session.js

'use strict';

const nkn = require('../lib');

const numBytes = 16 << 20;
const numSubClients = 4;
const writeChunkSize = 1024;

(async function () {
  let alice = new nkn.MultiClient({ numSubClients, identifier: 'alice' });
  let bob = new nkn.MultiClient({ numSubClients, identifier: 'bob', seed: alice.getSeed() });

  console.log('Secret seed:', alice.getSeed());

  await Promise.all([
    new Promise((resolve, reject) => alice.onConnect(resolve)),
    new Promise((resolve, reject) => bob.onConnect(resolve)),
  ]);

  await new Promise((resolve, reject) => setTimeout(resolve, 1000));

  bob.onSession(async (session) => {
    console.log(session.localAddr, 'accepted a sesison');
    await read(session);
  });

  bob.listen();
  console.log('bob listening at', bob.addr);

  let session = await alice.dial(bob.addr);
  console.log(session.localAddr, 'dialed a session');

  await write(session, numBytes);
})();

async function read(session) {
  let timeStart = Date.now();
  let buf = new Uint8Array(0);
  while (buf.length < 4) {
    buf = nkn.util.mergeTypedArrays(buf, await session.read(4 - buf.length));
  }
  let dv = new DataView(buf.buffer);
  let numBytes = dv.getUint32(0, true);
  for (let n = 0; n < numBytes; n += buf.length) {
    buf = await session.read();
    for (let i = 0; i < buf.length; i++) {
      if (buf[i] !== byteAt(n + i)) {
        throw 'wrong value at' + (n+i) + 'byte';
      }
    }
    if (Math.floor((n + buf.length) * 10 / numBytes) !== Math.floor(n * 10 / numBytes)) {
      console.log(session.localAddr, 'received', n + buf.length, 'bytes', (n + buf.length) / (1<<20) / (Date.now() - timeStart) * 1000, 'MB/s');
    }
  }
  console.log(session.localAddr, 'finished receiving', numBytes, 'bytes', numBytes / (1<<20) / (Date.now() - timeStart) * 1000, 'MB/s');
  process.exit()
}

async function write(session, numBytes) {
  let timeStart = Date.now();
  let buffer = new ArrayBuffer(4);
  let dv = new DataView(buffer);
  dv.setUint32(0, numBytes, true);
  await session.write(new Uint8Array(buffer));
  let buf;
  for (let n = 0; n < numBytes; n += buf.length) {
    buf = new Uint8Array(Math.min(numBytes - n, writeChunkSize));
    for (let i = 0; i < buf.length; i++) {
      buf[i] = byteAt(n + i);
    }
    await session.write(buf);
    if (Math.floor((n + buf.length) * 10 / numBytes) !== Math.floor(n * 10 / numBytes)) {
      console.log(session.localAddr, 'sent', n + buf.length, 'bytes', (n + buf.length) / (1<<20) / (Date.now() - timeStart) * 1000, 'MB/s');
    }
  }
  console.log(session.localAddr, 'finished sending', numBytes, 'bytes', numBytes / (1<<20) / (Date.now() - timeStart) * 1000, 'MB/s');
}

function byteAt(n) {
  return n % 256;
}