Move recalculation of content lengths to background job

app/jobs/recalculate_content_lengths_job.rb

@@ -0,0 +1,13 @@
+class RecalculateContentLengthsJob < ApplicationJob
+  queue_as :within_5_minutes
+
+  def perform
+    AudioFile.find_each do |af|
+      next unless Rails.application.config.recalculate_content_length_if.call af
+
+      CodecConversion.find_each do |cc|
+        CalculateContentLengthJob.set(queue: :whenever).perform_later(af, cc)
+      end
+    end
+  end
+end

app/models/content_length.rb

@@ -14,16 +14,4 @@ class ContentLength < ApplicationRecord
 
   validates :audio_file, uniqueness: { scope: :codec_conversion }
   validates :length, presence: true
-
-  def self.destroy_all_and_recalculate
-    destroy_all
-
-    AudioFile.find_each do |af|
-      next unless Rails.application.config.recalculate_content_length_if.call af
-
-      CodecConversion.find_each do |cc|
-        CalculateContentLengthJob.set(queue: :whenever).perform_later(af, cc)
-      end
-    end
-  end
 end

lib/tasks/ffmpeg.rake

@@ -18,7 +18,8 @@ namespace :ffmpeg do
 
     exit if prev_version == new_version
 
-    ContentLength.destroy_all_and_recalculate
+    ContentLength.destroy_all
+    RecalculateContentLengthsJob.perform_later
 
     File.write(path, new_version)
   end

test/jobs/recalculate_content_lengths_job_test.rb

@@ -0,0 +1,63 @@
+require 'test_helper'
+
+class RecalculateContentLengthsJobTest < ActiveJob::TestCase
+  def setup
+    # ContentLengths are automatically created when we create an AudioFile and CodecConversion. Manually creating one would result in an error due to uniqueness contraints.
+    io = StringIO.new Rails.root.join('test/files/base.flac').read
+    AudioFile.any_instance.stubs(:convert).returns(io)
+    @audio_file = create(:audio_file)
+    @codec_conversion = create(:codec_conversion)
+
+    ContentLength.destroy_all
+  end
+
+  test 'should not shedule job if audio is longer than config and track is older than config' do
+    @track = create(:track, audio_file: @audio_file)
+
+    # rubocop:disable Rails/SkipsModelValidations
+    # We want to avoid our own before_save callbacks to manually set audio_file length and track age
+    @audio_file.update_column(:length, 1)
+    @audio_file.track.update_column(:created_at, 1.year.ago)
+    # rubocop:enable Rails/SkipsModelValidations
+
+    assert_no_enqueued_jobs do
+      RecalculateContentLengthsJob.perform_now
+    end
+  end
+
+  test 'should enqueue job if audio is longer than config' do
+    io = StringIO.new Rails.root.join('test/files/base.flac').read
+    AudioFile.any_instance.stubs(:convert).returns(io)
+    @track = create(:track, audio_file: @audio_file)
+
+    # rubocop:disable Rails/SkipsModelValidations
+    # We want to avoid our own before_save callbacks to manually set the audio_file length and track age
+    @audio_file.update_column(:length, 1000)
+    @audio_file.track.update_column(:created_at, 1.year.ago)
+    # rubocop:enable Rails/SkipsModelValidations
+
+    assert_enqueued_jobs 1 do
+      RecalculateContentLengthsJob.perform_now
+    end
+  end
+
+  test 'should enqueue job if track is newer than config' do
+    io = StringIO.new Rails.root.join('test/files/base.flac').read
+    AudioFile.any_instance.stubs(:convert).returns(io)
+    @track = create(:track, audio_file: @audio_file)
+
+    # rubocop:disable Rails/SkipsModelValidations
+    # We want to avoid our own before_save callbacks to manually set the audio_file length and track age
+    @audio_file.update_column(:length, 1)
+    @audio_file.track.update_column(:created_at, 1.day.ago)
+    # rubocop:enable Rails/SkipsModelValidations
+
+    assert_enqueued_jobs 1 do
+      RecalculateContentLengthsJob.perform_now
+    end
+
+    @audio_file.reload
+
+    assert_equal 1, @audio_file.content_lengths.length
+  end
+end

test/models/content_length_test.rb

@@ -11,61 +11,4 @@
 require 'test_helper'
 
 class ContentLengthTest < ActiveSupport::TestCase
-  def setup
-    # ContentLengths are automatically created when we create an AudioFile and CodecConversion. Manually creating one would result in an error due to uniqueness contraints.
-    io = StringIO.new Rails.root.join('test/files/base.flac').read
-    AudioFile.any_instance.stubs(:convert).returns(io)
-    @audio_file = create(:audio_file)
-    @codec_conversion = create(:codec_conversion)
-  end
-
-  test 'should not create new ContentLength if audio is longer than config and track is older than config' do
-    @track = create(:track, audio_file: @audio_file)
-
-    # rubocop:disable Rails/SkipsModelValidations
-    # We want to avoid our own before_save callbacks to manually set audio_file length and track age
-    @audio_file.update_column(:length, 1)
-    @audio_file.track.update_column(:created_at, 1.year.ago)
-    # rubocop:enable Rails/SkipsModelValidations
-
-    assert_difference('ContentLength.count', -1) do
-      ContentLength.destroy_all_and_recalculate
-    end
-  end
-
-  test 'should create new ContentLength if audio is longer than config' do
-    io = StringIO.new Rails.root.join('test/files/base.flac').read
-    AudioFile.any_instance.stubs(:convert).returns(io)
-    @track = create(:track, audio_file: @audio_file)
-
-    # rubocop:disable Rails/SkipsModelValidations
-    # We want to avoid our own before_save callbacks to manually set the audio_file length and track age
-    @audio_file.update_column(:length, 1000)
-    @audio_file.track.update_column(:created_at, 1.year.ago)
-    # rubocop:enable Rails/SkipsModelValidations
-
-    assert_difference('ContentLength.count', 0) do
-      ContentLength.destroy_all_and_recalculate
-    end
-  end
-
-  test 'should create new ContentLength if track is newer than config' do
-    io = StringIO.new Rails.root.join('test/files/base.flac').read
-    AudioFile.any_instance.stubs(:convert).returns(io)
-    @track = create(:track, audio_file: @audio_file)
-
-    # rubocop:disable Rails/SkipsModelValidations
-    # We want to avoid our own before_save callbacks to manually set the audio_file length and track age
-    @audio_file.update_column(:length, 1)
-    @audio_file.track.update_column(:created_at, 1.day.ago)
-    # rubocop:enable Rails/SkipsModelValidations
-
-    assert_difference('ContentLength.count', 0) do
-      ContentLength.destroy_all_and_recalculate
-    end
-
-    @audio_file.reload
-
-    assert_equal 1, @audio_file.content_lengths.length
-  end
 end