module Internals

  module Index
  
    class Redis
    
      class ListHash < Basic
      
        # Writes the hash into Redis.
        #
        # TODO Performance: rpush as you get the values instead of putting it together in an array first.
        #
        def dump hash
          hash.each_pair do |key, values|
            redis_key = "#{namespace}:#{key}"
            i = 0
            @backend.multi do
              @backend.del redis_key
            
              values.each do |value|
                i += 1
                @backend.zadd redis_key, i, value
              end
            end
          end
        end
      
        # Get a collection.
        #
        def collection sym
          @backend.lrange "#{namespace}:#{sym}", 0, -1
        end
      
        # Get a single value.
        #
        def member sym
          raise "Can't retrieve a single value from a Redis ListHash. Use Index::Redis::StringHash."
        end
      
      end
    
    end
  
  end

end