ledown/src/TaskMeta.js

A library for nodejs to download http large file in pauseable and resumable way

/** @flow */
import ByteSheet, { type ByteRange } from './ByteSheet'

export default class TaskMeta {
  url: string = ''
  createDate: Date = null
  mimeType: string = ''
  downloadPath: string = ''
  totalBytes: number = 0
  resumable: boolean = false
  byteSheet: ByteSheet = null

  constructor (param: {
    url: string,
    mimeType: string,
    downloadPath: string,
    totalBytes: number,
    resumable: boolean,
    createDate?: number,
    refererUrl?: string,
    byteSheet?: Array<ByteRange[]>
  }) {
    Object.assign(this, param)
    const { createDate, byteSheet } = param
    if (createDate) {
      this.createDate = new Date(createDate)
    } else {
      this.createDate = new Date()
    }

    if (byteSheet && this.resumable) {
      this.byteSheet = new ByteSheet(byteSheet)
    } else {
      this.byteSheet = new ByteSheet(param.totalBytes)
    }
  }

  allocRange (size: number): ByteRange {
    if (!this.resumable) {
      size = this.totalBytes
    }
    return this.byteSheet.allocRangeToDownload(size)
  }

  completeRange (range: ByteRange): void {
    return this.byteSheet.setRangeAsCompleted(range)
  }

  resetDownloadingRange (): void {
    return this.byteSheet.resetDownloading()
  }

  get progress (): number {
    return this.completedByteCount / this.totalBytes
  }

  get remainingByteCount (): number {
    return this.byteSheet.remainingByteCount
  }

  get completedByteCount (): number {
    return this.byteSheet.completedByteCount
  }

  get downloadingByteCount (): number {
    return this.byteSheet.downloadingByteCount
  }

  toJSONObject (): Object {
    return {
      url: this.url,
      refererUrl: this.refererUrl,
      mimeType: this.mimeType,
      resumable: this.resumable,
      downloadPath: this.downloadPath,
      totalBytes: this.totalBytes,
      createDate: this.createDate.valueOf(),
      byteSheet: this.byteSheet.toJSONObject()
    }
  }
}