}
	return
}

// url may contain a #fragment, and the fragment is then noted as needing to exist.
func crawl(url string, sourceURL string) {
	if strings.Contains(url, "/devel/release") {
		return
	}
	mu.Lock()
	defer mu.Unlock()
	if u, frag, ok := strings.Cut(url, "#"); ok {
		url = u
		if frag != "" {
			uf := urlFrag{url, frag}
			neededFrags[uf] = append(neededFrags[uf], sourceURL)
		}
	}
	if crawled[url] {

}

type pooledFlateWriter struct {
	mu sync.Mutex // guards Close and Write
	fw *flate.Writer
}

func (w *pooledFlateWriter) Write(p []byte) (n int, err error) {
	w.mu.Lock()
	defer w.mu.Unlock()
	if w.fw == nil {
		return 0, errors.New("Write after Close")
	}
	return w.fw.Write(p)
}

func (w *pooledFlateWriter) Close() error {
	w.mu.Lock()
	defer w.mu.Unlock()
	var err error
	if w.fw != nil {

//   pthread_mutex_init(&mu, NULL);
//   for (i = 0; i < nts; i++) {
//     pthread_create(&t[i], NULL, aFn, NULL);
//   }
// }
//
// void cleanup(void) {
//   int i;
//   pthread_mutex_lock(&mu);
//   all_done = 1;
//   pthread_mutex_unlock(&mu);
//   for (i = 0; i < nts; i++) {
//     pthread_join(t[i], NULL);
//   }
//   pthread_mutex_destroy(&mu);
//   free(t);
// }
import "C"