Fixes broken alignment of catlinks in cologneblue and simple skins.

[lhc/web/wiklou.git] / includes / ExternalStoreDB.php

diff --git a/includes/ExternalStoreDB.php b/includes/ExternalStoreDB.php
index 18aa972..fee49f2 100644 (file)
--- a/includes/ExternalStoreDB.php
+++ b/includes/ExternalStoreDB.php
@@ -1,25 +1,5 @@
 <?php
 
-/**
- * External database storage will use one (or more) separate connection pools
- * from what the main wiki uses. If we load many revisions, such as when doing
- * bulk backups or maintenance, we want to keep them around over the lifetime
- * of the script.
- *
- * Associative array of LoadBalancer objects, indexed by cluster name.
- */
-global $wgExternalLoadBalancers;
-$wgExternalLoadBalancers = array();
-
-/**
- * One-step cache variable to hold base blobs; operations that
- * pull multiple revisions may often pull multiple times from
- * the same blob. By keeping the last-used one open, we avoid
- * redundant unserialization and decompression overhead.
- */
-global $wgExternalBlobCache;
-$wgExternalBlobCache = array();
-
 /**
  * DB accessable external objects
  * @ingroup ExternalStorage
@@ -30,28 +10,58 @@ class ExternalStoreDB {
                $this->mParams = $params;
        }
 
-       /** @todo Document.*/
+       /**
+        * Get a LoadBalancer for the specified cluster
+        *
+        * @param $cluster String: cluster name
+        * @return LoadBalancer object
+        */
        function &getLoadBalancer( $cluster ) {
                $wiki = isset($this->mParams['wiki']) ? $this->mParams['wiki'] : false;
-               
+
                return wfGetLBFactory()->getExternalLB( $cluster, $wiki );
        }
 
-       /** @todo Document.*/
+       /**
+        * Get a slave database connection for the specified cluster
+        *
+        * @param $cluster String: cluster name
+        * @return DatabaseBase object
+        */
        function &getSlave( $cluster ) {
+               global $wgDefaultExternalStore;
+
                $wiki = isset($this->mParams['wiki']) ? $this->mParams['wiki'] : false;
                $lb =& $this->getLoadBalancer( $cluster );
+
+               if ( !in_array( "DB://" . $cluster, (array)$wgDefaultExternalStore ) ) {
+                       wfDebug( "read only external store" );
+                       $lb->allowLagged(true);
+               } else {
+                       wfDebug( "writable external store" );
+               }
+
                return $lb->getConnection( DB_SLAVE, array(), $wiki );
        }
 
-       /** @todo Document.*/
+       /**
+        * Get a master database connection for the specified cluster
+        *
+        * @param $cluster String: cluster name
+        * @return DatabaseBase object
+        */
        function &getMaster( $cluster ) {
                $wiki = isset($this->mParams['wiki']) ? $this->mParams['wiki'] : false;
                $lb =& $this->getLoadBalancer( $cluster );
                return $lb->getConnection( DB_MASTER, array(), $wiki );
        }
 
-       /** @todo Document.*/
+       /**
+        * Get the 'blobs' table name for this database
+        *
+        * @param $db DatabaseBase
+        * @return String: table name ('blobs' by default)
+        */
        function getTable( &$db ) {
                $table = $db->getLBInfo( 'blobs table' );
                if ( is_null( $table ) ) {
@@ -62,7 +72,7 @@ class ExternalStoreDB {
 
        /**
         * Fetch data from given URL
-        * @param string $url An url of the form DB://cluster/id or DB://cluster/id/itemid for concatened storage.
+        * @param $url String: an url of the form DB://cluster/id or DB://cluster/id/itemid for concatened storage.
         */
        function fetchFromURL( $url ) {
                $path = explode( '/', $url );
@@ -93,11 +103,18 @@ class ExternalStoreDB {
         * @private
         */
        function &fetchBlob( $cluster, $id, $itemID ) {
-               global $wgExternalBlobCache;
+               /**
+                * One-step cache variable to hold base blobs; operations that
+                * pull multiple revisions may often pull multiple times from
+                * the same blob. By keeping the last-used one open, we avoid
+                * redundant unserialization and decompression overhead.
+                */
+               static $externalBlobCache = array();
+
                $cacheID = ( $itemID === false ) ? "$cluster/$id" : "$cluster/$id/";
-               if( isset( $wgExternalBlobCache[$cacheID] ) ) {
+               if( isset( $externalBlobCache[$cacheID] ) ) {
                        wfDebug( "ExternalStoreDB::fetchBlob cache hit on $cacheID\n" );
-                       return $wgExternalBlobCache[$cacheID];
+                       return $externalBlobCache[$cacheID];
                }
 
                wfDebug( "ExternalStoreDB::fetchBlob cache miss on $cacheID\n" );
@@ -118,7 +135,7 @@ class ExternalStoreDB {
                        $ret = unserialize( $ret );
                }
 
-               $wgExternalBlobCache = array( $cacheID => &$ret );
+               $externalBlobCache = array( $cacheID => &$ret );
                return $ret;
        }
 
@@ -132,8 +149,8 @@ class ExternalStoreDB {
        function store( $cluster, $data ) {
                $dbw = $this->getMaster( $cluster );
                $id = $dbw->nextSequenceValue( 'blob_blob_id_seq' );
-               $dbw->insert( $this->getTable( $dbw ), 
-                       array( 'blob_id' => $id, 'blob_text' => $data ), 
+               $dbw->insert( $this->getTable( $dbw ),
+                       array( 'blob_id' => $id, 'blob_text' => $data ),
                        __METHOD__ );
                $id = $dbw->insertId();
                if ( !$id ) {