Horizon::Networking::Socket< SocketType > Class Template Reference

A Socket object that handles a single connection. More...

#include <Socket.hpp>

Inheritance diagram for Horizon::Networking::Socket< SocketType >:

Collaboration diagram for Horizon::Networking::Socket< SocketType >:

Public Member Functions
	Socket (uint64_t socket_id)
	Socket (uint64_t socket_id, std::shared_ptr< tcp::socket > socket)
virtual	~Socket ()
virtual void	start ()=0
	Initial method invoked once from the network thread that handles the AuthSocket. More...
virtual bool	update ()
	Socket update loop called from its NetworkThread every n nanoseconds. More...
uint64_t	get_socket_id ()
std::string &	remote_ip_address ()
uint16_t	remote_port () const
void	async_read ()
	Asynchronous read operation @thread NetworkThread. More...
void	async_read_with_callback (ByteBuffer &buf, void(Socket< SocketType >::*)(boost::system::error_code, std::size_t))
	Asynchronous read operation with callback handler @thread NetworkThread. More...
virtual void	queue_buffer (ByteBuffer &&buffer)
bool	is_open ()
void	close_socket ()
	Socket close operation that performs cleanups before shutting down the connection. More...
void	delayed_close_socket ()
ByteBuffer &	get_read_buffer ()

Protected Member Functions
virtual void	on_close ()=0
virtual void	read_handler ()=0
virtual void	on_error ()=0
bool	async_process_queue ()
	Socket write operation. More...
void	set_no_delay (bool enable)
	Disable the Nagle Algorithm on our socket. More...
std::size_t	write_buffer_and_send (ByteBuffer &to_send, boost::system::error_code &error)
	Write a message to the buffer. More...

Private Member Functions
void	read_handler_internal (boost::system::error_code error, size_t transferredBytes)
	Aysnchronous reading handler method. More...
void	write_handler_wrapper (boost::system::error_code, std::size_t)
	Write handler wrapper. More...
bool	handle_queue ()
	Handle the queue. More...
std::shared_ptr< tcp::socket >	get_socket ()

Private Attributes
uint64_t	_socket_id
std::shared_ptr< tcp::socket >	_socket
	After accepting, the reference count of this pointer should be 1. More...
std::string	_remote_ip_address
uint16_t	_remote_port
ByteBuffer	_read_buffer
ThreadSafeQueue< ByteBuffer >	_write_queue
std::atomic< bool >	_closed
std::atomic< bool >	_closing
bool	_is_writing_async

Detailed Description

template<class SocketType>
class Horizon::Networking::Socket< SocketType >

A Socket object that handles a single connection.

Sockets are moved into the thread by SocketMgr, once accepted or connected. Once started, the object blocks to handle I/O events and requires explicit stopping.

Template Parameters

SocketType

The type of the Socket object. The Socket object is templated to allow the SocketMgr to handle different types of Socket objects. The Socket object must inherit from the Socket class. The SocketMgr will call the start() method of the Socket object. The Socket object must implement the start() method. The start() method is called once from the NetworkThread. The Socket object must implement the update() method. The update() method is called every n nanoseconds from the NetworkThread.

Parameters

socket_id	The unique identifier of the Socket object.
socket	The boost::asio::ip::tcp::socket object.
_remote_ip_address	The remote IP address of the Socket object.
_remote_port	The remote port of the Socket object.
_read_buffer	The ByteBuffer object that holds the read buffer.
_closed	The atomic boolean that indicates whether the Socket object is closed. The variables are set only from the NetworkThread. Once set, the Socket object will not accept any new read/write requests.
_closing	The atomic boolean that indicates whether the Socket object is closing. The variables are set only from the NetworkThread. Once set, the Socket object will not accept any new write requests. The Socket object will continue to read until the read buffer is empty. Once the read buffer is empty, the Socket object will be closed.
_is_writing_async	The atomic boolean that indicates whether the Socket object is writing asynchronously.
_write_queue	The ThreadSafeQueue object that holds the write queue. The write queue is processed in the NetworkThread.

Constructor & Destructor Documentation

Socket() [1/2]

template<class SocketType >

Horizon::Networking::Socket< SocketType >::Socket ( uint64_t  socket_id )

inlineexplicit

    : _socket_id(socket_id), _socket(nullptr), _read_buffer(), _closed(false), _closing(false), _is_writing_async(false)
    {
        _read_buffer.resize(READ_BLOCK_SIZE);
    }

References Horizon::Networking::Socket< SocketType >::_read_buffer, READ_BLOCK_SIZE, and ByteBuffer::resize().

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Socket() [2/2]

template<class SocketType >

Horizon::Networking::Socket< SocketType >::Socket ( uint64_t  socket_id, std::shared_ptr< tcp::socket >  socket  )

inlineexplicit

    : _socket_id(socket_id), _socket(socket), _remote_ip_address(_socket->remote_endpoint().address().to_string()),
    _remote_port(_socket->remote_endpoint().port()), _read_buffer(), _closed(false), _closing(false), _is_writing_async(false)
    {
        _read_buffer.resize(READ_BLOCK_SIZE);
    }

References Horizon::Networking::Socket< SocketType >::_read_buffer, READ_BLOCK_SIZE, and ByteBuffer::resize().

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~Socket()

template<class SocketType >

virtual Horizon::Networking::Socket< SocketType >::~Socket ( )

inlinevirtual

    {
        boost::system::error_code error;
        _socket->close(error);
    }

References Horizon::Networking::Socket< SocketType >::_socket.

Member Function Documentation

async_process_queue()

template<class SocketType >

bool Horizon::Networking::Socket< SocketType >::async_process_queue ( )

inlineprotected

Socket write operation.

@thread NetworkThread

    {
        if (_is_writing_async)
            return false;
 
        _is_writing_async = true;
 
        _socket->async_write_some(boost::asio::null_buffers(),
                                  boost::bind(&Socket<SocketType>::write_handler_wrapper,
                                              this, boost::placeholders::_1, boost::placeholders::_2));
 
        return true;
    }

References Horizon::Networking::Socket< SocketType >::_is_writing_async, and Horizon::Networking::Socket< SocketType >::_socket.

Referenced by Horizon::Networking::Socket< SocketType >::handle_queue().

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async_read()

template<class SocketType >

void Horizon::Networking::Socket< SocketType >::async_read ( )

inline

Asynchronous read operation @thread NetworkThread.

    {
        if (!is_open())
            return;
 
        _read_buffer.flush();
        _read_buffer.ensure_free_space();
        
        _socket->async_read_some(boost::asio::buffer(_read_buffer.get_write_pointer(), _read_buffer.remaining_space()),
                                 boost::bind(&Socket<SocketType>::read_handler_internal, this, boost::placeholders::_1, boost::placeholders::_2));
    }

References Horizon::Networking::Socket< SocketType >::_read_buffer, Horizon::Networking::Socket< SocketType >::_socket, ByteBuffer::ensure_free_space(), ByteBuffer::flush(), ByteBuffer::get_write_pointer(), Horizon::Networking::Socket< SocketType >::is_open(), and ByteBuffer::remaining_space().

Referenced by Horizon::Networking::Socket< SocketType >::read_handler_internal().

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async_read_with_callback()

template<class SocketType >

void Horizon::Networking::Socket< SocketType >::async_read_with_callback ( ByteBuffer &  buf, void(Socket< SocketType >::*)(boost::system::error_code, std::size_t)    )

inline

Asynchronous read operation with callback handler @thread NetworkThread.

    {
        if (!is_open())
            return;
 
        _read_buffer.flush();
        _read_buffer.ensure_free_space();
 
        _socket->async_read_some(boost::asio::buffer(buf.get_write_pointer(), buf.remaining_space()),
                                 boost::bind(&Socket<SocketType>::read_handler_internal, this, boost::placeholders::_1, boost::placeholders::_2));
    }

References Horizon::Networking::Socket< SocketType >::_read_buffer, Horizon::Networking::Socket< SocketType >::_socket, ByteBuffer::ensure_free_space(), ByteBuffer::flush(), ByteBuffer::get_write_pointer(), Horizon::Networking::Socket< SocketType >::is_open(), and ByteBuffer::remaining_space().

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close_socket()

template<class SocketType >

void Horizon::Networking::Socket< SocketType >::close_socket ( )

inline

Socket close operation that performs cleanups before shutting down the connection.

@thread NetworkThread

Socket finalisation.

    {
        boost::system::error_code socket_error;
 
        if (_closed.exchange(true))
            return;
 
        // Finalise the child-class socket first.
        on_close();
 
        // Shutdown the socket.
        _socket->shutdown(boost::asio::socket_base::shutdown_send, socket_error);
        // Close the socket.
        _socket->close();
 
        if (socket_error) {
            HLog(error) << "Error when shutting down socket from IP " <<
                           remote_ip_address() << "(error code:" << socket_error.value() << " - " << socket_error.message().c_str() << ")";
        }
    }

References Horizon::Networking::Socket< SocketType >::_closed, Horizon::Networking::Socket< SocketType >::_socket, HLog, Horizon::Networking::Socket< SocketType >::on_close(), and Horizon::Networking::Socket< SocketType >::remote_ip_address().

Referenced by Horizon::Networking::Socket< SocketType >::handle_queue(), and Horizon::Networking::Socket< SocketType >::read_handler_internal().

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delayed_close_socket()

template<class SocketType >

void Horizon::Networking::Socket< SocketType >::delayed_close_socket ( )

inline

{ if (_closing.exchange(true)) return; }

References Horizon::Networking::Socket< SocketType >::_closing.

get_read_buffer()

template<class SocketType >

ByteBuffer & Horizon::Networking::Socket< SocketType >::get_read_buffer ( )

inline

{ return _read_buffer; }

References Horizon::Networking::Socket< SocketType >::_read_buffer.

get_socket()

template<class SocketType >

std::shared_ptr< tcp::socket > Horizon::Networking::Socket< SocketType >::get_socket ( )

inlineprivate

{ return _socket; }

References Horizon::Networking::Socket< SocketType >::_socket.

get_socket_id()

template<class SocketType >

uint64_t Horizon::Networking::Socket< SocketType >::get_socket_id ( )

inline

{ return _socket_id; }

References Horizon::Networking::Socket< SocketType >::_socket_id.

handle_queue()

template<class SocketType >

bool Horizon::Networking::Socket< SocketType >::handle_queue ( )

inlineprivate

Handle the queue.

Returns

true if the queue is not empty, false otherwise. @thread NetworkThread

If we have a would block error, we need to re-process the queue.

Re-process queue if we have remaining bytes.

    {
        boost::system::error_code error;
 
        if (_write_queue.empty())
            return false;
 
        std::shared_ptr<ByteBuffer> to_send = _write_queue.front();
 
        //HLog(debug) << "Sent bytes: " << to_send->to_string();
        
        std::size_t bytes_sent = write_buffer_and_send(*to_send, error);
 
        if (error == boost::asio::error::would_block || error == boost::asio::error::try_again)
            return async_process_queue();
 
        if (!error && bytes_sent < to_send->active_length()) {
            to_send->read_completed(bytes_sent);
            return async_process_queue();
        }
 
        // Pop the front element.
        _write_queue.try_pop();
 
        // Close if required.
        if (_closing && _write_queue.empty())
            close_socket();
 
        // Return true if the queue is not empty. Indicating that the sending operation was successful.
        return !_write_queue.empty() && bytes_sent;
    }

References Horizon::Networking::Socket< SocketType >::_closing, Horizon::Networking::Socket< SocketType >::_write_queue, Horizon::Networking::Socket< SocketType >::async_process_queue(), Horizon::Networking::Socket< SocketType >::close_socket(), ThreadSafeQueue< T >::empty(), ThreadSafeQueue< T >::front(), ThreadSafeQueue< T >::try_pop(), and Horizon::Networking::Socket< SocketType >::write_buffer_and_send().

Referenced by Horizon::Networking::Socket< SocketType >::update(), and Horizon::Networking::Socket< SocketType >::write_handler_wrapper().

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is_open()

template<class SocketType >

bool Horizon::Networking::Socket< SocketType >::is_open ( )

inline

{ return !_closed && !_closing; }

References Horizon::Networking::Socket< SocketType >::_closed, and Horizon::Networking::Socket< SocketType >::_closing.

Referenced by Horizon::Networking::Socket< SocketType >::async_read(), and Horizon::Networking::Socket< SocketType >::async_read_with_callback().

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on_close()

template<class SocketType >

virtual void Horizon::Networking::Socket< SocketType >::on_close ( )

protectedpure virtual

Implemented in Horizon::Auth::AuthSocket, Horizon::Char::CharSocket, and Horizon::Zone::ZoneSocket.

Referenced by Horizon::Networking::Socket< SocketType >::close_socket().

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on_error()

template<class SocketType >

virtual void Horizon::Networking::Socket< SocketType >::on_error ( )

protectedpure virtual

Implemented in Horizon::Auth::AuthSocket, Horizon::Char::CharSocket, and Horizon::Zone::ZoneSocket.

Referenced by Horizon::Networking::Socket< SocketType >::read_handler_internal().

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queue_buffer()

template<class SocketType >

virtual void Horizon::Networking::Socket< SocketType >::queue_buffer ( ByteBuffer &&  buffer )

inlinevirtual

{ _write_queue.push(std::move(buffer)); }

References Horizon::Networking::Socket< SocketType >::_write_queue, and ThreadSafeQueue< T >::push().

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read_handler()

template<class SocketType >

virtual void Horizon::Networking::Socket< SocketType >::read_handler ( )

protectedpure virtual

Implemented in Horizon::Auth::AuthSocket, Horizon::Char::CharSocket, and Horizon::Zone::ZoneSocket.

Referenced by Horizon::Networking::Socket< SocketType >::read_handler_internal().

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read_handler_internal()

template<class SocketType >

void Horizon::Networking::Socket< SocketType >::read_handler_internal ( boost::system::error_code  error, size_t  transferredBytes  )

inlineprivate

Aysnchronous reading handler method.

Parameters

error
transferredBytes	@thread NetworkThread

    {
        // If there is an error on the socket, we need to close it.
        if (error) {
            // If the socket is already closed, we don't need to do anything.
            if (error.value() == boost::asio::error::eof) {
                close_socket();
            // If the connection was reset or timed out, we need to close the socket.
            } else if (error.value() == boost::system::errc::connection_reset
                       || error.value() == boost::system::errc::timed_out) {
                on_error();
                close_socket();
            // If there was any unknown error on the socket, we need to close it.
            } else {
                on_error();
                close_socket();
            }
            // Retreive the error code and handle it accordingly.
            switch (error.value())
            {
            case 2: // End of file
                break;
            default:
                HLog(debug) << "Socket::read_handler_internal: " << error.value() << " (Code: " << error.message() << ").";
            }
            return;
        }
 
        if (transferredBytes > 0) {
            // write_completed will move the write pointer forward, so we need to save the current position of the write pointer.
            _read_buffer.write_completed(transferredBytes);
            // read handler will process the data that has been written to the buffer.
            read_handler();
        }
 
        // Invoke the next read operation.
        async_read();
    }

References Horizon::Networking::Socket< SocketType >::_read_buffer, Horizon::Networking::Socket< SocketType >::async_read(), Horizon::Networking::Socket< SocketType >::close_socket(), HLog, Horizon::Networking::Socket< SocketType >::on_error(), Horizon::Networking::Socket< SocketType >::read_handler(), and ByteBuffer::write_completed().

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remote_ip_address()

template<class SocketType >

std::string & Horizon::Networking::Socket< SocketType >::remote_ip_address ( )

inline

{ return _remote_ip_address; }

References Horizon::Networking::Socket< SocketType >::_remote_ip_address.

Referenced by Horizon::Networking::Socket< SocketType >::close_socket(), and Horizon::Networking::Socket< SocketType >::set_no_delay().

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remote_port()

template<class SocketType >

uint16_t Horizon::Networking::Socket< SocketType >::remote_port ( ) const

inline

{ return _remote_port; }

References Horizon::Networking::Socket< SocketType >::_remote_port.

set_no_delay()

template<class SocketType >

void Horizon::Networking::Socket< SocketType >::set_no_delay ( bool  enable )

inlineprotected

Disable the Nagle Algorithm on our socket.

Parameters

enable

    {
        boost::system::error_code error;
        _socket->set_option(tcp::no_delay(enable), error);
        if (error) {
            HLog(error) << "Networking: Socket::set_no_delay: failed to set_option(boost::asio::ip::tcp::no_delay) for IP " << remote_ip_address() << " (error_code: " << error.value() << " - " << error.message().c_str() << ")";
        }
    }

References Horizon::Networking::Socket< SocketType >::_socket, HLog, and Horizon::Networking::Socket< SocketType >::remote_ip_address().

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start()

template<class SocketType >

virtual void Horizon::Networking::Socket< SocketType >::start ( )

pure virtual

Initial method invoked once from the network thread that handles the AuthSocket.

@thread NetworkThread

Implemented in Horizon::Auth::AuthSocket, Horizon::Char::CharSocket, and Horizon::Zone::ZoneSocket.

update()

template<class SocketType >

virtual bool Horizon::Networking::Socket< SocketType >::update ( )

inlinevirtual

Socket update loop called from its NetworkThread every n nanoseconds.

Processes the message queue. @thread NetworkThread

Reimplemented in Horizon::Auth::AuthSocket, Horizon::Char::CharSocket, and Horizon::Zone::ZoneSocket.

    {
        if (_closed)
            return false;
 
        if (_is_writing_async || (_write_queue.empty() && !_closing)) {
            return true;
        }
 
        while (handle_queue())
            ;
 
        return true;
    }

References Horizon::Networking::Socket< SocketType >::_closed, Horizon::Networking::Socket< SocketType >::_closing, Horizon::Networking::Socket< SocketType >::_is_writing_async, Horizon::Networking::Socket< SocketType >::_write_queue, ThreadSafeQueue< T >::empty(), and Horizon::Networking::Socket< SocketType >::handle_queue().

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write_buffer_and_send()

template<class SocketType >

std::size_t Horizon::Networking::Socket< SocketType >::write_buffer_and_send ( ByteBuffer &  to_send, boost::system::error_code &  error  )

inlineprotected

Write a message to the buffer.

Parameters

to_send
error

Returns

    {
        int16_t packet_id;
        std::size_t bytes_to_send = to_send.active_length();
        memcpy(&packet_id, to_send.get_read_pointer(), sizeof(int16_t));
        std::size_t bytes_sent = _socket->write_some(boost::asio::buffer(to_send.get_read_pointer(), bytes_to_send), error);
        return bytes_sent;
    }

References Horizon::Networking::Socket< SocketType >::_socket, ByteBuffer::active_length(), and ByteBuffer::get_read_pointer().

Referenced by Horizon::Networking::Socket< SocketType >::handle_queue().

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write_handler_wrapper()

template<class SocketType >

void Horizon::Networking::Socket< SocketType >::write_handler_wrapper ( boost::system::error_code  , std::size_t    )

inlineprivate

Write handler wrapper.

Parameters

error
transferedBytes

    {
        _is_writing_async = false;
        handle_queue();
    }

References Horizon::Networking::Socket< SocketType >::_is_writing_async, and Horizon::Networking::Socket< SocketType >::handle_queue().

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Member Data Documentation

_closed

template<class SocketType >

std::atomic<bool> Horizon::Networking::Socket< SocketType >::_closed

private

Referenced by Horizon::Networking::Socket< SocketType >::close_socket(), Horizon::Networking::Socket< SocketType >::is_open(), and Horizon::Networking::Socket< SocketType >::update().

_closing

template<class SocketType >

std::atomic<bool> Horizon::Networking::Socket< SocketType >::_closing

private

Referenced by Horizon::Networking::Socket< SocketType >::delayed_close_socket(), Horizon::Networking::Socket< SocketType >::handle_queue(), Horizon::Networking::Socket< SocketType >::is_open(), and Horizon::Networking::Socket< SocketType >::update().

_is_writing_async

template<class SocketType >

bool Horizon::Networking::Socket< SocketType >::_is_writing_async

private

Referenced by Horizon::Networking::Socket< SocketType >::async_process_queue(), Horizon::Networking::Socket< SocketType >::update(), and Horizon::Networking::Socket< SocketType >::write_handler_wrapper().

_read_buffer

template<class SocketType >

ByteBuffer Horizon::Networking::Socket< SocketType >::_read_buffer

private

Referenced by Horizon::Networking::Socket< SocketType >::async_read(), Horizon::Networking::Socket< SocketType >::async_read_with_callback(), Horizon::Networking::Socket< SocketType >::get_read_buffer(), Horizon::Networking::Socket< SocketType >::read_handler_internal(), and Horizon::Networking::Socket< SocketType >::Socket().

_remote_ip_address

template<class SocketType >

std::string Horizon::Networking::Socket< SocketType >::_remote_ip_address

private

Referenced by Horizon::Networking::Socket< SocketType >::remote_ip_address().

_remote_port

template<class SocketType >

uint16_t Horizon::Networking::Socket< SocketType >::_remote_port

private

Referenced by Horizon::Networking::Socket< SocketType >::remote_port().

_socket

template<class SocketType >

std::shared_ptr<tcp::socket> Horizon::Networking::Socket< SocketType >::_socket

private

After accepting, the reference count of this pointer should be 1.

Referenced by Horizon::Networking::Socket< SocketType >::async_process_queue(), Horizon::Networking::Socket< SocketType >::async_read(), Horizon::Networking::Socket< SocketType >::async_read_with_callback(), Horizon::Networking::Socket< SocketType >::close_socket(), Horizon::Networking::Socket< SocketType >::get_socket(), Horizon::Networking::Socket< SocketType >::set_no_delay(), Horizon::Networking::Socket< SocketType >::write_buffer_and_send(), and Horizon::Networking::Socket< SocketType >::~Socket().

_socket_id

template<class SocketType >

uint64_t Horizon::Networking::Socket< SocketType >::_socket_id

private

Referenced by Horizon::Networking::Socket< SocketType >::get_socket_id().

_write_queue

template<class SocketType >

ThreadSafeQueue<ByteBuffer> Horizon::Networking::Socket< SocketType >::_write_queue

private

Referenced by Horizon::Networking::Socket< SocketType >::handle_queue(), Horizon::Networking::Socket< SocketType >::queue_buffer(), and Horizon::Networking::Socket< SocketType >::update().

---

The documentation for this class was generated from the following file:

• src/Libraries/Networking/Socket.hpp