Fixed XF:ReactionScore triggered for any Reaction entity change

[Xon]

Affected version

2.1.7

XF\Job\ReactionScore is being triggered for any change (including insert of new records!) even if the reaction_score has not changed;

protected function _postSave()
{
   $this->app()->jobManager()->enqueueUnique('reactionChange' . $this->reaction_id, 'XF:ReactionScore', [
      'reaction_id' => $this->reaction_id
   ]);

   $this->rebuildReactionCache();
}

This query;

SELECT DISTINCT content_user_id
FROM xf_reaction_content
WHERE reaction_id=1 AND content_user_id > 0
ORDER BY content_user_id
limit 100;

Has a very suboptimal query plan when there are a large number of rows;

+------+-------------+---------------------+-------+-------------------------------+-------------------------------+---------+------+----------+------------------------------------+
| id   | select_type | table               | type  | possible_keys                 | key                           | key_len | ref  | rows     | Extra                              |
+------+-------------+---------------------+-------+-------------------------------+-------------------------------+---------+------+----------+------------------------------------+
|    1 | SIMPLE      | xf_reaction_content | range | content_user_id_reaction_date | content_user_id_reaction_date | 4       | NULL | 66001380 | Using index condition; Using where |
+------+-------------+---------------------+-------+-------------------------------+-------------------------------+---------+------+----------+------------------------------------+

This query takes about 2 seconds or so per run, and degenerates massively as the batch size increases and the rebuild performance rapidly throttles the batch size down massively.

Simply put; the entire reaction_id specific path probably isn't worth keeping. And this definitely should not be triggered for any change to the reaction definition.

 

[XF Bug Bot]

Thank you for reporting this issue, it has now been resolved. We are aiming to include any changes that have been made in a future XF release (2.1.8).

Change log:

Only enqueue a reaction score rebuild when a reaction's score has changed, and simply rebuild scores for all reactions

There may be a delay before changes are rolled out to the XenForo Community.