Rate limit guard
Lazy rate limit semaphore (a.k.a fixed window algorithm without queueing) implementation to control your asynchronous code frequency execution
Documentation: lib.rs/raliguard
Overview
use std::{thread, sync, time};
use raliguard::Semaphore;
// Create a semaphore with restriction `5 tasks per 1 second`
let originl_sem = Semaphore::new(5, time::Duration::from_secs(1));
// Make it sharable between treads (or you can share between tasks)
let shared_sem = sync::Arc::new(
sync::Mutex::new(originl_sem)
);
// This is a counter that increments when a thread completed
let shared_done_count = sync::Arc::new(sync::Mutex::new(0));
// Spawn 15 threads
for _ in 0..15 {
let cloned_sem = shared_sem.clone();
let cloned_done_state = shared_done_count.clone();
let thread = thread::spawn(move || {
let mut local_sem = cloned_sem.lock().unwrap();
// Get required delay
let calculated_delay = local_sem.calc_delay();
drop(local_sem);
// If delay exists, sleep it
if let Some(delay) = calculated_delay {
dbg!(&delay);
thread::sleep(delay);
}
// Mark the thread is done
let mut local_done_count = cloned_done_state.lock().unwrap();
*local_done_count += 1;
});
}
// So sleep 1 second (add some millis to let threads complete incrementing)
thread::sleep(time::Duration::from_secs(1) + time::Duration::from_millis(50));
let cloned_done_count = shared_done_count.clone();
let current_done = cloned_done_count.lock().unwrap();
// And then maximum 10 threads should be completed
// after 1 second sleeping
// (the first 5 with no delay and the another 5 after 1 second)
assert_eq!(*current_done, 10);
Features
- Calculated delay for sleep can be used with any async/await runtime backend or with threads
- Minimum memory used to save calls data