}

	region := globalSite.Region
	date := UTCNow()
	scope := getScope(date, region)
	credential := fmt.Sprintf("%s/%s", accessKeyID, scope)

	// Set URL query.
	query := req.URL.Query()
	query.Set("X-Amz-Algorithm", signV4Algorithm)
	query.Set("X-Amz-Date", date.Format(iso8601Format))
	query.Set("X-Amz-Expires", strconv.FormatInt(expires, 10))

	if de.Empty() {
		return nil
	}

	type delMarkerExpiration DelMarkerExpiration
	return enc.EncodeElement(delMarkerExpiration(de), start)
}

// NextDue returns upcoming DelMarkerExpiration date for obj if
// applicable, returns false otherwise.
func (de DelMarkerExpiration) NextDue(obj ObjectOpts) (time.Time, bool) {
	if !obj.IsLatest || !obj.DeleteMarker {
		return time.Time{}, false
	}

	// Compare only necessary headers
	compareKeys := []string{
		"Expires",
		"Cache-Control",
		"Content-Language",
		"Content-Disposition",
		"X-Amz-Object-Lock-Mode",
		"X-Amz-Object-Lock-Retain-Until-Date",
		"X-Amz-Object-Lock-Legal-Hold",
		"X-Amz-Website-Redirect-Location",
		"X-Amz-Meta-",
	}

	// compare metadata on both maps to see if meta is identical
	compareMeta1 := make(map[string]string)

	// Add the algorithm condition, only accept AWS SignV4 Sha256.
	algorithmConditionStr := `["eq", "$x-amz-algorithm", "AWS4-HMAC-SHA256"]`
	// Add the date condition, only accept the current date.
	dateConditionStr := fmt.Sprintf(`["eq", "$x-amz-date", "%s"]`, t.Format(iso8601DateFormat))
	// Add the credential string, only accept the credential passed.

// Objects under site wide WORM can never be overwritten.
// For objects in "Governance" mode, overwrite is allowed if a) object retention date is past OR
// governance bypass headers are set and user has governance bypass permissions.
// Objects in "Compliance" mode can be overwritten only if retention date is past.

	},
	ErrMalformedDate: {
		Code:           "MalformedDate",
		Description:    "Invalid date format header, expected to be in ISO8601, RFC1123 or RFC1123Z time format.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrMalformedPresignedDate: {
		Code:           "AuthorizationQueryParametersError",
		Description:    "X-Amz-Date must be in the ISO8601 Long Format \"yyyyMMdd'T'HHmmss'Z'\"",
		HTTPStatusCode: http.StatusBadRequest,

//
// The above means that any added/deleted fields are incompatible.
//
//msgp:tuple VolInfo
type VolInfo struct {
	// Name of the volume.
	Name string

	// Date and time when the volume was created.
	Created time.Time
}

// FilesInfo represent a list of files, additionally
// indicates if the list is last.
//
//msgp:tuple FileInfo
type FilesInfo struct {

// String returns x-amz-restore compatible representation of r.
func (r restoreObjStatus) String() string {
	if r.Ongoing() {
		return `ongoing-request="true"`
	}
	return fmt.Sprintf(`ongoing-request="false", expiry-date="%s"`, r.expiry.Format(http.TimeFormat))
}

// Expiry returns expiry of restored object and true if restore-object has completed.
// Otherwise returns zero value of time.Time and false.

	// can reach that size according to https://aws.amazon.com/articles/1434
	maxFormFieldSize = int64(1 * humanize.MiByte)

	// The maximum allowed time difference between the incoming request
	// date and server date during signature verification.
	globalMaxSkewTime = 15 * time.Minute // 15 minutes skew allowed.

	// GlobalStaleUploadsExpiry - Expiry duration after which the uploads in multipart,
	// tmp directory are deemed stale.

	receivedCount      MetricName = "received_count"
	sentCount          MetricName = "sent_count"
	currTransferRate   MetricName = "current_transfer_rate"
	avgTransferRate    MetricName = "average_transfer_rate"
	maxTransferRate    MetricName = "max_transfer_rate"
	credentialErrors   MetricName = "credential_errors"

	currLinkLatency MetricName = "current_link_latency_ms"
	avgLinkLatency  MetricName = "average_link_latency_ms"