}

// exponentialMovingAverage calculates the exponential moving average
func exponentialMovingAverage(beta, previousAvg, incrementAvg float64) float64 {
	return (1-beta)*incrementAvg + beta*previousAvg
}

// getExpMovingAvgBytesPerSecond returns the exponential moving average for the bucket in bytes
func (m *bucketMeasurement) getExpMovingAvgBytesPerSecond() float64 {
	m.lock.Lock()

		panic(err)
	}

	tr := &http.Transport{
		Proxy:                 http.ProxyFromEnvironment,
		MaxIdleConnsPerHost:   1024,
		WriteBufferSize:       32 << 10, // 32KiB moving up from 4KiB default
		ReadBufferSize:        32 << 10, // 32KiB moving up from 4KiB default
		IdleConnTimeout:       15 * time.Second,
		ResponseHeaderTimeout: 15 * time.Minute, // Set conservative timeouts for MinIO internode.

		Proxy:                 http.ProxyFromEnvironment,
		DialContext:           dialContext,
		MaxIdleConnsPerHost:   maxIdleConnsPerHost,
		WriteBufferSize:       64 << 10, // 64KiB moving up from 4KiB default
		ReadBufferSize:        64 << 10, // 64KiB moving up from 4KiB default
		IdleConnTimeout:       15 * time.Second,
		ResponseHeaderTimeout: 15 * time.Minute, // Conservative timeout is the default (for MinIO internode)

		// writes an error in JSON form to stderr, if we cannot
		// compress.
		if err := w.compress(); err != nil {
			msg := fmt.Sprintf("unable to compress log file %v: %v, ignoring and moving on", w.f.Name(), err)
			stdErrEnc.Encode(&log.Entry{
				Level:   ErrorKind,
				Message: msg,
				Time:    time.Now().UTC(),
				Trace:   &log.Trace{Message: msg},
			})
		}
	}

	// 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 {
	ReplicatedSize int64 `json:"completedReplicationSize"`

	sync.RWMutex                 // mutex for Cache
	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 {

	Rotational bool
	Metrics    DiskMetrics
	Error      string // carries the error over the network
}

// DiskMetrics has the information about XL Storage APIs
// the number of calls of each API and the moving average of
// the duration of each API.
type DiskMetrics struct {
	LastMinute              map[string]AccElem `json:"apiLatencies,omitempty"`
	APICalls                map[string]uint64  `json:"apiCalls,omitempty"`

		var hint string
		if endpoint.URL != nil {
			hint = fmt.Sprintf("Drive '%s' does not support O_DIRECT flags, MinIO erasure coding requires filesystems with O_DIRECT support", endpoint.Path)
		} else {
			hint = "Drives do not support O_DIRECT flags, MinIO erasure coding requires filesystems with O_DIRECT support"
		}
		logger.Fatal(config.ErrUnsupportedBackend(err).Hint(hint), "Unable to initialize backend")

	// this value is kept here to calculate the max API
	// requests based on RAM size for existing content.
	blockSizeV1 = 10 * humanize.MiByte

	// Block size used in erasure coding version 2.
	blockSizeV2 = 1 * humanize.MiByte

	// Buckets meta prefix.
	bucketMetaPrefix = "buckets"

	// Deleted Buckets prefix.
	deletedBucketsPrefix = ".deleted"

	"github.com/minio/madmin-go/v3"
	"github.com/minio/pkg/v2/wildcard"
)

const (
	mrfOpsQueueSize = 100000
)

// partialOperation is a successful upload/delete of an object
// but not written in all disks (having quorum)
type partialOperation struct {
	bucket              string
	object              string
	versionID           string
	versions            []byte
	setIndex, poolIndex int
	queued              time.Time