Factored out a small filebackend getContentType() function

Change-Id: I221483ab4a0ed36ea34c19db1740dfaecf223677

2 files changed, 33 insertions, 14 deletions

diff --git a/includes/filebackend/FileBackendStore.php b/includes/filebackend/FileBackendStore.php
index e976a7aa9c8b..8ff383bd212c 100644
--- a/includes/filebackend/FileBackendStore.php
+++ b/includes/filebackend/FileBackendStore.php
@@ -38,13 +38,16 @@
 abstract class FileBackendStore extends FileBackend {
 	/** @var BagOStuff */
 	protected $memCache;
-	/** @var ProcessCacheLRU */
-	protected $cheapCache; // Map of paths to small (RAM/disk) cache items
-	/** @var ProcessCacheLRU */
-	protected $expensiveCache; // Map of paths to large (RAM/disk) cache items
+	/** @var ProcessCacheLRU Map of paths to small (RAM/disk) cache items */
+	protected $cheapCache;
+	/** @var ProcessCacheLRU Map of paths to large (RAM/disk) cache items */
+	protected $expensiveCache;
 
-	/** @var Array Map of container names to sharding settings */
-	protected $shardViaHashLevels = array(); // (container name => config array)
+	/** @var Array Map of container names to sharding config */
+	protected $shardViaHashLevels = array();
+
+	/** @var callback Method to get the MIME type of files */
+	protected $mimeCallback;
 
 	protected $maxFileSize = 4294967296; // integer bytes (4GiB)
 
@@ -54,11 +57,21 @@ abstract class FileBackendStore extends FileBackend {
 
 	/**
 	 * @see FileBackend::__construct()
+	 * Additional $config params include:
+	 *   - mimeCallback : Callback that takes (storage path, content, file system path) and
+	 *                    returns the MIME type of the file or 'unknown/unknown'. The file
+	 *                    system path parameter should be used if the content one is null.
 	 *
 	 * @param array $config
 	 */
 	public function __construct( array $config ) {
 		parent::__construct( $config );
+		$this->mimeCallback = isset( $config['mimeCallback'] )
+			? $config['mimeCallback']
+			: function( $storagePath, $content, $fsPath ) {
+				// @TODO: handle the case of extension-less files using the contents
+				return StreamFile::contentTypeFromPath( $storagePath ) ?: 'unknown/unknown';
+			};
 		$this->memCache = new EmptyBagOStuff(); // disabled by default
 		$this->cheapCache = new ProcessCacheLRU( self::CACHE_CHEAP_SIZE );
 		$this->expensiveCache = new ProcessCacheLRU( self::CACHE_EXPENSIVE_SIZE );
@@ -1583,6 +1596,18 @@ abstract class FileBackendStore extends FileBackend {
 		}
 		return $opts;
 	}
+
+	/**
+	 * Get the content type to use in HEAD/GET requests for a file
+	 *
+	 * @param string $storagePath
+	 * @param string|null $content File data
+	 * @param string|null $fsPath File system path
+	 * @return MIME type
+	 */
+	protected function getContentType( $storagePath, $content, $fsPath ) {
+		return call_user_func_array( $this->mimeCallback, func_get_args() );
+	}
 }
 
 /**
diff --git a/includes/filebackend/SwiftFileBackend.php b/includes/filebackend/SwiftFileBackend.php
index f3aa14598191..a620f883b951 100644
--- a/includes/filebackend/SwiftFileBackend.php
+++ b/includes/filebackend/SwiftFileBackend.php
@@ -252,10 +252,7 @@ class SwiftFileBackend extends FileBackendStore {
 			// The MD5 here will be checked within Swift against its own MD5.
 			$obj->set_etag( md5( $params['content'] ) );
 			// Use the same content type as StreamFile for security
-			$obj->content_type = StreamFile::contentTypeFromPath( $params['dst'] );
-			if ( !strlen( $obj->content_type ) ) { // special case
-				$obj->content_type = 'unknown/unknown';
-			}
+			$obj->content_type = $this->getContentType( $params['dst'], $params['content'], null );
 			// Set any other custom headers if requested
 			if ( isset( $params['headers'] ) ) {
 				$obj->headers += $this->sanitizeHdrs( $params['headers'] );
@@ -329,10 +326,7 @@ class SwiftFileBackend extends FileBackendStore {
 			// The MD5 here will be checked within Swift against its own MD5.
 			$obj->set_etag( md5_file( $params['src'] ) );
 			// Use the same content type as StreamFile for security
-			$obj->content_type = StreamFile::contentTypeFromPath( $params['dst'] );
-			if ( !strlen( $obj->content_type ) ) { // special case
-				$obj->content_type = 'unknown/unknown';
-			}
+			$obj->content_type = $this->getContentType( $params['dst'], null, $params['src'] );
 			// Set any other custom headers if requested
 			if ( isset( $params['headers'] ) ) {
 				$obj->headers += $this->sanitizeHdrs( $params['headers'] );