<?php
-function wfSpecialRandompage()
-{
- global $wgOut, $wgTitle, $wgArticle;
- $fname = "wfSpecialRandompage";
-
- wfSeedRandom();
- $rand = mt_rand() / mt_getrandmax();
- # 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 );
- } else {
- # No articles?!
- $rt = "";
+/**
+ * Special page to direct the user to a random page
+ *
+ * @addtogroup SpecialPage
+ * @author Rob Church <robchur@gmail.com>, Ilmari Karonen
+ * @license GNU General Public Licence 2.0 or later
+ */
+
+/**
+ * Main execution point
+ * @param $par Namespace to select the page from
+ */
+function wfSpecialRandompage( $par = null ) {
+ global $wgOut, $wgContLang;
+
+ $rnd = new RandomPage();
+ $rnd->setNamespace( $wgContLang->getNsIndex( $par ) );
+ $rnd->setRedirect( false );
+
+ $title = $rnd->getRandomTitle();
+
+ if( is_null( $title ) ) {
+ $wgOut->addWikiText( wfMsg( 'randompage-nopages' ) );
+ return;
+ }
+
+ $wgOut->reportTime();
+ $wgOut->redirect( $title->getFullUrl() );
+}
+
+
+/**
+ * Special page to direct the user to a random page
+ *
+ * @addtogroup SpecialPage
+ */
+class RandomPage {
+ private $namespace = NS_MAIN; // namespace to select pages from
+ private $redirect = false; // select redirects instead of normal pages?
+
+ public function getNamespace ( ) {
+ return $this->namespace;
+ }
+ public function setNamespace ( $ns ) {
+ if( $ns < NS_MAIN ) $ns = NS_MAIN;
+ $this->namespace = $ns;
+ }
+ public function getRedirect ( ) {
+ return $this->redirect;
}
+ public function setRedirect ( $redirect ) {
+ $this->redirect = $redirect;
+ }
+
+ /**
+ * Choose a random title.
+ * @return Title object (or null if nothing to choose from)
+ */
+ public function getRandomTitle ( ) {
+ $randstr = wfRandom();
+ $row = $this->selectRandomPageFromDB( $randstr );
+
+ /* If we picked a value that was higher than any in
+ * the DB, wrap around and select the page with the
+ * lowest value instead! One might think this would
+ * skew the distribution, but in fact it won't cause
+ * any more bias than what the page_random scheme
+ * causes anyway. Trust me, I'm a mathematician. :)
+ */
+ if( !$row )
+ $row = $this->selectRandomPageFromDB( "0" );
+
+ if( $row )
+ return Title::makeTitleSafe( $this->namespace, $row->page_title );
+ else
+ return null;
+ }
+
+ private function selectRandomPageFromDB ( $randstr ) {
+ global $wgExtraRandompageSQL;
+ $fname = 'RandomPage::selectRandomPageFromDB';
- $wgOut->reportTime(); # for logfile
- $wgOut->redirect( wfLocalUrl( $rt ) );
+ $dbr = wfGetDB( DB_SLAVE );
+
+ $use_index = $dbr->useIndexClause( 'page_random' );
+ $page = $dbr->tableName( 'page' );
+
+ $ns = (int) $this->namespace;
+ $redirect = $this->redirect ? 1 : 0;
+
+ $extra = $wgExtraRandompageSQL ? "AND ($wgExtraRandompageSQL)" : "";
+ $sql = "SELECT page_title
+ FROM $page $use_index
+ WHERE page_namespace = $ns
+ AND page_is_redirect = $redirect
+ AND page_random >= $randstr
+ $extra
+ ORDER BY page_random";
+
+ $sql = $dbr->limitResult( $sql, 1, 0 );
+ $res = $dbr->query( $sql, $fname );
+ return $dbr->fetchObject( $res );
+ }
}
-?>
+