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author | Pratik Naik <pratiknaik@gmail.com> | 2015-10-16 21:05:33 -0500 |
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committer | Pratik Naik <pratiknaik@gmail.com> | 2015-10-16 21:11:21 -0500 |
commit | 84b1f0a3e622d35bf1fb1b2662bc0262a040e119 (patch) | |
tree | cbfef05e91f6e071cc90379ebdf63cf227b91d83 /lib/action_cable/channel/base.rb | |
parent | df5a32dfbc94723d847aa8d8034041a2bd8751e2 (diff) | |
download | rails-84b1f0a3e622d35bf1fb1b2662bc0262a040e119.tar.gz rails-84b1f0a3e622d35bf1fb1b2662bc0262a040e119.tar.bz2 rails-84b1f0a3e622d35bf1fb1b2662bc0262a040e119.zip |
Send subscription confirmation from server to the client to avoid race conditions.
Without this, it's very easy to send messages over a subscription even before the
redis pubsub has been fully initialized.
Now we delay calling the subscription#connected method on the client side until we
receive a subscription confirmation message from the server.
Diffstat (limited to 'lib/action_cable/channel/base.rb')
-rw-r--r-- | lib/action_cable/channel/base.rb | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/lib/action_cable/channel/base.rb b/lib/action_cable/channel/base.rb index df87064195..c8292be183 100644 --- a/lib/action_cable/channel/base.rb +++ b/lib/action_cable/channel/base.rb @@ -73,6 +73,8 @@ module ActionCable include Naming include Broadcasting + SUBSCRIPTION_CONFIRMATION_INTERNAL_MESSAGE = 'confirm_subscription' + on_subscribe :subscribed on_unsubscribe :unsubscribed @@ -120,6 +122,10 @@ module ActionCable @identifier = identifier @params = params + # When a channel is streaming via redis pubsub, we want to delay the confirmation + # transmission until redis pubsub subscription is confirmed. + @defer_subscription_confirmation = false + delegate_connection_identifiers subscribe_to_channel end @@ -165,6 +171,15 @@ module ActionCable end + protected + def defer_subscription_confirmation! + @defer_subscription_confirmation = true + end + + def defer_subscription_confirmation? + @defer_subscription_confirmation + end + private def delegate_connection_identifiers connection.identifiers.each do |identifier| @@ -177,6 +192,7 @@ module ActionCable def subscribe_to_channel run_subscribe_callbacks + transmit_subscription_confirmation unless defer_subscription_confirmation? end @@ -213,6 +229,12 @@ module ActionCable def run_unsubscribe_callbacks self.class.on_unsubscribe_callbacks.each { |callback| send(callback) } end + + def transmit_subscription_confirmation + logger.info "#{self.class.name} is transmitting the subscription confirmation" + connection.transmit ActiveSupport::JSON.encode(identifier: @identifier, type: SUBSCRIPTION_CONFIRMATION_INTERNAL_MESSAGE) + end + end end end |