// Use Close to ensure resources are released on incomplete streams.
//
// input 'on' is always recommended such that this function works
// properly, because we do not wish to create an object even if
// client closed the stream prematurely.
func newS2CompressReader(r io.Reader, on int64, encrypted bool) (rc io.ReadCloser, idx func() []byte) {
	pr, pw := io.Pipe()
	// Copy input to compressor

)

const (
	ntpServerEnv = "MINIO_NTP_SERVER"
)

var ntpServer = env.Get(ntpServerEnv, "")

// UTCNowNTP - is similar in functionality to UTCNow()
// but only used when we do not wish to rely on system
// time.
func UTCNowNTP() (time.Time, error) {
	// ntp server is disabled
	if ntpServer == "" {
		return time.Now().UTC(), nil
	}
	return ntp.Time(ntpServer)
}

// with control characters, this is a specialized extension
// to support AWS S3 compatible behavior.
//
// Do not use this function for anything other than ListObjects()
// variants, please open a github discussion if you wish to use
// this in other places.
func encodeResponseList(response interface{}) []byte {
	var buf bytes.Buffer
	buf.WriteString(xxml.Header)
	if err := xxml.NewEncoder(&buf).Encode(response); err != nil {

// values such as ErasureInfo, ChecksumInfo.
//
// Metadata is only updated to new values, existing values
// stay as is, if you wish to update all values you should
// update all metadata freshly before calling this function
// in-case you wish to clear existing metadata.
func (x *xlMetaV2) UpdateObjectVersion(fi FileInfo) error {
	if fi.VersionID == "" {
		// this means versioning is not yet