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//! Streaming Rate Window Demo
//!
//! Demonstrates a simple streaming workload updating a `RateMeter` and
//! printing the observed rate periodically over a short window.
//!
//! Run with:
//! cargo run --example streaming_rate_window --release
use metrics_lib::{init, metrics};
use rand::{rngs::StdRng, Rng, SeedableRng};
use std::time::Duration;
#[tokio::main(flavor = "current_thread")]
async fn main() {
init();
let r = metrics().rate("demo.stream.rps");
let mut rng = StdRng::seed_from_u64(42);
// Producer task: generate ticks with light burstiness
let producer = tokio::spawn(async move {
let mut t = tokio::time::interval(Duration::from_millis(10));
for _ in 0..400u32 {
// ~4 seconds
t.tick().await;
let n = 1 + (rng.gen::<u8>() % 5) as u32; // 1..=5 ticks
r.tick_n(n);
}
});
// Reporter: sample and print current rate
let reporter = tokio::spawn(async move {
let mut t = tokio::time::interval(Duration::from_millis(250));
for _ in 0..16 {
// ~4 seconds
t.tick().await;
let rate = metrics().rate("demo.stream.rps").rate();
println!("stream rate ~{rate:.2} events/sec");
}
});
let _ = tokio::join!(producer, reporter);
}