Merge branch 'backstage/gb/improve-performance-environment-statuses-endpoint' into 'master'

Improve performance of fetching environments statuses

Closes #62589

See merge request gitlab-org/gitlab-ce!30560

app/models/environment_status.rb

@@ -40,7 +40,7 @@ class EnvironmentStatus
   end
 
   def changes
-    return [] if project.route_map_for(sha).nil?
+    return [] unless has_route_map?
 
     changed_files.map { |file| build_change(file) }.compact
   end
@@ -50,6 +50,10 @@ class EnvironmentStatus
       .merge_request_diff_files.where(deleted_file: false)
   end
 
+  def has_route_map?
+    project.route_map_for(sha).present?
+  end
+
   private
 
   PAGE_EXTENSIONS = /\A\.(s?html?|php|asp|cgi|pl)\z/i.freeze

app/models/project.rb

@@ -1914,9 +1914,8 @@ class Project < ApplicationRecord
     @route_maps_by_commit ||= Hash.new do |h, sha|
       h[sha] = begin
         data = repository.route_map_for(sha)
-        next unless data
 
-        Gitlab::RouteMap.new(data)
+        Gitlab::RouteMap.new(data) if data
       rescue Gitlab::RouteMap::FormatError
         nil
       end

changelogs/unreleased/backstage-gb-improve-performance-environment-statuses-endpoint.yml

+---
+title: Improve performance of fetching environments statuses
+merge_request: 30560
+author:
+type: performance

spec/controllers/projects/merge_requests_controller_spec.rb

@@ -878,7 +878,7 @@ describe Projects::MergeRequestsController do
         expect(control_count).to be <= 137
       end
 
-      it 'has no N+1 issues for environments', :request_store, retry: 0 do
+      it 'has no N+1 SQL issues for environments', :request_store, retry: 0 do
         # First run to insert test data from lets, which does take up some 30 queries
         get_ci_environments_status
 
@@ -893,18 +893,65 @@ describe Projects::MergeRequestsController do
         leeway = 11
         expect { get_ci_environments_status }.not_to exceed_all_query_limit(control_count + leeway)
       end
+    end
 
-      def get_ci_environments_status(extra_params = {})
-        params = {
-          namespace_id: merge_request.project.namespace.to_param,
-          project_id: merge_request.project,
-          id: merge_request.iid,
-          format: 'json'
-        }
+    context 'when a merge request has multiple environments with deployments' do
+      let(:sha) { merge_request.diff_head_sha }
+      let(:ref) { merge_request.source_branch }
+
+      let!(:build) { create(:ci_build, pipeline: pipeline) }
+      let!(:pipeline) { create(:ci_pipeline, sha: sha, project: project) }
+      let!(:environment) { create(:environment, name: 'env_a', project: project) }
+      let!(:another_environment) { create(:environment, name: 'env_b', project: project) }
+
+      before do
+        merge_request.update_head_pipeline
+
+        create(:deployment, :succeed, environment: environment, sha: sha, ref: ref, deployable: build)
+        create(:deployment, :succeed, environment: another_environment, sha: sha, ref: ref, deployable: build)
+      end
+
+      it 'exposes multiple environment statuses' do
+        get_ci_environments_status
+
+        expect(json_response.count).to eq 2
+      end
+
+      context 'when route map is not present in the project' do
+        it 'does not have N+1 Gitaly requests for environments', :request_store do
+          expect(merge_request).to be_present
+
+          expect { get_ci_environments_status }
+            .to change { Gitlab::GitalyClient.get_request_count }.by_at_most(1)
+        end
+      end
 
-        get :ci_environments_status, params: params.merge(extra_params)
+      context 'when there is route map present in a project' do
+        before do
+          allow_any_instance_of(EnvironmentStatus)
+            .to receive(:has_route_map?)
+            .and_return(true)
+        end
+
+        it 'does not have N+1 Gitaly requests for diff files', :request_store do
+          expect(merge_request.merge_request_diff.merge_request_diff_files).to be_many
+
+          expect { get_ci_environments_status }
+            .to change { Gitlab::GitalyClient.get_request_count }.by_at_most(1)
+        end
       end
     end
+
+    def get_ci_environments_status(extra_params = {})
+      params = {
+        namespace_id: merge_request.project.namespace.to_param,
+        project_id: merge_request.project,
+        id: merge_request.iid,
+        format: 'json'
+      }
+
+      get :ci_environments_status, params: params.merge(extra_params)
+    end
   end
 
   describe 'GET pipeline_status.json' do