high resource usage from last updates*

Not sure which updates specifically is the cause but we’ve had several customers now where easy-table-of-contents is bringing their sites down due to clogging the PHP queue, it causes processes to spawn and consume high amounts of CPU and run until all processes are in use.

Here is an example of a stack trace from PHP slow logging:

script_filename = /home/nginx/domains/domain.com/public/index.php
[0x00007f7d6a23f670] array_intersect() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/easy-table-of-contents.php:580
[0x00007f7d6a23f5e0] maybeApplyTheContentFilter() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/easy-table-of-contents.php:608
[0x00007f7d6a23f420] the_content() /home/nginx/domains/domain.com/public/wp-includes/class-wp-hook.php:307
[0x00007f7d6a23f340] apply_filters() /home/nginx/domains/domain.com/public/wp-includes/plugin.php:191
[0x00007f7d6a23f270] apply_filters() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/includes/class.post.php:137
[0x00007f7d6a23f200] applyContentFilter() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/includes/class.post.php:77
[0x00007f7d6a23f180] __construct() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/includes/class.post.php:102
[0x00007f7d6a23f100] get() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/easy-table-of-contents.php:504
[0x00007f7d6a23f060] get() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/easy-table-of-contents.php:627
[0x00007f7d6a23eea0] the_content() /home/nginx/domains/domain.com/public/wp-includes/class-wp-hook.php:307
[0x00007f7d6a23edc0] apply_filters() /home/nginx/domains/domain.com/public/wp-includes/plugin.php:191
[0x00007f7d6a23ecf0] apply_filters() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/includes/class.post.php:137
[0x00007f7d6a23ec80] applyContentFilter() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/includes/class.post.php:77
[0x00007f7d6a23ec00] __construct() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/includes/class.post.php:102
[0x00007f7d6a23eb80] get() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/easy-table-of-contents.php:504
[0x00007f7d6a23eae0] get() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/easy-table-of-contents.php:627
[0x00007f7d6a23e920] the_content() /home/nginx/domains/domain.com/public/wp-includes/class-wp-hook.php:307
[0x00007f7d6a23e840] apply_filters() /home/nginx/domains/domain.com/public/wp-includes/plugin.php:191
[0x00007f7d6a23e770] apply_filters() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/includes/class.post.php:137
[0x00007f7d6a23e700] applyContentFilter() /home/nginx/domains/domain.com/public/wp-content/plugins/easy-table-of-contents/includes/class.post.php:77

Hope this can help spot any areas which need some optimizing.