| /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ |
| /* |
| * Copyright (c) 2013-2018 Regents of the University of California. |
| * |
| * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions). |
| * |
| * ndn-cxx library is free software: you can redistribute it and/or modify it under the |
| * terms of the GNU Lesser General Public License as published by the Free Software |
| * Foundation, either version 3 of the License, or (at your option) any later version. |
| * |
| * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY |
| * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A |
| * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. |
| * |
| * You should have received copies of the GNU General Public License and GNU Lesser |
| * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see |
| * <http://www.gnu.org/licenses/>. |
| * |
| * See AUTHORS.md for complete list of ndn-cxx authors and contributors. |
| */ |
| |
| #ifndef NDN_TRANSPORT_STREAM_TRANSPORT_IMPL_HPP |
| #define NDN_TRANSPORT_STREAM_TRANSPORT_IMPL_HPP |
| |
| #include "transport.hpp" |
| |
| #include <boost/asio/deadline_timer.hpp> |
| #include <boost/asio/write.hpp> |
| |
| #include <list> |
| |
| namespace ndn { |
| |
| /** \brief Implementation detail of a Boost.Asio-based stream-oriented transport. |
| * \tparam BaseTransport a subclass of Transport |
| * \tparam Protocol a Boost.Asio stream-oriented protocol, e.g. boost::asio::ip::tcp |
| * or boost::asio::local::stream_protocol |
| */ |
| template<typename BaseTransport, typename Protocol> |
| class StreamTransportImpl : public std::enable_shared_from_this<StreamTransportImpl<BaseTransport, Protocol>> |
| { |
| public: |
| typedef StreamTransportImpl<BaseTransport, Protocol> Impl; |
| typedef std::list<Block> BlockSequence; |
| typedef std::list<BlockSequence> TransmissionQueue; |
| |
| StreamTransportImpl(BaseTransport& transport, boost::asio::io_service& ioService) |
| : m_transport(transport) |
| , m_socket(ioService) |
| , m_inputBufferSize(0) |
| , m_isConnecting(false) |
| , m_connectTimer(ioService) |
| { |
| } |
| |
| void |
| connect(const typename Protocol::endpoint& endpoint) |
| { |
| if (!m_isConnecting) { |
| m_isConnecting = true; |
| |
| // Wait at most 4 seconds to connect |
| /// @todo Decide whether this number should be configurable |
| m_connectTimer.expires_from_now(boost::posix_time::seconds(4)); |
| m_connectTimer.async_wait(bind(&Impl::connectTimeoutHandler, this->shared_from_this(), _1)); |
| |
| m_socket.open(); |
| m_socket.async_connect(endpoint, bind(&Impl::connectHandler, this->shared_from_this(), _1)); |
| } |
| } |
| |
| void |
| close() |
| { |
| m_isConnecting = false; |
| |
| boost::system::error_code error; // to silently ignore all errors |
| m_connectTimer.cancel(error); |
| m_socket.cancel(error); |
| m_socket.close(error); |
| |
| m_transport.m_isConnected = false; |
| m_transport.m_isReceiving = false; |
| m_transmissionQueue.clear(); |
| } |
| |
| void |
| pause() |
| { |
| if (m_isConnecting) |
| return; |
| |
| if (m_transport.m_isReceiving) { |
| m_transport.m_isReceiving = false; |
| m_socket.cancel(); |
| } |
| } |
| |
| void |
| resume() |
| { |
| if (m_isConnecting) |
| return; |
| |
| if (!m_transport.m_isReceiving) { |
| m_transport.m_isReceiving = true; |
| m_inputBufferSize = 0; |
| asyncReceive(); |
| } |
| } |
| |
| void |
| send(const Block& wire) |
| { |
| BlockSequence sequence; |
| sequence.push_back(wire); |
| send(std::move(sequence)); |
| } |
| |
| void |
| send(const Block& header, const Block& payload) |
| { |
| BlockSequence sequence; |
| sequence.push_back(header); |
| sequence.push_back(payload); |
| send(std::move(sequence)); |
| } |
| |
| protected: |
| void |
| connectHandler(const boost::system::error_code& error) |
| { |
| m_isConnecting = false; |
| m_connectTimer.cancel(); |
| |
| if (!error) { |
| m_transport.m_isConnected = true; |
| |
| if (!m_transmissionQueue.empty()) { |
| resume(); |
| asyncWrite(); |
| } |
| } |
| else { |
| m_transport.m_isConnected = false; |
| m_transport.close(); |
| BOOST_THROW_EXCEPTION(Transport::Error(error, "error while connecting to the forwarder")); |
| } |
| } |
| |
| void |
| connectTimeoutHandler(const boost::system::error_code& error) |
| { |
| if (error) // e.g., cancelled timer |
| return; |
| |
| m_transport.close(); |
| BOOST_THROW_EXCEPTION(Transport::Error(error, "error while connecting to the forwarder")); |
| } |
| |
| void |
| send(BlockSequence&& sequence) |
| { |
| m_transmissionQueue.emplace_back(sequence); |
| |
| if (m_transport.m_isConnected && m_transmissionQueue.size() == 1) { |
| asyncWrite(); |
| } |
| |
| // if not connected or there is transmission in progress (m_transmissionQueue.size() > 1), |
| // next write will be scheduled either in connectHandler or in asyncWriteHandler |
| } |
| |
| void |
| asyncWrite() |
| { |
| BOOST_ASSERT(!m_transmissionQueue.empty()); |
| boost::asio::async_write(m_socket, m_transmissionQueue.front(), |
| bind(&Impl::handleAsyncWrite, this->shared_from_this(), _1, m_transmissionQueue.begin())); |
| } |
| |
| void |
| handleAsyncWrite(const boost::system::error_code& error, TransmissionQueue::iterator queueItem) |
| { |
| if (error) { |
| if (error == boost::system::errc::operation_canceled) { |
| // async receive has been explicitly cancelled (e.g., socket close) |
| return; |
| } |
| |
| m_transport.close(); |
| BOOST_THROW_EXCEPTION(Transport::Error(error, "error while sending data to socket")); |
| } |
| |
| if (!m_transport.m_isConnected) { |
| return; // queue has been already cleared |
| } |
| |
| m_transmissionQueue.erase(queueItem); |
| |
| if (!m_transmissionQueue.empty()) { |
| asyncWrite(); |
| } |
| } |
| |
| void |
| asyncReceive() |
| { |
| m_socket.async_receive(boost::asio::buffer(m_inputBuffer + m_inputBufferSize, |
| MAX_NDN_PACKET_SIZE - m_inputBufferSize), 0, |
| bind(&Impl::handleAsyncReceive, this->shared_from_this(), _1, _2)); |
| } |
| |
| void |
| handleAsyncReceive(const boost::system::error_code& error, std::size_t nBytesRecvd) |
| { |
| if (error) { |
| if (error == boost::system::errc::operation_canceled) { |
| // async receive has been explicitly cancelled (e.g., socket close) |
| return; |
| } |
| |
| m_transport.close(); |
| BOOST_THROW_EXCEPTION(Transport::Error(error, "error while receiving data from socket")); |
| } |
| |
| m_inputBufferSize += nBytesRecvd; |
| // do magic |
| |
| std::size_t offset = 0; |
| bool hasProcessedSome = processAllReceived(m_inputBuffer, offset, m_inputBufferSize); |
| if (!hasProcessedSome && m_inputBufferSize == MAX_NDN_PACKET_SIZE && offset == 0) { |
| m_transport.close(); |
| BOOST_THROW_EXCEPTION(Transport::Error(boost::system::error_code(), |
| "input buffer full, but a valid TLV cannot be " |
| "decoded")); |
| } |
| |
| if (offset > 0) { |
| if (offset != m_inputBufferSize) { |
| std::copy(m_inputBuffer + offset, m_inputBuffer + m_inputBufferSize, m_inputBuffer); |
| m_inputBufferSize -= offset; |
| } |
| else { |
| m_inputBufferSize = 0; |
| } |
| } |
| |
| asyncReceive(); |
| } |
| |
| bool |
| processAllReceived(uint8_t* buffer, size_t& offset, size_t nBytesAvailable) |
| { |
| while (offset < nBytesAvailable) { |
| bool isOk = false; |
| Block element; |
| std::tie(isOk, element) = Block::fromBuffer(buffer + offset, nBytesAvailable - offset); |
| if (!isOk) |
| return false; |
| |
| m_transport.receive(element); |
| offset += element.size(); |
| } |
| return true; |
| } |
| |
| protected: |
| BaseTransport& m_transport; |
| |
| typename Protocol::socket m_socket; |
| uint8_t m_inputBuffer[MAX_NDN_PACKET_SIZE]; |
| size_t m_inputBufferSize; |
| |
| TransmissionQueue m_transmissionQueue; |
| bool m_isConnecting; |
| |
| boost::asio::deadline_timer m_connectTimer; |
| }; |
| |
| } // namespace ndn |
| |
| #endif // NDN_TRANSPORT_STREAM_TRANSPORT_IMPL_HPP |