Merge pull request #359 from alphagov/fix-memory-leak-when-bulk-emailing

Fix memory leak when queuing jobs inside a job

config/initializers/active_job.rb

@@ -0,0 +1,59 @@
+require 'active_job/logging'
+
+# TODO: remove this when the following issue is resolved:
+#       https://github.com/rails/rails/issues/21036
+
+# Unsubscribe all Active Job notifications
+ActiveSupport::Notifications.unsubscribe 'perform_start.active_job'
+ActiveSupport::Notifications.unsubscribe 'perform.active_job'
+ActiveSupport::Notifications.unsubscribe 'enqueue_at.active_job'
+ActiveSupport::Notifications.unsubscribe 'enqueue.active_job'
+
+module ActiveJob
+  module Logging
+    class LogSubscriber
+      # Remove all public methods so that we can use the class
+      # as the base class for our two new subscriber classes.
+      remove_method :enqueue
+      remove_method :enqueue_at
+      remove_method :perform_start
+      remove_method :perform
+    end
+
+    class EnqueueSubscriber < LogSubscriber
+      def enqueue(event)
+        info do
+          job = event.payload[:job]
+          "Enqueued #{job.class.name} (Job ID: #{job.job_id}) to #{queue_name(event)}" + args_info(job)
+        end
+      end
+
+      def enqueue_at(event)
+        info do
+          job = event.payload[:job]
+          "Enqueued #{job.class.name} (Job ID: #{job.job_id}) to #{queue_name(event)} at #{scheduled_at(event)}" + args_info(job)
+        end
+      end
+    end
+
+    class ExecutionSubscriber < LogSubscriber
+      def perform_start(event)
+        info do
+          job = event.payload[:job]
+          "Performing #{job.class.name} from #{queue_name(event)}" + args_info(job)
+        end
+      end
+
+      def perform(event)
+        info do
+          job = event.payload[:job]
+          "Performed #{job.class.name} from #{queue_name(event)} in #{event.duration.round(2)}ms"
+        end
+      end
+    end
+  end
+end
+
+# Suubscribe to Active Job notifications
+ActiveJob::Logging::EnqueueSubscriber.attach_to :active_job
+ActiveJob::Logging::ExecutionSubscriber.attach_to :active_job