5654f891bb
Formatting done via: git ls-files | grep -E '^rtc_base\/.*\.(h|cc|mm)' | xargs clang-format -i No-Iwyu: Includes didn't change and it isn't related to formatting Bug: webrtc:42225392 Change-Id: I11c1ae6d6ea49c744a4e60a1a032e3d5ae7bce1f Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/373906 Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/main@{#43688}
84 lines
2.8 KiB
C++
84 lines
2.8 KiB
C++
/*
|
|
* Copyright (c) 2016 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 RTC_BASE_NUMERICS_SEQUENCE_NUMBER_UTIL_H_
|
|
#define RTC_BASE_NUMERICS_SEQUENCE_NUMBER_UTIL_H_
|
|
|
|
#include <limits>
|
|
#include <type_traits>
|
|
|
|
#include "rtc_base/numerics/mod_ops.h"
|
|
|
|
namespace webrtc {
|
|
|
|
// Test if the sequence number `a` is ahead or at sequence number `b`.
|
|
//
|
|
// If `M` is an even number and the two sequence numbers are at max distance
|
|
// from each other, then the sequence number with the highest value is
|
|
// considered to be ahead.
|
|
template <typename T, T M>
|
|
inline typename std::enable_if<(M > 0), bool>::type AheadOrAt(T a, T b) {
|
|
static_assert(std::is_unsigned<T>::value,
|
|
"Type must be an unsigned integer.");
|
|
const T maxDist = M / 2;
|
|
if (!(M & 1) && MinDiff<T, M>(a, b) == maxDist)
|
|
return b < a;
|
|
return ForwardDiff<T, M>(b, a) <= maxDist;
|
|
}
|
|
|
|
template <typename T, T M>
|
|
inline typename std::enable_if<(M == 0), bool>::type AheadOrAt(T a, T b) {
|
|
static_assert(std::is_unsigned<T>::value,
|
|
"Type must be an unsigned integer.");
|
|
const T maxDist = std::numeric_limits<T>::max() / 2 + T(1);
|
|
if (a - b == maxDist)
|
|
return b < a;
|
|
return ForwardDiff(b, a) < maxDist;
|
|
}
|
|
|
|
template <typename T>
|
|
inline bool AheadOrAt(T a, T b) {
|
|
return AheadOrAt<T, 0>(a, b);
|
|
}
|
|
|
|
// Test if the sequence number `a` is ahead of sequence number `b`.
|
|
//
|
|
// If `M` is an even number and the two sequence numbers are at max distance
|
|
// from each other, then the sequence number with the highest value is
|
|
// considered to be ahead.
|
|
template <typename T, T M = 0>
|
|
inline bool AheadOf(T a, T b) {
|
|
static_assert(std::is_unsigned<T>::value,
|
|
"Type must be an unsigned integer.");
|
|
return a != b && AheadOrAt<T, M>(a, b);
|
|
}
|
|
|
|
// Comparator used to compare sequence numbers in a continuous fashion.
|
|
//
|
|
// WARNING! If used to sort sequence numbers of length M then the interval
|
|
// covered by the sequence numbers may not be larger than floor(M/2).
|
|
template <typename T, T M = 0>
|
|
struct AscendingSeqNumComp {
|
|
bool operator()(T a, T b) const { return AheadOf<T, M>(a, b); }
|
|
};
|
|
|
|
// Comparator used to compare sequence numbers in a continuous fashion.
|
|
//
|
|
// WARNING! If used to sort sequence numbers of length M then the interval
|
|
// covered by the sequence numbers may not be larger than floor(M/2).
|
|
template <typename T, T M = 0>
|
|
struct DescendingSeqNumComp {
|
|
bool operator()(T a, T b) const { return AheadOf<T, M>(b, a); }
|
|
};
|
|
|
|
} // namespace webrtc
|
|
|
|
#endif // RTC_BASE_NUMERICS_SEQUENCE_NUMBER_UTIL_H_
|