The base of the WebSocket clients WsSession and WssSession: connecting, sending, receiving, closing and reconnecting. More...

#include <algotradelib/src/network/ws_session_base.hpp>

Inheritance diagram for algotradelib::network::WebSocketSessionBase< Derived, Stream >:

Collaboration diagram for algotradelib::network::WebSocketSessionBase< Derived, Stream >:

Public Member Functions
void	connect ()
	Connects asynchronously (does nothing if connected, connecting or closing), and re-enables reconnection after a close().
void	send (std::string message)
	Queues a message; messages are sent in order once connected.
void	close ()
	Closes the session asynchronously after any write in progress, and disables reconnection; on_closed is called when done.

Protected Member Functions
	WebSocketSessionBase (net::io_context &ioc, std::string host, std::string port, WebSocketSessionOptions options)
	Constructs the session; nothing connects until connect().
virtual	~WebSocketSessionBase ()=default
	Destroys the session.
virtual void	on_message (std::string_view message)=0
	Called with each complete message received.
virtual void	on_open ()
	Called when the session is connected (after each successful upgrade, reconnects included).
virtual void	on_error (std::string_view stage, beast::error_code error)
	Called after a failed stage has torn the session down; it then reconnects if automatic_reconnect_ is set and close() was not called.
virtual void	on_closed ()
	Called when the session has closed (by close() or by the server).
std::shared_ptr< Derived >	shared_derived ()
	Returns a shared pointer to this session as the transport type.
void	start_resolve ()
	Starts the DNS lookup; called by the transport class's do_connect() once ws_ is ready.
void	start_ws_handshake ()
	Sends the upgrade request; called once connected (WsSession) or after the TLS handshake (WssSession).
bool	abandon_if_closing ()
	Ends a connect that close() interrupted, if it did; called first by each connect stage that completed without an error.
void	fail (std::string_view stage, beast::error_code error)
	Tears the session down after a failure, calls on_error (and on_closed if closing), and schedules a reconnect if configured.

Protected Attributes
net::strand< net::io_context::executor_type >	strand_
	The strand every handler runs on.
tcp::resolver	resolver_
	The resolver.
net::steady_timer	reconnect_timer_
	The reconnect timer.
std::unique_ptr< Stream >	ws_
	The stream, created by the transport class on each connect.
beast::flat_buffer	buffer_
	The read buffer.
std::deque< std::string >	write_queue_
	Messages waiting to be sent; the front one may be being written.
std::string	host_
	The host.
std::string	port_
	The port.
std::string	host_header_
	The Host header value (host:port), set on connect.
WebSocketSessionOptions	options_
	The options.
bool	connected_ {false}
	Whether the session is connected.
bool	connecting_ {false}
	Whether a connect is in progress.
bool	closing_ {false}
	Whether a close is in progress.
bool	writing_ {false}
	Whether a write is in progress.
bool	stop_requested_ {false}
	Whether close() was called (no reconnection).
unsigned int	reconnect_attempt_ {0}
	Reconnect attempts since the last successful connect.
std::minstd_rand	reconnect_rng_
	The random source for reconnect jitter.

Friends
struct	WebSocketSessionTestAccess

Detailed Description

template<typename Derived, typename Stream>
class algotradelib::network::WebSocketSessionBase< Derived, Stream >

The base of the WebSocket clients WsSession and WssSession: connecting, sending, receiving, closing and reconnecting.

To use a session, derive from WsSession or WssSession, override on_message (and optionally on_open, on_error, on_closed), create it with std::make_shared, and call connect(). All handlers run on the session's strand.

Template Parameters

Derived	The transport class (WsSession or WssSession).
Stream	The WebSocket stream type.

Definition at line 72 of file ws_session_base.hpp.

Constructor & Destructor Documentation

◆ WebSocketSessionBase()

template<typename Derived, typename Stream>

algotradelib::network::WebSocketSessionBase< Derived, Stream >::WebSocketSessionBase	(	net::io_context &	ioc,
		std::string	host,
		std::string	port,
		WebSocketSessionOptions	options )

inlineprotected

Constructs the session; nothing connects until connect().

Parameters

ioc	The I/O context.
host	The host.
port	The port.
options	The options.

Definition at line 139 of file ws_session_base.hpp.

Member Function Documentation

◆ abandon_if_closing()

template<typename Derived, typename Stream>

bool algotradelib::network::WebSocketSessionBase< Derived, Stream >::abandon_if_closing ( )

inlineprotected

Ends a connect that close() interrupted, if it did; called first by each connect stage that completed without an error.

close() cancels the stage in progress, but a stage whose completion was already queued arrives without an error. Going on would open a session whose close() is spent: on_closed would never be called, and a later close() would return early because one is in progress.

Returns: true if the session was closing: it is torn down and on_closed has been called.

Definition at line 255 of file ws_session_base.hpp.

◆ close()

template<typename Derived, typename Stream>

void algotradelib::network::WebSocketSessionBase< Derived, Stream >::close ( )

inline

Closes the session asynchronously after any write in progress, and disables reconnection; on_closed is called when done.

Definition at line 106 of file ws_session_base.hpp.

◆ connect()

template<typename Derived, typename Stream>

void algotradelib::network::WebSocketSessionBase< Derived, Stream >::connect ( )

inline

Connects asynchronously (does nothing if connected, connecting or closing), and re-enables reconnection after a close().

Definition at line 78 of file ws_session_base.hpp.

◆ fail()

template<typename Derived, typename Stream>

void algotradelib::network::WebSocketSessionBase< Derived, Stream >::fail	(	std::string_view	stage,
		beast::error_code	error )

inlineprotected

Tears the session down after a failure, calls on_error (and on_closed if closing), and schedules a reconnect if configured.

Parameters

stage	The stage that failed.
error	The error.

Definition at line 275 of file ws_session_base.hpp.

◆ on_closed()

template<typename Derived, typename Stream>

virtual void algotradelib::network::WebSocketSessionBase< Derived, Stream >::on_closed ( )

inlineprotectedvirtual

Called when the session has closed (by close() or by the server).

Definition at line 172 of file ws_session_base.hpp.

Referenced by abandon_if_closing(), and fail().

◆ on_error()

template<typename Derived, typename Stream>

virtual void algotradelib::network::WebSocketSessionBase< Derived, Stream >::on_error	(	std::string_view	stage,
		beast::error_code	error )

inlineprotectedvirtual

Called after a failed stage has torn the session down; it then reconnects if automatic_reconnect_ is set and close() was not called.

Parameters

stage	The stage, such as "connect", "handshake", "read" or "write".
error	The error.

Definition at line 167 of file ws_session_base.hpp.

Referenced by fail().

◆ on_message()

template<typename Derived, typename Stream>

virtual void algotradelib::network::WebSocketSessionBase< Derived, Stream >::on_message ( std::string_view message )

protectedpure virtual

Called with each complete message received.

Parameters

message The message; valid only during the call.

◆ on_open()

template<typename Derived, typename Stream>

virtual void algotradelib::network::WebSocketSessionBase< Derived, Stream >::on_open ( )

inlineprotectedvirtual

Called when the session is connected (after each successful upgrade, reconnects included).

Definition at line 159 of file ws_session_base.hpp.

◆ send()

template<typename Derived, typename Stream>

void algotradelib::network::WebSocketSessionBase< Derived, Stream >::send ( std::string message )

inline

Queues a message; messages are sent in order once connected.

A message whose write failed stays queued and is sent again after a reconnect, so the server may receive it twice. close() does not clear the queue.

Parameters

message The message.

Definition at line 93 of file ws_session_base.hpp.

◆ shared_derived()

template<typename Derived, typename Stream>

std::shared_ptr< Derived > algotradelib::network::WebSocketSessionBase< Derived, Stream >::shared_derived ( )

inlineprotected

Returns a shared pointer to this session as the transport type.

Returns: The pointer.

Definition at line 213 of file ws_session_base.hpp.

Referenced by close(), connect(), send(), start_resolve(), and start_ws_handshake().

◆ start_resolve()

template<typename Derived, typename Stream>

void algotradelib::network::WebSocketSessionBase< Derived, Stream >::start_resolve ( )

inlineprotected

Starts the DNS lookup; called by the transport class's do_connect() once ws_ is ready.

Definition at line 218 of file ws_session_base.hpp.

◆ start_ws_handshake()

template<typename Derived, typename Stream>

void algotradelib::network::WebSocketSessionBase< Derived, Stream >::start_ws_handshake ( )

inlineprotected

Sends the upgrade request; called once connected (WsSession) or after the TLS handshake (WssSession).

Definition at line 229 of file ws_session_base.hpp.

◆ WebSocketSessionTestAccess

template<typename Derived, typename Stream>

friend struct WebSocketSessionTestAccess

friend

Definition at line 293 of file ws_session_base.hpp.

Member Data Documentation

◆ buffer_

template<typename Derived, typename Stream>

beast::flat_buffer algotradelib::network::WebSocketSessionBase< Derived, Stream >::buffer_

protected

The read buffer.

Definition at line 183 of file ws_session_base.hpp.

◆ closing_

template<typename Derived, typename Stream>

bool algotradelib::network::WebSocketSessionBase< Derived, Stream >::closing_ {false}

protected

Whether a close is in progress.

Definition at line 199 of file ws_session_base.hpp.

Referenced by abandon_if_closing(), and fail().

◆ connected_

template<typename Derived, typename Stream>

bool algotradelib::network::WebSocketSessionBase< Derived, Stream >::connected_ {false}

protected

Whether the session is connected.

Definition at line 195 of file ws_session_base.hpp.

Referenced by fail().

◆ connecting_

template<typename Derived, typename Stream>

bool algotradelib::network::WebSocketSessionBase< Derived, Stream >::connecting_ {false}

protected

Whether a connect is in progress.

Definition at line 197 of file ws_session_base.hpp.

Referenced by abandon_if_closing(), fail(), and start_resolve().

◆ host_

template<typename Derived, typename Stream>

std::string algotradelib::network::WebSocketSessionBase< Derived, Stream >::host_

protected

The host.

Definition at line 187 of file ws_session_base.hpp.

Referenced by start_resolve(), and WebSocketSessionBase().

◆ host_header_

template<typename Derived, typename Stream>

std::string algotradelib::network::WebSocketSessionBase< Derived, Stream >::host_header_

protected

The Host header value (host:port), set on connect.

Definition at line 191 of file ws_session_base.hpp.

Referenced by start_ws_handshake().

◆ options_

template<typename Derived, typename Stream>

WebSocketSessionOptions algotradelib::network::WebSocketSessionBase< Derived, Stream >::options_

protected

The options.

Definition at line 193 of file ws_session_base.hpp.

Referenced by start_ws_handshake(), and WebSocketSessionBase().

◆ port_

template<typename Derived, typename Stream>

std::string algotradelib::network::WebSocketSessionBase< Derived, Stream >::port_

protected

The port.

Definition at line 189 of file ws_session_base.hpp.

Referenced by start_resolve(), and WebSocketSessionBase().

◆ reconnect_attempt_

template<typename Derived, typename Stream>

unsigned int algotradelib::network::WebSocketSessionBase< Derived, Stream >::reconnect_attempt_ {0}

protected

Reconnect attempts since the last successful connect.

Definition at line 205 of file ws_session_base.hpp.

◆ reconnect_rng_

template<typename Derived, typename Stream>

std::minstd_rand algotradelib::network::WebSocketSessionBase< Derived, Stream >::reconnect_rng_

protected

The random source for reconnect jitter.

Definition at line 207 of file ws_session_base.hpp.

Referenced by WebSocketSessionBase().

◆ reconnect_timer_

template<typename Derived, typename Stream>

net::steady_timer algotradelib::network::WebSocketSessionBase< Derived, Stream >::reconnect_timer_

protected

The reconnect timer.

Definition at line 179 of file ws_session_base.hpp.

Referenced by WebSocketSessionBase().

◆ resolver_

template<typename Derived, typename Stream>

tcp::resolver algotradelib::network::WebSocketSessionBase< Derived, Stream >::resolver_

protected

The resolver.

Definition at line 177 of file ws_session_base.hpp.

Referenced by start_resolve(), and WebSocketSessionBase().

◆ stop_requested_

template<typename Derived, typename Stream>

bool algotradelib::network::WebSocketSessionBase< Derived, Stream >::stop_requested_ {false}

protected

Whether close() was called (no reconnection).

Definition at line 203 of file ws_session_base.hpp.

◆ strand_

template<typename Derived, typename Stream>

net::strand<net::io_context::executor_type> algotradelib::network::WebSocketSessionBase< Derived, Stream >::strand_

protected

The strand every handler runs on.

Definition at line 175 of file ws_session_base.hpp.

Referenced by close(), connect(), send(), and WebSocketSessionBase().

◆ write_queue_

template<typename Derived, typename Stream>

std::deque<std::string> algotradelib::network::WebSocketSessionBase< Derived, Stream >::write_queue_

protected

Messages waiting to be sent; the front one may be being written.

Definition at line 185 of file ws_session_base.hpp.

◆ writing_

template<typename Derived, typename Stream>

bool algotradelib::network::WebSocketSessionBase< Derived, Stream >::writing_ {false}

protected

Whether a write is in progress.

Definition at line 201 of file ws_session_base.hpp.

Referenced by fail().

◆ ws_

template<typename Derived, typename Stream>

std::unique_ptr<Stream> algotradelib::network::WebSocketSessionBase< Derived, Stream >::ws_

protected

The stream, created by the transport class on each connect.

Definition at line 181 of file ws_session_base.hpp.

Referenced by abandon_if_closing(), fail(), and start_ws_handshake().

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

algotradelib/src/network/ws_session_base.hpp

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ WebSocketSessionBase()

Member Function Documentation

◆ abandon_if_closing()

◆ close()

◆ connect()

◆ fail()

◆ on_closed()

◆ on_error()

◆ on_message()

◆ on_open()

◆ send()

◆ shared_derived()

◆ start_resolve()

◆ start_ws_handshake()

Friends And Related Symbol Documentation

◆ WebSocketSessionTestAccess

Member Data Documentation

◆ buffer_

◆ closing_

◆ connected_

◆ connecting_

◆ host_

◆ host_header_

◆ options_

◆ port_

◆ reconnect_attempt_

◆ reconnect_rng_

◆ reconnect_timer_

◆ resolver_

◆ stop_requested_

◆ strand_

◆ write_queue_

◆ writing_

◆ ws_