class DRb::DRbUNIXSocket

def self.open(uri, config)
  filename, = parse_uri(uri)
  soc = UNIXSocket.open(filename)
  self.new(uri, soc, config)
end

def self.open_server(uri, config)
  filename, = parse_uri(uri)
  if filename.size == 0
    soc = temp_server
    filename = soc.path
    uri = 'drbunix:' + soc.path
  else
    soc = UNIXServer.open(filename)
  end
  owner = config[:UNIXFileOwner]
  group = config[:UNIXFileGroup]
  if owner || group
    require 'etc'
    owner = Etc.getpwnam( owner ).uid  if owner
    group = Etc.getgrnam( group ).gid  if group
    File.chown owner, group, filename
  end
  mode = config[:UNIXFileMode]
  File.chmod(mode, filename) if mode
  self.new(uri, soc, config, true)
end

def self.parse_uri(uri)
  if /\Adrbunix:(.*?)(\?(.*))?\z/ =~ uri
    filename = $1
    option = $3
    [filename, option]
  else
    raise(DRbBadScheme, uri) unless uri.start_with?('drbunix:')
    raise(DRbBadURI, 'can\'t parse uri:' + uri)
  end
end

def self.temp_server
  tmpdir = Dir::tmpdir
  n = 0
  while true
    begin
      tmpname = sprintf('%s/druby%d.%d', tmpdir, $$, n)
      lock = tmpname + '.lock'
      unless File.exist?(tmpname) or File.exist?(lock)
        Dir.mkdir(lock)
        break
      end
    rescue
      raise "cannot generate tempfile '%s'" % tmpname if n >= Max_try
      #sleep(1)
    end
    n += 1
  end
  soc = UNIXServer.new(tmpname)
  Dir.rmdir(lock)
  soc
end

def self.uri_option(uri, config)
  filename, option = parse_uri(uri)
  return "drbunix:#{filename}", option
end

def accept
  s = accept_or_shutdown
  return nil unless s
  self.class.new(nil, s, @config)
end

def close
  return unless @socket
  shutdown # DRbProtocol#shutdown
  path = @socket.path if @server_mode
  @socket.close
  File.unlink(path) if @server_mode
  @socket = nil
  close_shutdown_pipe
end

def initialize(uri, soc, config={}, server_mode = false)
  super(uri, soc, config)
  set_sockopt(@socket)
  @server_mode = server_mode
  @acl = nil
end

def set_sockopt(soc)
  # no-op for now
end