如何进行Go大文件上传?

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前端分割数据 这里可自行设定分片的大小 要不就是请求多分片小 要不就是分片多请求少

 const chunkSize = 2 * 1024 * 1024; // 每个chunk的大小,设置为2兆 
 const blobSlice = File.prototype.slice || File.prototype.mozSlice || File.prototype.webkitSlice;
  const hashFile = (file) => {
            return new Promise((resolve, reject) => {
                const chunks = Math.ceil(file.size / chunkSize);
                let currentChunk = 0;
                const spark = new SparkMD5.ArrayBuffer();
                const fileReader = new FileReader();
                function loadNext() {
                    const start = currentChunk * chunkSize;
                    const end = start + chunkSize >= file.size ? file.size : start + chunkSize;
                    fileReader.readAsArrayBuffer(blobSlice.call(file, start, end));
                }
                fileReader.onload = e => {
                    spark.append(e.target.result); // Append array buffer
                    currentChunk++;
                    if (currentChunk < chunks) {
                        loadNext();
                        console.log(`第${currentChunk}分片解析完成,开始解析${currentChunk + 1}分片`);
                    } else {
                        console.log('finished loading');
                        const result = spark.end();
                        // 如果单纯的使用result 作为hash值的时候, 如果文件内容相同,而名称不同的时候
                        // 想保留两个文件无法保留。所以把文件名称加上。
                        const sparkMd5 = new SparkMD5();
                        sparkMd5.append(result);
                        sparkMd5.append(file.name);
                        const hexHash = sparkMd5.end();
                        resolve(hexHash);
                    }
                };
                fileReader.onerror = () => {
                    console.warn('文件读取失败!');
                };
                loadNext();
            }).catch(err => {
                console.log(err);
            });
        }
 const fileDom = $('#file')[0];
   // 获取到的files为一个File对象数组,如果允许多选的时候,文件为多个
    const files = fileDom.files;
    const file = files[0];
    if (!file) {
      alert('没有获取文件');
      return;
     }
     const blockCount = Math.ceil(file.size / chunkSize); // 分片总数
            const axiosPromiseArray = []; // axiosPromise数组
            const hash = await hashFile(file); //文件 hash 
            // 获取文件hash之后,如果需要做断点续传,可以根据hash值去后台进行校验。
            // 看看是否已经上传过该文件,并且是否已经传送完成以及已经上传的切片。
            for (let i = 0; i < blockCount; i++) {
                const start = i * chunkSize;
                const end = start + chunkSize >= file.size ? file.size : start + chunkSize;
                // 构建表单
                const form = new FormData();
                form.append('file', blobSlice.call(file, start, end));
                form.append('name', file.name);
                form.append('total', blockCount);
                form.append('index', i);
                form.append('size', file.size);
                form.append('hash', hash);
                console.log(blockCount, blobSlice.call(file, start, end), i, start, end, file.size);
                // ajax提交 分片,此时 content-type 为 multipart/form-data
                const axiosOptions = {
                    onUploadProgress: e => {
                        // 处理上传的进度
                        // console.log(blockCount, i, e, file);
                    },
                };
                // 加入到 Promise 数组中
                axiosPromiseArray.push(axios.post('/uploadFile', form, axiosOptions));
            }
            await axios.all(axiosPromiseArray).then((result) => {
                // 合并chunks
                const data = {
                    size: file.size,
                    name: file.name,
                    total: blockCount,
                    hash
                };
                const form = new FormData();
                form.append('size', file.size);
                form.append('name', file.name);
                form.append('total', blockCount);
                form.append('hash', hash);
                console.log(result);
                axios.post("/file/chunks", form).then(res => {
                    console.log(res)
                })
            }).catch((err) => {

            });
            console.log("全部上传完毕");
        })

后端接受后创建一个临时文件夹存储前端上传的文件 这里可以用redis存储上传的信息做断点续传

var dir, _ = os.Getwd()
var uploadPath = path.Join(dir, "uploads")
var uploadTempPath = path.Join(uploadPath, "temp")

func sayhello(w http.ResponseWriter, r *http.Request) {
	r.ParseForm() //解析参数,默认是不会解析的
	t, err := template.ParseFiles("static/index.html")
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	t.Execute(w, "张三")
	return
}
// 判断文件夹是否存在
func PathExists(path string) (bool, error) {
	_, err := os.Stat(path)
	if err == nil {
		return true, nil
	}
	if os.IsNotExist(err) {
		return false, nil
	}
	return false, err
}
func uploadFile(w http.ResponseWriter, r *http.Request) {
	file, _, err := r.FormFile("file")
	// total := r.PostFormValue("total")
	index := r.PostFormValue("index")
	// size, err := strconv.ParseInt(r.PostFormValue("size"), 10, 64)
	hash := r.PostFormValue("hash")
	// name := r.PostFormValue("name")
    // 获取uploads下所有的文件夹
	nameList, err := ioutil.ReadDir(uploadPath)
	m := map[string]interface{}{
		"code": 46900,
		"msg":  "文件已上传",
	}
	result, _ := json.MarshalIndent(m, "", "    ")
    // 循环判断hash是否在文件里如果有就返回上传已完成
	for _, name := range nameList {
		tmpName := strings.Split(name.Name(), "_")[0]
		if tmpName == hash {
			fmt.Fprintf(w, string(result))
			return
		}
	}

	chunksPath := path.Join(uploadTempPath, hash, "/")

	isPathExists, err := PathExists(chunksPath)
	if !isPathExists {
		err = os.MkdirAll(chunksPath, os.ModePerm)
	}
	destFile, err := os.OpenFile(path.Join(chunksPath+"/"+hash+"-"+index), syscall.O_CREAT|syscall.O_WRONLY, 0777)
	reader := bufio.NewReader(file)
	writer := bufio.NewWriter(destFile)
	buf := make([]byte, 1024*1024) // 1M buf
	for {
		n, err := reader.Read(buf)
		if err == io.EOF {
			writer.Flush()
			break
		} else if err != nil {
			return
		} else {
			writer.Write(buf[:n])
		}
	}

	defer file.Close()
	defer destFile.Close()
	if err != nil {
		log.Fatal("%v", err)
	}
}
// 合并文件
func chunks(w http.ResponseWriter, r *http.Request) {
	// total, _ := strconv.Atoi(r.PostFormValue("total"))
	// index := r.PostFormValue("index")
	size, _ := strconv.ParseInt(r.PostFormValue("size"), 10, 64)
	hash := r.PostFormValue("hash")
	name := r.PostFormValue("name")

	toSize, _ := DirSize(path.Join(uploadTempPath, hash, "/"))
	if size != toSize {
		fmt.Fprintf(w, "文件上传错误")
	}
	chunksPath := path.Join(uploadTempPath, hash, "/")
	files, _ := ioutil.ReadDir(chunksPath)
	fs, _ := os.OpenFile(path.Join(uploadPath, hash+"_"+name), os.O_CREATE|os.O_RDWR|os.O_APPEND, os.ModeAppend|os.ModePerm)
	var wg sync.WaitGroup
	wg.Add(len(files))
	for i, f := range files {
		go func(f os.FileInfo) {
        // 这里一定要注意按顺序读取不然文件就会损坏
			name := strings.Split(f.Name(), "-")[0] + "-" + 	strconv.Itoa(i)
			fileName := path.Join(chunksPath, "/"+name)
			data, _ := ioutil.ReadFile(fileName)
			fs.Write(data)
			os.RemoveAll(path.Join(chunksPath, "/"))
			defer wg.Done()
		}(f)

	}
	wg.Wait()
	m := map[string]interface{}{
		"code": 20000,
		"msg":  "上传成功",
	}
	result, _ := json.MarshalIndent(m, "", "    ")
	fmt.Fprintf(w, string(result))
	defer fs.Close()

}
// 获取整体文件夹大小
func DirSize(path string) (int64, error) {
	var size int64
	err := filepath.Walk(path, func(_ string, info os.FileInfo, err error) error {
		if !info.IsDir() {
			size += info.Size()
		}
		return err
	})
	return size, err
}
func main() {
	http.HandleFunc("/", sayhello) // set router
	http.HandleFunc("/uploadFile", uploadFile)
	http.HandleFunc("/file/chunks", chunks)
	err := http.ListenAndServe(":8080", nil) // set listen port
	if err != nil {
		log.Fatal("Error while starting GO http server on port - 8080 : ", err) //log error and exit in case of error at server boot up
	}
}

第一次写可能不是最优解 写的不好请大家多多包涵