<?php
+/**
+ * @package MediaWiki
+ * @subpackage SpecialPage
+ */
-function wfSpecialRandompage()
-{
- global $wgOut, $wgTitle, $wgArticle;
- $fname = "wfSpecialRandompage";
+/**
+ * Constructor
+ */
+function wfSpecialRandompage() {
+ global $wgOut, $wgTitle, $wgArticle, $wgExtraRandompageSQL;
+ $fname = 'wfSpecialRandompage';
- wfSeedRandom();
- $rand = mt_rand() / mt_getrandmax();
+ # NOTE! We use a literal constant in the SQL instead of the RAND()
+ # function because RAND() will return a different value for every row
+ # in the table. That's both very slow and returns results heavily
+ # biased towards low values, as rows later in the table will likely
+ # never be reached for comparison.
+ #
+ # Using a literal constant means the whole thing gets optimized on
+ # the index, and the comparison is both fast and fair.
+
# interpolation and sprintf() can muck up with locale-specific decimal separator
- $randstr = number_format( $rand, 12, ".", "" );
- $sqlget = "SELECT cur_id,cur_title
- FROM cur USE INDEX (cur_random)
- WHERE cur_namespace=0 AND cur_is_redirect=0
- AND cur_random>$randstr
- ORDER BY cur_random
- LIMIT 1";
- $res = wfQuery( $sqlget, DB_READ, $fname );
- if( $s = wfFetchObject( $res ) ) {
- $rt = wfUrlEncode( $s->cur_title );
+ $randstr = wfRandom();
+
+ $db =& wfGetDB( DB_SLAVE );
+ $use_index = $db->useIndexClause( 'page_random' );
+ $page = $db->tableName( 'page' );
+
+ if ( $wgExtraRandompageSQL ) {
+ $extra = "AND ($wgExtraRandompageSQL)";
} else {
- # No articles?!
- $rt = "";
+ $extra = '';
+ }
+ $sqlget = "SELECT page_id,page_title
+ FROM $page $use_index
+ WHERE page_namespace=".NS_MAIN." AND page_is_redirect=0 $extra
+ AND page_random>$randstr
+ ORDER BY page_random
+ LIMIT 1";
+ $res = $db->query( $sqlget, $fname );
+
+ $title = null;
+ if( $s = $db->fetchObject( $res ) ) {
+ $title =& Title::makeTitle( NS_MAIN, $s->page_title );
+ }
+ if( is_null( $title ) ) {
+ # That's not supposed to happen :)
+ $title =& Title::newFromText( wfMsg( 'mainpage' ) );
}
-
$wgOut->reportTime(); # for logfile
- $wgOut->redirect( wfLocalUrl( $rt ) );
+ $wgOut->redirect( $title->getFullUrl() );
}
?>