interface Performance { start(mark: string);
end(mark: string);
dump();}
type Value = { mark: string; total: number; count: number; children: Value[];};
export default createPerformance();export function createPerformance(): Performance { const o = new Map<string, Value>(); const f = new Map<string, number>(); function start(mark: string) { f.set(mark, performance.now()); }
function end(mark: string) { const n = performance.now(); const s = f.get(mark) || n; let v = o.get(mark); if (!v) { v = { total: 0, count: 0, mark, children: [] }; o.set(mark, v); } v.total += n - s; v.count += 1; }
function dump() { for (const [k, v] of o.entries()) { const round = (v: number) => Math.round(v * 100) / 100; console.log( `${k}:\ttotal=${round(v.total)}ms\taverage=${round( v.total / v.count )}ms` ); } }
return { start, end, dump };}