Convert hook_queue_info() to plugin system

+++ b/core/lib/Drupal/Core/Annotation/QueueItem.phpundefined
@@ -0,0 +1,60 @@
+class QueueItem extends Plugin {

As written one day in IRC the name is quite odd. If nothing helps choose QueuePlugin

+++ b/core/core.services.ymlundefined
@@ -175,6 +175,9 @@ services:
+  plugin.manager.queue.item:

I guess we should also rename the plugin manager service then.

+++ b/core/lib/Drupal/Core/Queue/QueuePluginManager.phpundefined
@@ -0,0 +1,46 @@
+  public function __construct(\Traversable $namespaces, ModuleHandlerInterface $module_handler) {
+    parent::__construct('QueuePlugin', $namespaces, array(), 'Drupal\Core\Annotation\QueuePlugin');

No caching?

I guess removing the tag was not intended.

I'll check this out

Re rolled against latest HEAD

1. +++ b/core/includes/common.inc
   @@ -3203,8 +3203,8 @@ function drupal_cron_run() {
   +  $manager = Drupal::service('plugin.manager.queue.item');
   

   This requires "\Drupal" now.

2. +++ b/core/lib/Drupal/Core/Queue/QueuePluginInterface.php
   @@ -0,0 +1,22 @@
   + * @todo.
   
   +++ b/core/lib/Drupal/Core/Queue/QueuePluginBase.php
   @@ -0,0 +1,17 @@
   + * @todo.
   
   +++ b/core/lib/Drupal/Core/Queue/QueuePluginInterface.php
   @@ -0,0 +1,22 @@
   +  /**
   +   * @param mixed $data
   +   */
   

   Let's ensure to not forget this todo before commit

• +++ b/core/lib/Drupal/Core/Queue/QueuePluginManager.php
  @@ -0,0 +1,46 @@
  +    parent::__construct('QueuePlugin', $namespaces, array(), 'Drupal\Core\Annotation\QueuePlugin');
  

  The parent constructor (DefaultPluginManager) only has three parameters, the array() here is wrong.

• Re-rolled, since drupal_cron_run has been removed, and Cron is now a service (https://drupal.org/node/2181921).
• Added basic documentation to replace the @todo's (mentioned in #15).
• Changed Drupal::service('plugin.manager.queue.item'); to use \Drupal (reported in #15).

To the testbot!

+++ b/core/lib/Drupal/Core/Queue/QueuePluginManager.php
@@ -0,0 +1,46 @@
+    parent::__construct('QueuePlugin', $namespaces, 'Drupal\Core\Annotation\QueuePlugin');

Should be 'Plugin/QueuePlugin' as $subdir.

After talking out loud in IRC I think my concern with this is currently the terminology. The plugin stuff we're doing isn't really connected to the QueueAPI, we're replacing the hook callback runner weirdness(which was sort of its own thing) with a runners based on plugins.

I think I would prefer this if the QueueManager was maybe QueueRunnerManager or QueueProcessorManager and if the surrounding implementation followed that terminology. That'll seperate it from the Queue and QueueItem concepts that already exist. I don't know what is the right term but I think either of those would be acceptable until I hear something better.

I think @neclimdul is happy know. I have seen him ++ @tim.plunkett in IRC. I reviewed the patch and didn't find anything objectionable so this is good to go.

1. +++ b/core/lib/Drupal/Core/Queue/QueueWorkerBase.php
   @@ -0,0 +1,17 @@
   +abstract class QueueWorkerBase extends PluginBase implements QueueWorkerInterface {
   

   Why we need this class?

2. +++ b/core/modules/locale/src/Plugin/QueueWorker/LocaleTranslation.php
   @@ -0,0 +1,120 @@
   +class LocaleTranslation extends QueueWorkerBase implements ContainerFactoryPluginInterface {
   

   Oh, I got it. This is the reason. :)

1. +++ b/core/modules/aggregator/src/Plugin/QueueWorker/AggregatorRefresh.php
   @@ -0,0 +1,31 @@
   +  public function processItem($data) {
   +    if ($data instanceof FeedInterface) {
   

   We should really not do this, but this is not the fault of this issue.

2. +++ b/core/modules/aggregator/src/Tests/AggregatorCronTest.php
   @@ -21,11 +21,11 @@ public function testCron() {
   -    $this->assertEqual(5, db_query('SELECT COUNT(*) FROM {aggregator_item} WHERE fid = :fid', array(':fid' => $feed->id()))->fetchField(), 'Expected number of items in database.');
   +    $this->assertEqual(5, db_query('SELECT COUNT(*) FROM {aggregator_item} WHERE fid = :fid', array(':fid' => $feed->id()))->fetchField());
   ...
   -    $this->assertEqual(0, db_query('SELECT COUNT(*) FROM {aggregator_item} WHERE fid = :fid', array(':fid' => $feed->id()))->fetchField(), 'Expected number of items in database.');
   +    $this->assertEqual(0, db_query('SELECT COUNT(*) FROM {aggregator_item} WHERE fid = :fid', array(':fid' => $feed->id()))->fetchField());
   ...
   -    $this->assertEqual(5, db_query('SELECT COUNT(*) FROM {aggregator_item} WHERE fid = :fid', array(':fid' => $feed->id()))->fetchField(), 'Expected number of items in database.');
   +    $this->assertEqual(5, db_query('SELECT COUNT(*) FROM {aggregator_item} WHERE fid = :fid', array(':fid' => $feed->id()))->fetchField());
   

   Any reason we are removing those messages? Just wondering.

We need to bring this in line with the plugin api documentation efforts see \Drupal\Core\Annotation\Action for an example.

1. +++ b/core/lib/Drupal/Core/Queue/QueueWorkerBase.php
   @@ -0,0 +1,17 @@
   +/**
   + * Provides a basis for queue worker plugins.
   + */
   +abstract class QueueWorkerBase extends PluginBase implements QueueWorkerInterface {
   
   +++ b/core/lib/Drupal/Core/Queue/QueueWorkerInterface.php
   @@ -0,0 +1,23 @@
   +/**
   + * Defines an interface for queue workers.
   + */
   +interface QueueWorkerInterface extends PluginInspectionInterface {
   
   +++ b/core/lib/Drupal/Core/Queue/QueueWorkerManager.php
   @@ -0,0 +1,60 @@
   +/**
   + * Defines the queue worker manager.
   + */
   +class QueueWorkerManager extends DefaultPluginManager implements QueueWorkerManagerInterface {
   

   Needs docs update for the aforementioned plugin api docs standards.

2. +++ b/core/modules/aggregator/aggregator.module
   @@ -138,22 +138,6 @@ function aggregator_cron() {
   -    'worker callback' => function (FeedInterface $feed) {
   

   Can remove use Drupal\aggregator\FeedInterface; from aggregator.module now

3. +++ b/core/modules/locale/src/Plugin/QueueWorker/LocaleTranslation.php
   @@ -0,0 +1,120 @@
   +/**
   + * @QueueWorker(
   + *   id = "locale_translation",
   + *   title = @Translation("Update translations"),
   + *   cron = {"time" = 30}
   + * )
   + */
   +class LocaleTranslation extends QueueWorkerBase implements ContainerFactoryPluginInterface {
   

   Missing docs

4. +++ b/core/modules/system/system.api.php
   @@ -157,35 +118,6 @@ function hook_queue_info_alter(&$queues) {
   - * @throws \Exception
   - *   The worker callback may throw an exception to indicate there was a problem.
   - *   The cron process will log the exception, and leave the item in the queue to
   - *   be processed again later.
   - * @throws \Drupal\Core\Queue\SuspendQueueException
   - *   More specifically, a SuspendQueueException should be thrown when the
   - *   callback is aware that the problem will affect all subsequent workers of
   - *   its queue. For example, a callback that makes HTTP requests may find that
   - *   the remote server is not responding. The cron process will behave as with a
   - *   normal Exception, and in addition will not attempt to process further items
   - *   from the current item's queue during the current cron run.
   

   Where has this documentation gone? I would expect it to be on the QueueWorkerInterface.

Also the issue summary could be better and maybe we need a change record (8.x to 8.x I think).

alexpott asked me to help with the docs here.

What we need is docs like what was added for each child issue of #2269389: [meta] Make sure plugin developer info is discoverable. The child issues all have detailed instructions; one example: #2290281: Tip plugin classes need more docs links. It should take about 5 minutes to do...

The docs additions look good, at least as far as formatting and completeness. Not being involved in this issue, I haven't reviewed them for accuracy. Thanks!

Couple of docs fixes. Looks good otherwise.

1. +++ b/core/lib/Drupal/Core/Annotation/QueueWorker.php
   @@ -0,0 +1,65 @@
   + * the queue in this hook if you want, however, you need to take care of
   

   Not a hook any more.

2. +++ b/core/lib/Drupal/Core/Queue/QueueWorkerInterface.php
   @@ -0,0 +1,45 @@
   +   *   callback is aware that the problem will affect all subsequent workers of
   

   method? worker?

Committed ac0cee8 and pushed to 8.0.x. Thanks!