GOLANG：从Google云端硬盘中排除垃圾文件

type listAllFilesArgs struct {
    query     string
    fields    []googleapi.Field
    sortOrder string
    maxFiles  int64
}
type Field string

func (self *Drive) listAllFiles(args listAllFilesArgs) ([]*drive.File, error) {
    var files []*drive.File
    var pageSize int64
    if args.maxFiles > 0 && args.maxFiles < 1000 {
        pageSize = args.maxFiles
    } else {
        pageSize = 1000
    }
    controlledStop := fmt.Errorf("Controlled stop")
    err := self.service.Files.List().Q(args.query).Fields(args.fields...).OrderBy(args.sortOrder).PageSize(pageSize).Pages(context.TODO(), func(fl *drive.FileList) error {
        files = append(files, fl.Files...)

        // Stop when we have all the files we need
        if args.maxFiles > 0 && len(files) >= int(args.maxFiles) {
            return controlledStop
        }

        return nil
    })

    if err != nil && err != controlledStop {
        return nil, err
    }

    if args.maxFiles > 0 {
        n := min(len(files), int(args.maxFiles))
        return files[:n], nil
    }

    return files, nil
}

func (self *Drive) newPathfinder() *remotePathfinder {
    return &remotePathfinder{
        service: self.service.Files,
        files:   make(map[string]*drive.File),
    }
}

err = gDrive.List(listArgs)
    if err != nil {
        fmt.Errorf("Failed to list files: %s", err)
    }

func (self *Drive) List(args ListFilesArgs) (err error) {
    listArgs := listAllFilesArgs{
        query:     args.Query,
        fields:    []googleapi.Field{"nextPageToken", "files(id,name,md5Checksum,mimeType,size,createdTime,parents)"},
        sortOrder: args.SortOrder,
        maxFiles:  args.MaxFiles,
    }
    files, err := self.listAllFiles(listArgs)
    if err != nil {
        return fmt.Errorf("Failed to list files: %s /n", err)
    }

    pathfinder := self.newPathfinder()

    if args.AbsPath {
        // Replace name with absolute path
        for _, f := range files {
            f.Name, err = pathfinder.absPath(f)
            if err != nil {
                return err
            }
        }
    }

    PrintFileList(PrintFileListArgs{
        Out:         args.Out,
        Files:       files,
        NameWidth:   int(args.NameWidth),
        SkipHeader:  args.SkipHeader,
        SizeInBytes: args.SizeInBytes,
    })

    return
}