Testing performance of socket.write in node

socket-send.js

const net = require('net');
const stream = require('stream');

function createSource(count, batchSize, sep){
    const s = stream.Readable();
    let buf = '';
    for(let i = 0; i < count; i++){
        if(i > 0 && (i % batchSize) == 0) {
            s.push(buf + sep);
            buf = '';
        }
        buf = buf + '.';
    }
    buf.length > 0 && s.push(buf);
    s.push(null);
    return s;
}

function send(host, port, opt) {
    const source = createSource(opt.count, opt.batchSize, opt.sep);
    const client = new net.Socket();
    client.connect({
        host: host,
        port: port
    }, function () {
        console.log('Connected:', host, port, 'Sending ', opt.count, ' in batches of ', opt.batchSize);
        console.time('sending');
        stream.pipeline(source, client, () => {
            console.timeEnd('sending')
            client.destroy();
        })
    });
}

// run:
//     while true ; do nc -l 127.0.0.1 9999 | wc -wc ; done
// in another window to act as the server

// count: number of characters to send in total (not counting sep)
// batchSize: how many characters to push onto stream at a time
// sep: character to push to separate the batches
send('127.0.0.1', 9999, {count: 1e6, batchSize: 100000, sep: ''})