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|
module ActionCable
module Connection
class Base
include Registry
PING_INTERVAL = 3
attr_reader :env, :server
delegate :worker_pool, :pubsub, :logger, to: :server
def initialize(server, env)
@server = server
@env = env
@accept_messages = false
@pending_messages = []
end
def process
logger.info "[ActionCable] #{started_request_message}"
if websocket?
@subscriptions = {}
@websocket = Faye::WebSocket.new(@env)
@websocket.on(:open) do |event|
broadcast_ping_timestamp
@ping_timer = EventMachine.add_periodic_timer(PING_INTERVAL) { broadcast_ping_timestamp }
worker_pool.async.invoke(self, :initialize_connection)
end
@websocket.on(:message) do |event|
message = event.data
if message.is_a?(String)
if @accept_messages
worker_pool.async.invoke(self, :received_data, message)
else
@pending_messages << message
end
end
end
@websocket.on(:close) do |event|
logger.info "[ActionCable] #{finished_request_message}"
worker_pool.async.invoke(self, :on_connection_closed)
EventMachine.cancel_timer(@ping_timer) if @ping_timer
end
@websocket.rack_response
else
invalid_request
end
end
def received_data(data)
return unless websocket_alive?
data = ActiveSupport::JSON.decode data
case data['action']
when 'subscribe'
subscribe_channel(data)
when 'unsubscribe'
unsubscribe_channel(data)
when 'message'
process_message(data)
end
end
def cleanup_subscriptions
@subscriptions.each do |id, channel|
channel.unsubscribe
end
end
def broadcast(data)
logger.info "[ActionCable] Sending data: #{data}"
@websocket.send data
end
def handle_exception
logger.error "[ActionCable] Closing connection"
@websocket.close
end
private
def initialize_connection
connect if respond_to?(:connect)
register_connection
@accept_messages = true
worker_pool.async.invoke(self, :received_data, @pending_messages.shift) until @pending_messages.empty?
end
def on_connection_closed
cleanup_subscriptions
cleanup_internal_redis_subscriptions
disconnect if respond_to?(:disconnect)
end
def broadcast_ping_timestamp
broadcast({ identifier: '_ping', message: Time.now.to_i }.to_json)
end
def subscribe_channel(data)
id_key = data['identifier']
id_options = ActiveSupport::JSON.decode(id_key).with_indifferent_access
subscription_klass = server.registered_channels.detect { |channel_klass| channel_klass.find_name == id_options[:channel] }
if subscription_klass
logger.info "[ActionCable] Subscribing to channel: #{id_key}"
@subscriptions[id_key] = subscription_klass.new(self, id_key, id_options)
else
logger.error "[ActionCable] Subscription class not found (#{data.inspect})"
end
rescue Exception => e
logger.error "[ActionCable] Could not subscribe to channel (#{data.inspect})"
log_exception(e)
end
def process_message(message)
if @subscriptions[message['identifier']]
@subscriptions[message['identifier']].receive_data(ActiveSupport::JSON.decode message['data'])
else
logger.error "[ActionCable] Unable to process message because no subscription was found (#{message.inspect})"
end
rescue Exception => e
logger.error "[ActionCable] Could not process message (#{message.inspect})"
log_exception(e)
end
def unsubscribe_channel(data)
logger.info "[ActionCable] Unsubscribing from channel: #{data['identifier']}"
@subscriptions[data['identifier']].unsubscribe
@subscriptions.delete(data['identifier'])
end
def invalid_request
logger.info "[ActionCable] #{finished_request_message}"
[404, {'Content-Type' => 'text/plain'}, ['Page not found']]
end
def websocket_alive?
@websocket && @websocket.ready_state == Faye::WebSocket::API::OPEN
end
def request
@request ||= ActionDispatch::Request.new(env)
end
def websocket?
@is_websocket ||= Faye::WebSocket.websocket?(@env)
end
def started_request_message
'Started %s "%s"%s for %s at %s' % [
request.request_method,
request.filtered_path,
websocket? ? ' [Websocket]' : '',
request.ip,
Time.now.to_default_s ]
end
def finished_request_message
'Finished "%s"%s for %s at %s' % [
request.filtered_path,
websocket? ? ' [Websocket]' : '',
request.ip,
Time.now.to_default_s ]
end
def log_exception(e)
logger.error "[ActionCable] There was an exception - #{e.class}(#{e.message})"
logger.error e.backtrace.join("\n")
end
end
end
end
|
