Function BenchmarkFieldAccess

eval_test.go:1093–1129

BenchmarkFieldAccess benchmarks executing a template that accesses fields in the current context. This measures the overhead from adding one additional field access to a template.

(b *testing.B)

// This measures the overhead from adding one additional field access to a
// template.
func BenchmarkFieldAccess(b *testing.B) {
	// This benchmark is disabled from normal execution due to being
	// limited by the parsing performance of this package. When the
	// benchmark len grows greater than about 100K, parsing performance is
	// degraded and this benchmark takes a long time to setup.
	//
	// To test this, comment out the following line and run this specific
	// benchmark with
	//   go test -run Bench -bench BenchmarkFieldAcces -benchtime 0.02s
	b.Skip("Can only run manually with -benchtime 0.02s")

	const numFields = 3 // Must match the structure below.
	tmplBuilder := new(strings.Builder)
	for i := 0; i < b.N; i++ {
		fmt.Fprintf(tmplBuilder, "{{ .Field%d }} ", i%numFields+1)
	}

	loader := NewInMemLoader()
	loader.Set("BenchFields", tmplBuilder.String())
	set := NewSet(loader, WithSafeWriter(nil))
	testCtx := struct {
		Field1 string
		Field2 int
		Field3 float64
	}{
		Field1: "secret",
		Field2: 42,
		Field3: 3.1415,
	}
	t, _ := set.GetTemplate("BenchFields")

	b.ResetTimer()
	err := t.Execute(ww, nil, testCtx)
	if err != nil {
		b.Error(err.Error())
	}
}