<?php
+
/**
+ * 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
*/
/**
- * Constructor
- *
- * @param $par The namespace to get a random page from (default NS_MAIN),
- * used as e.g. Special:Randompage/Category
+ * Main execution point
+ * @param $par Namespace to select the page from
*/
-function wfSpecialRandompage( $par = NS_MAIN ) {
- global $wgOut, $wgExtraRandompageSQL;
- $fname = 'wfSpecialRandompage';
-
- # Determine namespace
- $t = Title::newFromText ( $par . ":Dummy" ) ;
- $namespace = $t->getNamespace () ;
-
- # 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 = wfRandom();
-
- $db = wfGetDB( DB_SLAVE );
- $use_index = $db->useIndexClause( 'page_random' );
- $page = $db->tableName( 'page' );
-
- $extra = $wgExtraRandompageSQL ? "AND ($wgExtraRandompageSQL)" : '';
- $sql = "SELECT page_id,page_title
- FROM $page $use_index
- WHERE page_namespace=$namespace AND page_is_redirect=0 $extra
- AND page_random>$randstr
- ORDER BY page_random";
- $sql = $db->limitResult($sql, 1, 0);
- $res = $db->query( $sql, $fname );
-
- $title = null;
- if( $s = $db->fetchObject( $res ) ) {
- $title =& Title::makeTitle( $namespace, $s->page_title );
- }
+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 ) ) {
- # That's not supposed to happen :)
- $title = Title::newMainPage();
+ $wgOut->addWikiText( wfMsg( 'randompage-nopages' ) );
+ return;
}
- $wgOut->reportTime(); # for logfile
+
+ $wgOut->reportTime();
$wgOut->redirect( $title->getFullUrl() );
}
+
+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( $randstr );
+
+ if( !$row ) {
+ // Try again with a normalized value
+ $randstr = wfRandom( $this->getMaxPageRandom() );
+ $row = $this->selectRandomPageFromDB( $randstr );
+ }
+
+ if( $row )
+ return Title::makeTitleSafe( $this->namespace, $row->page_title );
+ else
+ return null;
+ }
+
+ private function selectRandomPageFromDB ( $randstr ) {
+ global $wgExtraRandompageSQL;
+ $fname = 'RandomPage::selectRandomPageFromDB';
+
+ $dbr = wfGetDB( DB_SLAVE );
+
+ $from = $this->getSQLFrom( $dbr );
+ $where = $this->getSQLWhere( $dbr );
+
+ $sql = "SELECT page_title FROM $from
+ WHERE $where AND page_random > $randstr
+ ORDER BY page_random";
+
+ $sql = $dbr->limitResult( $sql, 1, 0 );
+ $res = $dbr->query( $sql, $fname );
+ return $dbr->fetchObject( $res );
+ }
+
+ private function getMaxPageRandom () {
+ $fname = 'RandomPage::getMaxPageRandom';
+
+ $dbr = wfGetDB( DB_SLAVE );
+
+ $from = $this->getSQLFrom( $dbr );
+ $where = $this->getSQLWhere( $dbr );
+
+ $sql = "SELECT MAX(page_random) AS max FROM $from WHERE $where";
+
+ $sql = $dbr->limitResult( $sql, 1, 0 );
+ $res = $dbr->query( $sql, $fname );
+ $row = $dbr->fetchObject( $res );
+
+ return $row ? $row->max : 0;
+ }
+
+ private function getSQLFrom ( $dbr ) {
+ $use_index = $dbr->useIndexClause( 'page_random' );
+ $page = $dbr->tableName( 'page' );
+ return "$page $use_index";
+ }
+
+ private function getSQLWhere ( $dbr ) {
+ global $wgExtraRandompageSQL;
+ $ns = (int) $this->namespace;
+ $redirect = $this->redirect ? 1 : 0;
+ $extra = $wgExtraRandompageSQL ? " AND ($wgExtraRandompageSQL)" : "";
+ return "page_namespace = $ns AND page_is_redirect = $redirect" . $extra;
+ }
+}
+
?>
* Special page to direct the user to a random redirect page (minus the second redirect)
*
* @addtogroup SpecialPage
- * @author Rob Church <robchur@gmail.com>
+ * @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 redirect from
*/
-function wfSpecialRandomredirect( $par = NULL ) {
- global $wgOut, $wgExtraRandompageSQL, $wgContLang;
- $fname = 'wfSpecialRandomredirect';
+function wfSpecialRandomredirect( $par = null ) {
+ global $wgOut, $wgContLang;
- # Validate the namespace
- $namespace = $wgContLang->getNsIndex( $par );
- if( $namespace === false || $namespace < NS_MAIN )
- $namespace = NS_MAIN;
+ $rnd = new RandomPage();
+ $rnd->setNamespace( $wgContLang->getNsIndex( $par ) );
+ $rnd->setRedirect( true );
- # Same logic as RandomPage
- $randstr = wfRandom();
+ $title = $rnd->getRandomTitle();
- $dbr = wfGetDB( DB_SLAVE );
- $use_index = $dbr->useIndexClause( 'page_random' );
- $page = $dbr->tableName( 'page' );
+ if( is_null( $title ) ) {
+ $wgOut->addWikiText( wfMsg( 'randomredirect-nopages' ) );
+ return;
+ }
- $extra = $wgExtraRandompageSQL ? "AND ($wgExtraRandompageSQL)" : '';
- $sql = "SELECT page_id,page_title
- FROM $page $use_index
- WHERE page_namespace = $namespace AND page_is_redirect = 1 $extra
- AND page_random > $randstr
- ORDER BY page_random";
-
- $sql = $dbr->limitResult( $sql, 1, 0 );
- $res = $dbr->query( $sql, $fname );
-
- $title = NULL;
- if( $row = $dbr->fetchObject( $res ) )
- $title = Title::makeTitleSafe( $namespace, $row->page_title );
-
- # Catch dud titles and return to the main page
- if( is_null( $title ) )
- $title = Title::newMainPage();
-
$wgOut->reportTime();
$wgOut->redirect( $title->getFullUrl( 'redirect=no' ) );
}