includes/search/SearchIBM_DB2.php

   1 <?php
   2 /**
   3  * IBM DB2 search engine
   4  *
   5  * Copyright © 2004 Brion Vibber <brion@pobox.com>
   6  * http://www.mediawiki.org/
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  21  * http://www.gnu.org/copyleft/gpl.html
  22  *
  23  * @file
  24  * @ingroup Search
  25  */
  26
  27 /**
  28  * Search engine hook base class for IBM DB2
  29  * @ingroup Search
  30  */
  31 class SearchIBM_DB2 extends SearchEngine {
  32         function __construct($db) {
  33                 $this->db = $db;
  34         }
  35
  36         /**
  37          * Perform a full text search query and return a result set.
  38          *
  39          * @param $term String: raw search term
  40          * @return SqlSearchResultSet
  41          */
  42         function searchText( $term ) {
  43                 $resultSet = $this->db->resultObject($this->db->query($this->getQuery($this->filter($term), true)));
  44                 return new SqlSearchResultSet($resultSet, $this->searchTerms);
  45         }
  46
  47         /**
  48          * Perform a title-only search query and return a result set.
  49          *
  50          * @param $term String: taw search term
  51          * @return SqlSearchResultSet
  52          */
  53         function searchTitle($term) {
  54                 $resultSet = $this->db->resultObject($this->db->query($this->getQuery($this->filter($term), false)));
  55                 return new SqlSearchResultSet($resultSet, $this->searchTerms);
  56         }
  57
  58
  59         /**
  60          * Return a partial WHERE clause to exclude redirects, if so set
  61          * @return String
  62          */
  63         function queryRedirect() {
  64                 if ($this->showRedirects) {
  65                         return '';
  66                 } else {
  67                         return 'AND page_is_redirect=0';
  68                 }
  69         }
  70
  71         /**
  72          * Return a partial WHERE clause to limit the search to the given namespaces
  73          * @return String
  74          */
  75         function queryNamespaces() {
  76                 if( is_null($this->namespaces) )
  77                         return '';
  78                 $namespaces = implode(',', $this->namespaces);
  79                 if ($namespaces == '') {
  80                         $namespaces = '0';
  81                 }
  82                 return 'AND page_namespace IN (' . $namespaces . ')';
  83         }
  84
  85         /**
  86          * Return a LIMIT clause to limit results on the query.
  87          * @return String
  88          */
  89         function queryLimit($sql) {
  90                 return $this->db->limitResult($sql, $this->limit, $this->offset);
  91         }
  92
  93         /**
  94          * Does not do anything for generic search engine
  95          * subclasses may define this though
  96          * @return String
  97          */
  98         function queryRanking($filteredTerm, $fulltext) {
  99                 // requires Net Search Extender or equivalent
 100                 // return ' ORDER BY score(1)';
 101                 return '';
 102         }
 103
 104         /**
 105          * Construct the full SQL query to do the search.
 106          * The guts shoulds be constructed in queryMain()
 107          * @param $filteredTerm String
 108          * @param $fulltext Boolean
 109          */
 110         function getQuery( $filteredTerm, $fulltext ) {
 111                 return $this->queryLimit($this->queryMain($filteredTerm, $fulltext) . ' ' .
 112                         $this->queryRedirect() . ' ' .
 113                         $this->queryNamespaces() . ' ' .
 114                         $this->queryRanking( $filteredTerm, $fulltext ) . ' ');
 115         }
 116
 117
 118         /**
 119          * Picks which field to index on, depending on what type of query.
 120          * @param $fulltext Boolean
 121          * @return String
 122          */
 123         function getIndexField($fulltext) {
 124                 return $fulltext ? 'si_text' : 'si_title';
 125         }
 126
 127         /**
 128          * Get the base part of the search query.
 129          *
 130          * @param $filteredTerm String
 131          * @param $fulltext Boolean
 132          * @return String
 133          */
 134         function queryMain( $filteredTerm, $fulltext ) {
 135                 $match = $this->parseQuery($filteredTerm, $fulltext);
 136                 $page        = $this->db->tableName('page');
 137                 $searchindex = $this->db->tableName('searchindex');
 138                 return 'SELECT page_id, page_namespace, page_title ' .
 139                         "FROM $page,$searchindex " .
 140                         'WHERE page_id=si_page AND ' . $match;
 141         }
 142
 143         /** @todo document */
 144         function parseQuery($filteredText, $fulltext) {
 145                 global $wgContLang;
 146                 $lc = SearchEngine::legalSearchChars();
 147                 $this->searchTerms = array();
 148
 149                 # FIXME: This doesn't handle parenthetical expressions.
 150                 $m = array();
 151                 $q = array();
 152
 153                 if (preg_match_all('/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
 154                           $filteredText, $m, PREG_SET_ORDER)) {
 155                         foreach($m as $terms) {
 156
 157                                 // Search terms in all variant forms, only
 158                                 // apply on wiki with LanguageConverter
 159                                 $temp_terms = $wgContLang->autoConvertToAllVariants( $terms[2] );
 160                                 if( is_array( $temp_terms )) {
 161                                         $temp_terms = array_unique( array_values( $temp_terms ));
 162                                         foreach( $temp_terms as $t )
 163                                                 $q[] = $terms[1] . $wgContLang->normalizeForSearch( $t );
 164                                 }
 165                                 else
 166                                         $q[] = $terms[1] . $wgContLang->normalizeForSearch( $terms[2] );
 167
 168                                 if (!empty($terms[3])) {
 169                                         $regexp = preg_quote( $terms[3], '/' );
 170                                         if ($terms[4])
 171                                                 $regexp .= "[0-9A-Za-z_]+";
 172                                 } else {
 173                                         $regexp = preg_quote(str_replace('"', '', $terms[2]), '/');
 174                                 }
 175                                 $this->searchTerms[] = $regexp;
 176                         }
 177                 }
 178
 179                 $searchon = $this->db->strencode(join(',', $q));
 180                 $field = $this->getIndexField($fulltext);
 181
 182                 // requires Net Search Extender or equivalent
 183                 //return " CONTAINS($field, '$searchon') > 0 ";
 184
 185                 return " lcase($field) LIKE lcase('%$searchon%')";
 186         }
 187
 188         /**
 189          * Create or update the search index record for the given page.
 190          * Title and text should be pre-processed.
 191          *
 192          * @param $id Integer
 193          * @param $title String
 194          * @param $text String
 195          */
 196         function update($id, $title, $text) {
 197                 $dbw = wfGetDB(DB_MASTER);
 198                 $dbw->replace('searchindex',
 199                         array('si_page'),
 200                         array(
 201                                 'si_page' => $id,
 202                                 'si_title' => $title,
 203                                 'si_text' => $text
 204                         ), 'SearchIBM_DB2::update' );
 205                 // ?
 206                 //$dbw->query("CALL ctx_ddl.sync_index('si_text_idx')");
 207                 //$dbw->query("CALL ctx_ddl.sync_index('si_title_idx')");
 208         }
 209
 210         /**
 211          * Update a search index record's title only.
 212          * Title should be pre-processed.
 213          *
 214          * @param $id Integer
 215          * @param $title String
 216          */
 217         function updateTitle($id, $title) {
 218                 $dbw = wfGetDB(DB_MASTER);
 219
 220                 $dbw->update('searchindex',
 221                         array('si_title' => $title),
 222                         array('si_page'  => $id),
 223                         'SearchIBM_DB2::updateTitle',
 224                         array());
 225         }
 226 }