Performance crusade in SpecialListredirects:

* Use the rd_* fields to build redirect objects directly rather than running additional queries to grab them
** If the rd_* fields are not available (i.e. when running from cache), use Article::getRedirectTarget() rather than grabbing the revision text
* Preload the existence status of the redirects and their targets in a LinkBatch so Linker::link() won't query them one at a time

diff --git a/includes/specials/SpecialListredirects.php b/includes/specials/SpecialListredirects.php
index 8504662..21f8aec 100644 (file)
--- a/includes/specials/SpecialListredirects.php
+++ b/includes/specials/SpecialListredirects.php
@@ -45,6 +45,8 @@ class ListredirectsPage extends QueryPage {
                                        'p1.page_title AS title',
                                        'rd_namespace',
                                        'rd_title',
+                                       'rd_fragment',
+                                       'rd_interwiki',
                                        'p2.page_id AS redirid' ),
                        'conds' => array( 'p1.page_is_redirect' => 1 ),
                        'join_conds' => array( 'redirect' => array(
@@ -58,6 +60,37 @@ class ListredirectsPage extends QueryPage {
        function getOrderFields() {
                return array ( 'p1.page_namespace', 'p1.page_title' );
        }
+       
+       /**
+        * Cache page existence for performance
+        */
+       function preprocessResults( $db, $res ) {
+               $batch = new LinkBatch;
+               foreach ( $res as $row ) {
+                       $batch->add( $row->namespace, $row->title );
+                       $batch->addObj( $this->getRedirectTarget( $row ) );
+               }
+               $batch->execute();
+
+               // Back to start for display
+               if ( $db->numRows( $res ) > 0 ) {
+                       // If there are no rows we get an error seeking.
+                       $db->dataSeek( $res, 0 );
+               }
+       }
+       
+       protected function getRedirectTarget( $row ) {
+               if ( isset( $row->rd_title ) ) {
+                       return Title::makeTitle( $row->rd_namespace,
+                               $row->rd_title, $row->rd_fragment,
+                               $row->rd_interwiki
+                       );
+               } else {
+                       $title = Title::makeTitle( $row->namespace, $row->title );
+                       $article = new Article( $title );
+                       return $article->getRedirectTarget();
+               }
+       }
 
        function formatResult( $skin, $result ) {
                global $wgContLang;
@@ -72,17 +105,12 @@ class ListredirectsPage extends QueryPage {
                );
 
                # Find out where the redirect leads
-               $revision = Revision::newFromTitle( $rd_title );
-               if( $revision ) {
+               $target = $this->getRedirectTarget( $result );
+               if( $target ) {
                        # Make a link to the destination page
-                       $target = Title::newFromRedirect( $revision->getText() );
-                       if( $target ) {
-                               $arr = $wgContLang->getArrow() . $wgContLang->getDirMark();
-                               $targetLink = $skin->link( $target );
-                               return "$rd_link $arr $targetLink";
-                       } else {
-                               return "<del>$rd_link</del>";
-                       }
+                       $arr = $wgContLang->getArrow() . $wgContLang->getDirMark();
+                       $targetLink = $skin->link( $target );
+                       return "$rd_link $arr $targetLink";
                } else {
                        return "<del>$rd_link</del>";
                }