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 <stdint.h> |
9 | #include <time.h> |
10 | |
11 | #include <chrono> |
12 | #include <iosfwd> |
13 | #include <limits> |
14 | |
15 | namespace fml { |
16 | |
17 | using namespace std::chrono_literals; |
18 | |
19 | using Milliseconds = std::chrono::duration<double, std::milli>; |
20 | |
21 | // Default to 60fps. |
22 | constexpr Milliseconds kDefaultFrameBudget = Milliseconds(1s) / 60; |
23 | |
24 | template <typename T> |
25 | Milliseconds RefreshRateToFrameBudget(T refresh_rate) { |
26 | return Milliseconds(1s) / refresh_rate; |
27 | } |
28 | |
29 | // A TimeDelta represents the difference between two time points. |
30 | class TimeDelta { |
31 | public: |
32 | constexpr TimeDelta() = default; |
33 | |
34 | static constexpr TimeDelta Zero() { return TimeDelta(); } |
35 | static constexpr TimeDelta Min() { |
36 | return TimeDelta(std::numeric_limits<int64_t>::min()); |
37 | } |
38 | static constexpr TimeDelta Max() { |
39 | return TimeDelta(std::numeric_limits<int64_t>::max()); |
40 | } |
41 | static constexpr TimeDelta FromNanoseconds(int64_t nanos) { |
42 | return TimeDelta(nanos); |
43 | } |
44 | static constexpr TimeDelta FromMicroseconds(int64_t micros) { |
45 | return FromNanoseconds(micros * 1000); |
46 | } |
47 | static constexpr TimeDelta FromMilliseconds(int64_t millis) { |
48 | return FromMicroseconds(millis * 1000); |
49 | } |
50 | static constexpr TimeDelta FromSeconds(int64_t seconds) { |
51 | return FromMilliseconds(seconds * 1000); |
52 | } |
53 | |
54 | static constexpr TimeDelta FromSecondsF(double seconds) { |
55 | return FromNanoseconds(seconds * (1000.0 * 1000.0 * 1000.0)); |
56 | } |
57 | |
58 | static constexpr TimeDelta FromMillisecondsF(double millis) { |
59 | return FromNanoseconds(millis * (1000.0 * 1000.0)); |
60 | } |
61 | |
62 | constexpr int64_t ToNanoseconds() const { return delta_; } |
63 | constexpr int64_t ToMicroseconds() const { return ToNanoseconds() / 1000; } |
64 | constexpr int64_t ToMilliseconds() const { return ToMicroseconds() / 1000; } |
65 | constexpr int64_t ToSeconds() const { return ToMilliseconds() / 1000; } |
66 | |
67 | constexpr double ToNanosecondsF() const { return delta_; } |
68 | constexpr double ToMicrosecondsF() const { return delta_ / 1000.0; } |
69 | constexpr double ToMillisecondsF() const { |
70 | return delta_ / (1000.0 * 1000.0); |
71 | } |
72 | constexpr double ToSecondsF() const { |
73 | return delta_ / (1000.0 * 1000.0 * 1000.0); |
74 | } |
75 | |
76 | constexpr TimeDelta operator-(TimeDelta other) const { |
77 | return TimeDelta::FromNanoseconds(delta_ - other.delta_); |
78 | } |
79 | |
80 | constexpr TimeDelta operator+(TimeDelta other) const { |
81 | return TimeDelta::FromNanoseconds(delta_ + other.delta_); |
82 | } |
83 | |
84 | constexpr TimeDelta operator/(int64_t divisor) const { |
85 | return TimeDelta::FromNanoseconds(delta_ / divisor); |
86 | } |
87 | |
88 | constexpr int64_t operator/(TimeDelta other) const { |
89 | return delta_ / other.delta_; |
90 | } |
91 | |
92 | constexpr TimeDelta operator*(int64_t multiplier) const { |
93 | return TimeDelta::FromNanoseconds(delta_ * multiplier); |
94 | } |
95 | |
96 | constexpr TimeDelta operator%(TimeDelta other) const { |
97 | return TimeDelta::FromNanoseconds(delta_ % other.delta_); |
98 | } |
99 | |
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 | bool operator>=(TimeDelta other) const { return delta_ >= other.delta_; } |
106 | |
107 | static constexpr TimeDelta FromTimespec(struct timespec ts) { |
108 | return TimeDelta::FromSeconds(ts.tv_sec) + |
109 | TimeDelta::FromNanoseconds(ts.tv_nsec); |
110 | } |
111 | struct timespec ToTimespec() { |
112 | struct timespec ts; |
113 | constexpr int64_t kNanosecondsPerSecond = 1000000000ll; |
114 | ts.tv_sec = static_cast<time_t>(ToSeconds()); |
115 | ts.tv_nsec = delta_ % kNanosecondsPerSecond; |
116 | return ts; |
117 | } |
118 | |
119 | private: |
120 | // Private, use one of the FromFoo() types |
121 | explicit constexpr TimeDelta(int64_t delta) : delta_(delta) {} |
122 | |
123 | int64_t delta_ = 0; |
124 | }; |
125 | |
126 | } // namespace fml |
127 | |
128 | #endif // FLUTTER_FML_TIME_TIME_DELTA_H_ |
129 |