Golang实现异步上传文件支持进度条查询的方法

func decompressZip(filePath, dest string) (string, string, error) {
  var csvName string
  imageFolder := path.Base(filePath)
  ext := path.Ext(filePath)
  folderName := strings.TrimSuffix(imageFolder, ext)
  src, err := os.Open(filePath)
  if err != nil {
    return "", "", err
  }
  defer src.Close()

  zipFile, err := zip.OpenReader(src.Name())
  if err != nil {
    return "", "", err
  }
  defer zipFile.Close()

  err = os.MkdirAll(path.Join(dest, folderName), os.ModePerm)
  for _, innerFile := range zipFile.File {
    info := innerFile.FileInfo()
    if info.IsDir() {
      continue
    }
    dst, err := os.Create(path.Join(dest, folderName, info.Name()))
    if err != nil {
      fmt.Println(err.Error())
      continue
    }
    src, err := innerFile.Open()
    if err != nil {
      fmt.Println(err.Error())
      continue
    }
    io.Copy(dst, src)
  }
  destPath, err := ioutil.ReadDir(path.Join(dest, folderName))
  if err != nil {
    return "", "", err
  }
  for _, v := range destPath {
    if path.Ext(v.Name()) == ".csv" {
      csvName = path.Join(dest, folderName, v.Name())
    }
  }
  return folderName, csvName, nil
}

import.zip

┝┅┅import.csv

┖┅┅images

func ValidUTF8(buf []byte) bool {
  nBytes := 0
  for i := 0; i < len(buf); i++ {
    if nBytes == 0 {
      if (buf[i] & 0x80) != 0 { //与操作之后不为0，说明首位为1
        for (buf[i] & 0x80) != 0 {
          buf[i] <<= 1 //左移一位
          nBytes++   //记录字符共占几个字节
        }
        if nBytes < 2 || nBytes > 6 { //因为UTF8编码单字符最多不超过6个字节
          return false
        }
        nBytes-- //减掉首字节的一个计数
      }
    } else { //处理多字节字符
      if buf[i]&0xc0 != 0x80 { //判断多字节后面的字节是否是10开头
        return false
      }
      nBytes--
    }
  }
  return nBytes == 0
}

type LineWrong struct {
  LineNumber int64 `json:"line_number"`
  Msg    string `json:"msg"`
}

func Import(/*自定义参数*/){
  // decompress zip file to destination address
  folder, csvName, err := Decompress(path.Join(constant.FolderPrefix, req.FilePath), dest)
  if err != nil {
    fmt.Println(err.Error())
  }

  // check if the file encoding is utf8
  b, err := ioutil.ReadFile(csvName)
  if err != nil {
    fmt.Println(err.Error())
  }
  if !utils.ValidUTF8(b) {
    fmt.Println(errors.New("数据编码错误，请使用utf-8格式csv！"))
  }

  // create goroutine to analysis data into mongodb
  var wg sync.WaitGroup
  wg.Add(1)

  // used to interrupt goroutine
  resultChan := make(chan error)
  // used to record wrong row in csv
  lW := make(chan []LineWrong)
  go func(ctx *gin.Context, Name, csvPath, dir, folder string) {
    defer wg.Done()
    tidT, ciT, lwT, err := importCsv(ctx, Name, csvPath, dir, folder)
    resultChan <- err
    if err != nil {
      fmt.Println(err.Error())
    }
    lW <- lwT
    if len(lwT) == 0 {
      importClassData(ctx, tidT, ciT)
    }
  }(ctx, req.Name, csvName, dest, folder)

  err = <-resultChan
  lineWrong := <-lW
  close(lW)
  ···
}

// pre-analysis data in csv and through wrong data with line numbers and information
func importCsv()(){
  ···
}

// analysis data again and save data into mongodb, if is there any error,through them same as import()
func importClassData()(){
  ···
  conn, err := connect()
  if err != nil {
    return err
  }
  defer conn.Close()
  conn.Do("hset", taskId, "task_id", (curLine*100)/totalLines)
  ···
}

func QueryImport()(){
  conn, err := connect()
  if err != nil {
    return nil, err
  }
  defer conn.Close()

  progress, _ := conn.Do("hget", key, field)
  if pro, ok := progress.([]uint8); ok {
    ba := []byte{}
    for _, b := range pro {
      ba = append(ba, byte(b))
    }
    progress,_ = strconv.Atoi(string(ba))
  }
  return progress
}