diff -r 000000000000 -r 6474c204b198 toolkit/mozapps/update/updater/archivereader.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/mozapps/update/updater/archivereader.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ArchiveReader_h__
+#define ArchiveReader_h__
+
+#include "mozilla/NullPtr.h"
+#include <stdio.h>
+#include "mar.h"
+
+#ifdef XP_WIN
+  typedef WCHAR NS_tchar;
+#else
+  typedef char NS_tchar;
+#endif
+
+// This class provides an API to extract files from an update archive.
+class ArchiveReader
+{
+public:
+  ArchiveReader() : mArchive(nullptr) {}
+  ~ArchiveReader() { Close(); }
+
+  int Open(const NS_tchar *path);
+  int VerifySignature();
+  int VerifyProductInformation(const char *MARChannelID, 
+                               const char *appVersion);
+  void Close();
+
+  int ExtractFile(const char *item, const NS_tchar *destination);
+  int ExtractFileToStream(const char *item, FILE *fp);
+
+private:
+  int ExtractItemToStream(const MarItem *item, FILE *fp);
+
+  MarFile *mArchive;
+};
+
+#endif  // ArchiveReader_h__