Merge pull request #22950 from maclover7/adapterize-storage-actioncable

Adapterize storage for ActionCable

3 files changed, 24 insertions, 26 deletions

diff --git a/actioncable/lib/action_cable/server/base.rb b/actioncable/lib/action_cable/server/base.rb
index 3785bbd154..3385a4c9f3 100644
--- a/actioncable/lib/action_cable/server/base.rb
+++ b/actioncable/lib/action_cable/server/base.rb
@@ -1,5 +1,3 @@
-require 'em-hiredis'
-
 module ActionCable
   module Server
     # A singleton ActionCable::Server instance is available via ActionCable.server. It's used by the rack process that starts the cable server, but
@@ -47,20 +45,9 @@ module ActionCable
         end
       end
 
-      # The redis pubsub adapter used for all streams/broadcasting.
+      # Adapter used for all streams/broadcasting.
       def pubsub
-        @pubsub ||= redis.pubsub
-      end
-
-      # The EventMachine Redis instance used by the pubsub adapter.
-      def redis
-        @redis ||= EM::Hiredis.connect(config.redis[:url]).tap do |redis|
-          redis.on(:reconnect_failed) do
-            logger.info "[ActionCable] Redis reconnect failed."
-            # logger.info "[ActionCable] Redis reconnected. Closing all the open connections."
-            # @connections.map &:close
-          end
-        end
+        @pubsub ||= config.pubsub_adapter.new(self)
       end
 
       # All the identifiers applied to the connection class associated with this server.
diff --git a/actioncable/lib/action_cable/server/broadcasting.rb b/actioncable/lib/action_cable/server/broadcasting.rb
index c759239a0e..4a26ed9269 100644
--- a/actioncable/lib/action_cable/server/broadcasting.rb
+++ b/actioncable/lib/action_cable/server/broadcasting.rb
@@ -1,5 +1,3 @@
-require 'redis'
-
 module ActionCable
   module Server
     # Broadcasting is how other parts of your application can send messages to the channel subscribers. As explained in Channel, most of the time, these
@@ -31,11 +29,6 @@ module ActionCable
         Broadcaster.new(self, broadcasting)
       end
 
-      # The redis instance used for broadcasting. Not intended for direct user use.
-      def broadcasting_redis
-        @broadcasting_redis ||= Redis.new(config.redis)
-      end
-
       private
         class Broadcaster
           attr_reader :server, :broadcasting
@@ -46,7 +39,7 @@ module ActionCable
 
           def broadcast(message)
             server.logger.info "[ActionCable] Broadcasting to #{broadcasting}: #{message}"
-            server.broadcasting_redis.publish broadcasting, ActiveSupport::JSON.encode(message)
+            server.pubsub.broadcast broadcasting, ActiveSupport::JSON.encode(message)
           end
         end
     end
diff --git a/actioncable/lib/action_cable/server/configuration.rb b/actioncable/lib/action_cable/server/configuration.rb
index 935133cbba..ebbf60c6e2 100644
--- a/actioncable/lib/action_cable/server/configuration.rb
+++ b/actioncable/lib/action_cable/server/configuration.rb
@@ -5,9 +5,9 @@ module ActionCable
     class Configuration
       attr_accessor :logger, :log_tags
       attr_accessor :connection_class, :worker_pool_size
-      attr_accessor :redis, :channels_path
+      attr_accessor :channels_path
       attr_accessor :disable_request_forgery_protection, :allowed_request_origins
-      attr_accessor :url
+      attr_accessor :cable, :url
 
       def initialize
         @log_tags = []
@@ -29,7 +29,25 @@ module ActionCable
           Pathname.new(channel_path).basename.to_s.split('.').first.camelize
         end
       end
+
+      # Returns constant of subscription adapter specified in config/cable.yml.
+      # If the adapter cannot be found, this will default to the Redis adapter.
+      # Also makes sure proper dependencies are required.
+      def pubsub_adapter
+        adapter = (cable.fetch('adapter') { 'redis' })
+        path_to_adapter = "action_cable/subscription_adapter/#{adapter}"
+        begin
+          require path_to_adapter
+        rescue Gem::LoadError => e
+          raise Gem::LoadError, "Specified '#{adapter}' for Action Cable pubsub adapter, but the gem is not loaded. Add `gem '#{e.name}'` to your Gemfile (and ensure its version is at the minimum required by Action Cable)."
+        rescue LoadError => e
+          raise LoadError, "Could not load '#{path_to_adapter}'. Make sure that the adapter in config/cable.yml is valid. If you use an adapter other than 'postgresql' or 'redis' add the necessary adapter gem to the Gemfile.", e.backtrace
+        end
+
+        adapter = adapter.camelize
+        adapter = 'PostgreSQL' if adapter == 'Postgresql'
+        "ActionCable::SubscriptionAdapter::#{adapter}".constantize
+      end
     end
   end
 end
-