Benchmark for golang/go#56480

go56480_test.go

func BenchmarkServeContent(b *testing.B) {
	type readSeekWriterTo interface {
		io.ReadSeeker
		io.WriterTo
	}

	content, err := os.ReadFile("../../testdata/Isaac.Newton-Opticks.txt")
	if err != nil {
		b.Fatalf("could not open source file: %v", err)
	}

	in := struct{ readSeekWriterTo }{bytes.NewReader(content)}

	req := httptest.NewRequest(MethodGet, "/", NoBody)
	// req.Header.Set("Range", "bytes=0-100000")
	rw := httptest.NewRecorder()
	rw.Header().Set("Content-Type", "text/plain")

	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i <= b.N; i++ {
		in.Seek(0, io.SeekStart)
		ServeContent(rw, req, "foo.txt", time.Time{}, in)
		b.SetBytes(rw.Result().ContentLength)
		rw.Body.Reset()
	}
}