m.wg.Add(1)
	defer m.wg.Done()

	if atomic.LoadInt32(&m.closing) == 1 {
		return
	}

	select {
	case m.opCh <- op:
	default:
	}
}

// Do not accept new MRF operations anymore and start to save
// the current heal status in one available disk
func (m *mrfState) shutdown() {
	atomic.StoreInt32(&m.closing, 1)
	m.wg.Wait()
	close(m.opCh)
	atomic.StoreInt32(&m.closed, 1)

	if len(m.opCh) > 0 {

Ce code ne sera pas exécuté dans votre application, nous en avons seulement besoin pour *documenter* à quoi devrait ressembler cette *API externe*.

Mais vous savez déjà comment créer facilement une documentation automatique pour une API avec **FastAPI**.

# Recommended: use a local+remote cache.
#
#   Bazel will cache your builds in tensorflow/build_output/cache,
#   and will also try using public build cache results to speed up
#   your builds. This usually saves a lot of time, especially when
#   re-running tests. However, note that:
#
#    - New environments like new CUDA versions, changes to manylinux,
#      compilers, etc. can cause undefined behavior such as build failures

And you want to have a way for the frontend to authenticate with the backend, using a **username** and **password**.

We can use **OAuth2** to build that with **FastAPI**.

But let's save you the time of reading the full long specification just to find those little pieces of information you need.

Let's use the tools provided by **FastAPI** to handle security.

## How it looks { #how-it-looks }

   */
  public static final String RTT = "RTT";

  /**
   * The HTTP <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Save-Data">{@code
   * Save-Data}</a> header field name.
   *
   * @since 31.0
   */
  public static final String SAVE_DATA = "Save-Data";

  /**
   * The HTTP <a
   * href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Viewport-Width">{@code

   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
   * Multimap#asMap()} will iterate through the keys in the order that they were first added to the
   * multimap, save that if all values associated with a key are removed and then the key is added
   * back into the multimap, that key will come last in the key iteration order.
   */

   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
   * Multimap#asMap()} will iterate through the keys in the order that they were first added to the
   * multimap, save that if all values associated with a key are removed and then the key is added
   * back into the multimap, that key will come last in the key iteration order.
   */

Ces exemples sont volontairement simples, mais ils montrent comment tout cela fonctionne.

Dans les chapitres sur la sécurité, il existe des fonctions utilitaires implémentées de la même manière.

Si vous avez compris tout cela, vous savez déjà comment ces outils utilitaires pour la sécurité fonctionnent en interne.

///

---

Si votre application (d'une certaine manière) n'a pas à communiquer avec une autre chose et à attendre sa réponse, utilisez `async def`, même si vous n'avez pas besoin d'utiliser `await` à l'intérieur.

---

Si vous ne savez pas, utilisez seulement `def`.

---

### Check the password { #check-the-password }

At this point we have the user data from our database, but we haven't checked the password.

Let's put that data in the Pydantic `UserInDB` model first.

You should never save plaintext passwords, so, we'll use the (fake) password hashing system.

If the passwords don't match, we return the same error.

#### Password hashing { #password-hashing }