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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef FLUTTER_FML_TIME_TIME_DELTA_H_
#define FLUTTER_FML_TIME_TIME_DELTA_H_
#include <chrono>
#include <cstdint>
#include <ctime>
#include <iosfwd>
#include <limits>
namespace fml {
using namespace std::chrono_literals;
using Milliseconds = std::chrono::duration<double, std::milli>;
// Default to 60fps.
constexpr Milliseconds kDefaultFrameBudget = Milliseconds(1s) / 60;
template <typename T>
Milliseconds RefreshRateToFrameBudget(T refresh_rate) {
return Milliseconds(1s) / refresh_rate;
}
// A TimeDelta represents the difference between two time points.
class TimeDelta {
public:
constexpr TimeDelta() = default;
static constexpr TimeDelta Zero() { return TimeDelta(); }
static constexpr TimeDelta Min() {
return TimeDelta(std::numeric_limits<int64_t>::min());
}
static constexpr TimeDelta Max() {
return TimeDelta(std::numeric_limits<int64_t>::max());
}
static constexpr TimeDelta FromNanoseconds(int64_t nanos) {
return TimeDelta(nanos);
}
static constexpr TimeDelta FromMicroseconds(int64_t micros) {
return FromNanoseconds(micros * 1000);
}
static constexpr TimeDelta FromMilliseconds(int64_t millis) {
return FromMicroseconds(millis * 1000);
}
static constexpr TimeDelta FromSeconds(int64_t seconds) {
return FromMilliseconds(seconds * 1000);
}
static constexpr TimeDelta FromSecondsF(double seconds) {
return FromNanoseconds(seconds * (1000.0 * 1000.0 * 1000.0));
}
static constexpr TimeDelta FromMillisecondsF(double millis) {
return FromNanoseconds(millis * (1000.0 * 1000.0));
}
constexpr int64_t ToNanoseconds() const { return delta_; }
constexpr int64_t ToMicroseconds() const { return ToNanoseconds() / 1000; }
constexpr int64_t ToMilliseconds() const { return ToMicroseconds() / 1000; }
constexpr int64_t ToSeconds() const { return ToMilliseconds() / 1000; }
constexpr double ToNanosecondsF() const { return delta_; }
constexpr double ToMicrosecondsF() const { return delta_ / 1000.0; }
constexpr double ToMillisecondsF() const {
return delta_ / (1000.0 * 1000.0);
}
constexpr double ToSecondsF() const {
return delta_ / (1000.0 * 1000.0 * 1000.0);
}
constexpr TimeDelta operator-(TimeDelta other) const {
return TimeDelta::FromNanoseconds(delta_ - other.delta_);
}
constexpr TimeDelta operator+(TimeDelta other) const {
return TimeDelta::FromNanoseconds(delta_ + other.delta_);
}
constexpr TimeDelta operator/(int64_t divisor) const {
return TimeDelta::FromNanoseconds(delta_ / divisor);
}
constexpr int64_t operator/(TimeDelta other) const {
return delta_ / other.delta_;
}
constexpr TimeDelta operator*(int64_t multiplier) const {
return TimeDelta::FromNanoseconds(delta_ * multiplier);
}
constexpr TimeDelta operator%(TimeDelta other) const {
return TimeDelta::FromNanoseconds(delta_ % other.delta_);
}
bool operator==(TimeDelta other) const { return delta_ == other.delta_; }
bool operator!=(TimeDelta other) const { return delta_ != other.delta_; }
bool operator<(TimeDelta other) const { return delta_ < other.delta_; }
bool operator<=(TimeDelta other) const { return delta_ <= other.delta_; }
bool operator>(TimeDelta other) const { return delta_ > other.delta_; }
bool operator>=(TimeDelta other) const { return delta_ >= other.delta_; }
static constexpr TimeDelta FromTimespec(struct timespec ts) {
return TimeDelta::FromSeconds(ts.tv_sec) +
TimeDelta::FromNanoseconds(ts.tv_nsec);
}
struct timespec ToTimespec() {
struct timespec ts;
constexpr int64_t kNanosecondsPerSecond = 1000000000ll;
ts.tv_sec = static_cast<time_t>(ToSeconds());
ts.tv_nsec = delta_ % kNanosecondsPerSecond;
return ts;
}
private:
// Private, use one of the FromFoo() types
explicit constexpr TimeDelta(int64_t delta) : delta_(delta) {}
int64_t delta_ = 0;
};
} // namespace fml
#endif // FLUTTER_FML_TIME_TIME_DELTA_H_