protection bits added automatically to provide the regular safety for these objects up to 50% of the number of drives.
This will allow normal write operations to take place on systems that exceed the write tolerance.

# Exceptions - `HTTPException` and `WebSocketException`

These are the exceptions that you can raise to show errors to the client.

When you raise an exception, as would happen with normal Python, the rest of the execution is aborted. This way you can raise these exceptions from anywhere in the code to abort a request and show the error to the client.

You can use:

* `HTTPException`
* `WebSocketException`

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <executions>
          <execution>
            <id>normal</id>

            <goals>
              <goal>compile</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

### Other utility functions { #other-utility-functions }

Any other utility function that you call directly can be created with normal `def` or `async def` and FastAPI won't affect the way you call it.

# 扩展 OpenAPI { #extending-openapi }

在某些情况下，你可能需要修改生成的 OpenAPI 架构（schema）。

本节将介绍如何实现。

## 常规流程 { #the-normal-process }

常规（默认）流程如下。

`FastAPI` 应用（实例）有一个 `.openapi()` 方法，预期返回 OpenAPI 架构。

在创建应用对象时，会注册一个用于 `/openapi.json`（或你在 `openapi_url` 中设置的路径）的路径操作。

它只会返回一个 JSON 响应，内容是应用 `.openapi()` 方法的结果。

默认情况下，`.openapi()` 方法会检查属性 `.openapi_schema` 是否已有内容，若有则直接返回。

如果没有，则使用 `fastapi.openapi.utils.get_openapi` 工具函数生成。

Es solo una función estándar que puede recibir parámetros.

Puede ser una función `async def` o una función normal `def`, **FastAPI** sabrá cómo manejarla correctamente.

En este caso, la función de tarea escribirá en un archivo (simulando el envío de un email).

Y como la operación de escritura no usa `async` y `await`, definimos la función con un `def` normal:

{* ../../docs_src/background_tasks/tutorial001_py310.py hl[6:9] *}

{* ../../docs_src/app_testing/tutorial001_py310.py hl[2,12,15:18] *}

/// tip | İpucu

Test fonksiyonlarının `async def` değil, normal `def` olduğuna dikkat edin.

Client'a yapılan çağrılar da `await` kullanılmadan, normal çağrılardır.

Bu sayede `pytest`'i ek bir karmaşıklık olmadan doğrudan kullanabilirsiniz.

///

/// note | Teknik Detaylar

## HTTPX { #httpx }

Even if your **FastAPI** application uses normal `def` functions instead of `async def`, it is still an `async` application underneath.

    assert response.json() == {"name": "widget", "price": 9.99}
    mock_dumps.assert_not_called()


def test_explicit_response_class_uses_json_dumps():
    """When response_class is explicitly set to JSONResponse, the normal path
    is used and json.dumps is called via JSONResponse.render()."""
    with patch(
        "starlette.responses.json.dumps", wraps=__import__("json").dumps
    ) as mock_dumps:
        response = client.get("/explicit")

	s := fmt.Sprintf("%s %s: %s", e.msg, e.context, loc)
	if e.readerErr != nil {
		s += "\nreader error: " + e.readerErr.Error()
	}
	return s
}

// quoteChar formats c as a quoted character literal
func quoteChar(c byte) string {
	// special cases - different from quoted strings
	if c == '\'' {
		return `'\''`
	}
	if c == '"' {
		return `'"'`
	}