boss-timer/src/index.ts

Timer for node

function calculateDifference (t1:Array<number>, t2:Array<number>): Array<number> {
  return [ t1[0] - t2[0], t1[1] - t2[1] ]
}

function addTimes (t1:Array<number>, t2:Array<number>): Array<number> {
  return [ t1[0] + t2[0], t1[1] + t2[1] ]
}

export class Timer {
  private version: string = "0.1.0";
  // 
  public start_time: Array<number> = null
  public intervals: Array<number> = []
  public total : Array<number> = [0,0]
  public end_time: Array<number> = null
  public split_times: Array<Array<number>> = []
  public debug:boolean = false
  public running:boolean = false
  
  /**
   * Constructor for the class
   * @param {boolean} start? - Optional: starts the time on creation of the class
   * @returns {Timer} this returns itself to allow command chaining
   */
  constructor(start: boolean) {
    if (start !== false) {
      this.start_time = process.hrtime()
      this.running = true
    }
  }
  
  /**
   * Starts the timer
   * @returns {Timer} this returns itself to allow command chaining
   */
  start(): Timer {
    if (!this.running) {
      this.start_time = process.hrtime()
      this.running = true
    } else {
      if(this.debug) console.log('[boss-timer] Timer already running')
    }
    return this

  }
   
  /**
   * Stops the timer
   * @returns {Timer} this returns itself to allow command chaining
   */
  stop(): Timer {
    if(!this.running){
      if(this.debug){
        console.log('[boss-timer] Timer is not running')
      }
    } else {
      this.end_time = process.hrtime()
    }
    this.total = calculateDifference(this.end_time, this.start_time)
    this.end_time = null
    this.start_time = null
    this.running = false
    return this
  }
  
  /**
   * Creates a split time in the timer
   * @returns {Timer} this returns itself to allow command chaining
   */
  split(): Timer {
    this.split_times.push(process.hrtime())
    return this
  }
  /**
   * Returns the elapsed time between when the timer was started and the end time, or the time elapsed so far
   * @param {number} split? array index of the the split time from which to calculate the elapsed time from the start time
   * @returns {number} time in miliseconds that have elapsed
   */
  elapsed(split?: number): Array<number> {
    var time: Array<number> = []
    if (split && this.split_times.length > 0) {
      if (split === -1) { // get last split
        time = calculateDifference(this.split_times[this.split_times.length - 1],  this.start_time)
      } else {
        if (typeof this.split_times[split] !== 'undefined') {
          time = calculateDifference( this.split_times[split], this.start_time)
        } else {
          if(this.debug){
            console.log('[boss-timer] Split time of index:"' + split + '" not found!')
          }
        }
      }
    } else if(split && this.split_times.length){
      if(this.debug){
        console.log('[boss-timer] No split times')
      }      
    } else if (!this.running) {
      time = this.total
    } else {
      time = addTimes(this.total, process.hrtime(this.start_time))
    }
    return time
  }
  /**
   * Renders the time in a human redable format
   * @param {Array<number>} time? time to render
   * @returns {string} returns the time as a string with the correct time denominator
   */
  render(time?:Array<number>): string {
    var timeToRender = time || this.elapsed()
    var ns = timeToRender[0] * 1e9 + timeToRender[1]
    var ms = ns / 1e6
    var s = ns / 1e9
    if (ns < 1000) {
      return ns + 'ns'
    }
    if (ms < 1000) {
      return ms.toFixed(2) + 'ms'
    }
    return s.toFixed(2) + 's'
  }
}