Golang ProgressBar.Set方法代碼示例

func (gd *GDrive) getMetadataChanges(svc *drive.Service, startChangeId int64,
	changeChan chan<- []*drive.Change, errorChan chan<- error) {
	var about *drive.About
	var err error

	// Get the Drive About information in order to figure out how many
	// changes we need to download to get up to date.
	for try := 0; ; try++ {
		about, err = svc.About.Get().Do()
		if err == nil {
			break
		} else {
			err = gd.tryToHandleDriveAPIError(err, try)
		}
		if err != nil {
			errorChan <- err
			return
		}
	}

	// Don't clutter the output with a progress bar unless it looks like
	// downloading changes may take a while.
	// TODO: consider using timer.AfterFunc to put up the progress bar if
	// we're not done after a few seconds?  It's not clear if this is worth
	// the trouble.
	var bar *pb.ProgressBar
	numChanges := about.LargestChangeId - startChangeId
	if numChanges > 1000 && !gd.quiet {
		bar = pb.New64(numChanges)
		bar.ShowBar = true
		bar.ShowCounters = false
		bar.Output = os.Stderr
		bar.Prefix("Updating metadata cache: ")
		bar.Start()
	}

	pageToken := ""
	try := 0
	// Keep asking Drive for more changes until we get through them all.
	for {
		// Only ask for the fields in the drive.Change structure that we
		// actually to be filled in to save some bandwidth...
		fields := []googleapi.Field{"nextPageToken",
			"items/id", "items/fileId", "items/deleted",
			"items/file/id", "items/file/parents", "items/file/title",
			"items/file/fileSize", "items/file/mimeType", "items/file/properties",
			"items/file/modifiedDate", "items/file/md5Checksum", "items/file/labels"}
		q := svc.Changes.List().MaxResults(1000).IncludeSubscribed(false).Fields(fields...)
		if startChangeId >= 0 {
			q = q.StartChangeId(startChangeId + 1)
		}
		if pageToken != "" {
			q = q.PageToken(pageToken)
		}

		r, err := q.Do()
		if err != nil {
			err = gd.tryToHandleDriveAPIError(err, try)
			if err != nil {
				errorChan <- err
				return
			}
			try++
			continue
		}

		// Success. Reset the try counter in case we had errors leading up
		// to this.
		try = 0

		if len(r.Items) > 0 {
			// Send the changes along to the goroutine that's updating the
			// local cache.
			changeChan <- r.Items

			if bar != nil {
				bar.Set(int(r.Items[len(r.Items)-1].Id - startChangeId))
			}
		}

		pageToken = string(r.NextPageToken)
		if pageToken == "" {
			break
		}
	}
	// Signal that no more changes are coming.
	close(changeChan)

	if bar != nil {
		bar.Finish()
	}

	gd.debug("Done updating metadata from Drive")
}

func main() {
	flag.Usage = usage

	help := flag.Bool("help", false, "show this message")
	version := flag.Bool("version", false, "show version")

	failpath := flag.String("faildir", "", "dir where failed torrentzips should be copied")

	flag.Parse()

	if *help {
		flag.Usage()
		os.Exit(0)
	}

	if *version {
		fmt.Fprintf(os.Stdout, "%s version %s, Copyright (c) 2013 Uwe Hoffmann. All rights reserved.\n", os.Args[0], versionStr)
		os.Exit(0)
	}

	if *failpath == "" {
		flag.Usage()
		os.Exit(0)
	}

	cv := new(countVisitor)

	for _, name := range flag.Args() {
		fmt.Fprintf(os.Stdout, "initial scan of %s to determine amount of work\n", name)

		err := filepath.Walk(name, cv.visit)
		if err != nil {
			fmt.Fprintf(os.Stderr, "failed to count in dir %s: %v\n", name, err)
			os.Exit(1)
		}
	}

	mg := int(cv.numBytes / megabyte)

	fmt.Fprintf(os.Stdout, "found %d files and %d MB to do. starting work...\n", cv.numFiles, mg)

	var byteProgress *pb.ProgressBar

	if mg > 10 {
		pb.BarStart = "MB ["

		byteProgress = pb.New(mg)
		byteProgress.RefreshRate = 5 * time.Second
		byteProgress.ShowCounters = true
		byteProgress.Start()
	}

	inwork := make(chan *workUnit)

	sv := &scanVisitor{
		inwork: inwork,
	}

	wg := new(sync.WaitGroup)
	wg.Add(cv.numFiles)

	for i := 0; i < 8; i++ {
		worker := &testWorker{
			byteProgress: byteProgress,
			failpath:     *failpath,
			inwork:       inwork,
			wg:           wg,
		}

		go worker.run()
	}

	for _, name := range flag.Args() {
		err := filepath.Walk(name, sv.visit)
		if err != nil {
			fmt.Fprintf(os.Stderr, "failed to scan dir %s: %v\n", name, err)
			os.Exit(1)
		}
	}

	wg.Wait()
	close(inwork)

	if byteProgress != nil {
		byteProgress.Set(int(byteProgress.Total))
		byteProgress.Finish()
	}

	fmt.Fprintf(os.Stdout, "Done.\n")
}