1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171

use std::collections::VecDeque;
use std::fmt::{Display, Formatter};
use std::sync::Arc;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::time::{Duration, Instant};


/// the number of nanoseconds in a microsecond.
pub const NANOSECONDS_PER_MICROSECOND: u64 = 1_000;

/// the number of nanoseconds in a millisecond.
pub const NANOSECONDS_PER_MILLISECOND: u64 = 1_000_000;

/// the number of nanoseconds in seconds.
pub const NANOSECONDS_PER_SECOND: u64 = 1_000_000_000;

/// the number of microseconds per second.
pub const MICROSECONDS_PER_SECOND: u64 = 1_000_000;

/// the number of milliseconds per second.
pub const MILLISECONDS_PER_SECOND: u64 = 1_000;

/// the number of seconds in a minute.
pub const SECONDS_PER_MINUTE: u64 = 60;

/// the number of seconds in an hour.
pub const SECONDS_PER_HOUR: u64 = 3_600;

/// the number of (non-leap) seconds in days.
pub const SECONDS_PER_DAY: u64 = 86_400;

/// the number of (non-leap) seconds in a week.
pub const SECONDS_PER_WEEK: u64 = 604_800;


#[derive(Debug, Clone, Copy)]
pub struct Stopwatch {
    elapsed: Duration, // the recorded elapsed duration before the most recent stopwatch start.
    started: Option<Instant>, // the instant at which it was started. when none, stopwatch is not running.
}

impl Stopwatch {
    pub fn new() -> Stopwatch {
        Stopwatch {
            elapsed: Duration::default(),
            started: None,
        }
    }

    pub fn start(&mut self) {
        if self.started == None {
            self.started = Some(Instant::now());
        }
    }

    pub fn started() -> Stopwatch {
        let mut stopwatch = Stopwatch::new();

        stopwatch.start();
        stopwatch
    }

    pub fn stop(&mut self) {
        if self.started != None {
            self.elapsed = self.elapsed();
            self.started = None;
        }
    }

    pub fn reset(&mut self) -> Duration {
        let elapsed = self.elapsed();

        self.elapsed = Duration::default();
        self.started = self.started.map(|_| Instant::now());

        elapsed
    }

    pub fn restart(&mut self) {
        self.reset();
        self.start();
    }

    pub fn running(&self) -> bool {
        self.started != None
    }

    pub fn elapsed(&self) -> Duration {
        match self.started {
            Some(started) => started.elapsed() + self.elapsed,
            None => self.elapsed,
        }
    }

    pub fn elapsed_seconds(&self) -> u64 {
        self.elapsed().as_secs()
    }

    pub fn elapsed_milliseconds(&self) -> u128 {
        self.elapsed().as_millis()
    }

    pub fn elapsed_microseconds(&self) -> u128 {
        self.elapsed().as_micros()
    }

    pub fn elapsed_nanoseconds(&self) -> u128 {
        self.elapsed().as_nanos()
    }
}

impl Default for Stopwatch {
    fn default() -> Stopwatch {
        Stopwatch::new()
    }
}

impl Display for Stopwatch {
    fn fmt(&self, formatter: &mut Formatter) -> Result<(), std::fmt::Error> {
        write!(formatter, "{:?}", self.elapsed())
    }
}


// a simple fps counter.
pub struct FpsClock {
    queue: VecDeque<Instant>,
    frames: Arc<AtomicUsize>,
}

impl FpsClock {
    pub fn new() -> FpsClock {
        FpsClock {
            queue: VecDeque::with_capacity(1024),
            frames: Arc::new(AtomicUsize::new(0)),
        }
    }

    pub fn update(&mut self) {
        let now = Instant::now();
        let previous = now - Duration::from_secs(1);

        self.queue.push_back(now);

        while self.queue.front().map(|x| *x < previous).unwrap_or(false) {
            self.queue.pop_front();
        }

        self.frames.store(self.queue.len(), Ordering::Relaxed);
    }

    pub fn client(&self) -> Fps {
        Fps {
            frames: self.frames.clone(),
        }
    }

    pub fn fps(&self) -> usize {
        self.frames.load(Ordering::Relaxed)
    }
}

pub struct Fps {
    frames: Arc<AtomicUsize>,
}

impl Fps {
    pub fn value(&self) -> usize {
        self.frames.load(Ordering::Relaxed)
    }
}