LinkBatch class for fast batch link lookup in special pages

diff --git a/includes/LinkCache.php b/includes/LinkCache.php
index fae8ff7..4ab4482 100644 (file)
--- a/includes/LinkCache.php
+++ b/includes/LinkCache.php
@@ -389,4 +389,93 @@ class LinkCache {
                }
        }
 }
+
+/**
+ * Class representing a list of titles
+ * The execute() method checks them all for existence and adds them to a LinkCache object
+ */
+class LinkBatch {
+       /** 
+        * 2-d array, first index namespace, second index dbkey, value arbitrary
+        */
+       var $data = array();
+
+       function addObj( $title ) {
+               $this->add( $title->getNamespace(), $title->getDBkey() );
+       }
+
+       function add( $ns, $dbkey ) {
+               if ( !array_key_exists( $ns, $this->data ) ) {
+                       $this->data[$ns] = array();
+               }
+
+               $this->data[$ns][$dbkey] = 1;
+       }
+
+       function execute( &$cache ) {
+               $fname = 'LinkBatch::execute';
+               $namespaces = array();
+
+               if ( !count( $this->data ) ) {
+                       return;
+               }
+
+               wfProfileIn( $fname );
+
+               // Construct query
+               // This is very similar to Parser::replaceLinkHolders
+               $dbr = wfGetDB( DB_SLAVE );
+               $page = $dbr->tableName( 'page' );
+               $sql = "SELECT page_id, page_namespace, page_title FROM $page WHERE ";
+               $first = true;
+               
+               foreach ( $this->data as $ns => $dbkeys ) {
+                       if ( !count( $dbkeys ) ) {
+                               continue;
+                       }
+
+                       if ( $first ) {
+                               $first = false;
+                       } else {
+                               $sql .= ' OR ';
+                       }
+                       $sql .= "(page_namespace=$ns AND page_title IN (";
+
+                       $firstTitle = true;
+                       foreach( $dbkeys as $dbkey => $nothing ) {
+                               if ( $firstTitle ) {
+                                       $firstTitle = false;
+                               } else {
+                                       $sql .= ',';
+                               }
+                               $sql .= $dbr->addQuotes( $dbkey );
+                       }
+
+                       $sql .= '))';
+               }
+               
+               // Do query
+               $res = $dbr->query( $sql, $fname );
+
+               // Process results
+               // For each returned entry, add it to the list of good links, and remove it from $data
+               while ( $row = $dbr->fetchObject( $res ) ) {
+                       $title = Title::makeTitle( $row->page_namespace, $row->page_title );
+                       $cache->addGoodLink( $row->page_id, $title->getPrefixedDBkey() );
+                       unset( $this->data[$row->page_namespace][$row->page_title] );
+               }
+               $dbr->freeResult( $res );
+
+               // The remaining links in $data are bad links, register them as such
+               foreach ( $this->data as $ns => $dbkeys ) {
+                       foreach ( $dbkeys as $dbkey => $nothing ) {
+                               $title = Title::makeTitle( $ns, $dbkey );
+                               $cache->addBadLink( $title->getPrefixedText() );
+                       }
+               }
+
+               wfProfileOut( $fname );
+       }
+}
+
 ?>