<input class="video" type="file" />
<button type="submit" onclick="handleVideo(event, '.video', 'video')">
    提交
</button>

let count = 0; // 記錄需要上傳的文件下標(biāo)
const handleVideo = async (event, name, url) => {
// 阻止瀏覽器默認(rèn)表單事件
event.preventDefault();
let currentSize = document.querySelector("h2");
let files = document.querySelector(name).files;
// 默認(rèn)切片數(shù)量
const sectionLength = 100;
// 首先請(qǐng)求接口，獲取服務(wù)器是否存在此文件
// count為0則是第一次上傳，count不為0則服務(wù)器存在此文件，返回已上傳的切片數(shù)
count = await handleCancel(files[0]);

// 申明存放切片的數(shù)組對(duì)象
let fileCurrent = [];
// 循環(huán)file文件對(duì)象
for (const file of [...files]) {
  // 得出每個(gè)切片的大小
  let itemSize = Math.ceil(file.size / sectionLength);
  // 循環(huán)文件size，文件blob存入數(shù)組
  let current = 0;
  for (current; current < file.size; current += itemSize) {
    fileCurrent.push({ file: file.slice(current, current + itemSize) });
  }
  // axios模擬手動(dòng)取消請(qǐng)求
  const CancelToken = axios.CancelToken;
  const source = CancelToken.source();
  // 當(dāng)斷點(diǎn)續(xù)傳時(shí)，處理切片數(shù)量，已上傳切片則不需要再次請(qǐng)求上傳
  fileCurrent =
    count === 0 ? fileCurrent : fileCurrent.slice(count, sectionLength);
  // 循環(huán)切片請(qǐng)求接口
  for (const [index, item] of fileCurrent.entries()) {
    // 模擬請(qǐng)求暫停 || 網(wǎng)絡(luò)斷開(kāi)
    if (index > 90) {
      source.cancel("取消請(qǐng)求");
    }
    // 存入文件相關(guān)信息
    // file為切片blob對(duì)象
    // filename為文件名
    // index為當(dāng)前切片數(shù)
    // total為總切片數(shù)
    let formData = new FormData();
    formData.append("file", item.file);
    formData.append("filename", file.name);
    formData.append("total", sectionLength);
    formData.append("index", index + count + 1);

    await axios({
      url: `http://localhost:8080/${url}`,
      method: "POST",
      data: formData,
      cancelToken: source.token,
    })
      .then((response) => {
        // 返回?cái)?shù)據(jù)顯示進(jìn)度
        currentSize.innerHTML = `進(jìn)度${response.data.size}%`;
      })
      .catch((err) => {
        console.log(err);
      });
  }
}
};

// 請(qǐng)求接口，查詢上傳文件是否存在
// count為0表示不存在，count不為0則已上傳對(duì)應(yīng)切片數(shù)
const handleCancel = (file) => {
return axios({
  method: "post",
  url: "http://localhost:8080/getSize",
  headers: { "Content-Type": "application/json; charset = utf-8" },
  data: {
    fileName: file.name,
  },
})
  .then((res) => {
    return res.data.count;
  })
  .catch((err) => {
    console.log(err);
  });
};

// 使用express構(gòu)建服務(wù)器api
const express = require("express");
// 引入上傳文件邏輯代碼
const upload = require("./upload_file");
// 處理所有響應(yīng)，設(shè)置跨域
app.all("*", (req, res, next) => {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "X-Requested-With");
  res.header("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");
  res.header("Access-Control-Allow-Headers", "Content-Type, X-Requested-With ");
  res.header("X-Powered-By", " 3.2.1");
  res.header("Content-Type", "application/json;charset=utf-8");
  next();
});
const app = express();

app.use(bodyParser.json({ type: "application/*+json" }));
// 視頻上傳（查詢當(dāng)前切片數(shù)）
app.post("/getSize", upload.getSize);
// 視頻上傳接口
app.post("/video", upload.video);

// 開(kāi)啟本地端口偵聽(tīng)
app.listen(8080);

// 文件上傳模塊
const formidable = require("formidable");
// 文件系統(tǒng)模塊
const fs = require("fs");
// 系統(tǒng)路徑模塊
const path = require("path");

// 操作寫(xiě)入文件流
const handleStream = (item, writeStream) => {
  // 讀取對(duì)應(yīng)目錄文件buffer
  const readFile = fs.readFileSync(item);
  // 將讀取的buffer || chunk寫(xiě)入到stream中
  writeStream.write(readFile);
  // 寫(xiě)入完后，清除暫存的切片文件
  fs.unlink(item, () => {});
};

// 視頻上傳(切片)
module.exports.video = (req, res) => {
  // 創(chuàng)建解析對(duì)象
  const form = new formidable.IncomingForm();
  // 設(shè)置視頻文件上傳路徑
  let dirPath = path.join(__dirname, "video");
  form.uploadDir = dirPath;
  // 是否保留上傳文件名后綴
  form.keepExtensions = true;
  // err 錯(cuò)誤對(duì)象 如果解析失敗包含錯(cuò)誤信息
  // fields 包含除了二進(jìn)制以外的formData的key-value對(duì)象
  // file 對(duì)象類型 上傳文件的信息
  form.parse(req, async (err, fields, file) => {
    // 獲取上傳文件blob對(duì)象
    let files = file.file;
    // 獲取當(dāng)前切片index
    let index = fields.index;
    // 獲取總切片數(shù)
    let total = fields.total;
    // 獲取文件名
    let filename = fields.filename;
    // 重寫(xiě)上傳文件名，設(shè)置暫存目錄
    let url =
      dirPath +
      "/" +
      filename.split(".")[0] +
      `_${index}.` +
      filename.split(".")[1];
    try {
      // 同步修改上傳文件名
      fs.renameSync(files.path, url);
      console.log(url);
      // 異步處理
      setTimeout(() => {
        // 判斷是否是最后一個(gè)切片上傳完成，拼接寫(xiě)入全部視頻
        if (index === total) {
          // 同步創(chuàng)建新目錄，用以存放完整視頻
          let newDir = __dirname + `/uploadFiles/${Date.now()}`;
          // 創(chuàng)建目錄
          fs.mkdirSync(newDir);
          // 創(chuàng)建可寫(xiě)流，用以寫(xiě)入文件
          let writeStream = fs.createWriteStream(newDir + `/${filename}`);
          let fsList = [];
          // 取出所有切片文件，放入數(shù)組
          for (let i = 0; i < total; i++) {
            const fsUrl =
              dirPath +
              "/" +
              filename.split(".")[0] +
              `_${i + 1}.` +
              filename.split(".")[1];
            fsList.push(fsUrl);
          }
          // 循環(huán)切片文件數(shù)組，進(jìn)行stream流的寫(xiě)入
          for (let item of fsList) {
            handleStream(item, writeStream);
          }
          // 全部寫(xiě)入，關(guān)閉stream寫(xiě)入流
          writeStream.end();
        }
      }, 100);
    } catch (e) {
      console.log(e);
    }
    res.send({
      code: 0,
      msg: "上傳成功",
      size: index,
    });
  });
};

// 獲取文件切片數(shù)
module.exports.getSize = (req, res) => {
  let count = 0;
  req.setEncoding("utf8");
  req.on("data", function (data) {
    let name = JSON.parse(data);
    let dirPath = path.join(__dirname, "video");
    // 計(jì)算已上傳的切片文件個(gè)數(shù)
    let files = fs.readdirSync(dirPath);
    files.forEach((item, index) => {
      let url =
        name.fileName.split(".")[0] +
        `_${index + 1}.` +
        name.fileName.split(".")[1];
      if (files.includes(url)) {
        ++count;
      }
    });
    res.send({
      code: 0,
      msg: "請(qǐng)繼續(xù)上傳",
      count,
    });
  });
};