file2-server.js

const net = require('net');
const fs = require('fs');
const path = require('path');

const fileName = "send-image.jpg";
const filePath = path.join(__dirname, fileName);
let packets = 0;
let totalBytes = 0;

const server = net.createServer(function(client){
  const readStream = fs.createReadStream(filePath, {highWaterMark: 16384});
  readStream.on('data', function(chunk){
    packets++;
    console.log('chunk', chunk);
    const head = new Buffer.from("FI");
    // content size를 16진수로 변환.
    const sizeHex = chunk.length.toString(16);
    console.log('sizeHex', sizeHex);
    while(sizeHex.length < 4){
      sizeHex = "0" + sizeHex;
    }
    const size = new Buffer.from(sizeHex);
    console.log("size byte", size, "size", chunk.length, "hex", sizeHex);
    const delimiter = new Buffer.from("@");
    const pack = Buffer.concat([head, size, chunk, delimiter]);
    totalBytes += pack.length;

    client.write(pack);
  });

  readStream.on('close', function(){
    client.write("EN");
    // client.end();
    console.log("total packets", packets);
    console.log("total bytes sent", totalBytes + 2);
  });

  client.on('error', function(){
    console.log("error del cliente");
  });

  client.on('close', function(){
    console.log("disconnect client");
  });
});

server.listen(5000);

server.on('listening', function(){
  console.log("servidor escuchando");
});

server.on('error', function(err){
  console.log("error del servidor");
});