tpitale · March 23, 2017 13:03 · pboling · Oct 6, 2015
diff --git a/reel_ws_pg_example.rb b/reel_ws_pg_example.rb
 require 'rubygems'
 require 'bundler/setup'
 require 'reel'
 require 'celluloid/io'
 require 'pg'

 module PGNotifications
  def self.included(actor)
    actor.send(:include, Celluloid::IO)
  end

  def actions
    @actions ||= {}
  end

  def pg_connection
    @pg_connection ||= PG.connect( dbname: 'ws_example' )
  end

  def notify(channel, value)
    pg_connection.exec("NOTIFY #{channel}, '#{value}';")
  end

  def listen(channel, action)
    actions[channel] = action
    pg_connection.exec("LISTEN #{channel}")
  end

  def start_listening
    info "Starting Listening"

    @listening = true

    wait_for_notify do |channel, pid, payload|
      info "Received notification: #{[channel, pid, payload].inspect}"
      send(actions[channel], channel, payload)
    end
  end

  def stop_listening
    @listening = false
  end

  def wait_for_notify(&block)
    io = pg_connection.socket_io

    while @listening do
      Celluloid::IO.wait_readable(io) # blocks execution, but unblocks this actor
      pg_connection.consume_input # fetch any input on this connection

      while notification = pg_connection.notifies do
        block.call(*[
          notification[:relname], # channel
          notification[:be_pid], # pid
          notification[:extra] # payload
        ])
      end
    end
  end

  def unlisten(channel)
    (@listening ||= {})[channel] = false

    pg_connection.exec("UNLISTEN #{channel}")
  end
 end

 class TimeServer
  include Celluloid
  include PGNotifications
  include Celluloid::Logger

  def initialize
    async.run
  end

  def run
    now = Time.now.to_f
    sleep now.ceil - now + 0.001

    every(1) { notify 'time_change', Time.now.inspect }
    info 'Registered to send time_change'

    every(10) { notify 'keepalive', Time.now.to_i }
    info 'Registered to send keepalive'
  end
 end

 class TimeClient
  include PGNotifications
  include Celluloid::Logger

  KEEPALIVE_LIMIT = 30 # keep it short

  def initialize(socket)
    info "Streaming time changes to client"
    @socket = socket
    @limit = Time.now.to_i + KEEPALIVE_LIMIT

    async.start_listening
    async.listen('time_change', :notify_time_change)
    async.listen('keepalive', :report_keepalive)
  end

  def notify_time_change(channel, new_time)
    @socket << new_time
  rescue Reel::SocketError
    info "Time client disconnected"
    unlisten(channel)
    terminate
  end

  def report_keepalive(channel, timestamp)
    info "Current keepalive timestamp: #{timestamp}"
    # unlisten(channel) if timestamp.to_i > @limit
  end
 end

 class WebServer < Reel::Server::HTTP
  include Celluloid::Logger

  def initialize(host = "127.0.0.1", port = 1234)
    info "Time server example starting on #{host}:#{port}"
    super(host, port, &method(:on_connection))
  end

  def on_connection(connection)
    connection.each_request do |request|
      if request.websocket?
        info "Received a WebSocket connection"
        handle_websocket request.websocket
      else
        handle_request request
      end
    end
  end

  def handle_request(request)
    if request.url == "/"
      return render_index(request)
    end

    info "404 Not Found: #{request.path}"
    request.respond :not_found, "Not found"
  end

  def handle_websocket(socket)
    if socket.url == "/timeinfo"
      TimeClient.new(socket)
    else
      info "Received invalid WebSocket request for: #{socket.url}"
      socket.close
    end
  end

  def render_index(request)
    info "200 OK: /"
    request.respond :ok, <<-HTML
      <!doctype html>
      <html lang="en">
      <head>
        <meta charset="utf-8">
        <title>Reel WebSockets time server example</title>
        <style>
          body {
            font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif;
            font-weight: 300;
            text-align: center;
          }

          #content {
            width: 800px;
            margin: 0 auto;
            background: #EEEEEE;
            padding: 1em;
          }
        </style>
      </head>
      <script>
        var SocketKlass = "MozWebSocket" in window ? MozWebSocket : WebSocket;
        var ws = new SocketKlass('ws://' + window.location.host + '/timeinfo');
        ws.onmessage = function(msg){
          document.getElementById('current-time').innerHTML = msg.data;
        }
      </script>
      <body>
        <div id="content">
          <h1>Time Server Example</h1>
          <div>The time is now: <span id="current-time">...</span></div>
        </div>
      </body>
      </html>
    HTML
  end
 end

 TimeServer.supervise_as :time_server
 WebServer.supervise_as :reel

 sleep
	require 'rubygems'
	require 'bundler/setup'
	require 'reel'
	require 'celluloid/io'
	require 'pg'

	module PGNotifications
	def self.included(actor)
	actor.send(:include, Celluloid::IO)
	end

	def actions
	@actions \|\|= {}
	end

	def pg_connection
	@pg_connection \|\|= PG.connect( dbname: 'ws_example' )
	end

	def notify(channel, value)
	pg_connection.exec("NOTIFY #{channel}, '#{value}';")
	end

	def listen(channel, action)
	actions[channel] = action
	pg_connection.exec("LISTEN #{channel}")
	end

	def start_listening
	info "Starting Listening"

	@listening = true

	wait_for_notify do \|channel, pid, payload\|
	info "Received notification: #{[channel, pid, payload].inspect}"
	send(actions[channel], channel, payload)
	end
	end

	def stop_listening
	@listening = false
	end

	def wait_for_notify(&block)
	io = pg_connection.socket_io

	while @listening do
	Celluloid::IO.wait_readable(io) # blocks execution, but unblocks this actor
	pg_connection.consume_input # fetch any input on this connection

	while notification = pg_connection.notifies do
	block.call(*[
	notification[:relname], # channel
	notification[:be_pid], # pid
	notification[:extra] # payload
	])
	end
	end
	end

	def unlisten(channel)
	(@listening \|\|= {})[channel] = false

	pg_connection.exec("UNLISTEN #{channel}")
	end
	end

	class TimeServer
	include Celluloid
	include PGNotifications
	include Celluloid::Logger

	def initialize
	async.run
	end

	def run
	now = Time.now.to_f
	sleep now.ceil - now + 0.001

	every(1) { notify 'time_change', Time.now.inspect }
	info 'Registered to send time_change'

	every(10) { notify 'keepalive', Time.now.to_i }
	info 'Registered to send keepalive'
	end
	end

	class TimeClient
	include PGNotifications
	include Celluloid::Logger

	KEEPALIVE_LIMIT = 30 # keep it short

	def initialize(socket)
	info "Streaming time changes to client"
	@socket = socket
	@limit = Time.now.to_i + KEEPALIVE_LIMIT

	async.start_listening
	async.listen('time_change', :notify_time_change)
	async.listen('keepalive', :report_keepalive)
	end

	def notify_time_change(channel, new_time)
	@socket << new_time
	rescue Reel::SocketError
	info "Time client disconnected"
	unlisten(channel)
	terminate
	end

	def report_keepalive(channel, timestamp)
	info "Current keepalive timestamp: #{timestamp}"
	# unlisten(channel) if timestamp.to_i > @limit
	end
	end

	class WebServer < Reel::Server::HTTP
	include Celluloid::Logger

	def initialize(host = "127.0.0.1", port = 1234)
	info "Time server example starting on #{host}:#{port}"
	super(host, port, &method(:on_connection))
	end

	def on_connection(connection)
	connection.each_request do \|request\|
	if request.websocket?
	info "Received a WebSocket connection"
	handle_websocket request.websocket
	else
	handle_request request
	end
	end
	end

	def handle_request(request)
	if request.url == "/"
	return render_index(request)
	end

	info "404 Not Found: #{request.path}"
	request.respond :not_found, "Not found"
	end

	def handle_websocket(socket)
	if socket.url == "/timeinfo"
	TimeClient.new(socket)
	else
	info "Received invalid WebSocket request for: #{socket.url}"
	socket.close
	end
	end

	def render_index(request)
	info "200 OK: /"
	request.respond :ok, <<-HTML
	<!doctype html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<title>Reel WebSockets time server example</title>
	<style>
	body {
	font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif;
	font-weight: 300;
	text-align: center;
	}

	#content {
	width: 800px;
	margin: 0 auto;
	background: #EEEEEE;
	padding: 1em;
	}
	</style>
	</head>
	<script>
	var SocketKlass = "MozWebSocket" in window ? MozWebSocket : WebSocket;
	var ws = new SocketKlass('ws://' + window.location.host + '/timeinfo');
	ws.onmessage = function(msg){
	document.getElementById('current-time').innerHTML = msg.data;
	}
	</script>
	<body>
	<div id="content">
	<h1>Time Server Example</h1>
	<div>The time is now: <span id="current-time">...</span></div>
	</div>
	</body>
	</html>
	HTML
	end
	end

	TimeServer.supervise_as :time_server
	WebServer.supervise_as :reel

	sleep