Media Galleries API Metadata: SafeMediaMetadataParser and IPCTunnelDataReader.

chrome/utility/media_galleries/ipc_data_source.h

+// Copyright 2014 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_DATA_SOURCE_H_
+#define CHROME_UTILITY_MEDIA_GALLERIES_IPC_DATA_SOURCE_H_
+
+#include <map>
+#include <string>
+
+#include "chrome/utility/utility_message_handler.h"
+#include "media/base/data_source.h"
+
+namespace metadata {
+
+// Provides the metadata parser with bytes from the browser process via IPC.
+class IPCDataSource: public media::DataSource,
+                     public chrome::UtilityMessageHandler {
+ public:
+  explicit IPCDataSource(int64 total_size);
+  virtual ~IPCDataSource();
+
+  // Implementation of DataSource.
+  virtual void set_host(media::DataSourceHost* host) OVERRIDE;
+  virtual void Stop(const base::Closure& callback) OVERRIDE;
+  virtual void Read(int64 position, int size, uint8* data,
+                    const ReadCB& read_cb) OVERRIDE;
+  virtual bool GetSize(int64* size_out) OVERRIDE;
+  virtual bool IsStreaming() OVERRIDE;
+  virtual void SetBitrate(int bitrate) OVERRIDE;
+
+  // Implementation of UtilityMessageHandler.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+ private:
+  struct Request {
+    Request();
+    ~Request();
+    uint8* destination;
+    ReadCB callback;
+  };
+
+  void OnRequestBlobBytesFinished(int64 request_id,
+                                  const std::string& bytes);
+
+  const int64 total_size_;
+  std::map<int64, Request> pending_requests_;
+  int64 next_request_id_;
+};
+
+}  // namespace metadata
+
+#endif  // CHROME_UTILITY_MEDIA_GALLERIES_IPC_DATA_SOURCE_H_