private val sinkBuffer: Buffer = sink.buffer
  private var writerClosed = false

  /** Lazily initialized on first use. */
  private var messageDeflater: MessageDeflater? = null

  // Masks are only a concern for client writers.
  private val maskKey: ByteArray? = if (isClient) ByteArray(4) else null
  private val maskCursor: Buffer.UnsafeCursor? = if (isClient) Buffer.UnsafeCursor() else null

import "k8s.io/apimachinery/pkg/runtime/schema/generated.proto";

// Package-wide variables from generator "generated".
option go_package = "k8s.io/api/authentication/v1beta1";

// ExtraValue masks the value so protobuf can generate
// +protobuf.nullable=true
// +protobuf.options.(gogoproto.goproto_stringer)=false
message ExtraValue {
  // items, if empty, will result in an empty slice

  repeated string items = 1;

  optional string apiVersion = 2;

  // Name of the referent.
  // +optional
  optional string name = 3;

  // UID of the referent.
  // +optional
  optional string uID = 4;
}

// ExtraValue masks the value so protobuf can generate
// +protobuf.nullable=true
// +protobuf.options.(gogoproto.goproto_stringer)=false
message ExtraValue {
  // items, if empty, will result in an empty slice

  repeated string items = 1;

  // If request was approved, the controller will place the issued certificate here.
  // +listType=atomic
  // +optional
  optional bytes certificate = 2;
}

// ExtraValue masks the value so protobuf can generate
// +protobuf.nullable=true
// +protobuf.options.(gogoproto.goproto_stringer)=false
message ExtraValue {
  // items, if empty, will result in an empty slice

	"math"
	"math/bits"
)

// Mask allows filtering by a bitset mask.
type Mask uint64

const (
	// MaskAll is the mask for all entries.
	MaskAll Mask = math.MaxUint64
)

// MaskFromMaskable extracts mask from an interface.
func MaskFromMaskable(m Maskable) Mask {
	return Mask(m.Mask())
}

// Contains returns whether *all* flags in other is present in t.
func (t Mask) Contains(other Mask) bool {
	return t&other == other

# Background Tasks

You can define background tasks to be run *after* returning a response.

This is useful for operations that need to happen after a request, but that the client doesn't really have to be waiting for the operation to complete before receiving the response.

This includes, for example:

* Email notifications sent after performing an action:

```Python hl_lines="6-9"
{!../../docs_src/background_tasks/tutorial001.py!}
```

## Добавление фоновой задачи

Внутри функции вызовите метод `.add_task()` у объекта *background tasks* и передайте ему функцию, которую хотите выполнить в фоне:

```Python hl_lines="14"
{!../../docs_src/background_tasks/tutorial001.py!}
```

`.add_task()` принимает следующие аргументы:

在FastAPI中仍然可以单独使用 `BackgroundTask`，但您必须在代码中创建对象，并返回包含它的Starlette `Response`。

更多细节查看 <a href="https://www.starlette.io/background/" class="external-link" target="_blank">Starlette's official docs for Background Tasks</a>.

## 告诫

如果您需要执行繁重的后台计算，并且不一定需要由同一进程运行（例如，您不需要共享内存、变量等），那么使用其他更大的工具（如 <a href="https://docs.celeryq.dev" class="external-link" target="_blank">Celery</a>）可能更好。

```Python hl_lines="6-9"
{!../../docs_src/background_tasks/tutorial001.py!}
```

## バックグラウンドタスクの追加

*path operations 関数* 内で、`.add_task()` メソッドを使用してタスク関数を *background tasks* オブジェクトに渡します。

```Python hl_lines="14"
{!../../docs_src/background_tasks/tutorial001.py!}
```

`.add_task()` は以下の引数を受け取ります:

* バックグラウンドで実行されるタスク関数 (`write_notification`)。
* タスク関数に順番に渡す必要のある引数の列 (`email`)。

import org.gradle.tooling.events.task.TaskOperationResult
import java.io.Serializable
import java.util.concurrent.CopyOnWriteArrayList

/**
 * Register a build service that monitors compilation tasks and code quality tasks (Checkstyle/CodeNarc/detekt)
 * and reports them as TeamCity build problems.
 */