Extract WaitableWorker out of AuthorizedProjectsWorker

app/workers/authorized_projects_worker.rb

 class AuthorizedProjectsWorker
   include ApplicationWorker
+  prepend WaitableWorker
 
-  # Schedules multiple jobs and waits for them to be completed.
-  def self.bulk_perform_and_wait(args_list)
-    # Short-circuit: it's more efficient to do small numbers of jobs inline
-    return bulk_perform_inline(args_list) if args_list.size <= 3
-
-    waiter = Gitlab::JobWaiter.new(args_list.size)
-
-    # Point all the bulk jobs at the same JobWaiter. Converts, [[1], [2], [3]]
-    # into [[1, "key"], [2, "key"], [3, "key"]]
-    waiting_args_list = args_list.map { |args| [*args, waiter.key] }
-    bulk_perform_async(waiting_args_list)
-
-    waiter.wait
-  end
-
-  # Performs multiple jobs directly. Failed jobs will be put into sidekiq so
-  # they can benefit from retries
-  def self.bulk_perform_inline(args_list)
-    failed = []
-
-    args_list.each do |args|
-      begin
-        new.perform(*args)
-      rescue
-        failed << args
-      end
-    end
-
-    bulk_perform_async(failed) if failed.present?
-  end
-
-  def perform(user_id, notify_key = nil)
+  def perform(user_id)
     user = User.find_by(id: user_id)
 
     user&.refresh_authorized_projects
-  ensure
-    Gitlab::JobWaiter.notify(notify_key, jid) if notify_key
   end
 end

app/workers/concerns/waitable_worker.rb

+module WaitableWorker
+  extend ActiveSupport::Concern
+
+  module ClassMethods
+    # Schedules multiple jobs and waits for them to be completed.
+    def bulk_perform_and_wait(args_list)
+      # Short-circuit: it's more efficient to do small numbers of jobs inline
+      return bulk_perform_inline(args_list) if args_list.size <= 3
+
+      waiter = Gitlab::JobWaiter.new(args_list.size)
+
+      # Point all the bulk jobs at the same JobWaiter. Converts, [[1], [2], [3]]
+      # into [[1, "key"], [2, "key"], [3, "key"]]
+      waiting_args_list = args_list.map { |args| [*args, waiter.key] }
+      bulk_perform_async(waiting_args_list)
+
+      waiter.wait
+    end
+
+    # Performs multiple jobs directly. Failed jobs will be put into sidekiq so
+    # they can benefit from retries
+    def bulk_perform_inline(args_list)
+      failed = []
+
+      args_list.each do |args|
+        begin
+          new.perform(*args)
+        rescue
+          failed << args
+        end
+      end
+
+      bulk_perform_async(failed) if failed.present?
+    end
+  end
+
+  def perform(*args)
+    notify_key = args.pop if Gitlab::JobWaiter.key?(args.last)
+
+    super(*args)
+  ensure
+    Gitlab::JobWaiter.notify(notify_key, jid) if notify_key
+  end
+end

lib/gitlab/job_waiter.rb

@@ -15,16 +15,22 @@ module Gitlab
   # push to that array when done. Once the waiter has popped `count` items, it
   # knows all the jobs are done.
   class JobWaiter
+    KEY_PREFIX = "gitlab:job_waiter".freeze
+
     def self.notify(key, jid)
       Gitlab::Redis::SharedState.with { |redis| redis.lpush(key, jid) }
     end
 
+    def self.key?(key)
+      key.is_a?(String) && key =~ /\A#{KEY_PREFIX}:\h{8}-\h{4}-\h{4}-\h{4}-\h{12}\z/
+    end
+
     attr_reader :key, :finished
     attr_accessor :jobs_remaining
 
     # jobs_remaining - the number of jobs left to wait for
     # key - The key of this waiter.
-    def initialize(jobs_remaining = 0, key = "gitlab:job_waiter:#{SecureRandom.uuid}")
+    def initialize(jobs_remaining = 0, key = "#{KEY_PREFIX}:#{SecureRandom.uuid}")
       @key = key
       @jobs_remaining = jobs_remaining
       @finished = []

spec/workers/authorized_projects_worker_spec.rb

 require 'spec_helper'
 
 describe AuthorizedProjectsWorker do
-  let(:project) { create(:project) }
-
-  def build_args_list(*ids, multiply: 1)
-    args_list = ids.map { |id| [id] }
-    args_list * multiply
-  end
-
-  describe '.bulk_perform_and_wait' do
-    it 'schedules the ids and waits for the jobs to complete' do
-      args_list = build_args_list(project.owner.id)
-
-      project.owner.project_authorizations.delete_all
-      described_class.bulk_perform_and_wait(args_list)
-
-      expect(project.owner.project_authorizations.count).to eq(1)
-    end
-
-    it 'inlines workloads <= 3 jobs' do
-      args_list = build_args_list(project.owner.id, multiply: 3)
-      expect(described_class).to receive(:bulk_perform_inline).with(args_list)
-
-      described_class.bulk_perform_and_wait(args_list)
-    end
-
-    it 'runs > 3 jobs using sidekiq' do
-      project.owner.project_authorizations.delete_all
-
-      expect(described_class).to receive(:bulk_perform_async).and_call_original
-
-      args_list = build_args_list(project.owner.id, multiply: 4)
-      described_class.bulk_perform_and_wait(args_list)
-
-      expect(project.owner.project_authorizations.count).to eq(1)
-    end
-  end
-
-  describe '.bulk_perform_inline' do
-    it 'refreshes the authorizations inline' do
-      project.owner.project_authorizations.delete_all
-
-      expect_any_instance_of(described_class).to receive(:perform).and_call_original
-
-      described_class.bulk_perform_inline(build_args_list(project.owner.id))
-
-      expect(project.owner.project_authorizations.count).to eq(1)
-    end
-
-    it 'enqueues jobs if an error is raised' do
-      invalid_id = -1
-      args_list = build_args_list(project.owner.id, invalid_id)
-
-      allow_any_instance_of(described_class).to receive(:perform).with(project.owner.id)
-      allow_any_instance_of(described_class).to receive(:perform).with(invalid_id).and_raise(ArgumentError)
-      expect(described_class).to receive(:bulk_perform_async).with(build_args_list(invalid_id))
-
-      described_class.bulk_perform_inline(args_list)
-    end
-  end
-
-  describe '.bulk_perform_async' do
-    it "uses it's respective sidekiq queue" do
-      args_list = build_args_list(project.owner.id)
-      push_bulk_args = {
-        'class' => described_class,
-        'args' => args_list
-      }
-
-      expect(Sidekiq::Client).to receive(:push_bulk).with(push_bulk_args).once
-
-      described_class.bulk_perform_async(args_list)
-    end
-  end
-
   describe '#perform' do
     let(:user) { create(:user) }
 
@@ -85,12 +12,6 @@ describe AuthorizedProjectsWorker do
       job.perform(user.id)
     end
 
-    it 'notifies the JobWaiter when done if the key is provided' do
-      expect(Gitlab::JobWaiter).to receive(:notify).with('notify-key', job.jid)
-
-      job.perform(user.id, 'notify-key')
-    end
-
     context "when the user is not found" do
       it "does nothing" do
         expect_any_instance_of(User).not_to receive(:refresh_authorized_projects)

spec/workers/concerns/waitable_worker_spec.rb

+require 'spec_helper'
+
+describe WaitableWorker do
+  let(:worker) do
+    Class.new do
+      def self.name
+        'Gitlab::Foo::Bar::DummyWorker'
+      end
+
+      class << self
+        cattr_accessor(:counter) { 0 }
+      end
+
+      include ApplicationWorker
+      prepend WaitableWorker
+
+      def perform(i = 0)
+        self.class.counter += i
+      end
+    end
+  end
+
+  subject(:job) { worker.new }
+
+  describe '.bulk_perform_and_wait' do
+    it 'schedules the jobs and waits for them to complete' do
+      worker.bulk_perform_and_wait([[1], [2]])
+
+      expect(worker.counter).to eq(3)
+    end
+
+    it 'inlines workloads <= 3 jobs' do
+      args_list = [[1], [2], [3]]
+      expect(worker).to receive(:bulk_perform_inline).with(args_list).and_call_original
+
+      worker.bulk_perform_and_wait(args_list)
+
+      expect(worker.counter).to eq(6)
+    end
+
+    it 'runs > 3 jobs using sidekiq' do
+      expect(worker).to receive(:bulk_perform_async)
+
+      worker.bulk_perform_and_wait([[1], [2], [3], [4]])
+    end
+  end
+
+  describe '.bulk_perform_inline' do
+    it 'runs the jobs inline' do
+      expect(worker).not_to receive(:bulk_perform_async)
+
+      worker.bulk_perform_inline([[1], [2]])
+
+      expect(worker.counter).to eq(3)
+    end
+
+    it 'enqueues jobs if an error is raised' do
+      expect(worker).to receive(:bulk_perform_async).with([['foo']])
+
+      worker.bulk_perform_inline([[1], ['foo']])
+    end
+  end
+
+  describe '#perform' do
+    shared_examples 'perform' do
+      it 'notifies the JobWaiter when done if the key is provided' do
+        key = Gitlab::JobWaiter.new.key
+        expect(Gitlab::JobWaiter).to receive(:notify).with(key, job.jid)
+
+        job.perform(*args, key)
+      end
+
+      it 'does not notify the JobWaiter when done if no key is provided' do
+        expect(Gitlab::JobWaiter).not_to receive(:notify)
+
+        job.perform(*args)
+      end
+    end
+
+    context 'when the worker takes arguments' do
+      let(:args) { [1] }
+
+      it_behaves_like 'perform'
+    end
+
+    context 'when the worker takes no arguments' do
+      let(:args) { [] }
+
+      it_behaves_like 'perform'
+    end
+  end
+end