Add packet logger and server

webrtc/tools/network_tester/packet_logger.cc

+/*
+ *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "webrtc/tools/network_tester/packet_logger.h"
+
+#include "webrtc/base/checks.h"
+
+namespace webrtc {
+
+PacketLogger::PacketLogger(const std::string& log_file_path)
+    : packet_logger_stream_(log_file_path,
+                            std::ios_base::out | std::ios_base::binary) {
+  RTC_DCHECK(packet_logger_stream_.is_open());
+  RTC_DCHECK(packet_logger_stream_.good());
+}
+
+PacketLogger::~PacketLogger() = default;
+
+void PacketLogger::LogPacket(const NetworkTesterPacket& packet) {
+  std::string log_data;
+  packet.SerializeToString(&log_data);
+  char size = packet.ByteSize();
+  packet_logger_stream_.write(&size, sizeof(size));
+  packet_logger_stream_.write(log_data.data(), log_data.length());
+}
+
+}  // namespace webrtc