Merge branch 'sh-fix-gitaly-find-commit-caching' into 'master'

Allow ref name caching CommitService#find_commit

Closes #57083

See merge request gitlab-org/gitlab-ce!26248

1 files changed, 20 insertions, 0 deletions

diff --git a/lib/gitlab/gitaly_client.rb b/lib/gitlab/gitaly_client.rb
index 49cff7517e9..f240387c28c 100644
--- a/lib/gitlab/gitaly_client.rb
+++ b/lib/gitlab/gitaly_client.rb
@@ -302,6 +302,26 @@ module Gitlab
       end
     end
 
+    # Normally a FindCommit RPC will cache the commit with its SHA
+    # instead of a ref name, since it's possible the branch is mutated
+    # afterwards. However, for read-only requests that never mutate the
+    # branch, this method allows caching of the ref name directly.
+    def self.allow_ref_name_caching
+      return yield unless Gitlab::SafeRequestStore.active?
+      return yield if ref_name_caching_allowed?
+
+      begin
+        Gitlab::SafeRequestStore[:allow_ref_name_caching] = true
+        yield
+      ensure
+        Gitlab::SafeRequestStore[:allow_ref_name_caching] = false
+      end
+    end
+
+    def self.ref_name_caching_allowed?
+      Gitlab::SafeRequestStore[:allow_ref_name_caching]
+    end
+
     def self.get_call_count(key)
       Gitlab::SafeRequestStore[key] || 0
     end