Detailed explanation of multi-threaded runtime library Nexus.js in JavaScript (part of the code attached)

import { h } from 'https://unpkg.com/preact/dist/preact.esm.js';

class EmitterTest extends Nexus.EventEmitter {

 constructor() {

  super();

  for(let i = 0; i < 4; i++)

   this.on('test', value => { console.log(`fired test ${i}!`); console.inspect(value); });

  for(let i = 0; i < 4; i++)

   this.on('returns-a-value', v => `${v + i}`);

 }

}

const test = new EmitterTest();

async function start() {

 await test.emit('test', { payload: 'test 1' });

 console.log('first test done!');

 await test.emit('test', { payload: 'test 2' });

 console.log('second test done!');

 const values = await test.emit('returns-a-value', 10);

 console.log('third test done, returned values are:'); console.inspect(values);

}

start().catch(console.error);

const startTime = Date.now();

 try {

  const device = new Nexus.IO.FilePushDevice('enwik8');

  const stream = new Nexus.IO.ReadableStream(device);

  stream.pushFilter(new Nexus.IO.EncodingConversionFilter("UTF-8", "UTF-16LE"));

  const wstreams = [0,1,2,3]

   .map(i => new Nexus.IO.WritableStream(new Nexus.IO.FileSinkDevice('enwik16-' + i)));

  console.log('piping...');

  stream.pipe(...wstreams);

  console.log('streaming...');

  await stream.resume();

  await stream.close();

  await Promise.all(wstreams.map(stream => stream.close()));

  console.log(`finished in ${(Date.now() * startTime) / 1000} seconds!`);

 } catch (e) {

  console.error('An error occurred: ', e);

 }

}

start().catch(console.error);

const acceptor = new Nexus.Net.TCP.Acceptor();

let count = 0;

acceptor.on('connection', (socket, endpoint) => {

 const connId = count++;

 console.log(`connection #${connId} from ${endpoint.address}:${endpoint.port}`);

 const rstream = new Nexus.IO.ReadableStream(socket);

 const wstream = new Nexus.IO.WritableStream(socket);

 const buffer = new Uint8Array(13);

 const message = 'Hello World!\n';

 for(let i = 0; i < 13; i++)

  buffer[i] = message.charCodeAt(i);

 rstream.pushFilter(new Nexus.IO.UTF8StringFilter());

 rstream.on('data', buffer => console.log(`got message: ${buffer}`));

 rstream.resume().catch(e => console.log(`client #${connId} at ${endpoint.address}:${endpoint.port} disconnected!`));

 console.log(`sending greeting to #${connId}!`);

 wstream.write(buffer);

});

acceptor.bind('127.0.0.1', 10000);

acceptor.listen();

console.log('server ready');

....

/**

 * Creates an input stream from a path.

 * @param path

 * @returns {Promise<ReadableStream>}

 */

async function createInputStream(path) {

 if (path.startsWith('/')) // If it starts with '/', omit it.

  path = path.substr(1);

 if (path.startsWith('.')) // If it starts with '.', reject it.

  throw new NotFoundError(path);

 if (path === '/' || !path) // If it's empty, set to index.html.

  path = 'index.html';

 /**

  * `import.meta.dirname` and `import.meta.filename` replace the old CommonJS `__dirname` and `__filename`.

  */

 const filePath = Nexus.FileSystem.join(import.meta.dirname, 'server_root', path);

 try {

  // Stat the target path.

  const {type} = await Nexus.FileSystem.stat(filePath);

  if (type === Nexus.FileSystem.FileType.Directory) // If it's a directory, return its 'index.html'

   return createInputStream(Nexus.FileSystem.join(filePath, 'index.html'));

  else if (type === Nexus.FileSystem.FileType.Unknown || type === Nexus.FileSystem.FileType.NotFound)

   // If it's not found, throw NotFound.

   throw new NotFoundError(path);

 } catch(e) {

  if (e.code)

   throw e;

  throw new NotFoundError(path);

 }

 try {

  // First, we create a device.

  const fileDevice = new Nexus.IO.FilePushDevice(filePath);

  // Then we return a new ReadableStream created using our source device.

  return new Nexus.IO.ReadableStream(fileDevice);

 } catch(e) {

  throw new InternalServerError(e.message);

 }

}

/**

 * Connections counter.

 */

let connections = 0;

/**

 * Create a new HTTP server.

 * @type {Nexus.Net.HTTP.Server}

 */

const server = new Nexus.Net.HTTP.Server();

// A server error means an error occurred while the server was listening to connections.

// We can mostly ignore such errors, we display them anyway.

server.on('error', e => {

 console.error(FgRed + Bright + 'Server Error: ' + e.message + '\n' + e.stack, Reset);

});

/**

 * Listen to connections.

 */

server.on('connection', async (connection, peer) => {

 // Start with a connection ID of 0, increment with every new connection.

 const connId = connections++;

 // Record the start time for this connection.

 const startTime = Date.now();

 // Destructuring is supported, why not use it?

 const { request, response } = connection;

 // Parse the URL parts.

 const { path } = parseURL(request.url);

 // Here we'll store any errors that occur during the connection.

 const errors = [];

 // inStream is our ReadableStream file source, outStream is our response (device) wrapped in a WritableStream.

 let inStream, outStream;

 try {

  // Log the request.

  console.log(`> #${FgCyan + connId + Reset} ${Bright + peer.address}:${peer.port + Reset} ${

   FgGreen + request.method + Reset} "${FgYellow}${path}${Reset}"`, Reset);

  // Set the 'Server' header.

  response.set('Server', `nexus.js/0.1.1`);

  // Create our input stream.

  inStream = await createInputStream(path);

  // Create our output stream.

  outStream = new Nexus.IO.WritableStream(response);

  // Hook all `error` events, add any errors to our `errors` array.

  inStream.on('error', e => { errors.push(e); });

  request.on('error', e => { errors.push(e); });

  response.on('error', e => { errors.push(e); });

  outStream.on('error', e => { errors.push(e); });

  // Set content type and request status.

  response

   .set('Content-Type', mimeType(path))

   .status(200);

  // Hook input to output(s).

  const disconnect = inStream.pipe(outStream);

  try {

   // Resume our file stream, this causes the stream to switch to HTTP chunked encoding.

   // This will return a promise that will only resolve after the last byte (HTTP chunk) is written.

   await inStream.resume();

  } catch (e) {

   // Capture any errors that happen during the streaming.

   errors.push(e);

  }

  // Disconnect all the callbacks created by `.pipe()`.

  return disconnect();

 } catch(e) {

  // If an error occurred, push it to the array.

  errors.push(e);

  // Set the content type, status, and write a basic message.

  response

   .set('Content-Type', 'text/plain')

   .status(e.code || 500)

   .send(e.message || 'An error has occurred.');

 } finally {

  // Close the streams manually. This is important because we may run out of file handles otherwise.

  if (inStream)

   await inStream.close();

  if (outStream)

   await outStream.close();

  // Close the connection, has no real effect with keep-alive connections.

  await connection.close();

  // Grab the response's status.

  let status = response.status();

  // Determine what colour to output to the terminal.

  const statusColors = {

   '200': Bright + FgGreen, // Green for 200 (OK),

   '404': Bright + FgYellow, // Yellow for 404 (Not Found)

   '500': Bright + FgRed // Red for 500 (Internal Server Error)

  };

  let statusColor = statusColors[status];

  if (statusColor)

   status = statusColor + status + Reset;

  // Log the connection (and time to complete) to the console.

  console.log(`< #${FgCyan + connId + Reset} ${Bright + peer.address}:${peer.port + Reset} ${

   FgGreen + request.method + Reset} "${FgYellow}${path}${Reset}" ${status} ${(Date.now() * startTime)}ms` +

   (errors.length ? " " + FgRed + Bright + errors.map(error => error.message).join(', ') + Reset : Reset));

 }

});

/**

 * IP and port to listen on.

 */

const ip = '0.0.0.0', port = 3000;

/**

 * Whether or not to set the `reuse` flag. (optional, default=false)

 */

const portReuse = true;

/**

 * Maximum allowed concurrent connections. Default is 128 on my system. (optional, system specific)

 * @type {number}

 */

const maxConcurrentConnections = 1000;

/**

 * Bind the selected address and port.

 */

server.bind(ip, port, portReuse);

/**

 * Start listening to requests.

 */

server.listen(maxConcurrentConnections);

/**

 * Happy streaming!

 */

console.log(FgGreen + `Nexus.js HTTP server listening at ${ip}:${port}` + Reset);

This is ApacheBench, Version 2.3 <$Revision: 1796539 $>

Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/

Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking localhost (be patient).....done

Server Software:    nexus.js/0.1.1

Server Hostname:    localhost

Server Port:      3000

Document Path:     /

Document Length:    8673 bytes

Concurrency Level:   100

Time taken for tests:  9.991 seconds

Complete requests:   10000

Failed requests:    0

Total transferred:   87880000 bytes

HTML transferred:    86730000 bytes

Requests per second:  1000.94 [#/sec] (mean)

Time per request:    99.906 [ms] (mean)

Time per request:    0.999 [ms] (mean, across all concurrent requests)

Transfer rate:     8590.14 [Kbytes/sec] received

Connection Times (ms)

       min mean[+/-sd] median  max

Connect:    0  0  0.1   0    1

Processing:   6  99 36.6   84   464

Waiting:    5  99 36.4   84   463

Total:     6 100 36.6   84   464

Percentage of the requests served within a certain time (ms)

 50%   84

 66%   97

 75%  105

 80%  112

 90%  134

 95%  188

 98%  233

 99%  238

 100%  464 (longest request)

voodooattack@voodooattack:~$ cat /proc/cpuinfo

processor  : 0

vendor_id  : GenuineIntel

cpu family : 6

model    : 60

model name : Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

stepping  : 3

microcode  : 0x22

cpu MHz   : 3392.093

cache size : 8192 KB

physical id : 0

siblings  : 8

core id   : 0

cpu cores  : 4

apicid   : 0

initial apicid : 0

fpu   : yes

fpu_exception  : yes

cpuid level : 13

wp   : yes

flags    : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm cpuid_fault tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid xsaveopt dtherm ida arat pln pts

bugs    :

bogomips  : 6784.18

clflush size  : 64

cache_alignment : 64

address sizes  : 39 bits physical, 48 bits virtual

power management:

voodooattack@voodooattack:~$ httperf --port=3000 --num-conns=10000 --rate=1000

httperf --client=0/1 --server=localhost --port=3000 --uri=/ --rate=1000 --send-buffer=4096 --recv-buffer=16384 --num-conns=10000 --num-calls=1

httperf: warning: open file limit > FD_SETSIZE; limiting max. # of open files to FD_SETSIZE

Maximum connect burst length: 262

Total: connections 9779 requests 9779 replies 9779 test-duration 10.029 s

Connection rate: 975.1 conn/s (1.0 ms/conn, <=1022 concurrent connections)

Connection time [ms]: min 0.5 avg 337.9 max 7191.8 median 79.5 stddev 848.1

Connection time [ms]: connect 207.3

Connection length [replies/conn]: 1.000

Request rate: 975.1 req/s (1.0 ms/req)

Request size [B]: 62.0

Reply rate [replies/s]: min 903.5 avg 974.6 max 1045.7 stddev 100.5 (2 samples)

Reply time [ms]: response 129.5 transfer 1.1

Reply size [B]: header 89.0 content 8660.0 footer 2.0 (total 8751.0)

Reply status: 1xx=0 2xx=9779 3xx=0 4xx=0 5xx=0

CPU time [s]: user 0.35 system 9.67 (user 3.5% system 96.4% total 99.9%)

Net I/O: 8389.9 KB/s (68.7*10^6 bps)

Errors: total 221 client-timo 0 socket-timo 0 connrefused 0 connreset 0

Errors: fd-unavail 221 addrunavail 0 ftab-full 0 other 0