Class: Synapse::EventBus::SimpleEventBus

Inherits:
EventBus
  • Object
show all
Defined in:
lib/synapse/event_bus/simple_event_bus.rb

Overview

Implementation of an event bus that notifies any subscribed event listeners in the calling thread. Listeners are expected to implement asynchronous handing themselves, if desired.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ SimpleEventBus

Returns a new instance of SimpleEventBus.



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# File 'lib/synapse/event_bus/simple_event_bus.rb', line 6

def initialize
  @listeners = Set.new
  @logger = Logging.logger[self.class]
end

Instance Method Details

#publish(*events) ⇒ undefined

Parameters:

  • events (EventMessage...)

Returns:

  • (undefined) 


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# File 'lib/synapse/event_bus/simple_event_bus.rb', line 14

def publish(*events)
  return if @listeners.empty?

  events.flatten!
  events.each do |event|
    @listeners.each do |listener|
      @logger.debug "Publishing event {#{event.payload_type}} to {#{listener.class}}"

      listener.notify event
    end
  end
end

#subscribe(listener) ⇒ undefined

Parameters:

Returns:

  • (undefined) 


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# File 'lib/synapse/event_bus/simple_event_bus.rb', line 39

def subscribe(listener)
  if @listeners.add? listener
    @logger.debug "Event listener {#{listener.class}} subscribed"
  else
    @logger.info "Event listener {#{listener.class}} is already subscribed"
  end
end

#subscribed?(listener) ⇒ Boolean

Returns true if the given listener is subscribed to this event bus

Parameters:

Returns:

  • (Boolean) 


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# File 'lib/synapse/event_bus/simple_event_bus.rb', line 32

def subscribed?(listener)
  @listeners.include? listener
end

#unsubscribe(listener) ⇒ undefined

Parameters:

Returns:

  • (undefined) 


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# File 'lib/synapse/event_bus/simple_event_bus.rb', line 50

def unsubscribe(listener)
  if @listeners.delete? listener
    @logger.debug "Event listener {#{listener.class}} unsubscribed"
  else
    @logger.info "Event listener {#{listener.class}} is not subscribed"
  end
end