root/content/renderer/media/rtc_data_channel_handler.cc

DEFINITIONS

1. IncrementCounter
2. webkit_client_
3. setClient
4. label
5. isReliable
6. ordered
7. maxRetransmitTime
8. maxRetransmits
9. protocol
10. negotiated
11. id
12. bufferedAmount
13. sendStringData
14. sendRawData
15. close
16. OnStateChange
17. OnMessage
18. RecordMessageSent

// Copyright (c) 2012 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.

#include "content/renderer/media/rtc_data_channel_handler.h"

#include <string>

#include "base/logging.h"
#include "base/metrics/histogram.h"
#include "base/strings/utf_string_conversions.h"

namespace content {

namespace {

enum DataChannelCounters {
  CHANNEL_CREATED,
  CHANNEL_OPENED,
  CHANNEL_RELIABLE,
  CHANNEL_ORDERED,
  CHANNEL_NEGOTIATED,
  CHANNEL_BOUNDARY
};

void IncrementCounter(DataChannelCounters counter) {
  UMA_HISTOGRAM_ENUMERATION("WebRTC.DataChannelCounters",
                            counter,
                            CHANNEL_BOUNDARY);
}

}  // namespace

RtcDataChannelHandler::RtcDataChannelHandler(
    webrtc::DataChannelInterface* channel)
    : channel_(channel),
      webkit_client_(NULL) {
  DVLOG(1) << "::ctor";
  channel_->RegisterObserver(this);

  IncrementCounter(CHANNEL_CREATED);
  if (isReliable())
    IncrementCounter(CHANNEL_RELIABLE);
  if (ordered())
    IncrementCounter(CHANNEL_ORDERED);
  if (negotiated())
    IncrementCounter(CHANNEL_NEGOTIATED);
}

RtcDataChannelHandler::~RtcDataChannelHandler() {
  DVLOG(1) << "::dtor";
  channel_->UnregisterObserver();
}

void RtcDataChannelHandler::setClient(
    blink::WebRTCDataChannelHandlerClient* client) {
  webkit_client_ = client;
}

blink::WebString RtcDataChannelHandler::label() {
  return base::UTF8ToUTF16(channel_->label());
}

bool RtcDataChannelHandler::isReliable() {
  return channel_->reliable();
}

bool RtcDataChannelHandler::ordered() const {
  return channel_->ordered();
}

unsigned short RtcDataChannelHandler::maxRetransmitTime() const {
  return channel_->maxRetransmitTime();
}

unsigned short RtcDataChannelHandler::maxRetransmits() const {
  return channel_->maxRetransmits();
}

blink::WebString RtcDataChannelHandler::protocol() const {
  return base::UTF8ToUTF16(channel_->protocol());
}

bool RtcDataChannelHandler::negotiated() const {
  return channel_->negotiated();
}

unsigned short RtcDataChannelHandler::id() const {
  return channel_->id();
}

unsigned long RtcDataChannelHandler::bufferedAmount() {
  return channel_->buffered_amount();
}

bool RtcDataChannelHandler::sendStringData(const blink::WebString& data) {
  std::string utf8_buffer = base::UTF16ToUTF8(data);
  talk_base::Buffer buffer(utf8_buffer.c_str(), utf8_buffer.length());
  webrtc::DataBuffer data_buffer(buffer, false);
  RecordMessageSent(data_buffer.size());
  return channel_->Send(data_buffer);
}

bool RtcDataChannelHandler::sendRawData(const char* data, size_t length) {
  talk_base::Buffer buffer(data, length);
  webrtc::DataBuffer data_buffer(buffer, true);
  RecordMessageSent(data_buffer.size());
  return channel_->Send(data_buffer);
}

void RtcDataChannelHandler::close() {
  channel_->Close();
}

void RtcDataChannelHandler::OnStateChange() {
  if (!webkit_client_) {
    LOG(ERROR) << "WebRTCDataChannelHandlerClient not set.";
    return;
  }
  DVLOG(1) << "OnStateChange " << channel_->state();
  switch (channel_->state()) {
    case webrtc::DataChannelInterface::kConnecting:
      webkit_client_->didChangeReadyState(
          blink::WebRTCDataChannelHandlerClient::ReadyStateConnecting);
      break;
    case webrtc::DataChannelInterface::kOpen:
      IncrementCounter(CHANNEL_OPENED);
      webkit_client_->didChangeReadyState(
          blink::WebRTCDataChannelHandlerClient::ReadyStateOpen);
      break;
    case webrtc::DataChannelInterface::kClosing:
      webkit_client_->didChangeReadyState(
          blink::WebRTCDataChannelHandlerClient::ReadyStateClosing);
      break;
    case webrtc::DataChannelInterface::kClosed:
      webkit_client_->didChangeReadyState(
          blink::WebRTCDataChannelHandlerClient::ReadyStateClosed);
      break;
    default:
      NOTREACHED();
      break;
  }
}

void RtcDataChannelHandler::OnMessage(const webrtc::DataBuffer& buffer) {
  if (!webkit_client_) {
    LOG(ERROR) << "WebRTCDataChannelHandlerClient not set.";
    return;
  }

  if (buffer.binary) {
    webkit_client_->didReceiveRawData(buffer.data.data(), buffer.data.length());
  } else {
    base::string16 utf16;
    if (!base::UTF8ToUTF16(buffer.data.data(), buffer.data.length(), &utf16)) {
      LOG(ERROR) << "Failed convert received data to UTF16";
      return;
    }
    webkit_client_->didReceiveStringData(utf16);
  }
}

void RtcDataChannelHandler::RecordMessageSent(size_t num_bytes) {
  // Currently, messages are capped at some fairly low limit (16 Kb?)
  // but we may allow unlimited-size messages at some point, so making
  // the histogram maximum quite large (100 Mb) to have some
  // granularity at the higher end in that eventuality. The histogram
  // buckets are exponentially growing in size, so we'll still have
  // good granularity at the low end.

  // This makes the last bucket in the histogram count messages from
  // 100 Mb to infinity.
  const int kMaxBucketSize = 100 * 1024 * 1024;
  const int kNumBuckets = 50;

  if (isReliable()) {
    UMA_HISTOGRAM_CUSTOM_COUNTS("WebRTC.ReliableDataChannelMessageSize",
                                num_bytes,
                                1, kMaxBucketSize, kNumBuckets);
  } else {
    UMA_HISTOGRAM_CUSTOM_COUNTS("WebRTC.UnreliableDataChannelMessageSize",
                                num_bytes,
                                1, kMaxBucketSize, kNumBuckets);
  }
}

}  // namespace content