"legacy_request_state_context_var", default=None
)

app = FastAPI()


async def set_up_request_state_dependency():
    request_state = {"user": "deadpond"}
    contextvar_token = legacy_request_state_context_var.set(request_state)
    yield request_state
    legacy_request_state_context_var.reset(contextvar_token)


@app.middleware("http")
async def custom_middleware(

	size      int
	r         int // next position to read
	w         int // next position to write
	isFull    bool
	err       error
	block     bool
	mu        sync.Mutex
	wg        sync.WaitGroup
	readCond  *sync.Cond // Signaled when data has been read.
	writeCond *sync.Cond // Signaled when data has been written.
}

// New returns a new RingBuffer whose buffer has the given size.
func New(size int) *RingBuffer {

Als Nächstes würden Sie den Server ausführen und die Konfigurationen als Umgebungsvariablen übergeben. Sie könnten beispielsweise `ADMIN_EMAIL` und `APP_NAME` festlegen mit:

<div class="termy">

```console
$ ADMIN_EMAIL="deadpool@example.com" APP_NAME="ChimichangApp" uvicorn main:app

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip | "Tipp"

<div class="termy">

```console
$ ADMIN_EMAIL="deadpool@example.com" APP_NAME="ChimichangApp" uvicorn main:app

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip

⚒ 💗 🇨🇻 {👁 📋 🎏 👫 ⏮️ 🚀, &amp; 🚮 👫 🌐 ⏭ 📋.

///

&amp; ⤴️ `admin_email` ⚒ 🔜 ⚒ `"deadpool@example.com"`.

`app_name` 🔜 `"ChimichangApp"`.

Next, you would run the server passing the configurations as environment variables, for example you could set an `ADMIN_EMAIL` and `APP_NAME` with:

<div class="termy">

```console
$ ADMIN_EMAIL="deadpool@example.com" APP_NAME="ChimichangApp" fastapi run main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip

<div class="termy">

```console
$ ADMIN_EMAIL="deadpool@example.com" APP_NAME="ChimichangApp" fastapi run main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// dica

<div class="termy">

```console
$ ADMIN_EMAIL="deadpool@example.com" APP_NAME="ChimichangApp"uvicorn main:app

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

/// tip

要为单个命令设置多个环境变量，只需用空格分隔它们，并将它们全部放在命令之前。

///

然后，`admin_email` 设置将为 `"deadpool@example.com"`。

`app_name` 将为 `"ChimichangApp"`。

legacy_request_state_context_var: ContextVar[Optional[Dict[str, Any]]] = ContextVar(
    "legacy_request_state_context_var", default=None
)

async def set_up_request_state_dependency():
    request_state = {"user": "deadpond"}
    contextvar_token = legacy_request_state_context_var.set(request_state)
    yield request_state
    legacy_request_state_context_var.reset(contextvar_token)
```

                **Example**

                ```python
                from fastapi import FastAPI

                app = FastAPI(summary="Deadpond's favorite app. Nuff said.")
                ```
                """
            ),
        ] = None,
        description: Annotated[
            str,
            Doc(
                '''