JS event loop problem - Codes Helper - Programming Question Answer

JS event loop problem

my requirements:

 
 chunksSizeN = file.size/chunkSize
 NNhttp.requestPost

The

code is as follows
(note: the upload function is used to calculate the start flag bit and the end flag bit of each block according to the number of blocks n, and call the senddataPromise function to operate on each piece)

function  upload(username,filepath,file_id,filelength,n,alreadychunks,chunkSize) {
    return new Promise(function (resolve,reject) {
            var start = 0,end = 0;
            var promiseall = [];
            for (let curindex = 0;curindex < n;curindexPP) {
                if(filelength - start <= chunkSize) {
                    end  =  filelength - 1;
                }else {
                    end = start+chunkSize - 1; // startend
                }
                if(alreadychunks.indexOf(curindex) == -1) {
                    let options = {
                        flags: "r",
                        highWaterMark: chunkSize,
                        start: start,
                        end: end
                    };
                    promiseall.push(senddataPromise(filepath,options,username,file_id,curindex,end-start+1));
                }
                start = end + 1;
            }
            let timer = setInterval(() => {
                if(promiseall.length == n) {
                    clearInterval(timer);
                    Promise.all(promiseall).then(values=>{
                        console.log(values);
                        console.log("all done");
                        resolve(true)
                    }).catch(err => {
                        console.log(err);
                        reject(err);
                    })
                }
            },500)
    })
}

The

senddataPromise function creates a read stream to read the contents of block I, and calls the doapost function to send it to the backend

function senddataPromise(path,options,username,summary,curindex,length) {
    return new Promise(function (resolve,reject) {
        let readSteam = fs.createReadStream(path,options);
        readSteam.on("data",(chunk) => {
            console.log(""+curindex+" JSON")
            let chunkjson = JSON.stringify(chunk);
            console.log(""+curindex+" JSON")
            let tempcell = {
                data: chunkjson,
                n: curindex,
                file_id: summary,
                username: username,
                length: length
            };
            chunk = null;
            chunkjson = null;
            doapost(tempcell).then(values=>{
                resolve(values)
            }).catch(err=>{
                reject(err);
            });
        })
    })
}

doapost function initiates a post request to send multipart data

function  doapost(data) {
    return new Promise(function (resolve,reject) {
        let i = data.n;
        console.log(""+i+"")
        let contents = queryString.stringify(data);
        data = null;
        let options = {
            host: "localhost",
            path: "/nodepost/",
            port: 8000,
            method: "POST",
            headers: {
                "Content-Type": "application/x-www-form-urlencoded",
                "Content-Length": contents.length
            }
        };
        let req = http.request(options, function (res) {
            console.log(""+i+"")
            res.on("data", function (chunk) {
                console.log(chunk.toString());
            });
            res.on("end", function (d) {
                resolve("end");
            });
            res.on("error", function (e) {
                reject(e);
            })
        });
        req.write(contents);
        req.end();
        contents = null;
        console.log(""+i+"")
    })
}

my question:

  
  npq**q < p**
  ***
  n***
  :()

{ 
 kind: "upload",
username: "moran999",
filepath: "F:/my_upload_test/NowTest.pdf",
file_id: "-196987878-472217752177633040957425519",
alreadychunks: [],
chunkSize: 1048576,
n: 9 }
0 JSON
0 JSON
0
0
1 JSON
1 JSON
1
1
2 JSON
2 JSON
2
2
3 JSON
3 JSON
3
3
5 JSON
5 JSON
5
5
4 JSON
4 JSON
4
4
6 JSON
6 JSON
6
6
8 JSON
8 JSON
8
8
7 JSON
7 JSON
7
7
8
moran999
4
moran999
6
moran999
1
moran999
2
moran999
0
moran999
3
moran999
7
moran999
5
moran999
[ "end", "end", "end", "end", "end", "end", "end", "end", "end" ]
all done

  POSTPOST
  
  ipost
  

  12 JSON
  postpost