preventing deadlocks on large Databases

Hello,

i've purchased this addon to automate the promotion-posts.
Unfortionately I wasn't able to install it.

After doing some debugging i've found out, that the query in Model/Post.php takes way too much time.
e.g. the initial setup will take around 8 Minutes on my board - thus leading to 504-errors.
This is due to the fact, that you join all Posts in the board to this table. So on very large boards, this will take ages.

Every Post will take additional ~25s till ~30s to post for the most popular posters on my board (around 25k-30k Posts).
Thus leading to database-deadlocks.

in Order to fix this, i've rewritten more or less the whole class. (Sorry to highjack your plugin)

Code:

class Brivium_ExtraPromotions_Model_Post extends XenForo_Model
{
...
            $where = '';
            $xf_postWhere = '';
        }else
        {
            $where = 'WHERE xf_user.user_id IN ('.$db->quote($userIds).')';
            $xf_postWhere = ' AND xf_post.user_id IN ('.$db->quote($userIds).') ';
        }
        $db->query('
            UPDATE xf_user
            LEFT JOIN (
                SELECT user_id, post_date AS last_post_date
                FROM xf_post
                WHERE message_state = '.$db->quote('visible').'
                '.$xf_postWhere.'
                ORDER BY post_date desc
                LIMIT 1
            ) AS post ON (post.user_id = xf_user.user_id)
            SET
                xf_user.brep_last_posted_date = IF(post.last_post_date IS NULL, 0, post.last_post_date)
            '.$where.'
...

This will decrease the additional time for the 25k-users from 25s to 0.01s

though i haven't tested the initial installation - but it should work.