* Futures.addCallback}.) Still, direct {@code addListener} calls are occasionally useful:
 *
 * {@snippet :
 * final String name = ...;
 * inFlight.add(name);
 * ListenableFuture<Result> future = service.query(name);
 * future.addListener(new Runnable() {
 *   public void run() {
 *     processedCount.incrementAndGet();
 *     inFlight.remove(name);
 *     lastProcessed.set(name);
 *     logger.info("Done with {0}", name);

   * unprivileged user may return a resource accessible only to a privileged user making a similar
   * call. To prevent this problem, create a key object that includes all values that affect the
   * result of the query. Or use {@code LoadingCache.get(K)}, which lacks the ability to refer to
   * state other than that in the key.
   *
   * <p><b>Warning:</b> as with {@link CacheLoader#load}, {@code loader} <b>must not</b> return

위 예제에서 입력 모델은 Pydantic v1 모델이고, 출력 모델(`response_model=ItemV2`로 정의됨)은 Pydantic v2 모델입니다.

### Pydantic v1 파라미터 { #pydantic-v1-parameters }

Pydantic v1 모델과 함께 `Body`, `Query`, `Form` 등 파라미터용 FastAPI 전용 도구 일부를 사용해야 한다면, Pydantic v2로의 마이그레이션을 마칠 때까지 `fastapi.temp_pydantic_v1_params`에서 import할 수 있습니다:

{* ../../docs_src/pydantic_v1_in_v2/tutorial004_an_py310.py hl[4,18] *}

{* ../../docs_src/request_files/tutorial001_an_py310.py hl[9] *}

/// info | Informação

`File` é uma classe que herda diretamente de `Form`.

Mas lembre-se que quando você importa `Query`, `Path`, `File` e outros de `fastapi`, eles são, na verdade, funções que retornam classes especiais.

///

/// tip | Dica

                        log.trace("Retrieved size info in additional query: {}", this.size);
                    }
                } catch (CIFSException e) {
                    // Size query failed, but we have basic info - continue
                    log.trace("Size query failed, continuing with basic info", e);
                }
            }

            return info;

 * class is symmetric with {@link java.net.InetAddress}.
 *
 *
 *  * <b>About NetBIOS:</b> The NetBIOS name
 * service is a dynamic distributed service that allows hosts to resolve
 * names by broadcasting a query, directing queries to a server such as
 * Samba or WINS. NetBIOS is currently the primary networking layer for
 * providing name service, datagram service, and session service to the

{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}

Neste exemplo, as mensagens serão escritas no arquivo `log.txt` *após* o envio da resposta.

Se houver uma query na request, ela será registrada em uma tarefa em segundo plano.

E então outra tarefa em segundo plano gerada na *função de operação de rota* escreverá uma mensagem usando o parâmetro de path `email`.

# 基准测试 { #benchmarks }

第三方机构 TechEmpower 的基准测试表明在 Uvicorn 下运行的 **FastAPI** 应用程序是 [可用的最快的 Python 框架之一](https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7)，仅次于 Starlette 和 Uvicorn 本身（由 FastAPI 内部使用）。

但是在查看基准得分和对比时，请注意以下几点。

## 基准测试和速度 { #benchmarks-and-speed }

当你查看基准测试时，几个不同类型的工具被等效地做比较是很常见的情况。

具体来说，是将 Uvicorn，Starlette 和 FastAPI 一起比较（在许多其它工具中）。

### Pydantic v1 Parametreleri { #pydantic-v1-parameters }

Pydantic v1 modelleriyle `Body`, `Query`, `Form` vb. parametreler için FastAPI'ye özgü bazı araçları kullanmanız gerekiyorsa, Pydantic v2'ye geçişi tamamlayana kadar bunları `fastapi.temp_pydantic_v1_params` içinden import edebilirsiniz:

# 基準測試 { #benchmarks }

由第三方機構 TechEmpower 的基準測試表明在 Uvicorn 下運行的 **FastAPI** 應用程式是 [最快的 Python 可用框架之一](https://www.techempower.com/benchmarks/#section=test&runid=7464e520-0dc2-473d-bd34-dbdfd7e85911&hw=ph&test=query&l=zijzen-7)，僅次於 Starlette 和 Uvicorn 本身（於 FastAPI 內部使用）。

但是在查看基準得分和對比時，請注意以下幾點。

## 基準測試和速度 { #benchmarks-and-speed }

當你查看基準測試時，常見到不同類型的多個工具被視為等同來比較。

具體來說，是將 Uvicorn、Starlette 和 FastAPI 同時進行比較（以及許多其他工具）。