| /* |
| * Copyright (c) 2017 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 MODULES_INCLUDE_MODULE_COMMON_TYPES_PUBLIC_H_ |
| #define MODULES_INCLUDE_MODULE_COMMON_TYPES_PUBLIC_H_ |
| |
| #include <limits> |
| #include <optional> |
| |
| namespace webrtc { |
| |
| template <typename U> |
| inline bool IsNewer(U value, U prev_value) { |
| static_assert(!std::numeric_limits<U>::is_signed, "U must be unsigned"); |
| // kBreakpoint is the half-way mark for the type U. For instance, for a |
| // uint16_t it will be 0x8000, and for a uint32_t, it will be 0x8000000. |
| constexpr U kBreakpoint = (std::numeric_limits<U>::max() >> 1) + 1; |
| // Distinguish between elements that are exactly kBreakpoint apart. |
| // If t1>t2 and |t1-t2| = kBreakpoint: IsNewer(t1,t2)=true, |
| // IsNewer(t2,t1)=false |
| // rather than having IsNewer(t1,t2) = IsNewer(t2,t1) = false. |
| if (value - prev_value == kBreakpoint) { |
| return value > prev_value; |
| } |
| return value != prev_value && |
| static_cast<U>(value - prev_value) < kBreakpoint; |
| } |
| |
| // NB: Doesn't fulfill strict weak ordering requirements. |
| // Mustn't be used as std::map Compare function. |
| inline bool IsNewerSequenceNumber(uint16_t sequence_number, |
| uint16_t prev_sequence_number) { |
| return IsNewer(sequence_number, prev_sequence_number); |
| } |
| |
| // NB: Doesn't fulfill strict weak ordering requirements. |
| // Mustn't be used as std::map Compare function. |
| inline bool IsNewerTimestamp(uint32_t timestamp, uint32_t prev_timestamp) { |
| return IsNewer(timestamp, prev_timestamp); |
| } |
| |
| inline uint16_t LatestSequenceNumber(uint16_t sequence_number1, |
| uint16_t sequence_number2) { |
| return IsNewerSequenceNumber(sequence_number1, sequence_number2) |
| ? sequence_number1 |
| : sequence_number2; |
| } |
| |
| inline uint32_t LatestTimestamp(uint32_t timestamp1, uint32_t timestamp2) { |
| return IsNewerTimestamp(timestamp1, timestamp2) ? timestamp1 : timestamp2; |
| } |
| |
| } // namespace webrtc |
| #endif // MODULES_INCLUDE_MODULE_COMMON_TYPES_PUBLIC_H_ |