File Explorer

1const EE = require('events')2const onProgress = Symbol('onProgress')3const bars = Symbol('bars')4const listener = Symbol('listener')5const normData = Symbol('normData')6class Client extends EE {7  constructor ({ normalize = false, stopOnDone = false } = {}) {8    super()9    this.normalize = !!normalize10    this.stopOnDone = !!stopOnDone11    this[bars] = new Map()12    this[listener] = null13  }14 15  get size () {16    return this[bars].size17  }18 19  get listening () {20    return !!this[listener]21  }22 23  addListener (...args) {24    return this.on(...args)25  }26 27  on (ev, ...args) {28    if (ev === 'progress' && !this[listener]) {29      this.start()30    }31    return super.on(ev, ...args)32  }33 34  off (ev, ...args) {35    return this.removeListener(ev, ...args)36  }37 38  removeListener (ev, ...args) {39    const ret = super.removeListener(ev, ...args)40    if (ev === 'progress' && this.listeners(ev).length === 0) {41      this.stop()42    }43    return ret44  }45 46  stop () {47    if (this[listener]) {48      process.removeListener('progress', this[listener])49      this[listener] = null50    }51  }52 53  start () {54    if (!this[listener]) {55      this[listener] = (...args) => this[onProgress](...args)56      process.on('progress', this[listener])57    }58  }59 60  [onProgress] (key, data) {61    data = this[normData](key, data)62    if (!this[bars].has(key)) {63      this.emit('bar', key, data)64    }65    this[bars].set(key, data)66    this.emit('progress', key, data)67    if (data.done) {68      this[bars].delete(key)69      this.emit('barDone', key, data)70      if (this.size === 0) {71        if (this.stopOnDone) {72          this.stop()73        }74        this.emit('done')75      }76    }77  }78 79  [normData] (key, data) {80    const actualValue = data.value81    const actualTotal = data.total82    let value = actualValue83    let total = actualTotal84    const done = data.done || value >= total85    if (this.normalize) {86      const bar = this[bars].get(key)87      total = 10088      if (done) {89        value = 10090      } else {91        // show value as a portion of 10092        const pct = 100 * actualValue / actualTotal93        if (bar) {94          // don't ever go backwards, and don't stand still95          // move at least 1% of the remaining value if it wouldn't move.96          value = (pct > bar.value) ? pct97            : (100 - bar.value) / 100 + bar.value98        }99      }100    }101    // include the key102    return {103      ...data,104      key,105      name: data.name || key,106      value,107      total,108      actualValue,109      actualTotal,110      done,111    }112  }113}114module.exports = Client115