SearchIBM_DB2.php

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<?php
class SearchIBM_DB2 extends SearchEngine {

        function __construct($db) {
                parent::__construct( $db );
        }

        function searchText( $term ) {
                $resultSet = $this->db->resultObject($this->db->query($this->getQuery($this->filter($term), true)));
                return new SqlSearchResultSet($resultSet, $this->searchTerms);
        }

        function searchTitle($term) {
                $resultSet = $this->db->resultObject($this->db->query($this->getQuery($this->filter($term), false)));
                return new SqlSearchResultSet($resultSet, $this->searchTerms);
        }


        function queryRedirect() {
                if ($this->showRedirects) {
                        return '';
                } else {
                        return 'AND page_is_redirect=0';
                }
        }

        function queryNamespaces() {
                if( is_null($this->namespaces) )
                        return '';
                $namespaces = implode(',', $this->namespaces);
                if ($namespaces == '') {
                        $namespaces = '0';
                }
                return 'AND page_namespace IN (' . $namespaces . ')';
        }

        function queryLimit( $sql ) {
                return $this->db->limitResult($sql, $this->limit, $this->offset);
        }

        function queryRanking($filteredTerm, $fulltext) {
                // requires Net Search Extender or equivalent
                // return ' ORDER BY score(1)';
                return '';
        }

        function getQuery( $filteredTerm, $fulltext ) {
                return $this->queryLimit($this->queryMain($filteredTerm, $fulltext) . ' ' .
                        $this->queryRedirect() . ' ' .
                        $this->queryNamespaces() . ' ' .
                        $this->queryRanking( $filteredTerm, $fulltext ) . ' ');
        }


        function getIndexField($fulltext) {
                return $fulltext ? 'si_text' : 'si_title';
        }

        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 ' .
                        "FROM $page,$searchindex " .
                        'WHERE page_id=si_page AND ' . $match;
        }

        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) {

                                // Search terms in all variant forms, only
                                // apply on wiki with LanguageConverter
                                $temp_terms = $wgContLang->autoConvertToAllVariants( $terms[2] );
                                if( is_array( $temp_terms )) {
                                        $temp_terms = array_unique( array_values( $temp_terms ));
                                        foreach( $temp_terms as $t )
                                                $q[] = $terms[1] . $wgContLang->normalizeForSearch( $t );
                                }
                                else
                                        $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);
                
                // requires Net Search Extender or equivalent
                //return " CONTAINS($field, '$searchon') > 0 ";
                
                return " lcase($field) LIKE lcase('%$searchon%')";
        }

        function update($id, $title, $text) {
                $dbw = wfGetDB(DB_MASTER);
                $dbw->replace('searchindex',
                        array('si_page'),
                        array(
                                'si_page' => $id,
                                'si_title' => $title,
                                'si_text' => $text
                        ), 'SearchIBM_DB2::update' );
                // ?
                //$dbw->query("CALL ctx_ddl.sync_index('si_text_idx')");
                //$dbw->query("CALL ctx_ddl.sync_index('si_title_idx')");
        }

        function updateTitle($id, $title) {
                $dbw = wfGetDB(DB_MASTER);

                $dbw->update('searchindex',
                        array('si_title' => $title),
                        array('si_page'  => $id),
                        'SearchIBM_DB2::updateTitle',
                        array());
        }
}