| /* |
| * Copyright (c) 2018 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 API_UNITS_DATA_RATE_H_ |
| #define API_UNITS_DATA_RATE_H_ |
| |
| #ifdef UNIT_TEST |
| #include <ostream> // no-presubmit-check TODO(webrtc:8982) |
| #endif // UNIT_TEST |
| |
| #include <limits> |
| #include <string> |
| #include <type_traits> |
| |
| #include "api/units/data_size.h" |
| #include "api/units/time_delta.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/units/unit_base.h" |
| |
| namespace webrtc { |
| namespace data_rate_impl { |
| inline int64_t Microbits(const DataSize& size) { |
| constexpr int64_t kMaxBeforeConversion = |
| std::numeric_limits<int64_t>::max() / 8000000; |
| RTC_DCHECK_LE(size.bytes(), kMaxBeforeConversion) |
| << "size is too large to be expressed in microbytes"; |
| return size.bytes() * 8000000; |
| } |
| } // namespace data_rate_impl |
| |
| // DataRate is a class that represents a given data rate. This can be used to |
| // represent bandwidth, encoding bitrate, etc. The internal storage is bits per |
| // second (bps). |
| class DataRate final : public rtc_units_impl::RelativeUnit<DataRate> { |
| public: |
| DataRate() = delete; |
| static constexpr DataRate Infinity() { return PlusInfinity(); } |
| template <int64_t bps> |
| static constexpr DataRate BitsPerSec() { |
| return FromStaticValue<bps>(); |
| } |
| template <int64_t kbps> |
| static constexpr DataRate KilobitsPerSec() { |
| return FromStaticFraction<kbps, 1000>(); |
| } |
| template <typename T> |
| static constexpr DataRate bps(T bits_per_second) { |
| static_assert(std::is_arithmetic<T>::value, ""); |
| return FromValue(bits_per_second); |
| } |
| template <typename T> |
| static constexpr DataRate bytes_per_sec(T bytes_per_second) { |
| static_assert(std::is_arithmetic<T>::value, ""); |
| return FromFraction<8>(bytes_per_second); |
| } |
| template <typename T> |
| static constexpr DataRate kbps(T kilobits_per_sec) { |
| static_assert(std::is_arithmetic<T>::value, ""); |
| return FromFraction<1000>(kilobits_per_sec); |
| } |
| template <typename T = int64_t> |
| constexpr T bps() const { |
| return ToValue<T>(); |
| } |
| template <typename T = int64_t> |
| constexpr T bytes_per_sec() const { |
| return ToFraction<8, T>(); |
| } |
| template <typename T = int64_t> |
| T kbps() const { |
| return ToFraction<1000, T>(); |
| } |
| constexpr int64_t bps_or(int64_t fallback_value) const { |
| return ToValueOr(fallback_value); |
| } |
| constexpr int64_t kbps_or(int64_t fallback_value) const { |
| return ToFractionOr<1000>(fallback_value); |
| } |
| |
| private: |
| // Bits per second used internally to simplify debugging by making the value |
| // more recognizable. |
| friend class rtc_units_impl::UnitBase<DataRate>; |
| using RelativeUnit::RelativeUnit; |
| static constexpr bool one_sided = true; |
| }; |
| |
| inline DataRate operator/(const DataSize size, const TimeDelta duration) { |
| return DataRate::bps(data_rate_impl::Microbits(size) / duration.us()); |
| } |
| inline TimeDelta operator/(const DataSize size, const DataRate rate) { |
| return TimeDelta::us(data_rate_impl::Microbits(size) / rate.bps()); |
| } |
| inline DataSize operator*(const DataRate rate, const TimeDelta duration) { |
| int64_t microbits = rate.bps() * duration.us(); |
| return DataSize::bytes((microbits + 4000000) / 8000000); |
| } |
| inline DataSize operator*(const TimeDelta duration, const DataRate rate) { |
| return rate * duration; |
| } |
| |
| std::string ToString(DataRate value); |
| |
| #ifdef UNIT_TEST |
| inline std::ostream& operator<<( // no-presubmit-check TODO(webrtc:8982) |
| std::ostream& stream, // no-presubmit-check TODO(webrtc:8982) |
| DataRate value) { |
| return stream << ToString(value); |
| } |
| #endif // UNIT_TEST |
| |
| } // namespace webrtc |
| |
| #endif // API_UNITS_DATA_RATE_H_ |