Optimize memory allocations in permissions cache (#89645)

This PR reduces the number of allocations made while caching permissions from the database, fixes the hierarchy of spans and adds new spans for tracing.

---------

Signed-off-by: Dave Henderson <dave.henderson@grafana.com>
Co-authored-by: Dave Henderson <dave.henderson@grafana.com>

pkg/api/dashboard_test.go

@@ -81,6 +81,7 @@ func TestGetHomeDashboard(t *testing.T) {
 		preferenceService:       prefService,
 		dashboardVersionService: dashboardVersionService,
 		log:                     log.New("test-logger"),
+		tracer:                  tracing.InitializeTracerForTest(),
 	}
 
 	tests := []struct {
@@ -585,7 +586,8 @@ func TestDashboardAPIEndpoint(t *testing.T) {
 				DashboardID: 2,
 				Version:     1,
 				Data:        fakeDash.Data,
-			}}
+			},
+		}
 		mockSQLStore := dbtest.NewFakeDB()
 		origNewGuardian := guardian.New
 		guardian.MockDashboardGuardian(&guardian.FakeDashboardGuardian{CanSaveValue: true})
@@ -622,7 +624,8 @@ func TestDashboardAPIEndpoint(t *testing.T) {
 				DashboardID: 2,
 				Version:     1,
 				Data:        fakeDash.Data,
-			}}
+			},
+		}
 
 		cmd := dtos.RestoreDashboardVersionCommand{
 			Version: 1,
@@ -680,6 +683,7 @@ func TestDashboardAPIEndpoint(t *testing.T) {
 				DashboardService:             dashboardService,
 				Features:                     featuremgmt.WithFeatures(),
 				starService:                  startest.NewStarServiceFake(),
+				tracer:                       tracing.InitializeTracerForTest(),
 			}
 			hs.callGetDashboard(sc)
 
@@ -718,6 +722,7 @@ func TestDashboardVersionsAPIEndpoint(t *testing.T) {
 			userService:             userSvc,
 			CacheService:            localcache.New(5*time.Minute, 10*time.Minute),
 			log:                     log.New(),
+			tracer:                  tracing.InitializeTracerForTest(),
 		}
 	}
 
@@ -855,6 +860,7 @@ func getDashboardShouldReturn200WithConfig(t *testing.T, sc *scenarioContext, pr
 		DashboardService:             dashboardService,
 		Features:                     featuremgmt.WithFeatures(),
 		starService:                  startest.NewStarServiceFake(),
+		tracer:                       tracing.InitializeTracerForTest(),
 	}
 
 	hs.callGetDashboard(sc)
@@ -908,6 +914,7 @@ func postDashboardScenario(t *testing.T, desc string, url string, routePattern s
 			Features:              featuremgmt.WithFeatures(),
 			accesscontrolService:  actest.FakeService{},
 			log:                   log.New("test-logger"),
+			tracer:                tracing.InitializeTracerForTest(),
 		}
 
 		sc := setupScenarioContext(t, url)
@@ -927,7 +934,8 @@ func postDashboardScenario(t *testing.T, desc string, url string, routePattern s
 }
 
 func postDiffScenario(t *testing.T, desc string, url string, routePattern string, cmd dtos.CalculateDiffOptions,
-	role org.RoleType, fn scenarioFunc, sqlmock db.DB, fakeDashboardVersionService *dashvertest.FakeDashboardVersionService) {
+	role org.RoleType, fn scenarioFunc, sqlmock db.DB, fakeDashboardVersionService *dashvertest.FakeDashboardVersionService,
+) {
 	t.Run(fmt.Sprintf("%s %s", desc, url), func(t *testing.T) {
 		cfg := setting.NewCfg()
 
@@ -943,6 +951,7 @@ func postDiffScenario(t *testing.T, desc string, url string, routePattern string
 			dashboardVersionService: fakeDashboardVersionService,
 			Features:                featuremgmt.WithFeatures(),
 			DashboardService:        dashSvc,
+			tracer:                  tracing.InitializeTracerForTest(),
 		}
 
 		sc := setupScenarioContext(t, url)
@@ -967,7 +976,8 @@ func postDiffScenario(t *testing.T, desc string, url string, routePattern string
 
 func restoreDashboardVersionScenario(t *testing.T, desc string, url string, routePattern string,
 	mock *dashboards.FakeDashboardService, fakeDashboardVersionService *dashvertest.FakeDashboardVersionService,
-	cmd dtos.RestoreDashboardVersionCommand, fn scenarioFunc, sqlStore db.DB) {
+	cmd dtos.RestoreDashboardVersionCommand, fn scenarioFunc, sqlStore db.DB,
+) {
 	t.Run(fmt.Sprintf("%s %s", desc, url), func(t *testing.T) {
 		cfg := setting.NewCfg()
 		folderSvc := foldertest.NewFakeService()
@@ -986,6 +996,7 @@ func restoreDashboardVersionScenario(t *testing.T, desc string, url string, rout
 			dashboardVersionService: fakeDashboardVersionService,
 			accesscontrolService:    actest.FakeService{},
 			folderService:           folderSvc,
+			tracer:                  tracing.InitializeTracerForTest(),
 		}
 
 		sc := setupScenarioContext(t, url)
@@ -1022,12 +1033,12 @@ type mockDashboardProvisioningService struct {
 }
 
 func (s mockDashboardProvisioningService) GetProvisionedDashboardDataByDashboardID(ctx context.Context, dashboardID int64) (
-	*dashboards.DashboardProvisioning, error) {
+	*dashboards.DashboardProvisioning, error,
+) {
 	return nil, nil
 }
 
-type mockLibraryPanelService struct {
-}
+type mockLibraryPanelService struct{}
 
 var _ librarypanels.Service = (*mockLibraryPanelService)(nil)
 
@@ -1039,8 +1050,7 @@ func (m *mockLibraryPanelService) ImportLibraryPanelsForDashboard(c context.Cont
 	return nil
 }
 
-type mockLibraryElementService struct {
-}
+type mockLibraryElementService struct{}
 
 func (l *mockLibraryElementService) CreateElement(c context.Context, signedInUser identity.Requester, cmd model.CreateLibraryElementCommand) (model.LibraryElementDTO, error) {
 	return model.LibraryElementDTO{}, nil