// add an input buffer of this size.
	encryptBufferSize = 1 << 20

	// minCompressibleSize is the minimum size at which we enable compression.
	minCompressibleSize = 4096
)

// setHeadGetRespHeaders - set any requested parameters as response headers.
func setHeadGetRespHeaders(w http.ResponseWriter, reqParams url.Values) {
	for k, v := range reqParams {
		if header, ok := supportedHeadGetReqParams[strings.ToLower(k)]; ok {

		if !storageclass.IsValid(sc) {
			writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidStorageClass), r.URL)
			return
		}
	}

	encMetadata := map[string]string{}

	if crypto.Requested(r.Header) {
		if crypto.SSECopy.IsRequested(r.Header) {
			writeErrorResponse(ctx, w, toAPIError(ctx, errInvalidEncryptionParameters), r.URL)
			return
		}

		// Save the current part name and size.
		partSize := fi.Parts[partIndex].Size

		partLength := partSize - partOffset
		// partLength should be adjusted so that we don't write more data than what was requested.
		if partLength > (length - totalBytesRead) {
			partLength = length - totalBytesRead
		}

		tillOffset := erasure.ShardFileOffset(partOffset, partLength, partSize)
		// Get the checksums of the current part.