Module: DeclarativeCache

Defined in:
lib/ruby_ext/more/declarative_cache.rb

Constant Summary collapse

DISABLED = 
false

Class Method Summary collapse

Class Method Details

.cache_method(klass, *methods) ⇒ Object 



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# File 'lib/ruby_ext/more/declarative_cache.rb', line 28

def cache_method klass, *methods
  methods.each do |method|
    klass.class_eval do
      escaped_method = escape_method(method)
      method_with_cache, method_without_cache = "#{escaped_method}_with_cache".to_sym, "#{escaped_method}_without_cache".to_sym
      iv_check = "@#{escaped_method}_cache_check"
      iv = "@#{escaped_method}_cache"
    
      if instance_methods.include?(method_with_cache) or instance_methods.include?(method_without_cache)
        warn "can't cache the :#{method} twice!" 
      else
        alias_method method_without_cache, method

        define_method method_with_cache do |*args|
          raise "You tried to use cache without params for method with params (use 'cache_method_with_params' instead)!" unless args.empty?
          unless cached = instance_variable_get(iv)
            unless check = instance_variable_get(iv_check)
              cached = send method_without_cache
              instance_variable_set iv, cached
              instance_variable_set iv_check, true
            end
          end
          cached
        end

        alias_method method, method_with_cache
      end
    end
  end
end

.cache_method_with_params(klass, *methods) ⇒ Object 



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# File 'lib/ruby_ext/more/declarative_cache.rb', line 59

def cache_method_with_params klass, *methods        
  methods.each do |method|  
    klass.class_eval do      
      escaped_method = escape_method(method)
      method_with_cache, method_without_cache = "#{escaped_method}_with_cache".to_sym, "#{escaped_method}_without_cache".to_sym
      iv_check = "@#{escaped_method}_cache_check"
      iv = "@#{escaped_method}_cache"
    
      if instance_methods.include?(method_with_cache) or instance_methods.include?(method_without_cache)
        warn "can't cache the :#{method} twice!" 
      else
        alias_method method_without_cache, method

        define_method method_with_cache do |*args| 
          unless results = instance_variable_get(iv)
            results = Hash.new(NotDefined)
            instance_variable_set iv, results
          end

          result = results[args]

          if result.equal? NotDefined 
            result = send method_without_cache, *args
            results[args] = result
          end

          result
        end

        alias_method method, method_with_cache
      end
    end
  end
end