Module: GenCache::AssocationCache

Included in:
Caches
Defined in:
lib/gen_cache/cache_types/association_cache.rb

Instance Method Summary collapse

Instance Method Details

#cached_assoc_methods(name) ⇒ Object 



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# File 'lib/gen_cache/cache_types/association_cache.rb', line 13

def cached_assoc_methods(name)
  method_name = "cached_#{name}"
  define_method(method_name) do
    cache_key = GenCache.association_key(self, name)
    
    # an object's association cache holds a collection of the instance keys
    # for the objects returned by a call to that association. These are read first
    if instance_variable_get("@#{method_name}").nil?
      instance_keys = GenCache.fetch(cache_key) do
        Array.wrap(self.send(name)).map { |obj| GenCache.instance_key(obj.class, obj.id) }
      end
      
      # all of the instance keys are read in a single multi_read
      association = GenCache.fetch(instance_keys) do |key_blobs|
        result = {}
        instance_keys.each do |ik|
          key_parts = ik[:key].scan(/(^.*)\/(.*)\/(.*$)/).flatten
          result[ik] = Object.const_get(key_parts.first.singularize.capitalize).send(:find, key_parts.last.to_i)
        end
        result
      end

      # plural associations expect arrays, singular associations expect single objects
      association = if association.size == 0 
                      name.to_s.pluralize == name.to_s ? [] : nil
                    elsif association.size == 1
                      name.to_s.pluralize == name.to_s ? association : association.first
                    else
                      association
                    end

      instance_variable_set("@#{method_name}", association)
    end
    instance_variable_get("@#{method_name}")
  end
end

#with_association(*association_names) ⇒ Object 



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# File 'lib/gen_cache/cache_types/association_cache.rb', line 4

def with_association(*association_names)
  self.cached_associations ||= []
  self.cached_associations += association_names

  association_names.each do |assoc_name|
    cached_assoc_methods(assoc_name)
  end
end