Throttled‑Tracing Crate of the Week

// This program demonstrates a simple throttled logging mechanism.
// It prints a message only once every 5 calls to `log_throttled!`.
// The `throttled-tracing` crate is not available in this sandbox,
// so we implement the core idea manually using a static counter.

use std::sync::atomic::{AtomicUsize, Ordering};
use std::time::{Duration, Instant};

static CALL_COUNT: AtomicUsize = AtomicUsize::new(0);
static LAST_LOG: AtomicUsize = AtomicUsize::new(0);

/// Log a message only if at least `interval` calls have occurred
/// since the last log. This mimics the behaviour of the
/// `throttled_info!` macro from `throttled-tracing`.
macro_rules! log_throttled {
    ($interval:expr, $msg:expr) => {{
        let count = CALL_COUNT.fetch_add(1, Ordering::SeqCst) + 1;
        let last = LAST_LOG.load(Ordering::SeqCst);
        if count - last >= $interval {
            println!("[throttled] {}", $msg);
            LAST_LOG.store(count, Ordering::SeqCst);
        }
    }};
}

fn main() {
    // Simulate many log calls
    for i in 1..=20 {
        log_throttled!(5, format!("Iteration {}", i));
    }
}