Electron中實現(xiàn)大文件上傳和斷點續(xù)傳功能

singleUpload function(file){
 let path = file.path; //文件本地路徑 
 let stats = fs.statSync(path);//讀取文件信息
 let chunkSize = 3*1024*1024;//每片分塊的大小3M
 let size = stats.size;//文件大小
 let pieces = Math.ceil(size / chunkSize);//總共的分片數(shù) 
 function uploadPiece (i){ 
 //計算每塊的結(jié)束位置
 let enddata = Math.min(size, (i + 1) * chunkSize);
 let arr = [];
 //創(chuàng)建一個readStream對象，根據(jù)文件起始位置和結(jié)束位置讀取固定的分片
 let readStream = fs.createReadStream(path, { start: i * chunkSize, end: enddata-1 });
 //on data讀取數(shù)據(jù)
 readStream.on(‘data‘, (data)=>{
 arr.push(data)
 }) 
 //on end在該分片讀取完成時觸發(fā)
 readStream.on(‘end‘, ()=>{
 //這里服務(wù)端只接受blob對象，需要把原始的數(shù)據(jù)流轉(zhuǎn)成blob對象，這塊為了配合后端才轉(zhuǎn)
 let blob = new Blob(arr)
 //新建formdata數(shù)據(jù)對象
 var formdata = new FormData();
 let md5Val = md5(Buffer.concat(arr));
 formdata.append("file", blob);
 console.log(‘blob.size‘,blob.size)
 formdata.append("md5", md5Val);
 formdata.append("size", size + ‘‘); // 數(shù)字30被轉(zhuǎn)換成字符串"30"
 formdata.append("chunk", i + ‘‘);//第幾個分片，從0開始
 formdata.append("chunks", pieces + ‘‘);//分片數(shù)
 formdata.append("name", name);//文件名
 post(formdata)//這里是偽代碼，實現(xiàn)上傳，開發(fā)者自己實現(xiàn)
 }
}