# Geschichte, Design und Zukunft { #history-design-and-future }

Vor einiger Zeit fragte [ein **FastAPI**-Benutzer](https://github.com/fastapi/fastapi/issues/3#issuecomment-454956920):

> Was ist die Geschichte dieses Projekts? Es scheint aus dem Nichts in ein paar Wochen zu etwas Großartigem geworden zu sein [...]

Hier ist ein wenig über diese Geschichte.

## Alternativen { #alternatives }

# 역사, 디자인 그리고 미래 { #history-design-and-future }

얼마 전, [한 **FastAPI** 사용자가 이렇게 물었습니다](https://github.com/fastapi/fastapi/issues/3#issuecomment-454956920):

> 이 프로젝트의 역사는 무엇인가요? 몇 주 만에 아무 데서도 갑자기 나타나 엄청나게 좋아진 것처럼 보이네요 [...]

여기서 그 역사에 대해 간단히 설명하겠습니다.

## 대안 { #alternatives }

저는 여러 해 동안 복잡한 요구사항(머신러닝, 분산 시스템, 비동기 작업, NoSQL 데이터베이스 등)을 가진 API를 만들면서 여러 개발 팀을 이끌어 왔습니다.

그 과정에서 많은 대안을 조사하고, 테스트하고, 사용해야 했습니다.

      // at the beginning of the loop.
      int i = 0;
      for (ListenableFuture<? extends InputT> future : futures) {
        int index = i++;
        if (future.isDone()) {
          processAllMustSucceedDoneFuture(index, future);
        } else {
          future.addListener(
              () -> processAllMustSucceedDoneFuture(index, future), directExecutor());
        }
      }
    } else {
      /*

    assertFalse(future.isCancelled());

    ExecutorService executor = newSingleThreadExecutor();

    try {
      Future<Boolean> getResult = executor.submit(() -> future.get());

      // Release the future value.
      latch.countDown();

      assertTrue(getResult.get(10, SECONDS));
    } finally {
      executor.shutdownNow();
    }

    assertTrue(future.isDone());

 * <p>Useful for testing the behavior of Future utilities against odd futures.
 *
 * @author Anthony Zana
 */
@GwtCompatible
@NullUnmarked
final class UncheckedThrowingFuture<V> extends AbstractFuture<V> {

  public static <V> ListenableFuture<V> throwingError(Error error) {
    UncheckedThrowingFuture<V> future = new UncheckedThrowingFuture<V>();
    future.complete(checkNotNull(error));
    return future;
  }

 *       Future} is "completed" even if it is cancelled while its underlying work continues on a
 *       thread, an RPC, etc. The {@code Future} is also "completed" if it fails "early" -- for
 *       example, if the deadline expires on a {@code Future} returned from {@link
 *       Futures#withTimeout} while the {@code Future} it wraps continues its underlying work. So

    InterruptibleFuture future = new InterruptibleFuture();
    assertTrue(future.cancel(false));
    assertTrue(future.isCancelled());
    assertTrue(future.isDone());
    assertFalse(future.wasInterrupted());
    assertFalse(future.interruptTaskWasCalled);
    CancellationException e = assertThrows(CancellationException.class, future::get);
    assertThat(e).hasCauseThat().isNull();
  }

  }

  /**
   * Returns a new {@code Future} whose result is asynchronously derived from the result of this
   * {@code Future}. If the input {@code Future} fails, the returned {@code Future} fails with the
   * same exception (and the function is not invoked).
   *
   * <p>More precisely, the returned {@code Future} takes its result from a {@code Future} produced

    }

    @Override
    public <T> Future<T> submit(Callable<T> task) {
      throw new UnsupportedOperationException();
    }

    @Override
    public Future<?> submit(Runnable task) {
      throw new UnsupportedOperationException();
    }

    @Override
    public <T> Future<T> submit(Runnable task, T result) {
      throw new UnsupportedOperationException();
    }

    CountingRunnable listener = new CountingRunnable();
    future.addListener(listener, directExecutor());
    listener.assertRun();

    assertThat(future.isDone()).isTrue();
    assertCannotSet(future);
    assertCannotCancel(future);
  }

  private static void assertCannotSet(AbstractFuture<@Nullable Integer> future) {
    assertThat(future.set(99)).isFalse();