From 616fabe05a2b66e1c7ba7b93a632d2eaa32f184d Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 22 Sep 2016 21:54:49 -0700
Subject: [PATCH] Move FileBackendMultiWrite to /libs

Change-Id: I8079693a62db390028cd9f72b2bd7a81ae1164c3
---
 autoload.php                                             | 2 +-
 includes/DefaultSettings.php                             | 5 +++++
 includes/filebackend/FileBackendGroup.php                | 9 +++++++++
 .../{ => libs}/filebackend/FileBackendMultiWrite.php     | 8 --------
 4 files changed, 15 insertions(+), 9 deletions(-)
 rename includes/{ => libs}/filebackend/FileBackendMultiWrite.php (98%)

diff --git a/autoload.php b/autoload.php
index dd4bb9d1ac..767cb786fe 100644
--- a/autoload.php
+++ b/autoload.php
@@ -458,7 +458,7 @@ $wgAutoloadLocalClasses = [
 	'FileBackendDBRepoWrapper' => __DIR__ . '/includes/filerepo/FileBackendDBRepoWrapper.php',
 	'FileBackendError' => __DIR__ . '/includes/libs/filebackend/FileBackendError.php',
 	'FileBackendGroup' => __DIR__ . '/includes/filebackend/FileBackendGroup.php',
-	'FileBackendMultiWrite' => __DIR__ . '/includes/filebackend/FileBackendMultiWrite.php',
+	'FileBackendMultiWrite' => __DIR__ . '/includes/libs/filebackend/FileBackendMultiWrite.php',
 	'FileBackendStore' => __DIR__ . '/includes/filebackend/FileBackendStore.php',
 	'FileBackendStoreOpHandle' => __DIR__ . '/includes/filebackend/FileBackendStore.php',
 	'FileBackendStoreShardDirIterator' => __DIR__ . '/includes/filebackend/FileBackendStore.php',
diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 8180443347..7facf2fcf7 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -616,6 +616,11 @@ $wgUploadDialog = [
  * Additional parameters are specific to the file backend class used.
  * These settings should be global to all wikis when possible.
  *
+ * FileBackendMultiWrite::__construct() is augmented with a 'template' option that
+ * can be used in any of the values of the 'backends' array. Its value is the name of
+ * another backend in $wgFileBackends. When set, it pre-fills the array with all of the
+ * configuration of the named backend. Explicitly set values in the array take precedence.
+ *
  * There are two particularly important aspects about each backend:
  *   - a) Whether it is fully qualified or wiki-relative.
  *        By default, the paths of files are relative to the current wiki,
diff --git a/includes/filebackend/FileBackendGroup.php b/includes/filebackend/FileBackendGroup.php
index d9e5a540e2..1ebd0b9998 100644
--- a/includes/filebackend/FileBackendGroup.php
+++ b/includes/filebackend/FileBackendGroup.php
@@ -172,6 +172,15 @@ class FileBackendGroup {
 			$config['tmpDirectory'] = wfTempDir();
 			$config['logger'] = LoggerFactory::getInstance( 'FileOperation' );
 			$config['profiler'] = Profiler::instance();
+			if ( $class === 'FileBackendMultiWrite' ) {
+				foreach ( $config['backends'] as $index => $beConfig ) {
+					if ( isset( $beConfig['template'] ) ) {
+						// Config is just a modified version of a registered backend's.
+						// This should only be used when that config is used only by this backend.
+						$config['backends'][$index] += $this->config( $beConfig['template'] );
+					}
+				}
+			}
 
 			$this->backends[$name]['instance'] = new $class( $config );
 		}
diff --git a/includes/filebackend/FileBackendMultiWrite.php b/includes/libs/filebackend/FileBackendMultiWrite.php
similarity index 98%
rename from includes/filebackend/FileBackendMultiWrite.php
rename to includes/libs/filebackend/FileBackendMultiWrite.php
index db79155533..7c32d02e86 100644
--- a/includes/filebackend/FileBackendMultiWrite.php
+++ b/includes/libs/filebackend/FileBackendMultiWrite.php
@@ -74,9 +74,6 @@ class FileBackendMultiWrite extends FileBackend {
 	 *                        - class         : The name of the backend class
 	 *                        - isMultiMaster : This must be set for one backend.
 	 *                        - readAffinity  : Use this for reads without 'latest' set.
-	 *                        - template:     : If given a backend name, this will use
-	 *                                          the config of that backend as a template.
-	 *                                          Values specified here take precedence.
 	 *   - syncChecks     : Integer bitfield of internal backend sync checks to perform.
 	 *                      Possible bits include the FileBackendMultiWrite::CHECK_* constants.
 	 *                      There are constants for SIZE, TIME, and SHA1.
@@ -107,11 +104,6 @@ class FileBackendMultiWrite extends FileBackend {
 		// to keep these backends hidden from outside the proxy.
 		$namesUsed = [];
 		foreach ( $config['backends'] as $index => $config ) {
-			if ( isset( $config['template'] ) ) {
-				// Config is just a modified version of a registered backend's.
-				// This should only be used when that config is used only by this backend.
-				$config = $config + FileBackendGroup::singleton()->config( $config['template'] );
-			}
 			$name = $config['name'];
 			if ( isset( $namesUsed[$name] ) ) { // don't break FileOp predicates
 				throw new LogicException( "Two or more backends defined with the name $name." );
-- 
2.20.1