cache.rb

# before

def read(name, options = nil)
  super

  file_name = real_file_path(name)
  return nil unless File.exist?(file_name)

  if (expires = expires_in(options)) > 0 and
      (Time.now - File.mtime(file_name)) > expires
    return nil
  end
  File.open(file_name, 'rb') { |f| Marshal.load(f) } rescue nil
end

# after

def read(name, options = nil)
  super

  file_name = real_file_path(name)
  expires = expires_in(options)

  if File.exist?(file_name) && (expires <= 0 || Time.now - File.mtime(file_name) < expires)
    File.open(file_name, 'rb') { |f| Marshal.load(f) }
  end
end

# and again

def read(name, options = nil)
  super

  file_name = real_file_path(name)

  if File.exist?(file_name) && ((expires = expires_in(options)) <= 0 || Time.now - File.mtime(file_name) < expires)
    File.open(file_name, 'rb') { |f| Marshal.load(f) }
  end
end