[FileBackend] Added getFileHttpUrl() function.

* This can speed up certain video file operations for scripts that support
  specifying source files via URLs and support HTTP Range headers.
* Updated unit tests.

Change-Id: I60cb95c2e3dd9f7df1f740e9182be7c79af69d6e

4 files changed, 63 insertions, 0 deletions

diff --git a/includes/filebackend/FileBackend.php b/includes/filebackend/FileBackend.php
index e01bfc2e5bb0..b5e231540b5d 100644
--- a/includes/filebackend/FileBackend.php
+++ b/includes/filebackend/FileBackend.php
@@ -905,6 +905,24 @@ abstract class FileBackend {
 	abstract public function getLocalCopyMulti( array $params );
 
 	/**
+	 * Return an HTTP URL to a given file that requires no authentication to use.
+	 * The URL may be pre-authenticated (via some token in the URL) and temporary.
+	 * This will return null if the backend cannot make an HTTP URL for the file.
+	 *
+	 * This is useful for key/value stores when using scripts that seek around
+	 * large files and those scripts (and the backend) support HTTP Range headers.
+	 * Otherwise, one would need to use getLocalReference(), which involves loading
+	 * the entire file on to local disk.
+	 *
+	 * @param $params Array
+	 * $params include:
+	 *   - src : source storage path
+	 * @return string|null
+	 * @since 1.21
+	 */
+	abstract public function getFileHttpUrl( array $params );
+
+	/**
 	 * Check if a directory exists at a given storage path.
 	 * Backends using key/value stores will check if the path is a
 	 * virtual directory, meaning there are files under the given directory.
diff --git a/includes/filebackend/FileBackendMultiWrite.php b/includes/filebackend/FileBackendMultiWrite.php
index 90292ee0270a..a443a3aadd92 100644
--- a/includes/filebackend/FileBackendMultiWrite.php
+++ b/includes/filebackend/FileBackendMultiWrite.php
@@ -652,6 +652,15 @@ class FileBackendMultiWrite extends FileBackend {
 	}
 
 	/**
+	 * @see FileBackend::getFileHttpUrl()
+	 * @return string|null
+	 */
+	public function getFileHttpUrl( array $params ) {
+		$realParams = $this->substOpPaths( $params, $this->backends[$this->masterIndex] );
+		return $this->backends[$this->masterIndex]->getFileHttpUrl( $realParams );
+	}
+
+	/**
 	 * @see FileBackend::directoryExists()
 	 * @param $params array
 	 * @return bool|null
diff --git a/includes/filebackend/FileBackendStore.php b/includes/filebackend/FileBackendStore.php
index 7e91949e68d5..97e49a5a0925 100644
--- a/includes/filebackend/FileBackendStore.php
+++ b/includes/filebackend/FileBackendStore.php
@@ -805,6 +805,14 @@ abstract class FileBackendStore extends FileBackend {
 	abstract protected function doGetLocalCopyMulti( array $params );
 
 	/**
+	 * @see FileBackend::getFileHttpUrl()
+	 * @return string|null
+	 */
+	public function getFileHttpUrl( array $params ) {
+		return null; // not supported
+	}
+
+	/**
 	 * @see FileBackend::streamFile()
 	 * @return Status
 	 */
diff --git a/includes/filebackend/SwiftFileBackend.php b/includes/filebackend/SwiftFileBackend.php
index 8441f8fc8ec9..48db9d3c3f12 100644
--- a/includes/filebackend/SwiftFileBackend.php
+++ b/includes/filebackend/SwiftFileBackend.php
@@ -40,6 +40,7 @@ class SwiftFileBackend extends FileBackendStore {
 	/** @var CF_Authentication */
 	protected $auth; // Swift authentication handler
 	protected $authTTL; // integer seconds
+	protected $swiftTempUrlKey; // string; shared secret value for making temp urls
 	protected $swiftAnonUser; // string; username to handle unauthenticated requests
 	protected $swiftUseCDN; // boolean; whether CloudFiles CDN is enabled
 	protected $swiftCDNExpiry; // integer; how long to cache things in the CDN
@@ -66,6 +67,8 @@ class SwiftFileBackend extends FileBackendStore {
 	 *   - swiftUser          : Swift user used by MediaWiki (account:username)
 	 *   - swiftKey           : Swift authentication key for the above user
 	 *   - swiftAuthTTL       : Swift authentication TTL (seconds)
+	 *   - swiftTempUrlKey    : Swift "X-Account-Meta-Temp-URL-Key" value on the account.
+	 *                          Do not set this until it has been set in the backend.
 	 *   - swiftAnonUser      : Swift user used for end-user requests (account:username).
 	 *                          If set, then views of public containers are assumed to go
 	 *                          through this user. If not set, then public containers are
@@ -104,6 +107,9 @@ class SwiftFileBackend extends FileBackendStore {
 		$this->swiftAnonUser = isset( $config['swiftAnonUser'] )
 			? $config['swiftAnonUser']
 			: '';
+		$this->swiftTempUrlKey = isset( $config['swiftTempUrlKey'] )
+			? $config['swiftTempUrlKey']
+			: '';
 		$this->shardViaHashLevels = isset( $config['shardViaHashLevels'] )
 			? $config['shardViaHashLevels']
 			: '';
@@ -1120,6 +1126,28 @@ class SwiftFileBackend extends FileBackendStore {
 	}
 
 	/**
+	 * @see FileBackendStore::getFileHttpUrl()
+	 * @return string|null
+	 */
+	public function getFileHttpUrl( array $params ) {
+		if ( $this->swiftTempUrlKey != '' ) { // temp urls enabled
+			list( $srcCont, $srcRel ) = $this->resolveStoragePathReal( $params['src'] );
+			if ( $srcRel === null ) {
+				return null; // invalid path
+			}
+			try {
+				$sContObj = $this->getContainer( $srcCont );
+				$obj = new CF_Object( $sContObj, $srcRel, false, false ); // skip HEAD
+				return $obj->get_temp_url( $this->swiftTempUrlKey, 86400, "GET" );
+			} catch ( NoSuchContainerException $e ) {
+			} catch ( CloudFilesException $e ) { // some other exception?
+				$this->handleException( $e, null, __METHOD__, $params );
+			}
+		}
+		return null;
+	}
+
+	/**
 	 * @see FileBackendStore::directoriesAreVirtual()
 	 * @return bool
 	 */