Load commit in batches for pipelines#index

Uses `list_commits_by_oid` on the CommitService, to request the needed
commits for pipelines. These commits are needed to display the user that
created the commit and the commit title.

This includes fixes for tests failing that depended on the commit
being `nil`. However, now these are batch loaded, this doesn't happen
anymore and the commits are an instance of BatchLoader.

2 files changed, 22 insertions, 0 deletions

diff --git a/lib/gitlab/git/commit.rb b/lib/gitlab/git/commit.rb
index e90b158fb34..145721dea76 100644
--- a/lib/gitlab/git/commit.rb
+++ b/lib/gitlab/git/commit.rb
@@ -228,6 +228,19 @@ module Gitlab
             end
           end
         end
+
+        # Only to be used when the object ids will not necessarily have a
+        # relation to each other. The last 10 commits for a branch for example,
+        # should go through .where
+        def batch_by_oid(repo, oids)
+          repo.gitaly_migrate(:list_commits_by_oid) do |is_enabled|
+            if is_enabled
+              repo.gitaly_commit_client.list_commits_by_oid(oids)
+            else
+              oids.map { |oid| find(repo, oid) }.compact
+            end
+          end
+        end
       end
 
       def initialize(repository, raw_commit, head = nil)
diff --git a/lib/gitlab/gitaly_client/commit_service.rb b/lib/gitlab/gitaly_client/commit_service.rb
index 7985f5b5457..fb3e27770b4 100644
--- a/lib/gitlab/gitaly_client/commit_service.rb
+++ b/lib/gitlab/gitaly_client/commit_service.rb
@@ -169,6 +169,15 @@ module Gitlab
         consume_commits_response(response)
       end
 
+      def list_commits_by_oid(oids)
+        request = Gitaly::ListCommitsByOidRequest.new(repository: @gitaly_repo, oid: oids)
+
+        response = GitalyClient.call(@repository.storage, :commit_service, :list_commits_by_oid, request, timeout: GitalyClient.medium_timeout)
+        consume_commits_response(response)
+      rescue GRPC::Unknown # If no repository is found, happens mainly during testing
+        []
+      end
+
       def commits_by_message(query, revision: '', path: '', limit: 1000, offset: 0)
         request = Gitaly::CommitsByMessageRequest.new(
           repository: @gitaly_repo,