subscription_manager Class Reference

Manages client subscriptions to event notifications. More...

#include <subscription_manager.hpp>

Collaboration diagram for subscription_manager:

Public Member Functions
	subscription_manager (const subscription_manager &)=delete
subscription_manager &	operator= (const subscription_manager &)=delete
	subscription_manager (subscription_manager &&)=delete
subscription_manager &	operator= (subscription_manager &&)=delete
void	register_session (const session_id &id, notification_callback callback)
	Register a new session with the subscription manager.
void	unregister_session (const session_id &id)
	Unregister a session from the subscription manager.
bool	subscribe (const session_id &id, const std::string &event_type)
	Subscribe a session to an event type.
bool	unsubscribe (const session_id &id, const std::string &event_type)
	Unsubscribe a session from an event type.
std::size_t	notify (const std::string &event_type, std::chrono::system_clock::time_point timestamp)
	Notify all subscribers of an event.
std::size_t	subscriber_count (const std::string &event_type) const
	Get the number of subscribers for an event type.
std::size_t	session_count () const
	Get the total number of registered sessions.
std::vector< std::string >	get_subscriptions (const session_id &id) const
	Get the event types a session is subscribed to.

Detailed Description

Manages client subscriptions to event notifications.

This class tracks which clients are subscribed to which event types and provides the mechanism to broadcast notifications when events occur.

Thread Safety:

• All operations are thread-safe.
• Notification callbacks are invoked without holding the lock to avoid deadlocks, so they must be safe to call concurrently.

Usage:

subscription_manager mgr;
 
// Register a session when it connects
mgr.register_session("192.168.1.1:45678",
    [&conn](const std::string& event_type, auto ts) {
        return push_notification(conn, event_type, ts);
    });
 
// Subscribe to events
mgr.subscribe("192.168.1.1:45678", "ores.risk.currency_changed");
 
// Notify all subscribers of an event
mgr.notify("ores.risk.currency_changed", std::chrono::system_clock::now());
 
// Unregister when session ends
mgr.unregister_session("192.168.1.1:45678");

Member Function Documentation

register_session()

void register_session	(	const session_id &	id,
		notification_callback	callback
	)

Register a new session with the subscription manager.

Must be called when a session successfully completes handshake.

Parameters

id	The unique session identifier (typically remote address).
callback	The callback to invoke for pushing notifications.

unregister_session()

void unregister_session

(

const session_id &

id

)

Unregister a session from the subscription manager.

Removes all subscriptions for this session. Should be called when a session disconnects.

Parameters

id	The session identifier to unregister.

subscribe()

bool subscribe	(	const session_id &	id,
		const std::string &	event_type
	)

Subscribe a session to an event type.

Parameters

id	The session identifier.
event_type	The event type to subscribe to.

Returns

true if subscription succeeded, false if session not found.

unsubscribe()

bool unsubscribe	(	const session_id &	id,
		const std::string &	event_type
	)

Unsubscribe a session from an event type.

Parameters

id	The session identifier.
event_type	The event type to unsubscribe from.

Returns

true if unsubscription succeeded, false if session not found or was not subscribed.

notify()

std::size_t notify	(	const std::string &	event_type,
		std::chrono::system_clock::time_point	timestamp
	)

Notify all subscribers of an event.

Invokes the notification callback for each session subscribed to the given event type. Failed notifications (callback returns false) are logged but do not affect other subscribers.

Parameters

event_type	The event type that occurred.
timestamp	The timestamp of the event.

Returns

The number of successful notifications sent.

subscriber_count()

std::size_t subscriber_count

(

const std::string &

event_type

)

const

Get the number of subscribers for an event type.

Parameters

event_type

The event type to query.

Returns

The number of sessions subscribed to this event type.

session_count()

std::size_t session_count

(

)

const

Get the total number of registered sessions.

Returns

The number of active sessions.

get_subscriptions()

std::vector< std::string > get_subscriptions

(

const session_id &

id

)

const

Get the event types a session is subscribed to.

Parameters

id	The session identifier.

Returns

Vector of event type names, empty if session not found.