Class: Cache

Inherits:
Object show all
Defined in:
lib/more/facets/cachedelegator.rb

Overview

Cache

Cache objects are a kind of “delegator-with-cache”.

Usage

class X
  def initialize ; @tick = 0 ; end
  def tick; @tick + 1; end
  def cached; @cache ||= Cache.new( self ) ; end
end

x = X.new
x.tick  #=> 1
x.cached.tick  #=> 2
x.tick  #=> 3
x.cached.tick  #=> 2
x.tick  #=> 4
x.cached.tick  #=> 2

You can also use to cache a collections of objects to gain code speed ups.

points = points.collect{|point| Cache.cache(point)}

After our algorithm has finished using points, we want to get rid of these Cache objects. That’s easy:

points = points.collect{|point| point.self }

Or if you prefer (it is ever so slightly safer):

points = points.collect{|point| Cache.uncache(point)}

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(object) ⇒ Cache

Returns a new instance of Cache.



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# File 'lib/more/facets/cachedelegator.rb', line 70

def initialize(object)
  @self = object
  @cache = {}
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_name, *args, &block) ⇒ Object 



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# File 'lib/more/facets/cachedelegator.rb', line 75

def method_missing(method_name, *args, &block)
  # Not thread-safe! Speed is important in caches... ;]
  @cache[[method_name, args, block]] ||= @self.__send__(method_name, *args, &block)
end

Class Method Details

.cache(object) ⇒ Object 



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# File 'lib/more/facets/cachedelegator.rb', line 82

def self.cache(object)
  Cache.new(object)
end

.uncache(cached_object) ⇒ Object 



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# File 'lib/more/facets/cachedelegator.rb', line 86

def self.uncache(cached_object)
  cached_object.self
end

Instance Method Details

#self ⇒ Object 



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# File 'lib/more/facets/cachedelegator.rb', line 80

def self; @self; end