Waves Gets Cached

cache.rb

module Waves

  class Cache
    attr_accessor :cache

    def initialize
      @cache = {}
    end

    def [](key)
      fetch(key)
    end

    def []=(key,value)
      store(key,value)
    end

    def store(key, value, ttl = {})
      @cache[key] = { 
        :expires => ttl.is_a?(Number) ? Time.now + ttl : nil,
        :value => value
      }
    end

    def delete(keys*)
      keys.each {|key| @cache[key].delete }
    end

    def clear
      @cache.clear
    end

    def fetch(key)
      if (@cache[key][:expires] > Time.now) or (@cache[key][:expires].nil?)
        @cache[key][:value]
      else
        @cache[key][:value]
        @cache[key].delete
      end
    end

  end
end

file_cache.rb

module Waves

  module Layers

    class FileCache < Waves::Cache

      def initialize(dir)
        @directory = dir
        super
      end

      def store(key, value, ttl = {})
        super(key, value, ttl)

        key_file = @directory / key

        file = File.new(key_file,'w') unless File.exists?(key_file)
        Marshal.dump(@cache[key], file)
        file.close
      end

      def delete(*keys)
        keys.each {|key| File.delete(@directory / key) }
        super keys
      end

      def clear
        @cache.each_key {|key| File.delete(@directory / key) }
        super 
      end

      def fetch(key)
        raise "No cache found for #{key}" unless File.exists?(@directory / key)
        @cache[key] = Marshal.load(@directory / key)

        if (@cache[key][:expires] > Time.now) or (@cache[key][:expires].nil?)
          @cache[key][:value]
        else
          @cache[key][:value]
          delete(key)
        end
      end

    end

  end

end

verify_cache.rb

require File.join(File.dirname(__FILE__) , "helpers")

def fill_cache(cache)
  cache[:key1] = "value1"
  cache[:key2] = "value2"
end

describe "Waves::Cache" do
  before do
    cache = Waves::Cache.new
    fill_cache cache
  end
  
  it "can find a value in the cache" do
    cache[:key1].should == "value1"
  end
  
  it "can delete a value from the cache" do
    fill_cache cache
    cache.delete(:key1)
    cache[:key1].should == nil
    cache[:key2].should == "value2"
  end
  
  it "can clear the cache" do
    fill_cache cache
    cache.clear
    cache[:key1].should == nil
    cache[:key2].should == nil
  end
  
end

require 'layers/cache/file_cache'
describe "Waves::Layers::FileCache" do
  
  before do
    cache = Waves::Layers::FileCache.new('.')
    fill_cache cache
  end
  
    it "can find a value in the cache" do
    cache[:key1].should == "value1"
  end
  
  it "can delete a value from the cache" do
    fille_cache cache
    cache.delete(:key1)
    cache[:key1].should == nil
    cache[:key2].should == "value2"
  end
  
  it "can clear the cache" do
    fill_cache cache
    cache.clear
    cache[:key1].should == nil
    cache[:key2].should == nil
  end
  
end