Pass __METHOD__ to DatabaseBase::commit() and DatabaseBase::rollback()

[mediawiki.git] / includes / search / SearchMssql.php

<?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.
         *
         * @param $sql string
         *
         * @return String
         */
        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
         */
        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
         * @return String
         */
        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
         * @return string
         */
        function parseQuery( $filteredText, $fulltext ) {
                global $wgContLang;
                $lc = SearchEngine::legalSearchChars();
                $this->searchTerms = array();

                # @todo 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
         * @return bool|\ResultWrapper
         */
        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
         * @return bool|\ResultWrapper
         */
        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 );
        }
}