includes/SearchMySQL.php

   1 <?php
   2 # Copyright (C) 2004 Brion Vibber <brion@pobox.com>
   3 # http://www.mediawiki.org/
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License along
  16 # with this program; if not, write to the Free Software Foundation, Inc.,
  17 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18 # http://www.gnu.org/copyleft/gpl.html
  19
  20 /**
  21  * Search engine hook base class for MySQL.
  22  * Specific bits for MySQL 3 and 4 variants are in child classes.
  23  * @addtogroup Search
  24  */
  25
  26 class SearchMySQL extends SearchEngine {
  27         /**
  28          * Perform a full text search query and return a result set.
  29          *
  30          * @param string $term - Raw search term
  31          * @return MySQLSearchResultSet
  32          * @access public
  33          */
  34         function searchText( $term ) {
  35                 $resultSet = $this->db->resultObject( $this->db->query( $this->getQuery( $this->filter( $term ), true ) ) );
  36                 return new MySQLSearchResultSet( $resultSet, $this->searchTerms );
  37         }
  38
  39         /**
  40          * Perform a title-only search query and return a result set.
  41          *
  42          * @param string $term - Raw search term
  43          * @return MySQLSearchResultSet
  44          * @access public
  45          */
  46         function searchTitle( $term ) {
  47                 $resultSet = $this->db->resultObject( $this->db->query( $this->getQuery( $this->filter( $term ), false ) ) );
  48                 return new MySQLSearchResultSet( $resultSet, $this->searchTerms );
  49         }
  50
  51
  52         /**
  53          * Return a partial WHERE clause to exclude redirects, if so set
  54          * @return string
  55          * @private
  56          */
  57         function queryRedirect() {
  58                 if( $this->showRedirects ) {
  59                         return '';
  60                 } else {
  61                         return 'AND page_is_redirect=0';
  62                 }
  63         }
  64
  65         /**
  66          * Return a partial WHERE clause to limit the search to the given namespaces
  67          * @return string
  68          * @private
  69          */
  70         function queryNamespaces() {
  71                 $namespaces = implode( ',', $this->namespaces );
  72                 if ($namespaces == '') {
  73                         $namespaces = '0';
  74                 }
  75                 return 'AND page_namespace IN (' . $namespaces . ')';
  76         }
  77
  78         /**
  79          * Return a LIMIT clause to limit results on the query.
  80          * @return string
  81          * @private
  82          */
  83         function queryLimit() {
  84                 return $this->db->limitResult( '', $this->limit, $this->offset );
  85         }
  86
  87         /**
  88          * Does not do anything for generic search engine
  89          * subclasses may define this though
  90          * @return string
  91          * @private
  92          */
  93         function queryRanking( $filteredTerm, $fulltext ) {
  94                 return '';
  95         }
  96
  97         /**
  98          * Construct the full SQL query to do the search.
  99          * The guts shoulds be constructed in queryMain()
 100          * @param string $filteredTerm
 101          * @param bool $fulltext
 102          * @private
 103          */
 104         function getQuery( $filteredTerm, $fulltext ) {
 105                 return $this->queryMain( $filteredTerm, $fulltext ) . ' ' .
 106                         $this->queryRedirect() . ' ' .
 107                         $this->queryNamespaces() . ' ' .
 108                         $this->queryRanking( $filteredTerm, $fulltext ) . ' ' .
 109                         $this->queryLimit();
 110         }
 111
 112
 113         /**
 114          * Picks which field to index on, depending on what type of query.
 115          * @param bool $fulltext
 116          * @return string
 117          */
 118         function getIndexField( $fulltext ) {
 119                 return $fulltext ? 'si_text' : 'si_title';
 120         }
 121
 122         /**
 123          * Get the base part of the search query.
 124          * The actual match syntax will depend on the server
 125          * version; MySQL 3 and MySQL 4 have different capabilities
 126          * in their fulltext search indexes.
 127          *
 128          * @param string $filteredTerm
 129          * @param bool $fulltext
 130          * @return string
 131          * @private
 132          */
 133         function queryMain( $filteredTerm, $fulltext ) {
 134                 $match = $this->parseQuery( $filteredTerm, $fulltext );
 135                 $page        = $this->db->tableName( 'page' );
 136                 $searchindex = $this->db->tableName( 'searchindex' );
 137                 return 'SELECT page_id, page_namespace, page_title ' .
 138                         "FROM $page,$searchindex " .
 139                         'WHERE page_id=si_page AND ' . $match;
 140         }
 141
 142         /**
 143          * Create or update the search index record for the given page.
 144          * Title and text should be pre-processed.
 145          *
 146          * @param int $id
 147          * @param string $title
 148          * @param string $text
 149          */
 150         function update( $id, $title, $text ) {
 151                 $dbw = wfGetDB( DB_MASTER );
 152                 $dbw->replace( 'searchindex',
 153                         array( 'si_page' ),
 154                         array(
 155                                 'si_page' => $id,
 156                                 'si_title' => $title,
 157                                 'si_text' => $text
 158                         ), 'SearchMySQL4::update' );
 159         }
 160
 161         /**
 162          * Update a search index record's title only.
 163          * Title should be pre-processed.
 164          *
 165          * @param int $id
 166          * @param string $title
 167          */
 168     function updateTitle( $id, $title ) {
 169                 $dbw = wfGetDB( DB_MASTER );
 170
 171                 $dbw->update( 'searchindex',
 172                         array( 'si_title' => $title ),
 173                         array( 'si_page'  => $id ),
 174                         'SearchMySQL4::updateTitle',
 175                         array( $dbw->lowPriorityOption() ) );
 176         }
 177 }
 178
 179 class MySQLSearchResultSet extends SearchResultSet {
 180         function MySQLSearchResultSet( $resultSet, $terms ) {
 181                 $this->mResultSet = $resultSet;
 182                 $this->mTerms = $terms;
 183         }
 184
 185         function termMatches() {
 186                 return $this->mTerms;
 187         }
 188
 189         function numRows() {
 190                 return $this->mResultSet->numRows();
 191         }
 192
 193         function next() {
 194                 $row = $this->mResultSet->fetchObject();
 195                 if( $row === false ) {
 196                         return false;
 197                 } else {
 198                         return new SearchResult( $row );
 199                 }
 200         }
 201 }
 202
 203 ?>