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/*
* Copyright 2016 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.
*/
#ifndef WEBRTC_PC_QUICDATACHANNEL_H_
#define WEBRTC_PC_QUICDATACHANNEL_H_
#include <string>
#include <unordered_map>
#include <unordered_set>
#include "webrtc/api/datachannelinterface.h"
#include "webrtc/base/asyncinvoker.h"
#include "webrtc/base/sigslot.h"
#include "webrtc/base/thread.h"
namespace cricket {
class QuicTransportChannel;
class ReliableQuicStream;
class TransportChannel;
} // namepsace cricket
namespace net {
// TODO(mikescarlett): Make this uint64_t once QUIC uses 64-bit ids.
typedef uint32_t QuicStreamId;
} // namespace net
namespace rtc {
class CopyOnWriteBuffer;
} // namespace rtc
namespace webrtc {
// Encodes a QUIC message header with the data channel ID and message ID, then
// stores the result in |header|.
void WriteQuicDataChannelMessageHeader(int data_channel_id,
uint64_t message_id,
rtc::CopyOnWriteBuffer* header);
// Decodes the data channel ID and message ID from the initial data received by
// an incoming QUIC stream. The data channel ID is output to |data_channel_id|,
// the message ID is output to |message_id|, and the number of bytes read is
// output to |bytes_read|. Returns false if either ID cannot be read.
bool ParseQuicDataMessageHeader(const char* data,
size_t len,
int* data_channel_id,
uint64_t* message_id,
size_t* bytes_read);
// QuicDataChannel is an implementation of DataChannelInterface based on the
// QUIC protocol. It uses a QuicTransportChannel to establish encryption and
// transfer data, and a QuicDataTransport to receive incoming messages at
// the correct data channel. Currently this class implements unordered, reliable
// delivery and does not send an "OPEN" message.
//
// Each time a message is sent:
//
// - The QuicDataChannel prepends it with the data channel id and message id.
// The QuicTransportChannel creates a ReliableQuicStream, then the
// ReliableQuicStream sends the message with a FIN.
//
// - The remote QuicSession creates a ReliableQuicStream to receive the data.
// The remote QuicDataTransport dispatches the ReliableQuicStream to the
// QuicDataChannel with the same id as this data channel.
//
// - The remote QuicDataChannel queues data from the ReliableQuicStream. Once
// it receives a QUIC stream frame with a FIN, it provides the message to the
// DataChannelObserver.
//
// TODO(mikescarlett): Implement ordered delivery, unreliable delivery, and
// an OPEN message similar to the one for SCTP.
class QuicDataChannel : public rtc::RefCountedObject<DataChannelInterface>,
public sigslot::has_slots<> {
public:
// Message stores buffered data from the incoming QUIC stream. The QUIC stream
// is provided so that remaining data can be received from the remote peer.
struct Message {
uint64_t id;
rtc::CopyOnWriteBuffer buffer;
cricket::ReliableQuicStream* stream;
};
QuicDataChannel(rtc::Thread* signaling_thread,
rtc::Thread* worker_thread,
rtc::Thread* network_thread,
const std::string& label,
const DataChannelInit& config);
~QuicDataChannel() override;
// DataChannelInterface overrides.
std::string label() const override { return label_; }
bool reliable() const override { return true; }
bool ordered() const override { return false; }
uint16_t maxRetransmitTime() const override { return -1; }
uint16_t maxRetransmits() const override { return -1; }
bool negotiated() const override { return false; }
int id() const override { return id_; }
DataState state() const override { return state_; }
uint64_t buffered_amount() const override { return buffered_amount_; }
std::string protocol() const override { return protocol_; }
void RegisterObserver(DataChannelObserver* observer) override;
void UnregisterObserver() override;
void Close() override;
bool Send(const DataBuffer& buffer) override;
// Called from QuicDataTransport to set the QUIC transport channel that the
// QuicDataChannel sends messages with. Returns false if a different QUIC
// transport channel is already set or |channel| is NULL.
//
// The QUIC transport channel is not set in the constructor to allow creating
// the QuicDataChannel before the PeerConnection has a QUIC transport channel,
// such as before the session description is not set.
bool SetTransportChannel(cricket::QuicTransportChannel* channel);
// Called from QuicDataTransport when an incoming ReliableQuicStream is
// receiving a message received for this data channel. Once this function is
// called, |message| is owned by the QuicDataChannel and should not be
// accessed by the QuicDataTransport.
void OnIncomingMessage(Message&& message);
// Methods for testing.
// Gets the number of outgoing QUIC streams with write blocked data that are
// currently open for this data channel and are not finished writing a
// message. This is equivalent to the size of |write_blocked_quic_streams_|.
size_t GetNumWriteBlockedStreams() const;
// Gets the number of incoming QUIC streams with buffered data that are
// currently open for this data channel and are not finished receiving a
// message. This is equivalent to the size of |incoming_quic_messages_|.
size_t GetNumIncomingStreams() const;
private:
// Callbacks from ReliableQuicStream.
// Called when an incoming QUIC stream in |incoming_quic_messages_| has
// received a QUIC stream frame.
void OnDataReceived(net::QuicStreamId stream_id,
const char* data,
size_t len);
// Called when a write blocked QUIC stream that has been added to
// |write_blocked_quic_streams_| is closed.
void OnWriteBlockedStreamClosed(net::QuicStreamId stream_id, int error);
// Called when an incoming QUIC stream that has been added to
// |incoming_quic_messages_| is closed.
void OnIncomingQueuedStreamClosed(net::QuicStreamId stream_id, int error);
// Called when a write blocked QUIC stream in |write_blocked_quic_streams_|
// has written previously queued data.
void OnQueuedBytesWritten(net::QuicStreamId stream_id,
uint64_t queued_bytes_written);
// Callbacks from |quic_transport_channel_|.
void OnReadyToSend(cricket::TransportChannel* channel);
void OnConnectionClosed();
// Network thread methods.
// Sends the data buffer to the remote peer using an outgoing QUIC stream.
// Returns true if the data buffer can be successfully sent, or if it is
// queued to be sent later.
bool Send_n(const DataBuffer& buffer);
// Worker thread methods.
// Connects the |quic_transport_channel_| signals to this QuicDataChannel,
// then returns the new QuicDataChannel state.
DataState SetTransportChannel_w();
// Closes the QUIC streams associated with this QuicDataChannel.
void Close_w();
// Sets |buffered_amount_|.
void SetBufferedAmount_w(uint64_t buffered_amount);
// Signaling thread methods.
// Triggers QuicDataChannelObserver::OnMessage when a message from the remote
// peer is ready to be read.
void OnMessage_s(const DataBuffer& received_data);
// Triggers QuicDataChannel::OnStateChange if the state change is valid.
// Otherwise does nothing if |state| == |state_| or |state| != kClosed when
// the data channel is closing.
void SetState_s(DataState state);
// Triggers QuicDataChannelObserver::OnBufferedAmountChange when the total
// buffered data changes for a QUIC stream.
void OnBufferedAmountChange_s(uint64_t buffered_amount);
// QUIC transport channel which owns the QUIC session. It is used to create
// a QUIC stream for sending outgoing messages.
cricket::QuicTransportChannel* quic_transport_channel_ = nullptr;
// Signaling thread for DataChannelInterface methods.
rtc::Thread* const signaling_thread_;
// Worker thread for |quic_transport_channel_| callbacks.
rtc::Thread* const worker_thread_;
// Network thread for sending data and |quic_transport_channel_| callbacks.
rtc::Thread* const network_thread_;
rtc::AsyncInvoker invoker_;
// Map of QUIC stream ID => ReliableQuicStream* for write blocked QUIC
// streams.
std::unordered_map<net::QuicStreamId, cricket::ReliableQuicStream*>
write_blocked_quic_streams_;
// Map of QUIC stream ID => Message for each incoming QUIC stream.
std::unordered_map<net::QuicStreamId, Message> incoming_quic_messages_;
// Handles received data from the remote peer and data channel state changes.
DataChannelObserver* observer_ = nullptr;
// QuicDataChannel ID.
int id_;
// Connectivity state of the QuicDataChannel.
DataState state_;
// Total bytes that are buffered among the QUIC streams.
uint64_t buffered_amount_;
// Counter for number of sent messages that is used for message IDs.
uint64_t next_message_id_;
// Variables for application use.
const std::string& label_;
const std::string& protocol_;
};
} // namespace webrtc
#endif // WEBRTC_PC_QUICDATACHANNEL_H_