Cache gitly path requests for pipeline rules

app/models/ci/pipeline.rb

@@ -771,6 +771,18 @@ module Ci
       end
     end
 
+    def all_worktree_paths
+      strong_memoize(:all_worktree_paths) do
+        project.repository.ls_files(sha)
+      end
+    end
+
+    def top_level_worktree_paths
+      strong_memoize(:top_level_worktree_paths) do
+        project.repository.tree(sha).blobs.map(&:path)
+      end
+    end
+
     def default_branch?
       ref == project.default_branch
     end

lib/gitlab/ci/build/rules/rule/clause/exists.rb

@@ -4,7 +4,6 @@ module Gitlab
   module Ci
     module Build
       class Rules::Rule::Clause::Exists < Rules::Rule::Clause
-
         # The maximum number of patterned glob comparisons that will be
         # performed before the rule assumes that it has a match
         MAX_PATTERN_COMPARISONS = 10_000
@@ -26,9 +25,9 @@ module Gitlab
 
         def worktree_paths(pipeline)
           if @top_level_only
-            pipeline.project.repository.tree(pipeline.sha).blobs.map(&:path)
+            pipeline.top_level_worktree_paths
           else
-            pipeline.project.repository.ls_files(pipeline.sha)
+            pipeline.all_worktree_paths
           end
         end
 

spec/models/ci/pipeline_spec.rb

@@ -1755,6 +1755,30 @@ describe Ci::Pipeline, :mailer do
     end
   end
 
+  describe '#all_worktree_paths' do
+    let(:files) { { 'main.go' => '', 'mocks/mocks.go' => '' } }
+    let(:project) { create(:project, :custom_repo, files: files) }
+    let(:pipeline) { build(:ci_pipeline, project: project, sha: project.repository.head_commit.sha) }
+
+    it 'returns all file paths cached' do
+      expect(project.repository).to receive(:ls_files).with(pipeline.sha).once.and_call_original
+      expect(pipeline.all_worktree_paths).to eq(files.keys)
+      expect(pipeline.all_worktree_paths).to eq(files.keys)
+    end
+  end
+
+  describe '#top_level_worktree_paths' do
+    let(:files) { { 'main.go' => '', 'mocks/mocks.go' => '' } }
+    let(:project) { create(:project, :custom_repo, files: files) }
+    let(:pipeline) { build(:ci_pipeline, project: project, sha: project.repository.head_commit.sha) }
+
+    it 'returns top-level file paths cached' do
+      expect(project.repository).to receive(:tree).with(pipeline.sha).once.and_call_original
+      expect(pipeline.top_level_worktree_paths).to eq(['main.go'])
+      expect(pipeline.top_level_worktree_paths).to eq(['main.go'])
+    end
+  end
+
   describe '#has_kubernetes_active?' do
     context 'when kubernetes is active' do
       context 'when user configured kubernetes from CI/CD > Clusters' do