diff options
Diffstat (limited to 'actioncable/lib/action_cable/subscription_adapter')
6 files changed, 288 insertions, 0 deletions
diff --git a/actioncable/lib/action_cable/subscription_adapter/async.rb b/actioncable/lib/action_cable/subscription_adapter/async.rb new file mode 100644 index 0000000000..c88b03947a --- /dev/null +++ b/actioncable/lib/action_cable/subscription_adapter/async.rb @@ -0,0 +1,22 @@ +require 'action_cable/subscription_adapter/inline' + +module ActionCable + module SubscriptionAdapter + class Async < Inline # :nodoc: + private + def subscriber_map + @subscriber_map ||= AsyncSubscriberMap.new + end + + class AsyncSubscriberMap < SubscriberMap + def add_subscriber(*) + Concurrent.global_io_executor.post { super } + end + + def invoke_callback(*) + Concurrent.global_io_executor.post { super } + end + end + end + end +end diff --git a/actioncable/lib/action_cable/subscription_adapter/base.rb b/actioncable/lib/action_cable/subscription_adapter/base.rb new file mode 100644 index 0000000000..796db5ffa3 --- /dev/null +++ b/actioncable/lib/action_cable/subscription_adapter/base.rb @@ -0,0 +1,28 @@ +module ActionCable + module SubscriptionAdapter + class Base + attr_reader :logger, :server + + def initialize(server) + @server = server + @logger = @server.logger + end + + def broadcast(channel, payload) + raise NotImplementedError + end + + def subscribe(channel, message_callback, success_callback = nil) + raise NotImplementedError + end + + def unsubscribe(channel, message_callback) + raise NotImplementedError + end + + def shutdown + raise NotImplementedError + end + end + end +end diff --git a/actioncable/lib/action_cable/subscription_adapter/inline.rb b/actioncable/lib/action_cable/subscription_adapter/inline.rb new file mode 100644 index 0000000000..4a2a8d23a2 --- /dev/null +++ b/actioncable/lib/action_cable/subscription_adapter/inline.rb @@ -0,0 +1,26 @@ +module ActionCable + module SubscriptionAdapter + class Inline < Base # :nodoc: + def broadcast(channel, payload) + subscriber_map.broadcast(channel, payload) + end + + def subscribe(channel, callback, success_callback = nil) + subscriber_map.add_subscriber(channel, callback, success_callback) + end + + def unsubscribe(channel, callback) + subscriber_map.remove_subscriber(channel, callback) + end + + def shutdown + # nothing to do + end + + private + def subscriber_map + @subscriber_map ||= SubscriberMap.new + end + end + end +end diff --git a/actioncable/lib/action_cable/subscription_adapter/postgresql.rb b/actioncable/lib/action_cable/subscription_adapter/postgresql.rb new file mode 100644 index 0000000000..3ce1bbed68 --- /dev/null +++ b/actioncable/lib/action_cable/subscription_adapter/postgresql.rb @@ -0,0 +1,101 @@ +gem 'pg', '~> 0.18' +require 'pg' +require 'thread' + +module ActionCable + module SubscriptionAdapter + class PostgreSQL < Base # :nodoc: + def broadcast(channel, payload) + with_connection do |pg_conn| + pg_conn.exec("NOTIFY #{pg_conn.escape_identifier(channel)}, '#{pg_conn.escape_string(payload)}'") + end + end + + def subscribe(channel, callback, success_callback = nil) + listener.add_subscriber(channel, callback, success_callback) + end + + def unsubscribe(channel, callback) + listener.remove_subscriber(channel, callback) + end + + def shutdown + listener.shutdown + end + + def with_connection(&block) # :nodoc: + ActiveRecord::Base.connection_pool.with_connection do |ar_conn| + pg_conn = ar_conn.raw_connection + + unless pg_conn.is_a?(PG::Connection) + raise 'ActiveRecord database must be Postgres in order to use the Postgres ActionCable storage adapter' + end + + yield pg_conn + end + end + + private + def listener + @listener ||= Listener.new(self) + end + + class Listener < SubscriberMap + def initialize(adapter) + super() + + @adapter = adapter + @queue = Queue.new + + @thread = Thread.new do + Thread.current.abort_on_exception = true + listen + end + end + + def listen + @adapter.with_connection do |pg_conn| + catch :shutdown do + loop do + until @queue.empty? + action, channel, callback = @queue.pop(true) + + case action + when :listen + pg_conn.exec("LISTEN #{pg_conn.escape_identifier channel}") + Concurrent.global_io_executor << callback if callback + when :unlisten + pg_conn.exec("UNLISTEN #{pg_conn.escape_identifier channel}") + when :shutdown + throw :shutdown + end + end + + pg_conn.wait_for_notify(1) do |chan, pid, message| + broadcast(chan, message) + end + end + end + end + end + + def shutdown + @queue.push([:shutdown]) + Thread.pass while @thread.alive? + end + + def add_channel(channel, on_success) + @queue.push([:listen, channel, on_success]) + end + + def remove_channel(channel) + @queue.push([:unlisten, channel]) + end + + def invoke_callback(*) + Concurrent.global_io_executor.post { super } + end + end + end + end +end diff --git a/actioncable/lib/action_cable/subscription_adapter/redis.rb b/actioncable/lib/action_cable/subscription_adapter/redis.rb new file mode 100644 index 0000000000..a035e3988d --- /dev/null +++ b/actioncable/lib/action_cable/subscription_adapter/redis.rb @@ -0,0 +1,58 @@ +require 'thread' + +gem 'em-hiredis', '~> 0.3.0' +gem 'redis', '~> 3.0' +require 'em-hiredis' +require 'redis' + +EventMachine.epoll if EventMachine.epoll? +EventMachine.kqueue if EventMachine.kqueue? + +module ActionCable + module SubscriptionAdapter + class Redis < Base # :nodoc: + @@mutex = Mutex.new + + def broadcast(channel, payload) + redis_connection_for_broadcasts.publish(channel, payload) + end + + def subscribe(channel, message_callback, success_callback = nil) + redis_connection_for_subscriptions.pubsub.subscribe(channel, &message_callback).tap do |result| + result.callback { |reply| success_callback.call } if success_callback + end + end + + def unsubscribe(channel, message_callback) + redis_connection_for_subscriptions.pubsub.unsubscribe_proc(channel, message_callback) + end + + def shutdown + redis_connection_for_subscriptions.pubsub.close_connection + @redis_connection_for_subscriptions = nil + end + + private + def redis_connection_for_subscriptions + ensure_reactor_running + @redis_connection_for_subscriptions ||= EM::Hiredis.connect(@server.config.cable[:url]).tap do |redis| + redis.on(:reconnect_failed) do + @logger.info "[ActionCable] Redis reconnect failed." + end + end + end + + def redis_connection_for_broadcasts + @redis_connection_for_broadcasts ||= ::Redis.new(@server.config.cable) + end + + def ensure_reactor_running + return if EventMachine.reactor_running? + @@mutex.synchronize do + Thread.new { EventMachine.run } unless EventMachine.reactor_running? + Thread.pass until EventMachine.reactor_running? + end + end + end + end +end diff --git a/actioncable/lib/action_cable/subscription_adapter/subscriber_map.rb b/actioncable/lib/action_cable/subscription_adapter/subscriber_map.rb new file mode 100644 index 0000000000..37eed09793 --- /dev/null +++ b/actioncable/lib/action_cable/subscription_adapter/subscriber_map.rb @@ -0,0 +1,53 @@ +module ActionCable + module SubscriptionAdapter + class SubscriberMap + def initialize + @subscribers = Hash.new { |h,k| h[k] = [] } + @sync = Mutex.new + end + + def add_subscriber(channel, subscriber, on_success) + @sync.synchronize do + new_channel = !@subscribers.key?(channel) + + @subscribers[channel] << subscriber + + if new_channel + add_channel channel, on_success + elsif on_success + on_success.call + end + end + end + + def remove_subscriber(channel, subscriber) + @sync.synchronize do + @subscribers[channel].delete(subscriber) + + if @subscribers[channel].empty? + @subscribers.delete channel + remove_channel channel + end + end + end + + def broadcast(channel, message) + list = @sync.synchronize { @subscribers[channel].dup } + list.each do |subscriber| + invoke_callback(subscriber, message) + end + end + + def add_channel(channel, on_success) + on_success.call if on_success + end + + def remove_channel(channel) + end + + def invoke_callback(callback, message) + callback.call message + end + end + end +end |