Performance monitor in javascript

fps.js

var __LAST_CALLED_TIME__ = 0;

function requestAnimFrame() {
  if(!__LAST_CALLED_TIME__) {
     __LAST_CALLED_TIME__ = Date.now()
     return 0
  }
  var delta = (Date.now() - __LAST_CALLED_TIME__)/1000
  __LAST_CALLED_TIME__ = Date.now()
  console.log('fps = ', 1/delta)
  return 1/delta
}

perf-es6.js

/**
 *  @example
 *  var perf = new DevicePerf()
 *
 *  // When you init this Function will auto added a record named 'init'. You can change it on construtor. For example: new DevicePerf('MY_CUSTOM_NAME')
 *  perf.add('MY_FIRST_RECORD')
 *  perf.add('MY_SECUND_RECORD')
 * 
 *  // print record history and total time.
 *  perf.report()
 *
 *  // clear records
 *  perf.clear() // clear all records and add init
 *  perf.clear(true) // clear all records
 */
class DevicePerf {
    constructor(firstRecordName) {
        this.history = []
        this.firstRecordName = typeof(firstRecordName) === 'string' ? firstRecordName : 'init'
    }

    add (name = '') {
        name = String(name)
        this.history.push({
            name: name,
            ts: Date.now()
        })
    }
  
    clear(isEmpty = null) {
        this.history = []
        if(!isEmpty) this.add(this.firstRecordName)
    }
  
    report(isMute = null) {
        let len = history.length
        if(len < 2) return 'Record is less than 2'
        let result = { histroy: [] }
        let firstPoint = history[0]
        let lastPoint = history[len-1]
        let platform = null
        try {
            platform = WXEnvironment.platform
        }catch(e){}
    
        for(let i = 0; i < len-1; i++) {
            let p1 = history[i]
            let p2 = history[i+1]
            let obj = {
                from: p1.name,
                to: p2.name,
                time: p2.ts - p1.ts
            }
            this.log(obj, false, isMute)
            result.histroy.push(obj)
        }
        result.total = {
            from: firstPoint.name,
            to: lastPoint.name,
            time: lastPoint.ts - firstPoint.ts
        }
        this.log(result.total, true, isMute)
        return result

    }
  
    log (obj = {}, isTotal = false, isMute = false) {
        const logger = platform && platform === 'android' ? nativeLog : console.log
        const prefix = !!isTotal ? 'Total' : '     '
        !isMute && logger(prefix, 'from [', obj.from, '] to [', obj.to, ']:', obj.time)
    }
  
    get toString() {
        return this.report(true)
    }
}

perf.js

/**
 *  @example
 *  var perf = new DevicePerf()
 *
 *  // When you init this Function will auto added a record named 'init'. You can change it on construtor. For example: new DevicePerf('MY_CUSTOM_NAME')
 *  perf.add('MY_FIRST_RECORD')
 *  perf.add('MY_SECUND_RECORD')
 * 
 *  // print record history and total time.
 *  perf.report()
 *
 *  // clear records
 *  perf.clear() // clear all records and add init
 *  perf.clear(true) // clear all records
 */
function DevicePerf(firstRecordName) {
    var history = []
    firstRecordName = typeof(firstRecordName) === 'string' ? firstRecordName : 'init'

    Object.defineProperty(this, 'add', {
        value: function(name) {
            name = String(name)
            var obj = {
                name: name,
                ts: Date.now()
            }
            history.push(obj)
        }
    })

    Object.defineProperty(this, 'clear', {
        value: function(isEmpty) {
            history = []
            if(!isEmpty) this.add(firstRecordName)
        }
    })

    Object.defineProperty(this, 'report', {
        value: function(isMute) {
            var len = history.length
            if(len < 2) return 'Record is less than 2'
            var result = { histroy: [] }
            var firstPoint = history[0]
            var lastPoint = history[len-1]
            var platform = null
            try {
                platform = WXEnvironment.platform
            }catch(e){}
            var logformat = function(obj, isTotal) {
                var log = platform && platform === 'android' ? nativeLog : console.log
                var prefix = !!isTotal ? 'Total' : '     '
                !isMute && log(prefix, 'from [', obj.from, '] to [', obj.to, ']:', obj.time)
            }

            for(var i = 0; i < len-1; i++) {
                var p1 = history[i]
                var p2 = history[i+1]
                var obj = {
                    from: p1.name,
                    to: p2.name,
                    time: p2.ts - p1.ts
                }
                logformat(obj)
                result.histroy.push(obj)
            }
            result.total = {
                from: firstPoint.name,
                to: lastPoint.name,
                time: lastPoint.ts - firstPoint.ts
            }
            logformat(result.total, true)
            return result
        }
    })
    
    Object.defineProperty(this, 'toString', {
        value: function() {
            return this.report(true)
        }
    })

    this.add(firstRecordName)
}