Implemented X-Sendfile support

lib/filesystemview.php

@@ -195,6 +195,7 @@ class OC_FilesystemView {
 		return $this->basicOperation('filesize', $path);
 	}
 	public function readfile($path) {
+		$this->addSendfileHeaders($path);
 		@ob_end_clean();
 		$handle=$this->fopen($path, 'rb');
 		if ($handle) {
@@ -208,6 +209,19 @@ class OC_FilesystemView {
 		}
 		return false;
 	}
+	/* This adds the proper header to let the web server handle
+	* the file transfer, if it's configured through the right
+	* environment variable
+	*/
+	private function addSendfileHeaders($path) {
+		$storage = $this->getStorage($path);
+		if ($storage instanceof OC_Filestorage_Local) {
+			if (isset($_SERVER['MOD_X_ACCEL_REDIRECT_ENABLED']))
+				header("X-Accel-Redirect: " . $this->getLocalFile($path));
+			if (isset($_SERVER['MOD_X_SENDFILE_ENABLED']))
+				header("X-Sendfile: " . $this->getLocalFile($path));
+		}
+	}
 	/**
 	* @deprecated Replaced by isReadable() as part of CRUDS
 	*/