## Was sind virtuelle Umgebungen { #what-are-virtual-environments }

Die Lösung für die Probleme, alle Pakete in der globalen Umgebung zu haben, besteht darin, eine **virtuelle Umgebung für jedes Projekt** zu verwenden, an dem Sie arbeiten.

Eine virtuelle Umgebung ist ein **Verzeichnis**, sehr ähnlich zu dem globalen, in dem Sie die Pakete für ein Projekt installieren können.

Все утилиты безопасности, интегрируемые с OpenAPI (и автоматической документацией по API), наследуются от `SecurityBase`, — так **FastAPI** понимает, как интегрировать их в OpenAPI.

///

## Что он делает { #what-it-does }

Он будет искать в запросе заголовок `Authorization`, проверять, что его значение — это `Bearer ` плюс некоторый токен, и вернет токен как `str`.

Она спроектирована так, чтобы быть очень простой в использовании и облегчать любому разработчику интеграцию других компонентов с **FastAPI**.

## Что такое инъекция зависимостей («Dependency Injection») { #what-is-dependency-injection }

        // Calculate expected HMAC-MD5 using standard Java MessageDigest for comparison
        // This is a simplified HMAC-MD5 calculation for comparison, not a full RFC 2104 implementation.
        // The HMACT64 implementation is what we are testing.
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        byte[] ipad = new byte[64];
        byte[] opad = new byte[64];

        for (int i = 0; i < key.length; i++) {

            writer: DerWriter,
            value: String,
          ) = writer.writeUtf8(value)
        },
    )

  /**
   * Based on International Alphabet No. 5. Note that there are bytes that IA5 and US-ASCII
   * disagree on interpretation.
   *
   * TODO(jwilson): constrain to IA5 characters.
   */
  val IA5_STRING =
    BasicDerAdapter(
      name = "IA5 STRING",

### Data protection

  //   spinning, so we use SPIN_THRESHOLD_NANOS which is what AbstractQueuedSynchronizer uses for
  //   similar purposes.
  // * We want to behave reasonably for timeouts of 0
  // * We are more responsive to completion than timeouts. This is because parkNanos depends on
  //   system scheduling and as such we could either miss our deadline, or unpark() could be delayed

///

## Was es macht { #what-it-does }

FastAPI wird im <abbr title="Request – Anfrage: Daten, die der Client zum Server sendet">Request</abbr> nach diesem `Authorization`-Header suchen, prüfen, ob der Wert `Bearer ` plus ein Token ist, und den Token als `str` zurückgeben.

Wenn es keinen `Authorization`-Header sieht, oder der Wert keinen `Bearer `-Token hat, antwortet es direkt mit einem 401-Statuscode-Error (`UNAUTHORIZED`).

That information is available in the app's **OpenAPI schema**, and then shown in the API docs.

That same information from the models that is included in OpenAPI is what can be used to **generate the client code**.

### Hey API { #hey-api }

Once we have a FastAPI app with the models, we can use Hey API to generate a TypeScript client. The fastest way to do that is via npx.

```sh

   * absent, it will fall back to a heavyweight operation that will open a stream, read (or {@link
   * InputStream#skip(long) skip}, if possible) to the end of the stream and return the total number
   * of bytes that were read.
   *
   * <p>Note that for some sources that implement {@link #sizeIfKnown} to provide a more efficient
   * implementation, it is <i>possible</i> that this method will return a different number of bytes