Trait MetricsSink

Source

pub trait MetricsSink:
    Send
    + Sync
    + 'static {
    // Required methods
    fn counter(&self, name: &str, labels: &[(&str, &str)], value: u64);
    fn gauge(&self, name: &str, labels: &[(&str, &str)], value: f64);
    fn histogram(&self, name: &str, labels: &[(&str, &str)], value: f64);

    // Provided method
    fn inc(&self, name: &str) { ... }
}

Expand description

Push-based metrics interface.

Implementors are called from the framework’s hot path on every observable event, so they must be fast and lock-light. Allocation per call is acceptable — the framework doesn’t claim a fixed per-event budget — but blocking on I/O is not. Async sinks should drop events into a channel and process them on a separate task.

Send + Sync + 'static so an Arc<dyn MetricsSink> lives across supervised services.

§Example

A simple in-process counting sink, useful for tests and embedded dashboards.

use std::collections::HashMap;
use std::sync::Mutex;
use rustrade_core::MetricsSink;

#[derive(Default)]
struct CountingSink {
    counters: Mutex<HashMap<String, u64>>,
}

impl MetricsSink for CountingSink {
    fn counter(&self, name: &str, _labels: &[(&str, &str)], value: u64) {
        *self.counters.lock().unwrap().entry(name.into()).or_insert(0) += value;
    }
    fn gauge(&self, _name: &str, _labels: &[(&str, &str)], _value: f64) {}
    fn histogram(&self, _name: &str, _labels: &[(&str, &str)], _value: f64) {}
}

let sink = CountingSink::default();
sink.counter("rustrade_fills_routed_total", &[], 1);
sink.inc("rustrade_fills_routed_total");
assert_eq!(sink.counters.lock().unwrap()["rustrade_fills_routed_total"], 2);