err    error
}

// healRoutine receives heal tasks, to heal buckets, objects and format.json
type healRoutine struct {
	tasks   chan healTask
	workers int
}

func activeListeners() int {
	// Bucket notification and http trace are not costly, it is okay to ignore them
	// while counting the number of concurrent connections
	return int(globalHTTPListen.Subscribers()) + int(globalTrace.Subscribers())
}

}

func initAllSubsystems(ctx context.Context) {
	// Initialize notification peer targets
	globalNotificationSys = NewNotificationSys(globalEndpoints)

	// Create new notification system
	if globalEventNotifier == nil {
		globalEventNotifier = NewEventNotifier(GlobalContext)
	}

	// Create new bucket metadata system.

* Qualquer sequência de argumentos que deve ser passada para a função de tarefa na ordem (`email`).
* Quaisquer argumentos nomeados que devem ser passados para a função de tarefa (`message="some notification"`).

## Injeção de dependências { #dependency-injection }

	for _, arn := range globalLambdaTargetList.List(globalSite.Region()) {
		arnMsg += color.Bold(fmt.Sprintf("%s ", arn))
	}
	logger.Startup(arnMsg + "\n")
}

// Prints bucket notification configurations.
func printEventNotifiers() {
	if globalNotificationSys == nil {
		return
	}

	arns := globalEventNotifier.GetARNList()
	if len(arns) == 0 {
		return
	}

	auditCollectorPath         collectorPath = "/audit"
	loggerWebhookCollectorPath collectorPath = "/logger/webhook"
	replicationCollectorPath   collectorPath = "/replication"
	notificationCollectorPath  collectorPath = "/notification"
	scannerCollectorPath       collectorPath = "/scanner"
)

const (
	clusterBasePath = "/cluster"
)

type metricsV3Collection struct {
	mgMap       map[collectorPath]*MetricsGroup

	cred, _, _ = getReqAccessKeyV4(r, region, serviceS3)
	if cred.AccessKey == "" {
		cred, _, _ = getReqAccessKeyV2(r)
	}
	return cred
}

// Extract request params to be sent with event notification.
func extractReqParams(r *http.Request) map[string]string {
	if r == nil {
		return nil
	}

	region := globalSite.Region()
	cred := getReqAccessCred(r, region)

	principalID := cred.AccessKey

			Queries("versioning", "")
		// GetBucketNotification
		router.Methods(http.MethodGet).
			HandlerFunc(s3APIMiddleware(api.GetBucketNotificationHandler)).
			Queries("notification", "")
		// ListenNotification
		router.Methods(http.MethodGet).
			HandlerFunc(s3APIMiddleware(api.ListenNotificationHandler, noThrottleS3HFlag, traceHdrsS3HFlag)).
			Queries("events", "{events:.*}")

 * implementation can be created easily by extending this class and implementing the {@link
 * Multiset#entrySet()} method, plus optionally overriding {@link #add(Object, int)} and {@link
 * #remove(Object, int)} to enable modifications to the multiset.
 *
 * <p>The {@link #count} and {@link #size} implementations all iterate across the set returned by
 * {@link Multiset#entrySet()}, as do many methods acting on the set returned by {@link

{* ../../docs_src/background_tasks/tutorial001.py hl[14] *}

`.add_task()` 接收以下参数：

* 在后台运行的任务函数(`write_notification`)。
* 应按顺序传递给任务函数的任意参数序列(`email`)。
* 应传递给任务函数的任意关键字参数(`message="some notification"`)。

## 依赖注入

使用 `BackgroundTasks` 也适用于依赖注入系统，你可以在多个级别声明 `BackgroundTasks` 类型的参数：在 *路径操作函数* 里，在依赖中(可依赖)，在子依赖中，等等。

**FastAPI** 知道在每种情况下该做什么以及如何复用同一对象，因此所有后台任务被合并在一起并且随后在后台运行：

//// tab | Python 3.10+

		return nil, time.Time{}, BucketLifecycleNotFound{Bucket: bucket}
	}
	return meta.lifecycleConfig, meta.LifecycleConfigUpdatedAt, nil
}

// GetNotificationConfig returns configured notification config
// The returned object may not be modified.
func (sys *BucketMetadataSys) GetNotificationConfig(bucket string) (*event.Config, error) {
	meta, _, err := sys.GetConfig(GlobalContext, bucket)
	if err != nil {