Weekly EM

Larva.js

Larva.prototype.spawn = function larvaSpawn (addArgs) {
  /*
   * Some initialization, and arguments type checking,
   * deleted for the 50 lines rule!
   */
 
  process.nextTick(function () {
 
    var child = spawn(command, args, {
      env: env 
    });
 
    // Plug a life detector to check if the larva is alive
    child.stdout.on('data', function (msg) {
      that.lastHeartBeat = new Date().getTime();
    });
 
    child.on('exit', function () {
      that.emit('exit', arguments);
    });
 
    carrier.carry(child.stdout, function onLine (line) {
      var parsed;
      var event;
      var data;
      try {
        parsed = JSON.parse(line);
        event = parsed.event;
        if (typeof event === 'undefined') {
          event = 'info'; 
        }
        data = parsed.data;
        that.emit(event, data);
      } catch (err) {
        that.emit('info', line);
      }
    });
 
    carrier.carry(child.stderr, function onError (line) {
      that.emit('error', line);
    });
 
    that.childProcess = child;
 
  });
 
  // Make it chainable
  return that;
 
};
 
 
/*
 * Stdout signal flow:
 *
 *           /====> heartbeat
 * stdout === 
 *           \====> carrier ====> larva.emit
 *
 */