Enable autotrimming

README.md

@@ -62,13 +62,18 @@ production:
 The options are:
 
 - `connects_to` - set the Active Record database configuration for the Solid Cable models. All options available in Active Record can be used here.
-- `polling_interval` - sets the frequency of the polling interval.
-- `message_retention` - sets the retention time for messages kept in the database. Used as the cut-off when trimming is performed.
+- `polling_interval` - sets the frequency of the polling interval. (Defaults to
+  0.1.seconds)
+- `message_retention` - sets the retention time for messages kept in the database. Used as the cut-off when trimming is performed. (Defaults to 1.day)
+- `autotrim` - sets wether you want Solid Cable to handle autotrimming messages.
+  (Defaults to true)
 
 ## Trimming
 
-Currently, messages are kept around forever, and have to be manually pruned via the `SolidCable::PruneJob.perform_later` job.
-This job uses the `message_retention` setting to determine how long messages are to be kept around.
+Messages are autotrimmed based upon the `message_retention` setting to determine how long messages are to be kept around. If no `message_retention` is given or parsing fails, it defaults to `1.day`. Messages are trimmed when a subscriber unsubscribes.
+
+Autotrimming can negatively impact performance depending on your workload because it is doing a delete on ubsubscribe. If
+you would prefer, you can disable autotrimming by setting `autotrim: false` and you can manually enqueue the job later, `SolidCable::PruneJob.perform_later`, or run it on a recurring interval out of band.
 
 ## License
 

app/jobs/solid_cable/prune_job.rb → app/jobs/solid_cable/trim_job.rb

@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
 module SolidCable
-  class PruneJob < ActiveJob::Base
+  class TrimJob < ActiveJob::Base
     def perform
-      ::SolidCable::Message.prunable.delete_all
+      ::SolidCable::Message.trimmable.delete_all
     end
   end
 end

app/models/solid_cable/message.rb

@@ -2,7 +2,7 @@
 
 module SolidCable
   class Message < SolidCable::Record
-    scope :prunable, lambda {
+    scope :trimmable, lambda {
       where(created_at: ..::SolidCable.message_retention.ago)
     }
     scope :broadcastable, lambda { |channels, last_id|

lib/action_cable/subscription_adapter/solid_cable.rb

@@ -64,6 +64,8 @@ def add_channel(channel, on_success)
 
         def remove_channel(channel)
           channels.delete(channel)
+
+          ::SolidCable::TrimJob.perform_now if ::SolidCable.autotrim?
         end
 
         def invoke_callback(*)

lib/solid_cable.rb

@@ -22,6 +22,10 @@ def message_retention
       parse_duration(cable_config.message_retention, default: 1.day)
     end
 
+    def autotrim?
+      cable_config.autotrim != false
+    end
+
     private
 
     def cable_config

test/config_helpers.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module ConfigHelpers
+  extend ActiveSupport::Concern
+
+  class ConfigStub
+    def initialize(**)
+      @config = ActiveSupport::OrderedOptions.new.
+                update({ adapter: :test }.merge(**))
+    end
+
+    def config_for(_file)
+      @config
+    end
+  end
+
+  def with_cable_config(**)
+    Rails.stub(:application, ConfigStub.new(**)) { yield }
+  end
+end

test/lib/action_cable/subscription_adapter/solid_cable_test.rb

@@ -5,8 +5,10 @@
 
 require "active_support/core_ext/hash/indifferent_access"
 require "pathname"
+require "config_helpers"
 
 class ActionCable::SubscriptionAdapter::SolidCableTest < ActionCable::TestCase
+  include ConfigHelpers
 
   WAIT_WHEN_EXPECTING_EVENT = 1
   WAIT_WHEN_NOT_EXPECTING_EVENT = 0.2
@@ -28,7 +30,8 @@ def setup
   end
 
   def cable_config
-    { adapter: "solid_cable", polling_interval: "0.01.seconds" }
+    { adapter: "solid_cable", message_retention: "1.second",
+      polling_interval: "0.01.seconds" }
   end
 
   def teardown
@@ -82,6 +85,24 @@ def test_broadcast_after_unsubscribe
     assert_empty keep_queue
   end
 
+  def test_trims_after_unsubscribe
+    with_cable_config message_retention: "1.second" do
+      keep_queue = nil
+      subscribe_as_queue("channel") do |queue|
+        keep_queue = queue
+
+        @tx_adapter.broadcast("channel", "hello world")
+
+        assert_equal 1, SolidCable::Message.where(channel: "channel").count
+        assert_equal "hello world", queue.pop
+        sleep 2
+      end
+      sleep 3
+
+      assert_equal 0, SolidCable::Message.where(channel: "channel").count
+    end
+  end
+
   def test_multiple_broadcast
     subscribe_as_queue("channel") do |queue|
       @tx_adapter.broadcast("channel", "bananas")

test/solid_cable_test.rb

@@ -1,9 +1,29 @@
 # frozen_string_literal: true
 
 require "test_helper"
+require "config_helpers"
 
 class SolidCableTest < ActiveSupport::TestCase
+  include ConfigHelpers
+
   test "it has a version number" do
     assert SolidCable::VERSION
   end
+
+  test "autotrimming when nothing is set" do
+    assert_not Rails.application.config_for("cable").key?(:autotrim)
+    assert SolidCable.autotrim?
+  end
+
+  test "autotrimming when set to false" do
+    with_cable_config autotrim: false do
+      assert_not SolidCable.autotrim?
+    end
+  end
+
+  test "autotrimming when set to true" do
+    with_cable_config autotrim: true do
+      assert SolidCable.autotrim?
+    end
+  end
 end

test/test_helper.rb

@@ -8,6 +8,7 @@
 "../test/dummy/db/migrate", __dir__
 )]
 require "rails/test_help"
+require "minitest/autorun"
 
 # Load fixtures from the engine
 if ActiveSupport::TestCase.respond_to?(:fixture_paths=)