Instead of having to remember every time, just always wait until the
current transaction (if it exists) has committed before clearing any
DistributedCache.
The only exception to this is caches that aren't caching things from
postgres.
This means we have to do the test setup after setting the test
transaction, because doing the test setup involves clearing caches.
Reapplying this - it now doesn't use after_commit if skip_db is set
Instead of having to remember every time, just always wait until the
current transaction (if it exists) has committed before clearing any
DistributedCache.
The only exception to this is caches that aren't caching things from
postgres.
This means we have to do the test setup after setting the test
transaction, because doing the test setup involves clearing caches.
Themes often cache `nil` values in a DistributedCache. This bug meant that we were re-calculating some values on every request, AND triggering message-bus publishing on every request.
This fix should provide a significant performance improvement for busy sites.
Setting a key/value pair in DistributedCache involves waiting on the
write to Redis to finish. In most cases, we don't need to wait on the
setting of the cache to finish. We just need to take our return value
and move on.
