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module ActionCable
class Server
class_attribute :registered_channels
self.registered_channels = Set.new
class_attribute :worker_pool_size
self.worker_pool_size = 100
cattr_accessor(:logger, instance_reader: true) { Rails.logger }
PING_INTERVAL = 3
class << self
def register_channels(*channel_classes)
self.registered_channels += channel_classes
end
def call(env)
new(env).process
end
def worker_pool
@worker_pool ||= ActionCable::Worker.pool(size: worker_pool_size)
end
end
attr_reader :env
def initialize(env)
@env = env
@accept_messages = false
@pending_messages = []
end
def process
if Faye::WebSocket.websocket?(@env)
@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_client)
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|
worker_pool.async.invoke(self, :cleanup_subscriptions)
worker_pool.async.invoke(self, :disconnect) if respond_to?(:disconnect)
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 "Sending data: #{data}"
@websocket.send data
end
def worker_pool
self.class.worker_pool
end
def handle_exception
logger.error "[ActionCable] Closing connection"
@websocket.close
end
private
def initialize_client
connect if respond_to?(:connect)
@accept_messages = true
worker_pool.async.invoke(self, :received_data, @pending_messages.shift) until @pending_messages.empty?
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 = registered_channels.detect { |channel_klass| channel_klass.find_name == id_options[:channel] }
if subscription_klass
logger.info "Subscribing to channel: #{id_key}"
@subscriptions[id_key] = subscription_klass.new(self, id_key, id_options)
else
logger.error "Unable to subscribe to channel: #{id_key}"
end
end
def process_message(message)
if @subscriptions[message['identifier']]
@subscriptions[message['identifier']].receive_data(ActiveSupport::JSON.decode message['data'])
else
logger.error "Unable to process message: #{message}"
end
end
def unsubscribe_channel(data)
logger.info "Unsubscribing from channel: #{data['identifier']}"
@subscriptions[data['identifier']].unsubscribe
@subscriptions.delete(data['identifier'])
end
def invalid_request
[404, {'Content-Type' => 'text/plain'}, ['Page not found']]
end
def websocket_alive?
@websocket && @websocket.ready_state == Faye::WebSocket::API::OPEN
end
end
end
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