//
// ### SSE-S3 and KMS
//
// SSE-S3 requires that the KMS provides two functions:
//
//  1. Generate(KeyID) -> (Key, EncKey)
//
//  2. Unseal(KeyID, EncKey) -> Key
//
//  1. Encrypt:
//     Input: KeyID, bucket, object, metadata, object_data
//     -     Key, EncKey := Generate(KeyID)
//     -              IV := Random({0,1}²⁵⁶)
//     -       ObjectKey := SHA256(Key, Random({0,1}²⁵⁶))

	mostRecentStatsMu sync.Mutex // mutex for mostRecentStats

	wlock sync.RWMutex // mutex for active workers

	movingAvgTicker *time.Ticker // Ticker for calculating moving averages
	wTimer          *time.Ticker // ticker for calculating active workers
	qTimer          *time.Ticker // ticker for calculating queue stats
}

func (r *ReplicationStats) trackEWMA() {
	for {
		select {
		case <-r.movingAvgTicker.C:

// UnsealETag unseals the etag using the provided object key.
// It does not try to decrypt the ETag if len(etag) == 16
// because such ETags indicate that the S3 client hasn't sent
// an ETag = MD5(object) and the backend has picked an ETag value.
func (key ObjectKey) UnsealETag(etag []byte) ([]byte, error) {
	if !IsETagSealed(etag) {
		return etag, nil
	}
	mac := hmac.New(sha256.New, key[:])
	mac.Write([]byte("SSE-etag"))

	return &PutObjReader{Reader: rawReader, rawReader: rawReader}
}

func sealETag(encKey crypto.ObjectKey, md5CurrSum []byte) []byte {
	var emptyKey [32]byte
	if bytes.Equal(encKey[:], emptyKey[:]) {
		return md5CurrSum
	}
	return encKey.SealETag(md5CurrSum)
}

func sealETagFn(key crypto.ObjectKey) SealMD5CurrFn {
	fn := func(md5sumcurr []byte) []byte {

			} else {
				write([]byte{0})
			}
			xioutil.SafeClose(doneCh)
			return
		}
		defer xioutil.SafeClose(doneCh)
		// Initiate ticker after body has been read.
		ticker := time.NewTicker(time.Second * 10)
		defer ticker.Stop()

		for {
			select {
			case <-ticker.C:
				// The done() might have been called
				// concurrently, check for it before we
				// write the filler byte.
				select {

					BucketName: bucket,
					Object:     objInfo,
					UserAgent:  "Internal: [Replication]",
					Host:       globalLocalNodeName,
				})
			}
			// object with same VersionID already exists, replication kicked off by
			// PutObject might have completed
			if objInfo.TargetReplicationStatus(tgt.ARN) == replication.Pending ||
				objInfo.TargetReplicationStatus(tgt.ARN) == replication.Failed ||

	ReplicaSize int64 `json:"replicaSize"`
	// Total Replica received
	ReplicaCount int64                `json:"replicaCount"`
	M            map[string]*SRStatus `json:"srStatusMap"`

	movingAvgTicker *time.Ticker // Ticker for calculating moving averages
	lock            sync.RWMutex // mutex for srStats
}

// SRStatus has replication stats at deployment level
type SRStatus struct {

		if m.respErr.Load() == nil {
			xioutil.SafeClose(respHandler)
		}
	}()
	var pingTimer <-chan time.Time
	if m.deadline == 0 || m.deadline > clientPingInterval {
		ticker := time.NewTicker(clientPingInterval)
		defer ticker.Stop()
		pingTimer = ticker.C
		atomic.StoreInt64(&m.LastPong, time.Now().Unix())
	}
	defer m.parent.deleteMux(false, m.MuxID)
	for {
		select {
		case <-m.ctx.Done():
			if debugPrint {

			size: 200,
		},
	}
	createUsageTestFiles(t, base, bucket, files)
	err = os.RemoveAll(filepath.Join(base, bucket, "dir1/dira/dirasub/dcfile"))
	if err != nil {
		t.Fatal(err)
	}
	// Changed dir must be picked up in this many cycles.
	for i := 0; i < dataUsageUpdateDirCycles; i++ {
		got, err = scanDataFolder(context.Background(), nil, base, got, getSize, 0, weSleep)
		got.Info.NextCycle++
		if err != nil {
			t.Fatal(err)

		return false
	}

	writer.writer.(http.Flusher).Flush()
	return true
}

func (writer *messageWriter) start() {
	keepAliveTicker := time.NewTicker(1 * time.Second)
	var progressTicker *time.Ticker
	var progressTickerC <-chan time.Time
	if writer.getProgressFunc != nil {
		progressTicker = time.NewTicker(1 * time.Minute)
		progressTickerC = progressTicker.C
	}