Class: Concurrent::CopyOnNotifyObserverSet

Inherits:
Object
  • Object
show all
Defined in:
lib/concurrent/copy_on_notify_observer_set.rb

Overview

A thread safe observer set implemented using copy-on-read approach: observers are added and removed from a thread safe collection; every time a notification is required the internal data structure is copied to prevent concurrency issues

Instance Method Summary collapse

Constructor Details

#initialize ⇒ CopyOnNotifyObserverSet

Returns a new instance of CopyOnNotifyObserverSet.



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# File 'lib/concurrent/copy_on_notify_observer_set.rb', line 9

def initialize
  @mutex = Mutex.new
  @observers = {}
end

Instance Method Details

#add_observer(observer, func = :update) ⇒ Symbol

Adds an observer to this set

Parameters:

  • the observer to add

  • (defaults to: :update)

    the function to call on the observer during notification. Default is :update

Returns:

  • the added function



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# File 'lib/concurrent/copy_on_notify_observer_set.rb', line 18

def add_observer(observer, func=:update)
  @mutex.synchronize { @observers[observer] = func }
end

#count_observers ⇒ Integer

Returns the observers count.

Returns:

  • the observers count



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# File 'lib/concurrent/copy_on_notify_observer_set.rb', line 37

def count_observers
  @mutex.synchronize { @observers.count }
end

#delete_observer(observer) ⇒ Object

Returns the deleted observer.

Parameters:

  • the observer to remove

Returns:

  • the deleted observer



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# File 'lib/concurrent/copy_on_notify_observer_set.rb', line 24

def delete_observer(observer)
  @mutex.synchronize { @observers.delete(observer) }
  observer
end

#delete_observers ⇒ CopyOnWriteObserverSet

Deletes all observers

Returns:

  • self



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# File 'lib/concurrent/copy_on_notify_observer_set.rb', line 31

def delete_observers
  @mutex.synchronize { @observers.clear }
  self
end

#notify_and_delete_observers(*args, &block) ⇒ CopyOnWriteObserverSet

Notifies all registered observers with optional args and deletes them.

Parameters:

  • arguments to be passed to each observer

Returns:

  • self



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# File 'lib/concurrent/copy_on_notify_observer_set.rb', line 55

def notify_and_delete_observers(*args, &block)
  observers = duplicate_and_clear_observers
  notify_to(observers, *args, &block)

  self
end

#notify_observers(*args, &block) ⇒ CopyOnWriteObserverSet

Notifies all registered observers with optional args

Parameters:

  • arguments to be passed to each observer

Returns:

  • self



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# File 'lib/concurrent/copy_on_notify_observer_set.rb', line 44

def notify_observers(*args, &block)
  observers = @mutex.synchronize { @observers.dup }
  notify_to(observers, *args, &block)

  self
end