Memoize commit lookups between ChangeAccess callsjej/memoize-change-access-commits

2 files changed, 27 insertions, 3 deletions

diff --git a/app/models/repository.rb b/app/models/repository.rb
index 5ed2a7b4068..c169f29a99d 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -153,13 +153,17 @@ class Repository
   end
 
   # Returns a list of commits that are not present in any reference
+  # Uses commit_by to memoize commits between method calls
   def new_commits(newrev)
+    new_commit_shas(newrev).map { |sha| commit_by(oid: sha.strip) }
+  end
+
+  # Returns a list of commit shas that are not present in any reference
+  def new_commit_shas(newrev)
     # Gitaly migration: https://gitlab.com/gitlab-org/gitaly/issues/1233
-    refs = Gitlab::GitalyClient::StorageSettings.allow_disk_access do
+    Gitlab::GitalyClient::StorageSettings.allow_disk_access do
       ::Gitlab::Git::RevList.new(raw, newrev: newrev).new_refs
     end
-
-    refs.map { |sha| commit(sha.strip) }
   end
 
   # Gitaly migration: https://gitlab.com/gitlab-org/gitaly/issues/384
diff --git a/spec/lib/gitlab/git_access_spec.rb b/spec/lib/gitlab/git_access_spec.rb
index 6d11efb42c8..3d78c18361a 100644
--- a/spec/lib/gitlab/git_access_spec.rb
+++ b/spec/lib/gitlab/git_access_spec.rb
@@ -943,6 +943,26 @@ describe Gitlab::GitAccess do
         # There is still an N+1 query with protected branches
         expect { access.check('git-receive-pack', changes) }.not_to exceed_query_limit(control_count).with_threshold(1)
       end
+
+      context 'with multiple changes' do
+        let(:changes) do
+          [
+            "#{Gitlab::Git::BLANK_SHA} 570e7b2ab refs/heads/first",
+            "#{Gitlab::Git::BLANK_SHA} 570e7b2ab refs/heads/second"
+          ]
+        end
+
+        it 'caches commit lookups across changes' do
+          stub_lfs_setting(enabled: true)
+          create(:lfs_file_lock, user: create(:user), project: project, path: 'README')
+          allow(project.repository).to receive(:new_commit_shas) { ["b83d6e391c22777fca1ed3012fce84f633d7fed0"] }
+          #, "498214de67004b1da3d820901307bed2a68a8ef6"] }
+
+          expect(Gitlab::Git::Commit).to receive(:find).once.and_call_original
+
+          access.check('git-receive-pack', changes)
+        end
+      end
     end
   end