The NotificationService has to do quite a lot of work to calculate the
recipients for an email. Where possible, we should try to avoid doing this in an
HTTP request, because the mail are sent by Sidekiq anyway, so there's no need to
schedule those emails immediately.
This commit creates a generic Sidekiq worker that uses Global ID to serialise
and deserialise its arguments, then forwards them to the NotificationService.
The NotificationService gains an `#async` method, so you can replace:
notification_service.new_issue(issue, current_user)
With:
notification_service.async.new_issue(issue, current_user)
And have everything else work as normal, except that calculating the recipients
will be done by Sidekiq, which will then schedule further Sidekiq jobs to send
each email.
This ensures the open issues/MR count caches are refreshed properly when
creating new issues or MRs. This MR also includes a change to the cache
keys to ensure all caches are rebuilt on the fly.
This particular problem was not caught in the test suite due to a null
cache being used, resulting in all calls that would use a cache using
the underlying data directly. In production the code would fail because
a newly saved record returns an empty hash in #changes meaning checks
such as `state_changed? || confidential_changed?` would return false for
new rows, thus never updating the counters.
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/38061
When an issuable's state changes, or one is created, we should clear the cache
counts for a user's assigned issuables, and also the project-wide caches for
this user type.
