class Sass::CacheStores::Filesystem

def _retrieve(key, version, sha)
  return unless File.readable?(path_to(key))
  begin
    File.open(path_to(key), "rb") do |f|
      if f.readline("\n").strip == version && f.readline("\n").strip == sha
        return f.read
      end
    end
    File.unlink path_to(key)
  rescue Errno::ENOENT
    # Already deleted. Race condition?
  end
  nil
rescue EOFError, TypeError, ArgumentError => e
  Sass::Util.sass_warn "Warning. Error encountered while reading cache #{path_to(key)}: #{e}"
end