Class: Vissen::Input::Broker::PropagationControl

Inherits:
Object
  • Object
show all
Defined in:
lib/vissen/input/broker.rb

Overview

Internal class used by the Broker to control the propagation of a message and provide a control surface for subscription handlers, allowing them to stop the propagation at priorites lower than (not equal to) their own.

== Usage The following example uses a propagation control object to stop propagation at priority 1. Note that #stop? must be called for each message before #stop! to ensure that the correct priority is set.

ctrl = PropagationControl.new ctrl.stop? 2 # => false ctrl.stop? 1 # => false

ctrl.stop!

ctrl.stop? 1 # => false ctrl.stop? 0 # => true

Instance Method Summary collapse

Constructor Details

#initialize ⇒ PropagationControl

Returns a new instance of PropagationControl.



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# File 'lib/vissen/input/broker.rb', line 154

def initialize
  @stop_at_priority = -1
  @current_priority = 0
end

Instance Method Details

#stop! ⇒ nil

Sets the priority stopping threshold.

Returns:

  • (nil) 


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# File 'lib/vissen/input/broker.rb', line 172

def stop!
  @stop_at_priority = @current_priority
  nil
end

#stop?(priority) ⇒ true, false

Returns whether to stop or not.

Parameters:

  • priority (Integer) —

    the priority to check out stopping condition against.

Returns:

  • (true, false) —

    whether to stop or not.



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# File 'lib/vissen/input/broker.rb', line 162

def stop?(priority)
  return true if priority < @stop_at_priority

  @current_priority = priority
  false
end