require 'rack'
require 'faye/websocket'
-require 'oj'
require 'eventmachine'
+# A Rack middleware to handle inbound websocket connection requests and hand
+# them over to the faye websocket library.
class RackSocket
DEFAULT_ENDPOINT = '/websocket'
+ # Stop EventMachine on signal, this should give it a chance to to unwind any
+ # open connections.
def die_gracefully_on_signal
Signal.trap("INT") { EM.stop }
Signal.trap("TERM") { EM.stop }
end
+ # Create a new RackSocket handler
+ # +app+ The next layer of the Rack stack.
+ #
+ # Accepts options:
+ # +:handler+ (Required) A class to handle new connections. #initialize will
+ # call handler.new to create the actual handler instance object. When a new
+ # websocket connection is established, #on_connect on the handler instance
+ # object will be called with the new connection.
+ #
+ # +:mount+ The HTTP request path that will be recognized for websocket
+ # connect requests, defaults to '/websocket'.
+ #
+ # +:websocket_only+ If true, the server will only handle websocket requests,
+ # and all other requests will result in an error. If false, unhandled
+ # non-websocket requests will be passed along on to 'app' in the usual Rack
+ # way.
def initialize(app = nil, options = nil)
@app = app if app.respond_to?(:call)
@options = [app, options].grep(Hash).first || {}
@endpoint = @options[:mount] || DEFAULT_ENDPOINT
+ @websocket_only = @options[:websocket_only] || false
# from https://gist.github.com/eatenbyagrue/1338545#file-eventmachine-rb
if defined?(PhusionPassenger)
}
end
- @channel = EventMachine::Channel.new
- @bgthread = nil
+ # Create actual handler instance object from handler class.
+ @handler = @options[:handler].new
end
+ # Handle websocket connection request, or pass on to the next middleware
+ # supplied in +app+ initialize (unless +:websocket_only+ option is true, in
+ # which case return an error response.)
+ # +env+ the Rack environment with information about the request.
def call env
request = Rack::Request.new(env)
if request.path_info == @endpoint and Faye::WebSocket.websocket?(env)
- ws = Faye::WebSocket.new(env)
+ ws = Faye::WebSocket.new(env, nil, :ping => 30)
- sub = @channel.subscribe do |msg|
- puts "sending #{msg}"
- ws.send({:message => "log"}.to_json)
- end
-
- ws.on :message do |event|
- puts "got #{event.data}"
- ws.send(event.data)
- end
-
- ws.on :close do |event|
- p [:close, event.code, event.reason]
- @channel.unsubscribe sub
- ws = nil
- end
-
- unless @bgthread
- @bgthread = true
- Thread.new do
- # from http://stackoverflow.com/questions/16405520/postgres-listen-notify-rails
- ActiveRecord::Base.connection_pool.with_connection do |connection|
- conn = connection.instance_variable_get(:@connection)
- begin
- conn.async_exec "LISTEN logs"
- while true
- conn.wait_for_notify do |channel, pid, payload|
- puts "Received a NOTIFY on channel #{channel}"
- puts "from PG backend #{pid}"
- puts "saying #{payload}"
- @channel.push true
- end
- end
- ensure
- # Don't want the connection to still be listening once we return
- # it to the pool - could result in weird behavior for the next
- # thread to check it out.
- conn.async_exec "UNLISTEN *"
- end
- end
- end
- end
+ # Notify handler about new connection
+ @handler.on_connect ws
# Return async Rack response
ws.rack_response
- else
+ elsif not @websocket_only
@app.call env
+ else
+ [406, {"Content-Type" => "text/plain"}, ["Only websocket connections are permitted on this port."]]
end
end
end
-
-