MediaWiki  REL1_22
SearchMySQL.php
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00001 <?php
00031 class SearchMySQL extends SearchEngine {
00032     var $strictMatching = true;
00033     static $mMinSearchLength;
00034 
00039     function __construct( $db ) {
00040         parent::__construct( $db );
00041     }
00042 
00052     function parseQuery( $filteredText, $fulltext ) {
00053         global $wgContLang;
00054         $lc = SearchEngine::legalSearchChars(); // Minus format chars
00055         $searchon = '';
00056         $this->searchTerms = array();
00057 
00058         # @todo FIXME: This doesn't handle parenthetical expressions.
00059         $m = array();
00060         if ( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
00061                 $filteredText, $m, PREG_SET_ORDER ) ) {
00062             foreach ( $m as $bits ) {
00063                 @list( /* all */, $modifier, $term, $nonQuoted, $wildcard ) = $bits;
00064 
00065                 if ( $nonQuoted != '' ) {
00066                     $term = $nonQuoted;
00067                     $quote = '';
00068                 } else {
00069                     $term = str_replace( '"', '', $term );
00070                     $quote = '"';
00071                 }
00072 
00073                 if ( $searchon !== '' ) {
00074                     $searchon .= ' ';
00075                 }
00076                 if ( $this->strictMatching && ( $modifier == '' ) ) {
00077                     // If we leave this out, boolean op defaults to OR which is rarely helpful.
00078                     $modifier = '+';
00079                 }
00080 
00081                 // Some languages such as Serbian store the input form in the search index,
00082                 // so we may need to search for matches in multiple writing system variants.
00083                 $convertedVariants = $wgContLang->autoConvertToAllVariants( $term );
00084                 if ( is_array( $convertedVariants ) ) {
00085                     $variants = array_unique( array_values( $convertedVariants ) );
00086                 } else {
00087                     $variants = array( $term );
00088                 }
00089 
00090                 // The low-level search index does some processing on input to work
00091                 // around problems with minimum lengths and encoding in MySQL's
00092                 // fulltext engine.
00093                 // For Chinese this also inserts spaces between adjacent Han characters.
00094                 $strippedVariants = array_map(
00095                     array( $wgContLang, 'normalizeForSearch' ),
00096                     $variants );
00097 
00098                 // Some languages such as Chinese force all variants to a canonical
00099                 // form when stripping to the low-level search index, so to be sure
00100                 // let's check our variants list for unique items after stripping.
00101                 $strippedVariants = array_unique( $strippedVariants );
00102 
00103                 $searchon .= $modifier;
00104                 if ( count( $strippedVariants ) > 1 ) {
00105                     $searchon .= '(';
00106                 }
00107                 foreach ( $strippedVariants as $stripped ) {
00108                     $stripped = $this->normalizeText( $stripped );
00109                     if ( $nonQuoted && strpos( $stripped, ' ' ) !== false ) {
00110                         // Hack for Chinese: we need to toss in quotes for
00111                         // multiple-character phrases since normalizeForSearch()
00112                         // added spaces between them to make word breaks.
00113                         $stripped = '"' . trim( $stripped ) . '"';
00114                     }
00115                     $searchon .= "$quote$stripped$quote$wildcard ";
00116                 }
00117                 if ( count( $strippedVariants ) > 1 ) {
00118                     $searchon .= ')';
00119                 }
00120 
00121                 // Match individual terms or quoted phrase in result highlighting...
00122                 // Note that variants will be introduced in a later stage for highlighting!
00123                 $regexp = $this->regexTerm( $term, $wildcard );
00124                 $this->searchTerms[] = $regexp;
00125             }
00126             wfDebug( __METHOD__ . ": Would search with '$searchon'\n" );
00127             wfDebug( __METHOD__ . ': Match with /' . implode( '|', $this->searchTerms ) . "/\n" );
00128         } else {
00129             wfDebug( __METHOD__ . ": Can't understand search query '{$filteredText}'\n" );
00130         }
00131 
00132         $searchon = $this->db->strencode( $searchon );
00133         $field = $this->getIndexField( $fulltext );
00134         return " MATCH($field) AGAINST('$searchon' IN BOOLEAN MODE) ";
00135     }
00136 
00137     function regexTerm( $string, $wildcard ) {
00138         global $wgContLang;
00139 
00140         $regex = preg_quote( $string, '/' );
00141         if ( $wgContLang->hasWordBreaks() ) {
00142             if ( $wildcard ) {
00143                 // Don't cut off the final bit!
00144                 $regex = "\b$regex";
00145             } else {
00146                 $regex = "\b$regex\b";
00147             }
00148         } else {
00149             // For Chinese, words may legitimately abut other words in the text literal.
00150             // Don't add \b boundary checks... note this could cause false positives
00151             // for latin chars.
00152         }
00153         return $regex;
00154     }
00155 
00156     public static function legalSearchChars() {
00157         return "\"*" . parent::legalSearchChars();
00158     }
00159 
00166     function searchText( $term ) {
00167         return $this->searchInternal( $term, true );
00168     }
00169 
00176     function searchTitle( $term ) {
00177         return $this->searchInternal( $term, false );
00178     }
00179 
00180     protected function searchInternal( $term, $fulltext ) {
00181         global $wgCountTotalSearchHits;
00182 
00183         // This seems out of place, why is this called with empty term?
00184         if ( trim( $term ) === '' ) {
00185             return null;
00186         }
00187 
00188         $filteredTerm = $this->filter( $term );
00189         $query = $this->getQuery( $filteredTerm, $fulltext );
00190         $resultSet = $this->db->select(
00191             $query['tables'], $query['fields'], $query['conds'],
00192             __METHOD__, $query['options'], $query['joins']
00193         );
00194 
00195         $total = null;
00196         if ( $wgCountTotalSearchHits ) {
00197             $query = $this->getCountQuery( $filteredTerm, $fulltext );
00198             $totalResult = $this->db->select(
00199                 $query['tables'], $query['fields'], $query['conds'],
00200                 __METHOD__, $query['options'], $query['joins']
00201             );
00202 
00203             $row = $totalResult->fetchObject();
00204             if ( $row ) {
00205                 $total = intval( $row->c );
00206             }
00207             $totalResult->free();
00208         }
00209 
00210         return new MySQLSearchResultSet( $resultSet, $this->searchTerms, $total );
00211     }
00212 
00213     public function supports( $feature ) {
00214         switch ( $feature ) {
00215         case 'title-suffix-filter':
00216             return true;
00217         default:
00218             return parent::supports( $feature );
00219         }
00220     }
00221 
00227     protected function queryFeatures( &$query ) {
00228         foreach ( $this->features as $feature => $value ) {
00229             if ( $feature === 'list-redirects' && !$value ) {
00230                 $query['conds']['page_is_redirect'] = 0;
00231             } elseif ( $feature === 'title-suffix-filter' && $value ) {
00232                 $query['conds'][] = 'page_title' . $this->db->buildLike( $this->db->anyString(), $value );
00233             }
00234         }
00235     }
00236 
00242     function queryNamespaces( &$query ) {
00243         if ( is_array( $this->namespaces ) ) {
00244             if ( count( $this->namespaces ) === 0 ) {
00245                 $this->namespaces[] = '0';
00246             }
00247             $query['conds']['page_namespace'] = $this->namespaces;
00248         }
00249     }
00250 
00256     protected function limitResult( &$query ) {
00257         $query['options']['LIMIT'] = $this->limit;
00258         $query['options']['OFFSET'] = $this->offset;
00259     }
00260 
00269     function getQuery( $filteredTerm, $fulltext ) {
00270         $query = array(
00271             'tables' => array(),
00272             'fields' => array(),
00273             'conds' => array(),
00274             'options' => array(),
00275             'joins' => array(),
00276         );
00277 
00278         $this->queryMain( $query, $filteredTerm, $fulltext );
00279         $this->queryFeatures( $query );
00280         $this->queryNamespaces( $query );
00281         $this->limitResult( $query );
00282 
00283         return $query;
00284     }
00285 
00291     function getIndexField( $fulltext ) {
00292         return $fulltext ? 'si_text' : 'si_title';
00293     }
00294 
00303     function queryMain( &$query, $filteredTerm, $fulltext ) {
00304         $match = $this->parseQuery( $filteredTerm, $fulltext );
00305         $query['tables'][] = 'page';
00306         $query['tables'][] = 'searchindex';
00307         $query['fields'][] = 'page_id';
00308         $query['fields'][] = 'page_namespace';
00309         $query['fields'][] = 'page_title';
00310         $query['conds'][] = 'page_id=si_page';
00311         $query['conds'][] = $match;
00312     }
00313 
00318     function getCountQuery( $filteredTerm, $fulltext ) {
00319         $match = $this->parseQuery( $filteredTerm, $fulltext );
00320 
00321         $query = array(
00322             'tables' => array( 'page', 'searchindex' ),
00323             'fields' => array( 'COUNT(*) as c' ),
00324             'conds' => array( 'page_id=si_page', $match ),
00325             'options' => array(),
00326             'joins' => array(),
00327         );
00328 
00329         $this->queryFeatures( $query );
00330         $this->queryNamespaces( $query );
00331 
00332         return $query;
00333     }
00334 
00343     function update( $id, $title, $text ) {
00344         $dbw = wfGetDB( DB_MASTER );
00345         $dbw->replace( 'searchindex',
00346             array( 'si_page' ),
00347             array(
00348                 'si_page' => $id,
00349                 'si_title' => $this->normalizeText( $title ),
00350                 'si_text' => $this->normalizeText( $text )
00351             ), __METHOD__ );
00352     }
00353 
00361     function updateTitle( $id, $title ) {
00362         $dbw = wfGetDB( DB_MASTER );
00363 
00364         $dbw->update( 'searchindex',
00365             array( 'si_title' => $this->normalizeText( $title ) ),
00366             array( 'si_page' => $id ),
00367             __METHOD__,
00368             array( $dbw->lowPriorityOption() ) );
00369     }
00370 
00378     function delete( $id, $title ) {
00379         $dbw = wfGetDB( DB_MASTER );
00380 
00381         $dbw->delete( 'searchindex', array( 'si_page' => $id ), __METHOD__ );
00382     }
00383 
00389     function normalizeText( $string ) {
00390         global $wgContLang;
00391 
00392         wfProfileIn( __METHOD__ );
00393 
00394         $out = parent::normalizeText( $string );
00395 
00396         // MySQL fulltext index doesn't grok utf-8, so we
00397         // need to fold cases and convert to hex
00398         $out = preg_replace_callback(
00399             "/([\\xc0-\\xff][\\x80-\\xbf]*)/",
00400             array( $this, 'stripForSearchCallback' ),
00401             $wgContLang->lc( $out ) );
00402 
00403         // And to add insult to injury, the default indexing
00404         // ignores short words... Pad them so we can pass them
00405         // through without reconfiguring the server...
00406         $minLength = $this->minSearchLength();
00407         if ( $minLength > 1 ) {
00408             $n = $minLength - 1;
00409             $out = preg_replace(
00410                 "/\b(\w{1,$n})\b/",
00411                 "$1u800",
00412                 $out );
00413         }
00414 
00415         // Periods within things like hostnames and IP addresses
00416         // are also important -- we want a search for "example.com"
00417         // or "192.168.1.1" to work sanely.
00418         //
00419         // MySQL's search seems to ignore them, so you'd match on
00420         // "example.wikipedia.com" and "192.168.83.1" as well.
00421         $out = preg_replace(
00422             "/(\w)\.(\w|\*)/u",
00423             "$1u82e$2",
00424             $out );
00425 
00426         wfProfileOut( __METHOD__ );
00427 
00428         return $out;
00429     }
00430 
00437     protected function stripForSearchCallback( $matches ) {
00438         return 'u8' . bin2hex( $matches[1] );
00439     }
00440 
00447     protected function minSearchLength() {
00448         if ( is_null( self::$mMinSearchLength ) ) {
00449             $sql = "SHOW GLOBAL VARIABLES LIKE 'ft\\_min\\_word\\_len'";
00450 
00451             $dbr = wfGetDB( DB_SLAVE );
00452             $result = $dbr->query( $sql );
00453             $row = $result->fetchObject();
00454             $result->free();
00455 
00456             if ( $row && $row->Variable_name == 'ft_min_word_len' ) {
00457                 self::$mMinSearchLength = intval( $row->Value );
00458             } else {
00459                 self::$mMinSearchLength = 0;
00460             }
00461         }
00462         return self::$mMinSearchLength;
00463     }
00464 }
00465 
00469 class MySQLSearchResultSet extends SqlSearchResultSet {
00470     function __construct( $resultSet, $terms, $totalHits = null ) {
00471         parent::__construct( $resultSet, $terms );
00472         $this->mTotalHits = $totalHits;
00473     }
00474 
00475     function getTotalHits() {
00476         return $this->mTotalHits;
00477     }
00478 }