From: Aaron Schulz <aschulz@wikimedia.org>
Date: Tue, 18 Mar 2014 06:47:53 +0000 (-0700)
Subject: Make use of strong consistency with Ceph RGW
X-Git-Tag: 1.31.0-rc.0~16572
X-Git-Url: http://git.cyclocoop.org/%24action?a=commitdiff_plain;h=6112acac292e4a7cf926cf556138e7b711e2c9eb;p=lhc%2Fweb%2Fwiklou.git

Make use of strong consistency with Ceph RGW

Change-Id: Ic3b764363e91c3279d3dc017ddce630dae26bec5
---

diff --git a/includes/filebackend/FileBackendStore.php b/includes/filebackend/FileBackendStore.php
index 16300af3ae..2d8214edc5 100644
--- a/includes/filebackend/FileBackendStore.php
+++ b/includes/filebackend/FileBackendStore.php
@@ -648,7 +648,8 @@ abstract class FileBackendStore extends FileBackend {
 		$stat = $this->doGetFileStat( $params );
 		wfProfileOut( __METHOD__ . '-miss-' . $this->name );
 		if ( is_array( $stat ) ) { // file exists
-			$stat['latest'] = $latest;
+			// Strongly consistent backends can automatically set "latest"
+			$stat['latest'] = isset( $stat['latest'] ) ? $stat['latest'] : $latest;
 			$this->cheapCache->set( $path, 'stat', $stat );
 			$this->setFileCache( $path, $stat ); // update persistent cache
 			if ( isset( $stat['sha1'] ) ) { // some backends store SHA-1 as metadata
@@ -1295,7 +1296,8 @@ abstract class FileBackendStore extends FileBackend {
 				continue; // this shouldn't happen
 			}
 			if ( is_array( $stat ) ) { // file exists
-				$stat['latest'] = $latest;
+				// Strongly consistent backends can automatically set "latest"
+				$stat['latest'] = isset( $stat['latest'] ) ? $stat['latest'] : $latest;
 				$this->cheapCache->set( $path, 'stat', $stat );
 				$this->setFileCache( $path, $stat ); // update persistent cache
 				if ( isset( $stat['sha1'] ) ) { // some backends store SHA-1 as metadata
diff --git a/includes/filebackend/SwiftFileBackend.php b/includes/filebackend/SwiftFileBackend.php
index 706da96c46..7050226985 100644
--- a/includes/filebackend/SwiftFileBackend.php
+++ b/includes/filebackend/SwiftFileBackend.php
@@ -72,6 +72,9 @@ class SwiftFileBackend extends FileBackendStore {
 	/** @var int UNIX timestamp */
 	protected $authErrorTimestamp = null;
 
+	/** @var bool Whether the server is an Ceph RGW */
+	protected $isRGW = false;
+
 	/**
 	 * @see FileBackendStore::__construct()
 	 * Additional $config params include:
@@ -1518,6 +1521,9 @@ class SwiftFileBackend extends FileBackendStore {
 					'md5'   => ctype_xdigit( $rhdrs['etag'] ) ? $rhdrs['etag'] : null,
 					'xattr' => array( 'metadata' => $metadata, 'headers' => $headers )
 				);
+				if ( $this->isRGW ) {
+					$stat['latest'] = true; // strong consistency
+				}
 			} elseif ( $rcode === 404 ) {
 				$stat = false;
 			} else {
@@ -1582,6 +1588,10 @@ class SwiftFileBackend extends FileBackendStore {
 					return null;
 				}
 			}
+			// Ceph RGW does not use <account> in URLs (OpenStack Swift uses "/v1/<account>")
+			if ( substr( $this->authCreds['storage_url'], -3 ) === '/v1' ) {
+				$this->isRGW = true; // take advantage of strong consistency
+			}
 		}
 
 		return $this->authCreds;