Introduce Streams as the domain language for the pubsub channels Channels redeliver messages from

lib/action_cable/channel.rb

@@ -1,7 +1,7 @@
 module ActionCable
   module Channel
     autoload :Callbacks, 'action_cable/channel/callbacks'
-    autoload :Redis, 'action_cable/channel/redis'
+    autoload :Streams, 'action_cable/channel/streams'
     autoload :Base, 'action_cable/channel/base'
   end
 end

lib/action_cable/channel/base.rb

@@ -2,7 +2,7 @@ module ActionCable
   module Channel
     class Base
       include Callbacks
-      include Redis
+      include Streams
 
       on_subscribe   :start_periodic_timers
       on_unsubscribe :stop_periodic_timers

lib/action_cable/channel/redis.rb

@@ -1,37 +0,0 @@
-module ActionCable
-  module Channel
-    module Redis
-      extend ActiveSupport::Concern
-
-      included do
-        on_unsubscribe :unsubscribe_from_all_channels
-        delegate :pubsub, to: :connection
-      end
-
-      def subscribe_to(redis_channel, callback = nil)
-        callback ||= default_subscription_callback(redis_channel)
-        @_redis_channels ||= []
-        @_redis_channels << [ redis_channel, callback ]
-
-        pubsub.subscribe(redis_channel, &callback)
-        logger.info "#{channel_name} subscribed to broadcasts from #{redis_channel}"
-      end
-
-      def unsubscribe_from_all_channels
-        if @_redis_channels
-          @_redis_channels.each do |redis_channel, callback|
-            pubsub.unsubscribe_proc(redis_channel, callback)
-            logger.info "#{channel_name} unsubscribed to broadcasts from #{redis_channel}"
-          end
-        end
-      end
-
-      protected
-        def default_subscription_callback(channel)
-          -> (message) do
-            transmit ActiveSupport::JSON.decode(message), via: "broadcast from #{channel}"
-          end
-        end
-    end
-  end
-end

lib/action_cable/channel/streams.rb

@@ -0,0 +1,40 @@
+module ActionCable
+  module Channel
+    module Streams
+      extend ActiveSupport::Concern
+
+      included do
+        on_unsubscribe :stop_all_streams
+      end
+
+      def stream_from(broadcasting, callback = nil)
+        callback ||= default_stream_callback(broadcasting)
+
+        streams << [ broadcasting, callback ]
+        pubsub.subscribe broadcasting, &callback
+
+        logger.info "#{channel_name} is streaming from #{broadcasting}"
+      end
+
+      def stop_all_streams
+        streams.each do |broadcasting, callback|
+          pubsub.unsubscribe_proc broadcasting, callback
+          logger.info "#{channel_name} stopped streaming from #{broadcasting}"
+        end
+      end
+
+      private
+        delegate :pubsub, to: :connection
+
+        def streams
+          @_streams ||= []
+        end
+
+        def default_stream_callback(broadcasting)
+          -> (message) do
+            transmit ActiveSupport::JSON.decode(message), via: "streamed from #{broadcasting}"
+          end
+        end
+    end
+  end
+end

lib/action_cable/server/broadcasting.rb

@@ -1,12 +1,12 @@
 module ActionCable
   module Server
     module Broadcasting
-      def broadcast(channel, message)
-        broadcaster_for(channel).broadcast(message)
+      def broadcast(broadcasting, message)
+        broadcaster_for(broadcasting).broadcast(message)
       end
 
-      def broadcaster_for(channel)
-        Broadcaster.new(self, channel)
+      def broadcaster_for(broadcasting)
+        Broadcaster.new(self, broadcasting)
       end
 
       def broadcasting_redis
@@ -15,19 +15,19 @@ module ActionCable
 
       private
         class Broadcaster
-          attr_reader :server, :channel
+          attr_reader :server, :broadcasting
 
-          def initialize(server, channel)
-            @server, @channel = server, channel
+          def initialize(server, broadcasting)
+            @server, @broadcasting = server, broadcasting
           end
 
           def broadcast(message)
-            server.logger.info "[ActionCable] Broadcasting to #{channel}: #{message}"
+            server.logger.info "[ActionCable] Broadcasting to #{broadcasting}: #{message}"
             broadcast_without_logging(message)
           end
 
           def broadcast_without_logging(message)            
-            server.broadcasting_redis.publish channel, message.to_json
+            server.broadcasting_redis.publish broadcasting, message.to_json
           end
         end
     end