Merge branch 'connection-management'

11 files changed, 317 insertions, 146 deletions

diff --git a/Gemfile.lock b/Gemfile.lock
index e767e58784..6fcf4aa39f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,6 +4,7 @@ PATH
     action_cable (0.0.2)
       activesupport (>= 4.2.0)
       celluloid (~> 0.16.0)
+      em-hiredis (~> 0.3.0)
       faye-websocket (~> 0.9.2)
 
 GEM
@@ -17,10 +18,14 @@ GEM
       tzinfo (~> 1.1)
     celluloid (0.16.0)
       timers (~> 4.0.0)
+    em-hiredis (0.3.0)
+      eventmachine (~> 1.0)
+      hiredis (~> 0.5.0)
     eventmachine (1.0.7)
     faye-websocket (0.9.2)
       eventmachine (>= 0.12.0)
       websocket-driver (>= 0.5.1)
+    hiredis (0.5.2)
     hitimes (1.2.2)
     i18n (0.7.0)
     json (1.8.2)
@@ -34,9 +39,9 @@ GEM
       hitimes
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
-    websocket-driver (0.5.1)
+    websocket-driver (0.5.3)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.1)
+    websocket-extensions (0.1.2)
 
 PLATFORMS
   ruby
diff --git a/action_cable.gemspec b/action_cable.gemspec
index 1dade2a394..4f252d4b1e 100644
--- a/action_cable.gemspec
+++ b/action_cable.gemspec
@@ -12,6 +12,8 @@ Gem::Specification.new do |s|
   s.add_dependency('activesupport', '>= 4.2.0')
   s.add_dependency('faye-websocket', '~> 0.9.2')
   s.add_dependency('celluloid', '~> 0.16.0')
+  s.add_dependency('em-hiredis', '~> 0.3.0')
+  s.add_dependency('redis', '~> 3.0')
 
   s.files = Dir['README', 'lib/**/*']
   s.has_rdoc = false
diff --git a/lib/action_cable.rb b/lib/action_cable.rb
index 0681b8bdde..3352453491 100644
--- a/lib/action_cable.rb
+++ b/lib/action_cable.rb
@@ -7,10 +7,12 @@ require 'active_support'
 require 'active_support/json'
 require 'active_support/concern'
 require 'active_support/core_ext/hash/indifferent_access'
+require 'active_support/core_ext/module/delegation'
 require 'active_support/callbacks'
 
 require 'faye/websocket'
 require 'celluloid'
+require 'em-hiredis'
 
 require 'action_cable/engine' if defined?(Rails)
 
@@ -20,4 +22,7 @@ module ActionCable
   autoload :Channel, 'action_cable/channel'
   autoload :Worker, 'action_cable/worker'
   autoload :Server, 'action_cable/server'
+  autoload :Connection, 'action_cable/connection'
+  autoload :RemoteConnection, 'action_cable/remote_connection'
+  autoload :RemoteConnections, 'action_cable/remote_connections'
 end
diff --git a/lib/action_cable/channel/redis.rb b/lib/action_cable/channel/redis.rb
index bdbd3c95b1..2691a3b145 100644
--- a/lib/action_cable/channel/redis.rb
+++ b/lib/action_cable/channel/redis.rb
@@ -6,11 +6,10 @@ module ActionCable
 
       included do
         on_unsubscribe :unsubscribe_from_redis_channels
+        delegate :pubsub, to: :connection
       end
 
       def subscribe_to(redis_channel, callback = nil)
-        raise "`ActionCable::Server.pubsub` class method is not defined" unless connection.class.respond_to?(:pubsub)
-
         callback ||= -> (message) { broadcast ActiveSupport::JSON.decode(message) }
         @_redis_channels ||= []
         @_redis_channels << [ redis_channel, callback ]
@@ -24,10 +23,6 @@ module ActionCable
             @_redis_channels.each { |channel, callback| pubsub.unsubscribe_proc(channel, callback) }
           end
         end
-
-        def pubsub
-          connection.class.pubsub
-        end
     end
 
   end
diff --git a/lib/action_cable/connection.rb b/lib/action_cable/connection.rb
new file mode 100644
index 0000000000..91fc73713c
--- /dev/null
+++ b/lib/action_cable/connection.rb
@@ -0,0 +1,7 @@
+module ActionCable
+  module Connection
+    autoload :Base, 'action_cable/connection/base'
+    autoload :Registry, 'action_cable/connection/registry'
+    autoload :Identifier, 'action_cable/connection/identifier'
+  end
+end
diff --git a/lib/action_cable/connection/base.rb b/lib/action_cable/connection/base.rb
new file mode 100644
index 0000000000..4ad1e7d065
--- /dev/null
+++ b/lib/action_cable/connection/base.rb
@@ -0,0 +1,145 @@
+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
+        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, :cleanup_internal_redis_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 handle_exception
+        logger.error "[ActionCable] Closing connection"
+
+        @websocket.close
+      end
+
+      private
+        def initialize_client
+          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 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})"
+          logger.error e.backtrace.join("\n")
+        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 (#{data.inspect})"
+          logger.error e.backtrace.join("\n")
+        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
+          [404, {'Content-Type' => 'text/plain'}, ['Page not found']]
+        end
+
+        def websocket_alive?
+          @websocket && @websocket.ready_state == Faye::WebSocket::API::OPEN
+        end
+
+    end
+  end
+end
diff --git a/lib/action_cable/connection/identifier.rb b/lib/action_cable/connection/identifier.rb
new file mode 100644
index 0000000000..9bfd773ab1
--- /dev/null
+++ b/lib/action_cable/connection/identifier.rb
@@ -0,0 +1,19 @@
+module ActionCable
+  module Connection
+    module Identifier
+
+      def internal_redis_channel
+        "action_cable/#{connection_identifier}"
+      end
+
+      def connection_identifier
+        @connection_identifier ||= connection_gid identifiers.map { |id| instance_variable_get("@#{id}")}
+      end
+
+      def connection_gid(ids)
+        ids.map {|o| o.to_global_id.to_s }.sort.join(":")
+      end
+
+    end
+  end
+end
diff --git a/lib/action_cable/connection/registry.rb b/lib/action_cable/connection/registry.rb
new file mode 100644
index 0000000000..03a0bf4fe9
--- /dev/null
+++ b/lib/action_cable/connection/registry.rb
@@ -0,0 +1,64 @@
+module ActionCable
+  module Connection
+    module Registry
+      extend ActiveSupport::Concern
+
+      included do
+        class_attribute :identifiers
+        self.identifiers = Set.new
+      end
+
+      module ClassMethods
+        def identified_by(*identifiers)
+          self.identifiers += identifiers
+        end
+      end
+
+      def register_connection
+        if connection_identifier.present?
+          callback = -> (message) { process_registry_message(message) }
+          @_internal_redis_subscriptions ||= []
+          @_internal_redis_subscriptions << [ internal_redis_channel, callback ]
+
+          pubsub.subscribe(internal_redis_channel, &callback)
+          logger.info "[ActionCable] Registered connection (#{connection_identifier})"
+        end
+      end
+
+      def internal_redis_channel
+        "action_cable/#{connection_identifier}"
+      end
+
+      def connection_identifier
+        @connection_identifier ||= connection_gid identifiers.map { |id| instance_variable_get("@#{id}")}
+      end
+
+      def connection_gid(ids)
+        ids.map {|o| o.to_global_id.to_s }.sort.join(":")
+      end
+
+      def cleanup_internal_redis_subscriptions
+        if @_internal_redis_subscriptions.present?
+          @_internal_redis_subscriptions.each { |channel, callback| pubsub.unsubscribe_proc(channel, callback) }
+        end
+      end
+
+      private
+        def process_registry_message(message)
+          message = ActiveSupport::JSON.decode(message)
+
+          case message['type']
+          when 'disconnect'
+            logger.info "[ActionCable] Removing connection (#{connection_identifier})"
+            @websocket.close
+          end
+        rescue Exception => e
+          logger.error "[ActionCable] There was an exception - #{e.class}(#{e.message})"
+          logger.error e.backtrace.join("\n")
+
+          handle_exception
+        end
+
+    end
+  end
+end
diff --git a/lib/action_cable/remote_connection.rb b/lib/action_cable/remote_connection.rb
new file mode 100644
index 0000000000..e2cb2d932c
--- /dev/null
+++ b/lib/action_cable/remote_connection.rb
@@ -0,0 +1,38 @@
+module ActionCable
+  class RemoteConnection
+    class InvalidIdentifiersError < StandardError; end
+
+    include Connection::Identifier
+
+    delegate :redis, to: :server
+
+    def initialize(server, ids)
+      @server = server
+      set_identifier_instance_vars(ids)
+    end
+
+    def disconnect
+      message = { type: 'disconnect' }.to_json
+      redis.publish(internal_redis_channel, message)
+    end
+
+    def identifiers
+      @server.connection_identifiers
+    end
+
+    def redis
+      @redis ||= Redis.new(@server.redis_config)
+    end
+
+    private
+      def set_identifier_instance_vars(ids)
+        raise InvalidIdentifiersError unless valid_identifiers?(ids)
+        ids.each { |k,v| instance_variable_set("@#{k}", v) }
+      end
+
+      def valid_identifiers?(ids)
+        keys = ids.keys
+        identifiers.all? { |id| keys.include?(id) }
+      end
+  end
+end
diff --git a/lib/action_cable/remote_connections.rb b/lib/action_cable/remote_connections.rb
new file mode 100644
index 0000000000..f9d7c49a27
--- /dev/null
+++ b/lib/action_cable/remote_connections.rb
@@ -0,0 +1,13 @@
+module ActionCable
+  class RemoteConnections
+    attr_reader :server
+
+    def initialize(server)
+      @server = server
+    end
+
+    def where(identifier)
+      RemoteConnection.new(server, identifier)
+    end
+  end
+end
diff --git a/lib/action_cable/server.rb b/lib/action_cable/server.rb
index ebf98171c1..222c77fd51 100644
--- a/lib/action_cable/server.rb
+++ b/lib/action_cable/server.rb
@@ -1,157 +1,35 @@
 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
+    attr_accessor :registered_channels, :redis_config
 
-      def worker_pool
-        @worker_pool ||= ActionCable::Worker.pool(size: worker_pool_size)
-      end
+    def initialize(redis_config:, channels:, worker_pool_size: 100, connection: Connection)
+      @redis_config = redis_config
+      @registered_channels = Set.new(channels)
+      @worker_pool_size = worker_pool_size
+      @connection_class = connection
     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
+    def call(env)
+      @connection_class.new(self, env).process
     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
+    def worker_pool
+      @worker_pool ||= ActionCable::Worker.pool(size: @worker_pool_size)
     end
 
-    def broadcast(data)
-      logger.info "Sending data: #{data}"
-      @websocket.send data
+    def pubsub
+      @pubsub ||= EM::Hiredis.connect(@redis_config['url']).pubsub
     end
 
-    def worker_pool
-      self.class.worker_pool
+    def remote_connections
+      @remote_connections ||= RemoteConnections.new(self)
     end
 
-    def handle_exception
-      logger.error "[ActionCable] Closing connection"
-
-      @websocket.close
+    def connection_identifiers
+      @connection_class.identifiers
     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