dfx::Client::SocketClient Class Reference

Event-driven JSON socket client. More...

#include <dfx-client/SocketClient.hpp>

Public Types
using	Callback = std::move_only_function<void (Message)>
	Callback type used to deliver a received message or a response.

Public Member Functions
	SocketClient (FdWatch::Poller &poller, fs::path socketPath, int version=1)
	Construct a socket client bound to a poller.
	DFX_PRIVATE_STATE_DECLARE_RULE_OF_5 (SocketClient)
bool	isConnected () const noexcept
	Check whether the client is currently connected.
void	reconnect ()
	Attempt to (re)establish the connection. Previous connection (if any) will be closed if this function doesn't throw an exception.
void	disconnect ()
	Disconnect from the server and release underlying resources. If willAutoReconnect() returns true then a reconnection will be immediately attempted.
bool	willAutoReconnect () const noexcept
	Return whether the client will automatically attempt to reconnect.
void	setAutoReconnect (bool shouldReconnect)
	Enable or disable automatic reconnection.
void	setMessageCallback (Callback cb)
	Set the callback invoked for incoming messages.
std::string	sendCommand (std::string_view cmd, nlohmann::json const &params, Callback cb=nullptr, std::string_view id={})
	Send a request/command to the server.
void	sendNotification (nlohmann::json json)
	Send a one-way notification to the server.

Static Public Member Functions
static std::string	generateRequestId ()
	Generate a new request identifier.

Detailed Description

Event-driven JSON socket client.

SocketClient manages a client connection to a server via a Unix socket endpoint identified by a filesystem path (see constructor). It integrates with an external event loop through dfx::FdWatch::Poller.

The client supports:

• Connecting/disconnecting and manual reconnection.
• Optional automatic reconnection (toggle via setAutoReconnect()).
• Receiving incoming messages via a user callback set with setMessageCallback().
• Sending:
  • request/command messages expecting a response (via sendCommand()),
  • one-way notifications (via sendNotification()).

Requests and responses are wrapped as dfx::Client::Message objects on reception/dispatch.

Member Typedef Documentation

Callback

using dfx::Client::SocketClient::Callback = std::move_only_function<void (Message)>

Callback type used to deliver a received message or a response.

Constructor & Destructor Documentation

SocketClient()

dfx::Client::SocketClient::SocketClient	(	FdWatch::Poller &	poller,
		fs::path	socketPath,
		int	version = 1 )

Construct a socket client bound to a poller.

Parameters

poller	Event poller used to watch the underlying socket fd and dispatch callbacks.
socketPath	Path identifying the socket endpoint to connect to.
version	Protocol version to use (default: 1).

Member Function Documentation

disconnect()

void dfx::Client::SocketClient::disconnect

(

)

Disconnect from the server and release underlying resources. If willAutoReconnect() returns true then a reconnection will be immediately attempted.

generateRequestId()

std::string dfx::Client::SocketClient::generateRequestId ( )

static

Generate a new request identifier.

The format/uniqueness guarantees are implementation-defined, but it is intended for use with sendCommand().

Returns

A newly generated request id as a string.

isConnected()

bool dfx::Client::SocketClient::isConnected ( ) const

noexcept

Check whether the client is currently connected.

reconnect()

void dfx::Client::SocketClient::reconnect

(

)

Attempt to (re)establish the connection. Previous connection (if any) will be closed if this function doesn't throw an exception.

sendCommand()

std::string dfx::Client::SocketClient::sendCommand	(	std::string_view	cmd,
		nlohmann::json const &	params,
		Callback	cb = nullptr,
		std::string_view	id = {} )

Send a request/command to the server.

This method is intended for request/response interactions. If cb is provided, it is associated with the request id and invoked once a corresponding response is received.

Parameters

cmd	Command name/string.
params	Parameters encoded as JSON.
cb	Optional callback invoked with the response Message.
id	Optional request identifier. If empty, an id is generated using generateRequestId()

Returns

The request identifier used for this command.

sendNotification()

void dfx::Client::SocketClient::sendNotification

(

nlohmann::json

json

)

Send a one-way notification to the server.

Notifications do not expect a reply.

Parameters

json	Notification payload.

setAutoReconnect()

void dfx::Client::SocketClient::setAutoReconnect

(

bool

shouldReconnect

)

Enable or disable automatic reconnection.

setMessageCallback()

void dfx::Client::SocketClient::setMessageCallback

(

Callback

cb

)

Set the callback invoked for incoming messages.

This callback is used only for incomming messages which aren't associated to a command send previously using sendCommand(). Passing a null callback (default-constructed Callback) disables message delivery.

Parameters

cb	Callback to invoke when a message is received.

willAutoReconnect()

bool dfx::Client::SocketClient::willAutoReconnect ( ) const

noexcept

Return whether the client will automatically attempt to reconnect.

---

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

• lib/dfx-client/SocketClient.hpp