compress!

# File activesupport/lib/active_support/cache.rb, line 777
        def compress!(compress_threshold)
          case @value
          when nil, true, false, Numeric
            uncompressed_size = 0
          when String
            uncompressed_size = @value.bytesize
          else
            serialized = Marshal.dump(@value)
            uncompressed_size = serialized.bytesize
          end

          if uncompressed_size >= compress_threshold
            serialized ||= Marshal.dump(@value)
            compressed = Zlib::Deflate.deflate(serialized)

            if compressed.bytesize < uncompressed_size
              @value = compressed
              @compressed = true
            end
          end
        end