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Diffstat (limited to 'includes/search/SearchMssql.php')
-rw-r--r-- | includes/search/SearchMssql.php | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/includes/search/SearchMssql.php b/includes/search/SearchMssql.php new file mode 100644 index 00000000..8b850fae --- /dev/null +++ b/includes/search/SearchMssql.php @@ -0,0 +1,254 @@ +<?php +/** + * Mssql search engine + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * http://www.gnu.org/copyleft/gpl.html + * + * @file + * @ingroup Search + */ + +/** + * Search engine hook base class for Mssql (ConText). + * @ingroup Search + */ +class SearchMssql extends SearchEngine { + + /** + * Creates an instance of this class + * @param $db DatabaseMssql: database object + */ + function __construct( $db ) { + parent::__construct( $db ); + } + + /** + * Perform a full text search query and return a result set. + * + * @param $term String: raw search term + * @return MssqlSearchResultSet + * @access public + */ + function searchText( $term ) { + $resultSet = $this->db->resultObject( $this->db->query( $this->getQuery( $this->filter( $term ), true ) ) ); + return new MssqlSearchResultSet( $resultSet, $this->searchTerms ); + } + + /** + * Perform a title-only search query and return a result set. + * + * @param $term String: raw search term + * @return MssqlSearchResultSet + * @access public + */ + function searchTitle( $term ) { + $resultSet = $this->db->resultObject( $this->db->query( $this->getQuery( $this->filter( $term ), false ) ) ); + return new MssqlSearchResultSet( $resultSet, $this->searchTerms ); + } + + + /** + * Return a partial WHERE clause to exclude redirects, if so set + * + * @return String + * @private + */ + function queryRedirect() { + if ( $this->showRedirects ) { + return ''; + } else { + return 'AND page_is_redirect=0'; + } + } + + /** + * Return a partial WHERE clause to limit the search to the given namespaces + * + * @return String + * @private + */ + function queryNamespaces() { + $namespaces = implode( ',', $this->namespaces ); + if ( $namespaces == '' ) { + $namespaces = '0'; + } + return 'AND page_namespace IN (' . $namespaces . ')'; + } + + /** + * Return a LIMIT clause to limit results on the query. + * + * @return String + * @private + */ + function queryLimit( $sql ) { + return $this->db->limitResult( $sql, $this->limit, $this->offset ); + } + + /** + * Does not do anything for generic search engine + * subclasses may define this though + * + * @return String + * @private + */ + function queryRanking( $filteredTerm, $fulltext ) { + return ' ORDER BY ftindex.[RANK] DESC'; // return ' ORDER BY score(1)'; + } + + /** + * Construct the full SQL query to do the search. + * The guts shoulds be constructed in queryMain() + * + * @param $filteredTerm String + * @param $fulltext Boolean + * @private + */ + function getQuery( $filteredTerm, $fulltext ) { + return $this->queryLimit( $this->queryMain( $filteredTerm, $fulltext ) . ' ' . + $this->queryRedirect() . ' ' . + $this->queryNamespaces() . ' ' . + $this->queryRanking( $filteredTerm, $fulltext ) . ' ' ); + } + + + /** + * Picks which field to index on, depending on what type of query. + * + * @param $fulltext Boolean + * @return string + */ + function getIndexField( $fulltext ) { + return $fulltext ? 'si_text' : 'si_title'; + } + + /** + * Get the base part of the search query. + * + * @param $filteredTerm String + * @param $fulltext Boolean + * @return String + * @private + */ + function queryMain( $filteredTerm, $fulltext ) { + $match = $this->parseQuery( $filteredTerm, $fulltext ); + $page = $this->db->tableName( 'page' ); + $searchindex = $this->db->tableName( 'searchindex' ); + + return 'SELECT page_id, page_namespace, page_title, ftindex.[RANK]' . + "FROM $page,FREETEXTTABLE($searchindex , $match, LANGUAGE 'English') as ftindex " . + 'WHERE page_id=ftindex.[KEY] '; + } + + /** @todo document */ + function parseQuery( $filteredText, $fulltext ) { + global $wgContLang; + $lc = SearchEngine::legalSearchChars(); + $this->searchTerms = array(); + + # FIXME: This doesn't handle parenthetical expressions. + $m = array(); + $q = array(); + + if ( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/', + $filteredText, $m, PREG_SET_ORDER ) ) { + foreach ( $m as $terms ) { + $q[] = $terms[1] . $wgContLang->normalizeForSearch( $terms[2] ); + + if ( !empty( $terms[3] ) ) { + $regexp = preg_quote( $terms[3], '/' ); + if ( $terms[4] ) + $regexp .= "[0-9A-Za-z_]+"; + } else { + $regexp = preg_quote( str_replace( '"', '', $terms[2] ), '/' ); + } + $this->searchTerms[] = $regexp; + } + } + + $searchon = $this->db->strencode( join( ',', $q ) ); + $field = $this->getIndexField( $fulltext ); + return "$field, '$searchon'"; + } + + /** + * Create or update the search index record for the given page. + * Title and text should be pre-processed. + * + * @param $id Integer + * @param $title String + * @param $text String + */ + function update( $id, $title, $text ) { + // We store the column data as UTF-8 byte order marked binary stream + // because we are invoking the plain text IFilter on it so that, and we want it + // to properly decode the stream as UTF-8. SQL doesn't support UTF8 as a data type + // but the indexer will correctly handle it by this method. Since all we are doing + // is passing this data to the indexer and never retrieving it via PHP, this will save space + $table = $this->db->tableName( 'searchindex' ); + $utf8bom = '0xEFBBBF'; + $si_title = $utf8bom . bin2hex( $title ); + $si_text = $utf8bom . bin2hex( $text ); + $sql = "DELETE FROM $table WHERE si_page = $id;"; + $sql .= "INSERT INTO $table (si_page, si_title, si_text) VALUES ($id, $si_title, $si_text)"; + return $this->db->query( $sql, 'SearchMssql::update' ); + } + + /** + * Update a search index record's title only. + * Title should be pre-processed. + * + * @param $id Integer + * @param $title String + */ + function updateTitle( $id, $title ) { + $table = $this->db->tableName( 'searchindex' ); + + // see update for why we are using the utf8bom + $utf8bom = '0xEFBBBF'; + $si_title = $utf8bom . bin2hex( $title ); + $sql = "DELETE FROM $table WHERE si_page = $id;"; + $sql .= "INSERT INTO $table (si_page, si_title, si_text) VALUES ($id, $si_title, 0x00)"; + return $this->db->query( $sql, 'SearchMssql::updateTitle' ); + } +} + +/** + * @ingroup Search + */ +class MssqlSearchResultSet extends SearchResultSet { + function __construct( $resultSet, $terms ) { + $this->mResultSet = $resultSet; + $this->mTerms = $terms; + } + + function termMatches() { + return $this->mTerms; + } + + function numRows() { + return $this->mResultSet->numRows(); + } + + function next() { + $row = $this->mResultSet->fetchObject(); + if ( $row === false ) + return false; + return new SearchResult( $row ); + } +} + + |