// object should be returned by ObjectLayer.Walk method
type WalkVersionsSortOrder uint8

const (
	// WalkVersionsSortAsc - Sort in ascending order of ModTime
	WalkVersionsSortAsc WalkVersionsSortOrder = iota
	// WalkVersionsSortDesc - Sort in descending order of ModTime
	WalkVersionsSortDesc
)

// ObjectOptions represents object options for ObjectLayer object operations
type ObjectOptions struct {

}

// RQErrType reason for read quorum error.
type RQErrType int

const (
	// RQInsufficientOnlineDrives - not enough online drives.
	RQInsufficientOnlineDrives RQErrType = 1 << iota
	// RQInconsistentMeta - inconsistent metadata.
	RQInconsistentMeta
)

func (t RQErrType) String() string {
	switch t {
	case RQInsufficientOnlineDrives:
		return "InsufficientOnlineDrives"

}

//msgp:ignore batchJobMetric
//go:generate stringer -type=batchJobMetric -trimprefix=batchJobMetric $GOFILE
type batchJobMetric uint8

const (
	batchJobMetricReplication batchJobMetric = iota
	batchJobMetricKeyRotation
	batchJobMetricExpire
)

func batchJobTrace(d batchJobMetric, job string, startTime time.Time, duration time.Duration, info objTraceInfoer, attempts int, err error) madmin.TraceInfo {

type APIErrorCode int

//go:generate stringer -type=APIErrorCode -trimprefix=Err $GOFILE

// Error codes, non exhaustive list - http://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html
const (
	ErrNone APIErrorCode = iota
	ErrAccessDenied
	ErrBadDigest
	ErrEntityTooSmall
	ErrEntityTooLarge
	ErrPolicyTooLarge
	ErrIncompleteBody
	ErrInternalError
	ErrInvalidAccessKeyID
	ErrAccessKeyDisabled
	ErrInvalidArgument

	return req, nil
}

// Various signature types we are supporting, currently
// two main signature types.
type signerType int

const (
	signerV2 signerType = iota
	signerV4
)

func newTestSignedRequest(method, urlStr string, contentLength int64, body io.ReadSeeker, accessKey, secretKey string, signer signerType) (*http.Request, error) {
	if signer == signerV2 {