Implements RTP header dumping.

chrome/browser/media/webrtc_rtp_dump_writer.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_BROWSER_MEDIA_WEBRTC_RTP_DUMP_WRITER_H_
+#define CHROME_BROWSER_MEDIA_WEBRTC_RTP_DUMP_WRITER_H_
+
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/files/file_path.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "base/time/time.h"
+
+// This class is responsible for creating the compressed RTP header dump file:
+// - Adds the RTP headers to an in-memory buffer.
+// - When the in-memory buffer is full, compresses it, and writes it to the
+//   disk. Drop the packet and notifies the client if the max file size is
+//   reached.
+// - The uncompressed dump follows the standard RTPPlay format
+//   (http://www.cs.columbia.edu/irt/software/rtptools/).
+// - The caller is always responsible for cleaning up the dump file in all
+//   cases.
+// - WebRtcRtpDumpWriter does not stop writing to the dump after the max size
+//   limit is reached. The caller must stop calling WriteRtpPacket instead.
+//
+// This object must run on the IO thread.
+class WebRtcRtpDumpWriter {
+ public:
+  typedef base::Callback<void(bool)> EndDumpCallback;
+
+  // Returns the header length of the RTP packet.
+  static size_t GetRtpHeaderLen(const uint8* packet, size_t length);
+
+  // |dump_path| is the file path of the compressed dump file. |max_dump_size|
+  // is the max size of the compressed dump file in bytes.
+  // |max_dump_size_reached_callback| will be called when the on-disk file size
+  // reaches |max_dump_size|.
+  WebRtcRtpDumpWriter(const base::FilePath& incoming_dump_path,
+                      const base::FilePath& outgoing_dump_path,
+                      size_t max_dump_size,
+                      const base::Closure& max_dump_size_reached_callback);
+
+  virtual ~WebRtcRtpDumpWriter();
+
+  // Adds a RTP packet to the dump. The caller must make sure it's a valid RTP
+  // packet. No validation is done by this method.
+  virtual void WriteRtpPacket(const uint8* packet_header,
+                              size_t header_length,
+                              size_t packet_length,
+                              bool incoming);
+
+  // Flushes the in-memory buffer to the disk and ends the dump.
+  // |finished_callback| will be called to indicate whether the dump is valid.
+  // If this object is destroyed before the operation is finished, the callback
+  // will be canceled and the dump files will be deleted.
+  virtual void EndDump(bool incoming, const EndDumpCallback& finished_callback);
+
+  size_t max_dump_size() const { return max_dump_size_; }
+
+ private:
+  enum FlushResult {
+    // Flushing has succeeded and the dump size is under the max limit.
+    FLUSH_RESULT_SUCCESS,
+    // Nothing has been written to disk and the dump is empty.
+    FLUSH_RESULT_NO_DATA,
+    // Flushing has failed for other reasons.
+    FLUSH_RESULT_FAILURE
+  };
+
+  class FileThreadWorker;
+
+  static bool FlushResultToDumpValidity(FlushResult);
+
+  void FlushBuffer(bool incoming,
+                   bool end_stream,
+                   const EndDumpCallback& callback);
+
+  void OnFlushDone(const EndDumpCallback& callback,
+                   const scoped_ptr<FlushResult>& result,
+                   const scoped_ptr<size_t>& bytes_written);
+
+  // The max limit on the total size of incoming and outgoing dumps on disk.
+  const size_t max_dump_size_;
+
+  // The callback to call when the max size limit is reached.
+  const base::Closure max_dump_size_reached_callback_;
+
+  // The in-memory buffers for the uncompressed dumps.
+  std::vector<uint8> incoming_buffer_;
+  std::vector<uint8> outgoing_buffer_;
+
+  // The time when the first packet is dumped.
+  base::TimeTicks start_time_;
+
+  // The total on-disk size of the compressed incoming and outgoing dumps.
+  size_t total_dump_size_on_disk_;
+
+  // File thread workers must be called and deleted on the FILE thread.
+  scoped_ptr<FileThreadWorker> incoming_file_thread_worker_;
+  scoped_ptr<FileThreadWorker> outgoing_file_thread_worker_;
+
+  base::ThreadChecker thread_checker_;
+
+  base::WeakPtrFactory<WebRtcRtpDumpWriter> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebRtcRtpDumpWriter);
+};
+
+#endif  // CHROME_BROWSER_MEDIA_WEBRTC_RTP_DUMP_WRITER_H_