wsServer.addListener('request', function (request) {
logger.log('connection request received', 'origin=' + request.origin);
if (!originIsAllowed(request.origin)) {
// Make sure we only accept requests from an allowed origin
request.reject();
logger.info('connection rejected', 'origin=' + request.origin);
return;
}
var connection = request.accept('echo-protocol', request.origin);
connections.push(connection);
logger.info('connection accepted', 'origin=' + request.origin);
connection.addListener('message', function (message) {
var request = null;
var timing = null;
if (message.type === 'utf8') {
logger.info('received message', message.utf8Data);
try {
request = JSON.parse(message.utf8Data);
}
catch (err) {
logger.warn('could not parse message as JSON', err);
return;
}
timing = timingAndConnections[request.id];
switch (request.type) {
case 'info':
// The client wants detailed information about the timing object
// The command is also used to associate the Web socket connection
// with the timing object so that "change" events propagate to all
// connected clients
if (!timing) {
logger.warn('TODO: implement timing create/destroy mechanism');
timing = {
connections: [],
timing: new TimingObject(),
onchange: getChangeListenerFor(request.id)
};
timing.timing.addEventListener('change', timing.onchange);
timingAndConnections[request.id] = timing;
}
timing.connections.push(connection);
logger.log('new connection to timing object',
'id=' + request.id,
'nb=' + timing.connections.length);
logger.warn('TODO: add extra properties once available (e.g. range)');
connection.sendUTF(stringify({
type: 'info',
id: request.id,
vector: timing.timing.query()
}));
logger.log('sent timing info', 'id=' + request.id);
break;
case 'update':
// The client wants to update the Timing Object's vector
// Note that the update method will trigger a "change" event
// and thus send the update back to all connected connections
// including the one that sent the initial request
var vector = request.vector || {};
if (timing) {
timing.timing.update(
vector.position,
vector.velocity,
vector.acceleration);
logger.log('updated timing object', 'id=' + request.id);
logger.warn('TODO: send update ack back to requester?');
}
else {
logger.warn('received an update request on unknown timing object',
'id=' + request.id, 'ignored');
}
break;
case 'sync':
// The client wants to synchronize its clock with that of the server
// NB: in this implementation, it's hard to measure the time taken to
// process the message. This would require digging into Web socket
// frames to record the time when the first byte is received.
var now = Date.now();
connection.sendUTF(stringify({
type: 'sync',
id: request.id,
client: {
sent: (request.client || {}).sent
},
server: {
received: now,
sent: now
},
delta: delta
}));
logger.log('sync message sent', 'id=' + request.id);
break;
default:
logger.log('unknown command',
'id=' + request.id, 'cmd=' + request.type, 'ignored');
}
}
else if (message.type === 'binary') {
logger.info('received binary message', 'ignored',
'length=' + message.binaryData.length + ' bytes');
}
});
connection.addListener('close', function(reasonCode, description) {
logger.info('peer disconnected', 'address=' + connection.remoteAddress);
connection.removeAllListeners('message');
connection.removeAllListeners('close');
_.forEach(timingAndConnections, function (timingAndConnection) {
if (_.contains(timingAndConnection.connections, connection)) {
timingAndConnection.connections = _.without(
timingAndConnection.connections,
connection);
}
});
});
});