A queue that drops its content after a given amount of time.
To implement an FPS counter, you could use the following technique:
use std::thread;
use std::time::Duration;
use ttl_queue::TtlQueue;
fn main() {
let mut fps_counter = TtlQueue::new(Duration::from_secs_f64(1.0));
for i in 0..100 {
// Register a new frame and return the number of frames observed
// within the last second.
let fps = fps_counter.refresh_and_push_back(());
debug_assert!(fps >= 1);
// Sleep 10 ms to achieve a ~100 Hz frequency.
thread::sleep(Duration::from_millis(10));
}
let fps = fps_counter.refresh();
debug_assert!(fps >= 95 && fps <= 105);
}