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
  33         /**
  34          * Creates an instance of this class
  35          * @param $db DatabaseIbm_db2: database object
  36          */
  37         function __construct($db) {
  38                 parent::__construct( $db );
  39         }
  40
  41         /**
  42          * Perform a full text search query and return a result set.
  43          *
  44          * @param $term String: raw search term
  45          * @return SqlSearchResultSet
  46          */
  47         function searchText( $term ) {
  48                 $resultSet = $this->db->resultObject($this->db->query($this->getQuery($this->filter($term), true)));
  49                 return new SqlSearchResultSet($resultSet, $this->searchTerms);
  50         }
  51
  52         /**
  53          * Perform a title-only search query and return a result set.
  54          *
  55          * @param $term String: taw search term
  56          * @return SqlSearchResultSet
  57          */
  58         function searchTitle($term) {
  59                 $resultSet = $this->db->resultObject($this->db->query($this->getQuery($this->filter($term), false)));
  60                 return new SqlSearchResultSet($resultSet, $this->searchTerms);
  61         }
  62
  63
  64         /**
  65          * Return a partial WHERE clause to exclude redirects, if so set
  66          * @return String
  67          */
  68         function queryRedirect() {
  69                 if ($this->showRedirects) {
  70                         return '';
  71                 } else {
  72                         return 'AND page_is_redirect=0';
  73                 }
  74         }
  75
  76         /**
  77          * Return a partial WHERE clause to limit the search to the given namespaces
  78          * @return String
  79          */
  80         function queryNamespaces() {
  81                 if( is_null($this->namespaces) )
  82                         return '';
  83                 $namespaces = implode(',', $this->namespaces);
  84                 if ($namespaces == '') {
  85                         $namespaces = '0';
  86                 }
  87                 return 'AND page_namespace IN (' . $namespaces . ')';
  88         }
  89
  90         /**
  91          * Return a LIMIT clause to limit results on the query.
  92          * @return String
  93          */
  94         function queryLimit( $sql ) {
  95                 return $this->db->limitResult($sql, $this->limit, $this->offset);
  96         }
  97
  98         /**
  99          * Does not do anything for generic search engine
 100          * subclasses may define this though
 101          * @return String
 102          */
 103         function queryRanking($filteredTerm, $fulltext) {
 104                 // requires Net Search Extender or equivalent
 105                 // return ' ORDER BY score(1)';
 106                 return '';
 107         }
 108
 109         /**
 110          * Construct the full SQL query to do the search.
 111          * The guts shoulds be constructed in queryMain()
 112          * @param $filteredTerm String
 113          * @param $fulltext Boolean
 114          */
 115         function getQuery( $filteredTerm, $fulltext ) {
 116                 return $this->queryLimit($this->queryMain($filteredTerm, $fulltext) . ' ' .
 117                         $this->queryRedirect() . ' ' .
 118                         $this->queryNamespaces() . ' ' .
 119                         $this->queryRanking( $filteredTerm, $fulltext ) . ' ');
 120         }
 121
 122
 123         /**
 124          * Picks which field to index on, depending on what type of query.
 125          * @param $fulltext Boolean
 126          * @return String
 127          */
 128         function getIndexField($fulltext) {
 129                 return $fulltext ? 'si_text' : 'si_title';
 130         }
 131
 132         /**
 133          * Get the base part of the search query.
 134          *
 135          * @param $filteredTerm String
 136          * @param $fulltext Boolean
 137          * @return String
 138          */
 139         function queryMain( $filteredTerm, $fulltext ) {
 140                 $match = $this->parseQuery($filteredTerm, $fulltext);
 141                 $page        = $this->db->tableName('page');
 142                 $searchindex = $this->db->tableName('searchindex');
 143                 return 'SELECT page_id, page_namespace, page_title ' .
 144                         "FROM $page,$searchindex " .
 145                         'WHERE page_id=si_page AND ' . $match;
 146         }
 147
 148         /** @todo document */
 149         function parseQuery($filteredText, $fulltext) {
 150                 global $wgContLang;
 151                 $lc = SearchEngine::legalSearchChars();
 152                 $this->searchTerms = array();
 153
 154                 # @todo FIXME: This doesn't handle parenthetical expressions.
 155                 $m = array();
 156                 $q = array();
 157
 158                 if (preg_match_all('/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
 159                           $filteredText, $m, PREG_SET_ORDER)) {
 160                         foreach($m as $terms) {
 161
 162                                 // Search terms in all variant forms, only
 163                                 // apply on wiki with LanguageConverter
 164                                 $temp_terms = $wgContLang->autoConvertToAllVariants( $terms[2] );
 165                                 if( is_array( $temp_terms )) {
 166                                         $temp_terms = array_unique( array_values( $temp_terms ));
 167                                         foreach( $temp_terms as $t )
 168                                                 $q[] = $terms[1] . $wgContLang->normalizeForSearch( $t );
 169                                 }
 170                                 else
 171                                         $q[] = $terms[1] . $wgContLang->normalizeForSearch( $terms[2] );
 172
 173                                 if (!empty($terms[3])) {
 174                                         $regexp = preg_quote( $terms[3], '/' );
 175                                         if ($terms[4])
 176                                                 $regexp .= "[0-9A-Za-z_]+";
 177                                 } else {
 178                                         $regexp = preg_quote(str_replace('"', '', $terms[2]), '/');
 179                                 }
 180                                 $this->searchTerms[] = $regexp;
 181                         }
 182                 }
 183
 184                 $searchon = $this->db->strencode(join(',', $q));
 185                 $field = $this->getIndexField($fulltext);
 186
 187                 // requires Net Search Extender or equivalent
 188                 //return " CONTAINS($field, '$searchon') > 0 ";
 189
 190                 return " lcase($field) LIKE lcase('%$searchon%')";
 191         }
 192
 193         /**
 194          * Create or update the search index record for the given page.
 195          * Title and text should be pre-processed.
 196          *
 197          * @param $id Integer
 198          * @param $title String
 199          * @param $text String
 200          */
 201         function update($id, $title, $text) {
 202                 $dbw = wfGetDB(DB_MASTER);
 203                 $dbw->replace('searchindex',
 204                         array('si_page'),
 205                         array(
 206                                 'si_page' => $id,
 207                                 'si_title' => $title,
 208                                 'si_text' => $text
 209                         ), 'SearchIBM_DB2::update' );
 210                 // ?
 211                 //$dbw->query("CALL ctx_ddl.sync_index('si_text_idx')");
 212                 //$dbw->query("CALL ctx_ddl.sync_index('si_title_idx')");
 213         }
 214
 215         /**
 216          * Update a search index record's title only.
 217          * Title should be pre-processed.
 218          *
 219          * @param $id Integer
 220          * @param $title String
 221          */
 222         function updateTitle($id, $title) {
 223                 $dbw = wfGetDB(DB_MASTER);
 224
 225                 $dbw->update('searchindex',
 226                         array('si_title' => $title),
 227                         array('si_page'  => $id),
 228                         'SearchIBM_DB2::updateTitle',
 229                         array());
 230         }
 231 }