*/
  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

# 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 }

      val residentDuration = maxOf(0, nowMillis - receivedResponseMillis)
      return receivedAge + responseDuration + residentDuration
    }

    /**
     * Returns true if the request contains conditions that save the server from sending a response
     * that the client has locally. When a request is enqueued with its own conditions, the built-in
     * response cache won't be used.
     */

```

### Download the files { #download-the-files }

Download the static files needed for the docs and put them on that `static/` directory.

You can probably right-click each link and select an option similar to "Save link as...".

**Swagger UI** uses the files:

* <a href="https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui-bundle.js" class="external-link" target="_blank">`swagger-ui-bundle.js`</a>

Mais même si vous n'utilisez pas ou n'utiliserez jamais **FastAPI**, vous pourriez bénéficier d'apprendre quelques choses sur ces dernières.

/// note

Si vous êtes un expert Python, et que vous savez déjà **tout** sur les annotations de type, passez au chapitre suivant.

///

## Motivations

Prenons un exemple simple :

{*../../docs_src/python_types/tutorial001.py*}

Exécuter ce programe affiche :

	query.Set("AWSAccessKeyId", accessKeyID)
	// Fill in Expires for presigned query.
	query.Set("Expires", strconv.FormatInt(epochExpires, 10))

	// Encode query and save.
	req.URL.RawQuery = query.Encode()

	// Save signature finally.
	req.URL.RawQuery += "&Signature=" + url.QueryEscape(signature)
	return nil
}

// Sign given request using Signature V2.

### 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 }

## Pydantic

Toute la validation de données est effectué en arrière-plan avec <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic</a>,
dont vous bénéficierez de tous les avantages. Vous savez donc que vous êtes entre de bonnes mains.

## L'ordre importe

Quand vous créez des *fonctions de chemins*, vous pouvez vous retrouver dans une situation où vous avez un chemin fixe.

	return atomic.LoadInt32(&h.status) == statusOnline
}

// Send log message 'e' to kafka target.
func (h *Target) Send(ctx context.Context, entry any) error {
	if h.store != nil {
		// save the entry to the queue store which will be replayed to the target.
		_, err := h.store.Put(entry)
		return err
	}
	h.logChMu.RLock()
	defer h.logChMu.RUnlock()
	if h.logCh == nil {
		// We are closing...