Class: Needle::Lifecycle::Multiton

Inherits:
Pipeline::Element show all
Defined in:
lib/needle/lifecycle/multiton.rb

Overview

The instantiation pipeline element that enforces the multiton multiplicity. “Multiton” multiplicity is like singleton multiplicity, except that the guarded instance is unique for each unique set of arguments passed to the multiton.

Instance Attribute Summary

Attributes inherited from Pipeline::Element

#name, #options, #priority, #service_point, #succ

Instance Method Summary collapse

Methods inherited from Pipeline::Element

#<=>, #initialize, set_default_priority

Constructor Details

This class inherits a constructor from Needle::Pipeline::Element

Instance Method Details

#call(container, point, *args) ⇒ Object

Returns the cached reference for the given arguments, if it has been previously cached. Otherwise, invokes the next element in the pipeline and caches the result. The cached reference is returned.



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# File 'lib/needle/lifecycle/multiton.rb', line 40

def call( container, point, *args )
  unless @is_cached[ args ]
    @mutex.synchronize do
      unless @is_cached[ args ]
        @cached[ args ] = succ.call( container, point, *args )
        @is_cached[ args ] = true
      end
    end
  end

  @cached[ args ]
end

#initialize_element ⇒ Object

Creates the mutex to use and initializes the cache.



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# File 'lib/needle/lifecycle/multiton.rb', line 31

def initialize_element
  @mutex = QueryableMutex.new
  @cached = Hash.new
  @is_cached = Hash.new( false )
end

#reset! ⇒ Object

Resets the caches for this multiton object.



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# File 'lib/needle/lifecycle/multiton.rb', line 54

def reset!
  @mutex.synchronize do
    @cached = Hash.new
    @is_cached = Hash.new( false )
  end
end