original_context: Lifespan[Any], nested_context: Lifespan[Any]
) -> Lifespan[Any]:
    @asynccontextmanager
    async def merged_lifespan(
        app: AppType,
    ) -> AsyncIterator[Optional[Mapping[str, Any]]]:
        async with original_context(app) as maybe_original_state:
            async with nested_context(app) as maybe_nested_state:
                if maybe_nested_state is None and maybe_original_state is None:

            endLatch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        // despite all are back, we need to make sure all the events are processed (are async)
        // this one should block until all processed
        listener.transferSucceeded(new TransferEvent.Builder(session, resource)
                .setType(TransferEvent.EventType.SUCCEEDED)
                .build());

import org.codelibs.fess.util.RenderDataUtil;
import org.codelibs.fess.util.ResourceUtil;
import org.codelibs.fess.util.SearchEngineUtil;
import org.dbflute.bhv.readable.EntityRowHandler;
import org.lastaflute.core.magic.async.AsyncManager;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.ActionResponse;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.StreamResponse;

```Python hl_lines="4"
{!../../docs_src/dependencies/tutorial007.py!}
```

`yield` 语句后面的代码会在创建响应后，发送响应前执行：

```Python hl_lines="5-6"
{!../../docs_src/dependencies/tutorial007.py!}
```

/// tip | 提示

你可以使用 `async` 或普通函数。

**FastAPI** 会像处理普通依赖一样，对每个依赖做正确的处理。

///

## 包含 `yield` 和 `try` 的依赖项

如果在包含 `yield` 的依赖中使用 `try` 代码块，你会捕获到使用依赖时抛出的任何异常。

例如，如果某段代码在另一个依赖中或在 *路由函数* 中使数据库事务"回滚"或产生任何其他错误，你将会在依赖中捕获到异常。

```Python hl_lines="2  7  9"
{!../../docs_src/custom_response/tutorial006c.py!}
```

### `StreamingResponse`

Takes an async generator or a normal generator/iterator and streams the response body.

```Python hl_lines="2  14"
{!../../docs_src/custom_response/tutorial007.py!}
```

#### Using `StreamingResponse` with file-like objects

在高级使用场景中，如果不想使用「缓存」值，而是为需要在同一请求的每一步操作（多次）中都实际调用依赖项，可以把 `Depends` 的参数 `use_cache` 的值设置为 `False` :

```Python hl_lines="1"
async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):
    return {"fresh_value": fresh_value}
```

## 小结

千万别被本章里这些花里胡哨的词藻吓倒了，其实**依赖注入**系统非常简单。

依赖注入无非是与*路径操作函数*一样的函数罢了。

У даному випадку це асинхронна функція.

---

Ви також можете визначити її як звичайну функцію замість `async def`:

```Python hl_lines="7"
{!../../docs_src/first_steps/tutorial003.py!}
```

/// note | "Примітка"

Якщо не знаєте в чому різниця, подивіться [Конкурентність: *"Поспішаєш?"*](../async.md#in-a-hurry){.internal-link target=_blank}.

///

### Крок 5: поверніть результат

- Extend kube-apiserver /readyz with new "informer-sync" check ensuring that internal informers are synced. ([#92644](https://github.com/kubernetes/kubernetes/pull/92644), [@wojtek-t](https://github.com/wojtek-t)) [SIG API Machinery and Testing]

package dsync

// Code generated by github.com/tinylib/msgp DO NOT EDIT.

import (
	"bytes"
	"testing"

	"github.com/tinylib/msgp/msgp"
)

func TestMarshalUnmarshalLockArgs(t *testing.T) {
	v := LockArgs{}
	bts, err := v.MarshalMsg(nil)
	if err != nil {
		t.Fatal(err)
	}
	left, err := v.UnmarshalMsg(bts)
	if err != nil {
		t.Fatal(err)
	}
	if len(left) > 0 {

    from typing import Annotated

    from fastapi import Depends, FastAPI

    app = FastAPI()


    async def common_parameters(q: str | None = None, skip: int = 0, limit: int = 100):
        return {"q": q, "skip": skip, "limit": limit}


    @app.get("/items/")
    async def read_items(commons: Annotated[dict, Depends(common_parameters)]):
        return commons
    ```
    """