vor 0.2.0

Cross-platform performance instrumentation with an in-app egui panel and live system and GPU metrics.
Documentation 
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use hdrhistogram::Histogram;

/// Streaming p50 / p95 / p99 over per-frame nanosecond samples.
pub struct FrameStats {
    histogram: Histogram<u64>,
}

impl FrameStats {
    pub fn new() -> Self {
        Self {
            histogram: Histogram::new(3).unwrap(),
        }
    }

    pub fn record_ns(&mut self, ns: u64) {
        self.histogram.record(ns).unwrap();
    }

    pub fn count(&self) -> u64 {
        self.histogram.len()
    }

    pub fn p50_ns(&self) -> u64 {
        self.histogram.value_at_quantile(0.5)
    }

    pub fn p95_ns(&self) -> u64 {
        self.histogram.value_at_quantile(0.95)
    }

    pub fn p99_ns(&self) -> u64 {
        self.histogram.value_at_quantile(0.99)
    }

    pub fn mean_ns(&self) -> f64 {
        self.histogram.mean()
    }

    pub fn clear(&mut self) {
        self.histogram.reset();
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn frame_stats_percentiles() {
        let mut s = FrameStats::new();
        for i in 1..=1000u64 {
            s.record_ns(i * 1_000);
        }
        assert!((490_000..=510_000).contains(&s.p50_ns()));
        assert!((980_000..=1_000_000).contains(&s.p99_ns()));
    }
}