I noticed a problem combining this module and page caching. Fixing it led to some other findings and fixes.
We have a views page with a random seed. The page goes into the page cache and is cached without an expiry time. The idea being that a cache tag should be invalidated when necessary.
The module does invalidate a cache tag when a new seed is generated. But:
Add a views page with random seed sorting. Set the seed reset time to e.g. 10 minutes. Enable page caching. Wait for the seed to expire. The page is not invalidated in the page cache.
I have introduced setting a cache tag on the view and then a hook_cron implementation that'll invalidate cache tags based on expired seeds.
To avoid having the cron job load all views to find those using views_random_seed, I have reused the seed name as the cache tag. This way, I can locate the views via the stored seeds in the key/value table.
Some other issues identified
Seeds are never deleted from the key/value store. Not when a view no longer uses random seed, not when a view is deleted, and not even when the module is uninstalled.
I added a hook_uninstall() and added cleanup in the cron jobs as well.
Then I got a bit confused about the dual use of the seed as both a seed and a timestamp used for deciding if it's time to regenerate.
I could probably live with me being confused. But then I noticed that if you use PostgreSQL, the seed is reduced to a value between 0 and 1. That makes it unfit as a timestamp, as it would always be considered expired.
So, I introduced a new Seed class consisting of the seed value and a dedicated timestamp for its creation.
Finally, while at it, I fixed some code standard issues and introduced dependency injection for the remaining services that lacked it.
None that I'm aware of. Besides review etc.
None.
I don't think any of them has been advertised as a real API, but some people could have created custom code based on them.
The seed has changed its value from a single int to an int (the seed value) and a created timestamp. Both wrapped in a new class.
Needs work
1.0
Code
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It's likely this issue predates Contrib.social: some issue and comment data are missing.
In a setup with more than one webhead, the page stopped working after this module was installed. With this patch, the error was fixed.
I'm sorry I can't tell you more, but it only happened in production and the error had to do with cache (cache in redis). That is how I thought this patch might help and it did.