Perf class

Perf.js

class Perf {
  constructor () {
    this.init()
    this.phases = []
  }

  init () {
    const now = Date.now()
    this.start = now
    this.lastTime = now
  }

  getPhaseTime () {
    const now = Date.now()
    const phaseTime = now - this.lastTime
    this.lastTime = now
    return phaseTime
  }

  markPhase (label) {
    this.phases.push({ label, time: this.getPhaseTime() })
  }

  getAllPhases () {
    let result = ''
    this.phases.forEach(({ label, time }) => {
      result += `${label}: ${time}ms\n`
    })
    return result
  }

  getFullTime () {
    return Date.now() - this.start
  }
}