happn-primus/transformers/lws/server.js

Primus is a simple abstraction around real-time frameworks. It allows you to easily switch between different frameworks without any code changes.

'use strict';

var parse = require('url').parse
  , http = require('http');

[
  '',
  'The lws transformer has been deprecated in favor of its successor uws.',
  'We strongly suggest to switch to uws as lws will be removed in future',
  'versions of Primus.',
  ''
].forEach(function each(line) {
  console.error('Primus: '+ line);
});

/**
 * Minimum viable WebSocket server for Node.js that works through the Primus
 * interface.
 *
 * @runat server
 * @api private
 */
module.exports = function server() {
  var WebSocketServer = require('lws').Server
    , Spark = this.Spark;

  var service = this.service = new WebSocketServer({
    perMessageDeflate: !!this.primus.options.compression
  });

  service.on('message', function (socket, message, binary) {
    var spark = service.getUserData(socket);
    spark.emit('incoming::data', binary ? message : message.toString());
  });

  service.on('close', function (socket) {
    var spark = service.getUserData(socket);
    spark.emit('incoming::end');
  });

  //
  // Listen to upgrade requests.
  //
  this.on('upgrade', function upgrade(req, soc, head) {
    var socket = this.service.handleUpgrade(soc, req, head);

    if (!socket) return;

    var spark = new Spark(
        req.headers               // HTTP request headers.
      , req                       // IP address location.
      , parse(req.url).query      // Optional query string.
      , null                      // We don't have an unique id.
      , req                       // Reference to the HTTP req.
    );

    service.setUserData(socket, spark);

    spark.on('outgoing::end', function end() {
      service.close(socket);
    }).on('outgoing::data', function write(data) {
      if ('string' === typeof data) {
        // todo: take a string directly
        service.send(socket, new Buffer(data), false);
      } else {
        service.send(socket, data, true);
      }
    });
  });

  //
  // Listen to non-upgrade requests.
  //
  this.on('request', function request(req, res) {
    res.writeHead(426, { 'content-type': 'text/plain' });
    res.end(http.STATUS_CODES[426]);
  });

  this.on('close', function close() {
    service.close();
  });
};