third_party/WebKit/Source/modules/peerconnection/RTCDataChannel.cpp

/*
 * Copyright (C) 2012 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "modules/peerconnection/RTCDataChannel.h"

#include "bindings/core/v8/ExceptionState.h"
#include "core/dom/DOMArrayBuffer.h"
#include "core/dom/DOMArrayBufferView.h"
#include "core/dom/ExceptionCode.h"
#include "core/dom/ExecutionContext.h"
#include "core/events/MessageEvent.h"
#include "core/fileapi/Blob.h"
#include "modules/peerconnection/RTCPeerConnection.h"
#include "public/platform/WebRTCPeerConnectionHandler.h"
#include "wtf/PtrUtil.h"
#include <memory>

namespace blink {

static void throwNotOpenException(ExceptionState& exceptionState) {
  exceptionState.throwDOMException(InvalidStateError,
                                   "RTCDataChannel.readyState is not 'open'");
}

static void throwCouldNotSendDataException(ExceptionState& exceptionState) {
  exceptionState.throwDOMException(NetworkError, "Could not send data");
}

static void throwNoBlobSupportException(ExceptionState& exceptionState) {
  exceptionState.throwDOMException(NotSupportedError,
                                   "Blob support not implemented yet");
}

RTCDataChannel* RTCDataChannel::create(
    ExecutionContext* context,
    std::unique_ptr<WebRTCDataChannelHandler> handler) {
  DCHECK(handler);
  RTCDataChannel* channel = new RTCDataChannel(context, std::move(handler));
  channel->suspendIfNeeded();

  return channel;
}

RTCDataChannel* RTCDataChannel::create(
    ExecutionContext* context,
    WebRTCPeerConnectionHandler* peerConnectionHandler,
    const String& label,
    const WebRTCDataChannelInit& init,
    ExceptionState& exceptionState) {
  std::unique_ptr<WebRTCDataChannelHandler> handler =
      wrapUnique(peerConnectionHandler->createDataChannel(label, init));
  if (!handler) {
    exceptionState.throwDOMException(NotSupportedError,
                                     "RTCDataChannel is not supported");
    return nullptr;
  }
  RTCDataChannel* channel = new RTCDataChannel(context, std::move(handler));
  channel->suspendIfNeeded();

  return channel;
}

RTCDataChannel::RTCDataChannel(
    ExecutionContext* context,
    std::unique_ptr<WebRTCDataChannelHandler> handler)
    : ActiveScriptWrappable(this),
      ActiveDOMObject(context),
      m_handler(std::move(handler)),
      m_readyState(ReadyStateConnecting),
      m_binaryType(BinaryTypeArrayBuffer),
      m_scheduledEventTimer(this, &RTCDataChannel::scheduledEventTimerFired),
      m_bufferedAmountLowThreshold(0U),
      m_stopped(false) {
  ThreadState::current()->registerPreFinalizer(this);
  m_handler->setClient(this);
}

RTCDataChannel::~RTCDataChannel() {}

void RTCDataChannel::dispose() {
  if (m_stopped)
    return;

  // Promptly clears a raw reference from content/ to an on-heap object
  // so that content/ doesn't access it in a lazy sweeping phase.
  m_handler->setClient(nullptr);
  m_handler.reset();
}

RTCDataChannel::ReadyState RTCDataChannel::getHandlerState() const {
  return m_handler->state();
}

String RTCDataChannel::label() const {
  return m_handler->label();
}

bool RTCDataChannel::reliable() const {
  return m_handler->isReliable();
}

bool RTCDataChannel::ordered() const {
  return m_handler->ordered();
}

unsigned short RTCDataChannel::maxRetransmitTime() const {
  return m_handler->maxRetransmitTime();
}

unsigned short RTCDataChannel::maxRetransmits() const {
  return m_handler->maxRetransmits();
}

String RTCDataChannel::protocol() const {
  return m_handler->protocol();
}

bool RTCDataChannel::negotiated() const {
  return m_handler->negotiated();
}

unsigned short RTCDataChannel::id() const {
  return m_handler->id();
}

String RTCDataChannel::readyState() const {
  switch (m_readyState) {
    case ReadyStateConnecting:
      return "connecting";
    case ReadyStateOpen:
      return "open";
    case ReadyStateClosing:
      return "closing";
    case ReadyStateClosed:
      return "closed";
  }

  NOTREACHED();
  return String();
}

unsigned RTCDataChannel::bufferedAmount() const {
  return m_handler->bufferedAmount();
}

unsigned RTCDataChannel::bufferedAmountLowThreshold() const {
  return m_bufferedAmountLowThreshold;
}

void RTCDataChannel::setBufferedAmountLowThreshold(unsigned threshold) {
  m_bufferedAmountLowThreshold = threshold;
}

String RTCDataChannel::binaryType() const {
  switch (m_binaryType) {
    case BinaryTypeBlob:
      return "blob";
    case BinaryTypeArrayBuffer:
      return "arraybuffer";
  }
  NOTREACHED();
  return String();
}

void RTCDataChannel::setBinaryType(const String& binaryType,
                                   ExceptionState& exceptionState) {
  if (binaryType == "blob")
    throwNoBlobSupportException(exceptionState);
  else if (binaryType == "arraybuffer")
    m_binaryType = BinaryTypeArrayBuffer;
  else
    exceptionState.throwDOMException(TypeMismatchError,
                                     "Unknown binary type : " + binaryType);
}

void RTCDataChannel::send(const String& data, ExceptionState& exceptionState) {
  if (m_readyState != ReadyStateOpen) {
    throwNotOpenException(exceptionState);
    return;
  }
  if (!m_handler->sendStringData(data)) {
    // FIXME: This should not throw an exception but instead forcefully close
    // the data channel.
    throwCouldNotSendDataException(exceptionState);
  }
}

void RTCDataChannel::send(DOMArrayBuffer* data,
                          ExceptionState& exceptionState) {
  if (m_readyState != ReadyStateOpen) {
    throwNotOpenException(exceptionState);
    return;
  }

  size_t dataLength = data->byteLength();
  if (!dataLength)
    return;

  if (!m_handler->sendRawData(static_cast<const char*>((data->data())),
                              dataLength)) {
    // FIXME: This should not throw an exception but instead forcefully close
    // the data channel.
    throwCouldNotSendDataException(exceptionState);
  }
}

void RTCDataChannel::send(DOMArrayBufferView* data,
                          ExceptionState& exceptionState) {
  if (!m_handler->sendRawData(static_cast<const char*>(data->baseAddress()),
                              data->byteLength())) {
    // FIXME: This should not throw an exception but instead forcefully close
    // the data channel.
    throwCouldNotSendDataException(exceptionState);
  }
}

void RTCDataChannel::send(Blob* data, ExceptionState& exceptionState) {
  // FIXME: implement
  throwNoBlobSupportException(exceptionState);
}

void RTCDataChannel::close() {
  m_handler->close();
}

void RTCDataChannel::didChangeReadyState(
    WebRTCDataChannelHandlerClient::ReadyState newState) {
  if (m_readyState == ReadyStateClosed)
    return;

  m_readyState = newState;

  switch (m_readyState) {
    case ReadyStateOpen:
      scheduleDispatchEvent(Event::create(EventTypeNames::open));
      break;
    case ReadyStateClosed:
      scheduleDispatchEvent(Event::create(EventTypeNames::close));
      break;
    default:
      break;
  }
}

void RTCDataChannel::didDecreaseBufferedAmount(unsigned previousAmount) {
  if (previousAmount > m_bufferedAmountLowThreshold &&
      bufferedAmount() <= m_bufferedAmountLowThreshold) {
    scheduleDispatchEvent(Event::create(EventTypeNames::bufferedamountlow));
  }
}

void RTCDataChannel::didReceiveStringData(const WebString& text) {
  scheduleDispatchEvent(MessageEvent::create(text));
}

void RTCDataChannel::didReceiveRawData(const char* data, size_t dataLength) {
  if (m_binaryType == BinaryTypeBlob) {
    // FIXME: Implement.
    return;
  }
  if (m_binaryType == BinaryTypeArrayBuffer) {
    DOMArrayBuffer* buffer = DOMArrayBuffer::create(data, dataLength);
    scheduleDispatchEvent(MessageEvent::create(buffer));
    return;
  }
  NOTREACHED();
}

void RTCDataChannel::didDetectError() {
  scheduleDispatchEvent(Event::create(EventTypeNames::error));
}

const AtomicString& RTCDataChannel::interfaceName() const {
  return EventTargetNames::RTCDataChannel;
}

ExecutionContext* RTCDataChannel::getExecutionContext() const {
  return ActiveDOMObject::getExecutionContext();
}

// ActiveDOMObject
void RTCDataChannel::suspend() {
  m_scheduledEventTimer.stop();
}

void RTCDataChannel::resume() {
  if (!m_scheduledEvents.isEmpty() && !m_scheduledEventTimer.isActive())
    m_scheduledEventTimer.startOneShot(0, BLINK_FROM_HERE);
}

void RTCDataChannel::stop() {
  if (m_stopped)
    return;

  m_stopped = true;
  m_handler->setClient(nullptr);
  m_handler.reset();
}

// ActiveScriptWrappable
bool RTCDataChannel::hasPendingActivity() const {
  if (m_stopped)
    return false;

  // A RTCDataChannel object must not be garbage collected if its
  // * readyState is connecting and at least one event listener is registered
  //   for open events, message events, error events, or close events.
  // * readyState is open and at least one event listener is registered for
  //   message events, error events, or close events.
  // * readyState is closing and at least one event listener is registered for
  //   error events, or close events.
  // * underlying data transport is established and data is queued to be
  //   transmitted.
  bool hasValidListeners = false;
  switch (m_readyState) {
    case ReadyStateConnecting:
      hasValidListeners |= hasEventListeners(EventTypeNames::open);
    // fallthrough intended
    case ReadyStateOpen:
      hasValidListeners |= hasEventListeners(EventTypeNames::message);
    // fallthrough intended
    case ReadyStateClosing:
      hasValidListeners |= hasEventListeners(EventTypeNames::error) ||
                           hasEventListeners(EventTypeNames::close);
      break;
    default:
      break;
  }

  if (hasValidListeners)
    return true;

  return m_readyState != ReadyStateClosed && bufferedAmount() > 0;
}

void RTCDataChannel::scheduleDispatchEvent(Event* event) {
  m_scheduledEvents.append(event);

  if (!m_scheduledEventTimer.isActive())
    m_scheduledEventTimer.startOneShot(0, BLINK_FROM_HERE);
}

void RTCDataChannel::scheduledEventTimerFired(TimerBase*) {
  HeapVector<Member<Event>> events;
  events.swap(m_scheduledEvents);

  HeapVector<Member<Event>>::iterator it = events.begin();
  for (; it != events.end(); ++it)
    dispatchEvent((*it).release());

  events.clear();
}

DEFINE_TRACE(RTCDataChannel) {
  visitor->trace(m_scheduledEvents);
  EventTargetWithInlineData::trace(visitor);
  ActiveDOMObject::trace(visitor);
}

}  // namespace blink