import { monitorEventLoopDelay } from 'node:perf_hooks';

let started = false;
export function startPerformanceMonitor() {
    if (started || process.env.EC_PERF_LOG !== 'true') return;
    started = true;
    const delay = monitorEventLoopDelay({ resolution: 20 }); delay.enable();
    setInterval(() => {
        console.info('[performance]', { eventLoopP95Ms: Math.round(delay.percentile(95) / 1e6),
            eventLoopMaxMs: Math.round(delay.max / 1e6), rssMiB: Math.round(process.memoryUsage().rss / 1048576) });
        delay.reset();
    }, 60_000).unref();
}