複数の関数の実行時間計測

measure.js

export default (fns, measure_count, effective_rate) => {
	const data = []

	for (let i = 0; i < measure_count; i++) {
		for (const [fn_index, fn] of fns.entries()) {
			if (!data[fn_index]) {
				data[fn_index] = []
			}

			const start = performance.now()
			fn()
			const end = performance.now()
			data[fn_index].push(end - start)
		}
	}

	return data.map((fn_data, fn_index) => {
		return {
			name: fns[fn_index].name,
			...agg(fn_data, effective_rate),
		}
	})
}

const agg = (data, effective_rate) => {
	const sorted = data.sort((a, b) => a - b)
	const max = sorted.at(-1)
	const times = getEffective(sorted, effective_rate)
	const num = times.length
	const range = [times[0], times.at(-1)]
	const avg = times.reduce((a, b) => a + b, 0) / num
	const med = num % 2 === 0 ? ((times[num / 2] + times[num / 2 - 1]) / 2) : times[~~(num / 2)]
	return { range, max, avg, med, num }
}

const getEffective = (data, rate) => {
	const fixed_rate = Math.max(0, Math.min(100, rate))
	const effective_num = ~~(data.length * fixed_rate / 100)
	const remove_num = data.length - effective_num
	const edge = ~~(remove_num / 2)
	return data.slice(edge, edge + effective_num)
}