Expire project caches once per push instead of once per ref

Previously `ProjectCacheWorker` would be scheduled once per ref, which
would generate unnecessary I/O and load on Sidekiq, especially if many
tags or branches were pushed at once. `ProjectCacheWorker` would expire
three items:

1. Repository size: This only needs to be updated once per push.
2. Commit count: This only needs to be updated if the default branch
   is updated.
3. Project method caches: This only needs to be updated if the default
   branch changes, but only if certain files change (e.g. README,
   CHANGELOG, etc.).

Because the third item requires looking at the actual changes in the
commit deltas, we schedule one `ProjectCacheWorker` to handle the first
two cases, and schedule a separate `ProjectCacheWorker` for the third
case if it is needed. As a result, this brings down the number of
`ProjectCacheWorker` jobs from N to 2.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/52046

1 files changed, 6 insertions, 2 deletions

diff --git a/app/models/repository.rb b/app/models/repository.rb
index 9d45a12fa6e..6f63cd32da4 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -389,11 +389,15 @@ class Repository
     expire_statistics_caches
   end
 
-  # Runs code after a repository has been created.
-  def after_create
+  def expire_status_cache
     expire_exists_cache
     expire_root_ref_cache
     expire_emptiness_caches
+  end
+
+  # Runs code after a repository has been created.
+  def after_create
+    expire_status_cache
 
     repository_event(:create_repository)
   end