1 | // Copyright 2013 The Flutter Authors. All rights reserved. |
---|---|
2 | // Use of this source code is governed by a BSD-style license that can be |
3 | // found in the LICENSE file. |
4 | |
5 | #ifndef FLUTTER_FML_TIME_TIME_DELTA_H_ |
6 | #define FLUTTER_FML_TIME_TIME_DELTA_H_ |
7 | |
8 | #include <chrono> |
9 | #include <cstdint> |
10 | #include <ctime> |
11 | #include <iosfwd> |
12 | #include <limits> |
13 | |
14 | namespace fml { |
15 | |
16 | using namespace std::chrono_literals; |
17 | |
18 | using Milliseconds = std::chrono::duration<double, std::milli>; |
19 | |
20 | // Default to 60fps. |
21 | constexpr Milliseconds kDefaultFrameBudget = Milliseconds(1s) / 60; |
22 | |
23 | template <typename T> |
24 | Milliseconds RefreshRateToFrameBudget(T refresh_rate) { |
25 | return Milliseconds(1s) / refresh_rate; |
26 | } |
27 | |
28 | // A TimeDelta represents the difference between two time points. |
29 | class TimeDelta { |
30 | public: |
31 | constexpr TimeDelta() = default; |
32 | |
33 | static constexpr TimeDelta Zero() { return TimeDelta(); } |
34 | static constexpr TimeDelta Min() { |
35 | return TimeDelta(std::numeric_limits<int64_t>::min()); |
36 | } |
37 | static constexpr TimeDelta Max() { |
38 | return TimeDelta(std::numeric_limits<int64_t>::max()); |
39 | } |
40 | static constexpr TimeDelta FromNanoseconds(int64_t nanos) { |
41 | return TimeDelta(nanos); |
42 | } |
43 | static constexpr TimeDelta FromMicroseconds(int64_t micros) { |
44 | return FromNanoseconds(nanos: micros * 1000); |
45 | } |
46 | static constexpr TimeDelta FromMilliseconds(int64_t millis) { |
47 | return FromMicroseconds(micros: millis * 1000); |
48 | } |
49 | static constexpr TimeDelta FromSeconds(int64_t seconds) { |
50 | return FromMilliseconds(millis: seconds * 1000); |
51 | } |
52 | |
53 | static constexpr TimeDelta FromSecondsF(double seconds) { |
54 | return FromNanoseconds(nanos: seconds * (1000.0 * 1000.0 * 1000.0)); |
55 | } |
56 | |
57 | static constexpr TimeDelta FromMillisecondsF(double millis) { |
58 | return FromNanoseconds(nanos: millis * (1000.0 * 1000.0)); |
59 | } |
60 | |
61 | constexpr int64_t ToNanoseconds() const { return delta_; } |
62 | constexpr int64_t ToMicroseconds() const { return ToNanoseconds() / 1000; } |
63 | constexpr int64_t ToMilliseconds() const { return ToMicroseconds() / 1000; } |
64 | constexpr int64_t ToSeconds() const { return ToMilliseconds() / 1000; } |
65 | |
66 | constexpr double ToNanosecondsF() const { return delta_; } |
67 | constexpr double ToMicrosecondsF() const { return delta_ / 1000.0; } |
68 | constexpr double ToMillisecondsF() const { |
69 | return delta_ / (1000.0 * 1000.0); |
70 | } |
71 | constexpr double ToSecondsF() const { |
72 | return delta_ / (1000.0 * 1000.0 * 1000.0); |
73 | } |
74 | |
75 | constexpr TimeDelta operator-(TimeDelta other) const { |
76 | return TimeDelta::FromNanoseconds(nanos: delta_ - other.delta_); |
77 | } |
78 | |
79 | constexpr TimeDelta operator+(TimeDelta other) const { |
80 | return TimeDelta::FromNanoseconds(nanos: delta_ + other.delta_); |
81 | } |
82 | |
83 | constexpr TimeDelta operator/(int64_t divisor) const { |
84 | return TimeDelta::FromNanoseconds(nanos: delta_ / divisor); |
85 | } |
86 | |
87 | constexpr int64_t operator/(TimeDelta other) const { |
88 | return delta_ / other.delta_; |
89 | } |
90 | |
91 | constexpr TimeDelta operator*(int64_t multiplier) const { |
92 | return TimeDelta::FromNanoseconds(nanos: delta_ * multiplier); |
93 | } |
94 | |
95 | constexpr TimeDelta operator%(TimeDelta other) const { |
96 | return TimeDelta::FromNanoseconds(nanos: delta_ % other.delta_); |
97 | } |
98 | |
99 | bool operator==(TimeDelta other) const { return delta_ == other.delta_; } |
100 | bool operator!=(TimeDelta other) const { return delta_ != other.delta_; } |
101 | bool operator<(TimeDelta other) const { return delta_ < other.delta_; } |
102 | bool operator<=(TimeDelta other) const { return delta_ <= other.delta_; } |
103 | bool operator>(TimeDelta other) const { return delta_ > other.delta_; } |
104 | bool operator>=(TimeDelta other) const { return delta_ >= other.delta_; } |
105 | |
106 | static constexpr TimeDelta FromTimespec(struct timespec ts) { |
107 | return TimeDelta::FromSeconds(seconds: ts.tv_sec) + |
108 | TimeDelta::FromNanoseconds(nanos: ts.tv_nsec); |
109 | } |
110 | struct timespec ToTimespec() { |
111 | struct timespec ts; |
112 | constexpr int64_t kNanosecondsPerSecond = 1000000000ll; |
113 | ts.tv_sec = static_cast<time_t>(ToSeconds()); |
114 | ts.tv_nsec = delta_ % kNanosecondsPerSecond; |
115 | return ts; |
116 | } |
117 | |
118 | private: |
119 | // Private, use one of the FromFoo() types |
120 | explicit constexpr TimeDelta(int64_t delta) : delta_(delta) {} |
121 | |
122 | int64_t delta_ = 0; |
123 | }; |
124 | |
125 | } // namespace fml |
126 | |
127 | #endif // FLUTTER_FML_TIME_TIME_DELTA_H_ |
128 |