Media Galleries API Metadata: SafeMediaMetadataParser and IPCTunnelDataReader.

chrome/utility/media_galleries/ipc_tunnel_data_reader.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_UTILITY_MEDIA_GALLERIES_IPC_TUNNEL_DATA_READER_H_
+#define CHROME_UTILITY_MEDIA_GALLERIES_IPC_TUNNEL_DATA_READER_H_
+
+#include <map>
+
+#include "chrome/utility/media_galleries/media_metadata_parser.h"
+
+namespace metadata {
+
+// Provides the metadata parser with bytes from the browser process via IPC.
+class IPCTunnelDataReader : public metadata::DataReader {
+ public:
+  IPCTunnelDataReader();
+  virtual ~IPCTunnelDataReader();
+
+  virtual void ReadBytes(int64 offset, int64 length,
+                         const ReadBytesCallback& callback) OVERRIDE;
+
+  // Called by ChromeContentUtilityClient when it recieves the requested bytes.
+  void ReceiveBytes(int64 request_id, const std::string& bytes);
+
+ private:
+  std::map<int64, ReadBytesCallback> pending_callbacks_;
+  int64 next_request_id_;
+};
+
+}  // namespace metadata
+
+#endif  // CHROME_UTILITY_MEDIA_GALLERIES_IPC_TUNNEL_DATA_READER_H_