chromium/third_party/webrtc/net/dcsctp/common/sequence_numbers.h

/*
 *  Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#ifndef NET_DCSCTP_COMMON_SEQUENCE_NUMBERS_H_
#define NET_DCSCTP_COMMON_SEQUENCE_NUMBERS_H_

#include <cstdint>
#include <limits>
#include <utility>

#include "net/dcsctp/common/internal_types.h"
#include "rtc_base/numerics/sequence_number_unwrapper.h"

namespace dcsctp {

// UnwrappedSequenceNumber handles wrapping sequence numbers and unwraps them to
// an int64_t value space, to allow wrapped sequence numbers to be easily
// compared for ordering.
//
// Sequence numbers are expected to be monotonically increasing, but they do not
// need to be unwrapped in order, as long as the difference to the previous one
// is not larger than half the range of the wrapped sequence number.
//
// The WrappedType must be a webrtc::StrongAlias type.
template <typename WrappedType>
class UnwrappedSequenceNumber { … };

// Unwrapped Transmission Sequence Numbers (TSN)
UnwrappedTSN;

// Unwrapped Stream Sequence Numbers (SSN)
UnwrappedSSN;

// Unwrapped Message Identifier (MID)
UnwrappedMID;

}  // namespace dcsctp

#endif  // NET_DCSCTP_COMMON_SEQUENCE_NUMBERS_H_