Class: WEBrick::HTTPServer

Inherits:
Object
  • Object
show all
Defined in:
lib/webtube/webrick.rb,
lib/webtube/webrick.rb

Instance Method Summary collapse

Constructor Details

#initialize(config = {}, default = Config::HTTP) ⇒ HTTPServer

Returns a new instance of HTTPServer.



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# File 'lib/webtube/webrick.rb', line 30

def initialize config = {}, default = Config::HTTP
  orig_initialize_before_webtube_integration config, default
  @webtubes = Webtube::Vital_Statistics.new @logger
  return
end

Instance Method Details

#accept_webtube(request, response, listener, session: nil, context: nil) ⇒ Object

Given a [[request]] and a [[response]] object, as prepared by a [[WEBrick::HTTPServer]] for processing in a portlet, attempt to accept the client’s request to establish a WebSocket connection. The [[request]] must actually contain such a request; see [[websocket_upgrade_request?]].

The attempt will fail in the theoretical case the client and the server can’t agree on the protocol version to use. In such a case, [[accept_webtube]] will prepare a 426 ‘Upgrade required’ response, explaining in plain text what the problem is and advertising, using the

[Sec-WebSocket-Version]

header field, the protocol

version (specifically, 13) it is prepared to speak. When this happens, the WebSocket session will never be set up and no [[listener]] events will be called.

Note that [[accept_webtube]] will manipulate [[response]] and return immediately. The actual WebSocket session will begin once WEBrick attempts to deliver the [[response]], and will be marked by the newly constructed [[Webtube]] instance delivering an [[onopen]] event to [[listener]].

Also note that the loop to process incoming WebSocket frames will hog the whole thread; in order to deliver asynchronous messages over the WebSocket,

[Webtube#send_message]

needs to be called from another

thread. (For synchronous messages, it can safely be called from the handlers inside [[listener]].)

See [[Webtube#run]] for a list of the supported methods for the [[listener]].



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# File 'lib/webtube/webrick.rb', line 98

def accept_webtube request, response, listener,
    session: nil, context: nil
  # Check that the client speaks our version
  unless (request['Sec-WebSocket-Version'] || '').
      strip.split(/\s*,\s*/).
      include? '13' then
    @logger.error "Sec-WebSocket-Version mismatch"
    response.status, response.reason_phrase =
        '426', 'Upgrade required'
    response['Content-type'] = 'text/plain'
    response['Sec-WebSocket-Version'] = '13'
        # advertise the version we speak
    response.body = "This WebSocket server only speaks " +
        "version 13 of the protocol, as specified by " +
        "RFC 6455.\n"
  else
    response.status, response.reason_phrase =
        '101', 'Hello WebSocket'
    response['Upgrade'] = 'websocket'
    response['Sec-WebSocket-Accept'] =
        OpenSSL::Digest::SHA1.base64digest(
            request['Sec-WebSocket-Key'] +
            '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')
    response['Sec-WebSocket-Version'] = '13'
    response.keep_alive = false
        # so that WEBrick will close the TCP socket when
        # we're done
    vital_statistics = self.webtubes
    (class << response; self; end).instance_eval do
      # We'll need to deliver the [[Connection: Upgrade]]
      # header; unfortunately, HTTPResponse#setup_header
      # would munge it if we set this header field in the
      # ordinary way.  Accordingly, we'll have to override
      # the method.
      define_method :setup_header do ||
        super()
        @header['connection'] = 'Upgrade'
        return
      end

      # Replace [[response.send_body]] with the WS engine.
      # WEBrick will call it automatically after sending the
      # response header.
      #
      # Also notify the server's attached
      # [[Webtube::Vital_Statistics]] instance so that
      # server shutdown could also close all pending
      # Webtubes.
      define_method :send_body do |socket|
        webtube = Webtube.new socket, true,
            close_socket: false
        begin
          vital_statistics.birth webtube
          webtube.header = request
          webtube.session = session
          webtube.context = context
          # Reassign us from the WEBrick's thread group to
          # the one maintained by
          # [[Webtube::Vital_Statistics]].
          vital_statistics.thread_group.add Thread.current
          # And now, run!
          webtube.run listener
        ensure
          vital_statistics.death webtube
        end
        return
      end
    end
  end
  return
end

#mount_webtube(dir, listener) ⇒ Object 



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# File 'lib/webtube/webrick.rb', line 202

def mount_webtube dir, listener
  mount dir, HTTPServlet::WebtubeHandler.new(self, listener)
  return
end

#orig_initialize_before_webtube_integration ⇒ Object

Attach a [[Webtube::Vital_Statistics]] to new

[WEBrick::HTTPServer]

instances so that the live

webtubes could be closed upon shutdown



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# File 'lib/webtube/webrick.rb', line 29

alias orig_initialize_before_webtube_integration initialize

#orig_shutdown_before_webtube_integration ⇒ Object 



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# File 'lib/webtube/webrick.rb', line 54

alias orig_shutdown_before_webtube_integration shutdown

#shutdown ⇒ Object 



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# File 'lib/webtube/webrick.rb', line 55

def shutdown
  # We'll need to call the original shutdown code first, for
  # we want to stop accepting new Webtube connections before
  # 'close all Webtube connections' will have a proper,
  # thread-safe meaning.
  orig_shutdown_before_webtube_integration
  webtubes.close_all
  webtubes.thread_group.list.each &:join
  return
end

#webtubes ⇒ Object 



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# File 'lib/webtube/webrick.rb', line 36

def webtubes
  result = @webtubes
  # Usually, this should be it.
  if result.nil? then # ... but ...
    # Well, it would seem that our extended constructor was
    # not called.  How could this have happened?
    result = @webtubes = Webtube::Vital_Statistics.new
    @logger.warn "@webtubes (in a WEBrick::HTTPServer) " +
        "has not been set up before accessing it.  I " +
        "have attempted to correct this ex post facto, " +
        "but doing it now is a race condition, and I may " +
        "have lost track of some webtubes as a result.  " +
        "The next time, please load webtube/webrick.rb " +
        "/before/ instantiating your WEBrick::HTTPServer."
  end
  return result
end