return
		}
		pReader, err = pReader.WithEncryption(srcInfo.Reader, &objectEncryptionKey)
		if err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}
		if dstOpts.IndexCB != nil {
			dstOpts.IndexCB = compressionIndexEncrypter(objectEncryptionKey, dstOpts.IndexCB)
		}
	}

	srcInfo.PutObjReader = pReader
	copyObjectPart := objectAPI.CopyObjectPart

		if err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}

		if isTargetEncrypted {
			pReader, err = pReader.WithEncryption(srcInfo.Reader, &objEncKey)
			if err != nil {
				writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
				return
			}
			if dstOpts.IndexCB != nil {

func (b *Writer) Available() int { return len(b.buf) - b.n }

// AvailableBuffer returns an empty buffer with b.Available() capacity.
// This buffer is intended to be appended to and
// passed to an immediately succeeding [Writer.Write] call.
// The buffer is only valid until the next write operation on b.
func (b *Writer) AvailableBuffer() []byte {
	return b.buf[b.n:][:0]
}

		if err != nil {
			return setRestoreHeaderFn(oi, toObjectErr(err, bucket, object))
		}
		pReader := NewPutObjReader(hashReader)
		_, err = er.PutObject(ctx, bucket, object, pReader, ropts)
		return setRestoreHeaderFn(oi, toObjectErr(err, bucket, object))
	}

	res, err := er.NewMultipartUpload(ctx, bucket, object, ropts)
	if err != nil {