  * Contain site class
   4  * See search.doc
   5  * @package MediaWiki
   6  */
   7
   8 /**
   9  *
  10  */
  11 define( 'MW_SEARCH_OK', true );
  12 define( 'MW_SEARCH_BAD_QUERY', false );
  13
  14 /**
  15  * @todo document
  16  * @package MediaWiki
  17  */
  18 class SearchEngine {
  19         /* private */ var $rawText, $filteredText, $searchTerms;
  20         /* private */ var $titleCond, $textCond;
  21
  22         var $doSearchRedirects = true;
  23         var $addToQuery = array();
  24         var $namespacesToSearch = array();
  25         var $alternateTitle;
  26         var $allTitles = false;
  27
  28         function SearchEngine( $text ) {
  29                 $this->rawText = trim( $text );
  30
  31                 # We display the query, so let's strip it for safety
  32                 #
  33                 global $wgDBmysql4;
  34                 $lc = SearchEngine::legalSearchChars() . '()';
  35                 if( $wgDBmysql4 ) {
  36                         $lc .= "\"~<>*+-";
  37                 }
  38                 $this->filteredText = trim( preg_replace( "/[^{$lc}]/", " ", $text ) );
  39                 $this->searchTerms = array();
  40                 $this->strictMatching = true; # Google-style, add '+' on all terms
  41
  42                 $this->db =& wfGetDB( DB_SLAVE );
  43         }
  44
  45         /**
  46          * Return a partial WHERE clause to limit the search to the given namespaces
  47          */
  48         function queryNamespaces() {
  49                 $namespaces = implode( ',', $this->namespacesToSearch );
  50                 if ($namespaces == '') {
  51                         $namespaces = '0';
  52                 }
  53                 return "AND cur_namespace IN (" . $namespaces . ')';
  54         }
  55
  56         /**
  57          * Return a partial WHERE clause to include or exclude redirects from results
  58          */
  59         function searchRedirects() {
  60                 if ( $this->doSearchRedirects ) {
  61                         return '';
  62                 } else {
  63                         return 'AND cur_is_redirect=0 ';
  64                 }
  65         }
  66
  67         /**
  68          * @access private
  69          */ function initNamespaceCheckbox( $i ) {
  70                 global $wgUser, $wgNamespacesToBeSearchedDefault;
  71
  72                 if ($wgUser->getID()) {
  73                         // User is logged in so we retrieve his default namespaces
  74                         return $wgUser->getOption( 'searchNs'.$i );
  75                 } else {
  76                         // User is not logged in so we give him the global default namespaces
  77                         return !empty($wgNamespacesToBeSearchedDefault[ $i ]);
  78                 }
  79         }
  80
  81         /**
  82          * Display the "power search" footer. Does not actually perform the search,
  83          * that is done by showResults()
  84          */
  85         function powersearch() {
  86                 global $wgUser, $wgOut, $wgLang, $wgTitle, $wgRequest;
  87                 $sk =& $wgUser->getSkin();
  88
  89                 $search                 = $this->rawText;
  90                 $searchx                = $wgRequest->getVal( 'searchx' );
  91                 $listredirs             = $wgRequest->getVal( 'redirs' );
  92
  93                 $ret = wfMsg('powersearchtext'); # Text to be returned
  94                 $tempText = ''; # Temporary text, for substitution into $ret
  95
  96                 if( isset( $_REQUEST['searchx'] ) ) {
  97                         $this->addToQuery['searchx'] = '1';
  98                 }
  99
 100                 # Do namespace checkboxes
 101                 $namespaces = $wgLang->getNamespaces();
 102                 foreach ( $namespaces as $i => $namespace ) {
 103                         # Skip virtual namespaces
 104                         if ( $i < 0 ) {
 105                                 continue;
 106                         }
 107
 108                         $formVar = 'ns'.$i;
 109
 110                         # Initialise checkboxValues, either from defaults or from
 111                         # a previous invocation
 112                         if ( !isset( $searchx ) ) {
 113                                 $checkboxValue = $this->initNamespaceCheckbox( $i );
 114                         } else {
 115                                 $checkboxValue = $wgRequest->getVal( $formVar );
 116                         }
 117
 118                         $checked = '';
 119                         if ( $checkboxValue == 1 ) {
 120                                 $checked = ' checked="checked"';
 121                                 $this->addToQuery['ns'.$i] = 1;
 122                                 array_push( $this->namespacesToSearch, $i );
 123                         }
 124                         $name = str_replace( '_', ' ', $namespaces[$i] );
 125                         if ( '' == $name ) {
 126                                 $name = wfMsg( 'blanknamespace' );
 127                         }
 128
 129                         if ( $tempText !== '' ) {
 130                                 $tempText .= ' ';
 131                         }
 132                         $tempText .= "<input type='checkbox' value=\"1\" name=\"" .
 133                           "ns{$i}\"{$checked} />{$name}\n";
 134                 }
 135                 $ret = str_replace ( '$1', $tempText, $ret );
 136
 137                 # List redirects checkbox
 138
 139                 $checked = '';
 140                 if ( $listredirs == 1 ) {
 141                         $this->addToQuery['redirs'] = 1;
 142                         $checked = ' checked="checked"';
 143                 }
 144                 $tempText = "<input type='checkbox' value='1' name=\"redirs\"{$checked} />\n";
 145                 $ret = str_replace( '$2', $tempText, $ret );
 146
 147                 # Search field
 148
 149                 $tempText = "<input type='text' name=\"search\" value=\"" .
 150                         htmlspecialchars( $search ) ."\" width=\"80\" />\n";
 151         $ret = str_replace( "$3", $tempText, $ret );
 152
 153                 # Searchx button
 154
 155                 $tempText = '<input type="submit" name="searchx" value="' .
 156                   wfMsg('powersearch') . "\" />\n";
 157                 $ret = str_replace( '$9', $tempText, $ret );
 158
 159                 $action = $sk->escapeSearchLink();
 160                 $ret = "<br /><br />\n<form id=\"powersearch\" method=\"get\" " .
 161                   "action=\"$action\">\n{$ret}\n</form>\n";
 162
 163                 if ( isset ( $searchx ) ) {
 164                         if ( ! $listredirs ) {
 165                                 $this->doSearchRedirects = false;
 166                         }
 167                 }
 168                 return $ret;
 169         }
 170
 171         function setupPage() {
 172                 global $wgOut;
 173                 $wgOut->setPageTitle( wfMsg( 'searchresults' ) );
 174                 $wgOut->setSubtitle( wfMsg( 'searchquery', htmlspecialchars( $this->rawText ) ) );
 175                 $wgOut->setArticleRelated( false );
 176                 $wgOut->setRobotpolicy( 'noindex,nofollow' );
 177         }
 178
 179         /**
 180          * Perform the search and construct the results page
 181          */
 182         function showResults() {
 183                 global $wgUser, $wgTitle, $wgOut, $wgLang;
 184                 global $wgDisableTextSearch, $wgInputEncoding;
 185                 $fname = 'SearchEngine::showResults';
 186
 187                 $search = $this->rawText;
 188
 189                 $powersearch = $this->powersearch(); /* Need side-effects here? */
 190
 191                 $this->setupPage();
 192
 193                 $sk = $wgUser->getSkin();
 194                 $wgOut->addWikiText( wfMsg( 'searchresulttext' ) );
 195
 196                 if ( !$this->parseQuery() ) {
 197                         $wgOut->addWikiText(
 198                                 '==' . wfMsg( 'badquery' ) . "==\n" .
 199                                 wfMsg( 'badquerytext' ) );
 200                         return;
 201                 }
 202                 list( $limit, $offset ) = wfCheckLimits( 20, 'searchlimit' );
 203
 204                 if ( $wgDisableTextSearch ) {
 205                         $wgOut->addHTML( wfMsg( 'searchdisabled' ) );
 206                         $wgOut->addHTML( wfMsg( 'googlesearch',
 207                                 htmlspecialchars( $this->rawText ),
 208                                 htmlspecialchars( $wgInputEncoding ) ) );
 209                         return;
 210                 }
 211
 212                 $titleMatches = $this->getMatches( $this->titleCond, $limit, $offset );
 213                 $textMatches = $this->getMatches( $this->textCond, $limit, $offset );
 214
 215                 $sk = $wgUser->getSkin();
 216
 217                 $num = count( $titleMatches ) + count( $textMatches );
 218                 if ( $num >= $limit ) {
 219                         $top = wfShowingResults( $offset, $limit );
 220                 } else {
 221                         $top = wfShowingResultsNum( $offset, $limit, $num );
 222                 }
 223                 $wgOut->addHTML( "<p>{$top}</p>\n" );
 224
 225                 # For powersearch
 226                 $a2l = '';
 227                 $akk = array_keys( $this->addToQuery );
 228                 foreach ( $akk AS $ak ) {
 229                         $a2l .= "&{$ak}={$this->addToQuery[$ak]}" ;
 230                 }
 231
 232                 $prevnext = wfViewPrevNext( $offset, $limit, '',
 233                   'search=' . wfUrlencode( $this->filteredText ) . $a2l );
 234                 $wgOut->addHTML( "<br />{$prevnext}\n" );
 235
 236                 $foundsome = $this->showMatches( $titleMatches, $offset, 'notitlematches', 'titlematches' )
 237                                   || $this->showMatches( $textMatches,  $offset, 'notextmatches',  'textmatches'  );
 238
 239                 if ( !$foundsome ) {
 240                         $wgOut->addWikiText( wfMsg( 'nonefound' ) );
 241                 }
 242                 $wgOut->addHTML( "<p>{$prevnext}</p>\n" );
 243                 $wgOut->addHTML( $powersearch );
 244         }
 245
 246         function legalSearchChars() {
 247                 $lc = "A-Za-z_'0-9\\x80-\\xFF\\-";
 248                 return $lc;
 249         }
 250
 251         function parseQuery() {
 252                 global $wgDBmysql4;
 253                 if( $wgDBmysql4 ) {
 254                         # Use cleaner boolean search if available
 255                         return $this->parseQuery4();
 256                 } else {
 257                         # Fall back to ugly hack with multiple search clauses
 258                         return $this->parseQuery3();
 259                 }
 260         }
 261
 262         function parseQuery3() {
 263                 global $wgDBminWordLen, $wgLang;
 264
 265                 # on non mysql4 database: get list of words we don't want to search for
 266                 require_once( 'FulltextStoplist.php' );
 267
 268                 $lc = SearchEngine::legalSearchChars() . '()';
 269                 $q = preg_replace( "/([()])/", " \\1 ", $this->filteredText );
 270                 $q = preg_replace( "/\\s+/", " ", $q );
 271                 $w = explode( ' ', trim( $q ) );
 272
 273                 $last = $cond = '';
 274                 foreach ( $w as $word ) {
 275                         $word = $wgLang->stripForSearch( $word );
 276                         if ( 'and' == $word || 'or' == $word || 'not' == $word
 277                           || '(' == $word || ')' == $word ) {
 278                                 $cond .= ' ' . strtoupper( $word );
 279                                 $last = '';
 280                         } else if ( strlen( $word ) < $wgDBminWordLen ) {
 281                                 continue;
 282                         } else if ( FulltextStoplist::inList( $word ) ) {
 283                                 continue;
 284                         } else {
 285                                 if ( '' != $last ) { $cond .= ' AND'; }
 286                                 $cond .= " (MATCH (##field##) AGAINST ('" .
 287                                   $this->db->strencode( $word ). "'))";
 288                                 $last = $word;
 289                                 array_push( $this->searchTerms, "\\b" . $word . "\\b" );
 290                         }
 291                 }
 292                 if ( 0 == count( $this->searchTerms ) ) {
 293                         return MW_SEARCH_BAD_QUERY;
 294                 }
 295
 296                 $this->titleCond = '(' . str_replace( '##field##',
 297                   'si_title', $cond ) . ' )';
 298
 299                 $this->textCond = '(' . str_replace( '##field##',
 300                   'si_text', $cond ) . ' AND (cur_is_redirect=0) )';
 301
 302                 return MW_SEARCH_OK;
 303         }
 304
 305         function parseQuery4() {
 306                 global $wgLang;
 307                 $lc = SearchEngine::legalSearchChars();
 308                 $searchon = '';
 309                 $this->searchTerms = array();
 310
 311                 # FIXME: This doesn't handle parenthetical expressions.
 312                 if( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
 313                           $this->filteredText, $m, PREG_SET_ORDER ) ) {
 314                         foreach( $m as $terms ) {
 315                                 if( $searchon !== '' ) $searchon .= ' ';
 316                                 if( $this->strictMatching && ($terms[1] == '') ) {
 317                                         $terms[1] = '+';
 318                                 }
 319                                 $searchon .= $terms[1] . $wgLang->stripForSearch( $terms[2] );
 320                                 if( !empty( $terms[3] ) ) {
 321                                         $regexp = preg_quote( $terms[3] );
 322                                         if( $terms[4] ) $regexp .= "[0-9A-Za-z_]+";
 323                                 } else {
 324                                         $regexp = preg_quote( str_replace( '"', '', $terms[2] ) );
 325                                 }
 326                                 $this->searchTerms[] = $regexp;
 327                         }
 328                         wfDebug( "Would search with '$searchon'\n" );
 329                         wfDebug( "Match with /\b" . implode( '\b|\b', $this->searchTerms ) . "\b/\n" );
 330                 } else {
 331                         wfDebug( "Can't understand search query '{$this->filteredText}'\n" );
 332                 }
 333
 334                 $searchon = $this->db->strencode( $searchon );
 335                 $this->titleCond = " MATCH(si_title) AGAINST('$searchon' IN BOOLEAN MODE)";
 336                 $this->textCond = " (MATCH(si_text) AGAINST('$searchon' IN BOOLEAN MODE) AND cur_is_redirect=0)";
 337                 return MW_SEARCH_OK;
 338         }
 339
 340         function &getMatches( $cond, $limit, $offset = 0 ) {
 341                 $searchindex = $this->db->tableName( 'searchindex' );
 342                 $cur = $this->db->tableName( 'cur' );
 343                 $searchnamespaces = $this->queryNamespaces();
 344                 $redircond = $this->searchRedirects();
 345
 346                 $sql = "SELECT cur_id,cur_namespace,cur_title," .
 347                   "cur_text FROM $cur,$searchindex " .
 348                   "WHERE cur_id=si_page AND {$cond} " .
 349                   "{$searchnamespaces} {$redircond} " .
 350                   $this->db->limitResult( $limit, $offset );
 351
 352                 $res = $this->db->query( $sql, 'SearchEngine::getMatches' );
 353                 $matches = array();
 354                 while ( $row = $this->db->fetchObject( $res ) ) {
 355                         $matches[] = $row;
 356                 }
 357                 $this->db->freeResult( $res );
 358
 359                 return $matches;
 360         }
 361
 362         function showMatches( &$matches, $offset, $msgEmpty, $msgFound ) {
 363                 global $wgOut;
 364                 if ( 0 == count( $matches ) ) {
 365                         $wgOut->addHTML( "<h2>" . wfMsg( $msgEmpty ) .
 366                           "</h2>\n" );
 367                         return false;
 368                 } else {
 369                         $off = $offset + 1;
 370                         $wgOut->addHTML( "<h2>" . wfMsg( $msgFound ) .
 371                           "</h2>\n<ol start='{$off}'>" );
 372
 373                         foreach( $matches as $row ) {
 374                                 $this->showHit( $row );
 375                         }
 376                         $wgOut->addHTML( "</ol>\n" );
 377                         return true;
 378                 }
 379         }
 380
 381         function showHit( $row ) {
 382                 global $wgUser, $wgOut, $wgLang;
 383
 384                 $t = Title::makeName( $row->cur_namespace, $row->cur_title );
 385                 if( is_null( $t ) ) {
 386                         $wgOut->addHTML( "<!-- Broken link in search result -->\n" );
 387                         return;
 388                 }
 389                 $sk = $wgUser->getSkin();
 390
 391                 $contextlines = $wgUser->getOption( 'contextlines' );
 392                 if ( '' == $contextlines ) { $contextlines = 5; }
 393                 $contextchars = $wgUser->getOption( 'contextchars' );
 394                 if ( '' == $contextchars ) { $contextchars = 50; }
 395
 396                 $link = $sk->makeKnownLink( $t, '' );
 397                 $size = wfMsg( 'nbytes', strlen( $row->cur_text ) );
 398                 $wgOut->addHTML( "<li>{$link} ({$size})" );
 399
 400                 $lines = explode( "\n", $row->cur_text );
 401                 $pat1 = "/(.*)(" . implode( "|", $this->searchTerms ) . ")(.*)/i";
 402                 $lineno = 0;
 403
 404                 foreach ( $lines as $line ) {
 405                         if ( 0 == $contextlines ) {
 406                                 break;
 407                         }
 408                         --$contextlines;
 409                         ++$lineno;
 410                         if ( ! preg_match( $pat1, $line, $m ) ) {
 411                                 continue;
 412                         }
 413
 414                         $pre = $wgLang->truncate( $m[1], -$contextchars, '...' );
 415
 416                         if ( count( $m ) < 3 ) {
 417                                 $post = '';
 418                         } else {
 419                                 $post = $wgLang->truncate( $m[3], $contextchars, '...' );
 420                         }
 421
 422                         $found = $m[2];
 423
 424                         $line = htmlspecialchars( $pre . $found . $post );
 425                         $pat2 = '/(' . implode( '|', $this->searchTerms ) . ")/i";
 426                         $line = preg_replace( $pat2,
 427                           "<span class='searchmatch'>\\1</span>", $line );
 428
 429                         $wgOut->addHTML( "<br /><small>{$lineno}: {$line}</small>\n" );
 430                 }
 431                 $wgOut->addHTML( "</li>\n" );
 432         }
 433
 434         function getNearMatch() {
 435                 # Exact match? No need to look further.
 436                 $title = Title::newFromText( $this->rawText );
 437                 if ( $title->getNamespace() == NS_SPECIAL || 0 != $title->getArticleID() ) {
 438                         return $title;
 439                 }
 440
 441                 # Now try all lower case (i.e. first letter capitalized)
 442                 #
 443                 $title = Title::newFromText( strtolower( $this->rawText ) );
 444                 if ( 0 != $title->getArticleID() ) {
 445                         return $title;
 446                 }
 447
 448                 # Now try capitalized string
 449                 #
 450                 $title = Title::newFromText( ucwords( strtolower( $this->rawText ) ) );
 451                 if ( 0 != $title->getArticleID() ) {
 452                         return $title;
 453                 }
 454
 455                 # Now try all upper case
 456                 #
 457                 $title = Title::newFromText( strtoupper( $this->rawText ) );
 458                 if ( 0 != $title->getArticleID() ) {
 459                         return $title;
 460                 }
 461
 462                 # Entering an IP address goes to the contributions page
 463                 if ( preg_match( '/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/', $this->rawText ) ) {
 464                         $title = Title::makeTitle( NS_SPECIAL, "Contributions/" . $this->rawText );
 465                         return $title;
 466                 }
 467
 468                 return NULL;
 469         }
 470
 471         function goResult() {
 472                 global $wgOut, $wgGoToEdit;
 473                 global $wgDisableTextSearch;
 474                 $fname = 'SearchEngine::goResult';
 475
 476                 # Try to go to page as entered.
 477                 #
 478                 $t = Title::newFromText( $this->rawText );
 479
 480                 # If the string cannot be used to create a title
 481                 if( is_null( $t ) ){
 482                         $this->showResults();
 483                         return;
 484                 }
 485
 486                 # If there's an exact or very near match, jump right there.
 487                 $t = $this->getNearMatch();
 488                 if( !is_null( $t ) ) {
 489                         $wgOut->redirect( $t->getFullURL() );
 490                         return;
 491                 }
 492
 493                 # No match, generate an edit URL
 494                 $t = Title::newFromText( $this->rawText );
 495
 496                 # If the feature is enabled, go straight to the edit page
 497                 if ( $wgGoToEdit ) {
 498                         $wgOut->redirect( $t->getFullURL( 'action=edit' ) );
 499                         return;
 500                 }
 501
 502                 if( $t ) {
 503                         $editurl = $t->escapeLocalURL( 'action=edit' );
 504                 } else {
 505                         $editurl = ''; # ??
 506                 }
 507                 $wgOut->addHTML( '<p>' . wfMsg('nogomatch', $editurl ) . "</p>\n" );
 508
 509                 # Try a fuzzy title search
 510                 $anyhit = false;
 511                 global $wgDisableFuzzySearch;
 512                 if(! $wgDisableFuzzySearch ){
 513                         foreach( array(NS_MAIN, NS_PROJECT, NS_USER, NS_IMAGE, NS_MEDIAWIKI) as $namespace){
 514                                 $anyhit |= SearchEngine::doFuzzyTitleSearch( $this->rawText, $namespace );
 515                         }
 516                 }
 517
 518                 if( ! $anyhit ){
 519                         return $this->showResults();
 520                 }
 521         }
 522
 523         /**
 524          * @static
 525          */
 526         function doFuzzyTitleSearch( $search, $namespace ){
 527                 global $wgLang, $wgOut;
 528
 529                 $this->setupPage();
 530
 531                 $sstr = ucfirst($search);
 532                 $sstr = str_replace(' ', '_', $sstr);
 533                 $fuzzymatches = SearchEngine::fuzzyTitles( $sstr, $namespace );
 534                 $fuzzymatches = array_slice($fuzzymatches, 0, 10);
 535                 $slen = strlen( $search );
 536                 $wikitext = '';
 537                 foreach($fuzzymatches as $res){
 538                         $t = str_replace('_', ' ', $res[1]);
 539                         $tfull = $wgLang->getNsText( $namespace ) . ":$t|$t";
 540                         if( $namespace == NS_MAIN )
 541                                 $tfull = $t;
 542                         $distance = $res[0];
 543                         $closeness = (strlen( $search ) - $distance) / strlen( $search );
 544                         $percent = intval( $closeness * 100 ) . '%';
 545                         $stars = str_repeat('*', ceil(5 * $closeness) );
 546                         $wikitext .= "* [[$tfull]] $percent ($stars)\n";
 547                 }
 548                 if( $wikitext ){
 549                         if( $namespace != NS_MAIN )
 550                                 $wikitext = '=== ' . $wgLang->getNsText( $namespace ) . " ===\n" . $wikitext;
 551                         $wgOut->addWikiText( $wikitext );
 552                         return true;
 553                 }
 554                 return false;
 555         }
 556
 557         /**
 558          * @static
 559          */
 560         function fuzzyTitles( $sstr, $namespace = NS_MAIN ){
 561                 $span = 0.10; // weed on title length before doing levenshtein.
 562                 $tolerance = 0.35; // allowed percentage of erronous characters
 563                 $slen = strlen($sstr);
 564                 $tolerance_count = ceil($tolerance * $slen);
 565                 $spanabs = ceil($slen * (1 + $span)) - $slen;
 566                 # print "Word: $sstr, len = $slen, range = [$min, $max], tolerance_count = $tolerance_count<BR>\n";
 567                 $result = array();
 568                 $cnt = 0;
 569                 for( $i=0; $i <= $spanabs; $i++ ){
 570                         $titles = SearchEngine::getTitlesByLength( $slen + $i, $namespace );
 571                         if( $i != 0) {
 572                                 $titles = array_merge($titles, SearchEngine::getTitlesByLength( $slen - $i, $namespace ) );
 573                         }
 574                         foreach($titles as $t){
 575                                 $d = levenshtein($sstr, $t);
 576                                 if($d < $tolerance_count)
 577                                         $result[] = array($d, $t);
 578                                 $cnt++;
 579                         }
 580                 }
 581                 usort($result, 'SearchEngine_pcmp');
 582                 return $result;
 583         }
 584
 585         /**
 586          * static
 587          */
 588         function getTitlesByLength($aLength, $aNamespace = 0){
 589                 global $wgMemc, $wgDBname;
 590                 $fname = 'SearchEngin::getTitlesByLength';
 591
 592                 // to avoid multiple costly SELECTs in case of no memcached
 593                 if( $this->allTitles ){
 594                         if( isset( $this->allTitles[$aLength][$aNamespace] ) ){
 595                                 return $this->allTitles[$aLength][$aNamespace];
 596                         } else {
 597                                 return array();
 598                         }
 599                 }
 600
 601                 $mkey = "$wgDBname:titlesbylength:$aLength:$aNamespace";
 602                 $mkeyts = "$wgDBname:titlesbylength:createtime";
 603                 $ts = $wgMemc->get( $mkeyts );
 604                 $result = $wgMemc->get( $mkey );
 605
 606                 if( time() - $ts < 3600 ){
 607                         // note: in case of insufficient memcached space, we return
 608                         // an empty list instead of starting to hit the DB.
 609                         return is_array( $result ) ? $result : array();
 610                 }
 611
 612                 $wgMemc->set( $mkeyts, time() );
 613
 614                 $res = $this->db->select( 'cur', array( 'cur_title', 'cur_namespace' ), false, $fname );
 615                 $titles = array(); // length, ns, [titles]
 616                 while( $obj = $this->db->fetchObject( $res ) ){
 617                         $title = $obj->cur_title;
 618                         $ns = $obj->cur_namespace;
 619                         $len = strlen( $title );
 620                         $titles[$len][$ns][] = $title;
 621                 }
 622                 foreach($titles as $length => $length_arr){
 623                         foreach($length_arr as $ns => $title_arr){
 624                                 $mkey = "$wgDBname:titlesbylength:$length:$ns";
 625                                 $wgMemc->set( $mkey, $title_arr, 3600 * 24 );
 626                         }
 627                 }
 628                 $this->allTitles = $titles;
 629                 if( isset( $titles[$aLength][$aNamespace] ) )
 630                         return $titles[$aLength][$aNamespace];
 631                 else
 632                         return array();
 633         }
 634 }
 635
 636 /**
 637  * @access private
 638  * @static
 639  */
 640 function SearchEngine_pcmp($a, $b){ return $a[0] - $b[0]; }
 641
 642 ?>