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Merge pull request Spacebrew#51 from robotconscience/feature-binary
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Feature: accept binary messages
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@robotconscience
robotconscience committed Apr 10, 2014
2 parents 8ed4f75 + aee0934 commit 1b491b6
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6 changes: 3 additions & 3 deletions README.md
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Expand Up @@ -3,9 +3,9 @@ Spacebrew Server

A dynamically re-routable software toolkit for choreographing interactive spaces. Visit http://www.spacebrew.cc to learn more about spacebrew. On our site we feature a bunch of example apps and tutorials to help you get started. You'll also find a blog where we feature spacebrew projects and events.

@version: 0.3.2
@date: June 1, 2013
@contributors: Quin Kennedy, Brett Renfer, Josh Walton, James Tichenor, Julio Terra
@version: 0.4.0
@date: April 10, 2014
@contributors: LAB at Rockwell Group, Quin Kennedy, Brett Renfer, Josh Walton, James Tichenor, Julio Terra

Getting Started
---------------
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2 changes: 1 addition & 1 deletion package.json
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@@ -1,6 +1,6 @@
{
"name": "spacebrew",
"version": "0.3.2",
"version": "0.4.0",
"description": "A dynamically re-routable software toolkit for choreographing interactive spaces.",
"main": "node_server_forever.js",
"scripts": {
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185 changes: 180 additions & 5 deletions spacebrew.js
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Expand Up @@ -5,10 +5,10 @@
* This module holds the core functionality of the Spacebrew server. To run this module as
* standalone app you should use the node_server.js or node_server_forever.js script.
*
* @author: Quin Kennedy, Julio Terra, and other contributors
* @author: LAB at Rockwell Group, Quin Kennedy, Brett Renfer, Josh Walton, James Tichenor, Julio Terra
* @filename: node_server.js
* @date: May 31, 2013
* @updated with version: 0.3.2
* @updated with version: 0.4.0
*
*/

Expand Down Expand Up @@ -135,12 +135,14 @@ spacebrew.createServer = function( opts ){
* admin, config, message, and routing messages for setting up, managing, and communicating
* via spacebrew. This is the backbone of spacebrew.
* @param {obj} message The incoming message from an admin or client
* @param {obj} flags Incoming flags re: the message (e.g. is it binary?)
*/
ws.on('message', function(message) {
logger.log("info", "[wss.onmessage] new message received " + message);
ws.on('message', function(message, flags) {
logger.log("info", "[wss.onmessage] new message received");

var bValidMessage = false;
if (message) {
if (message && !flags.binary) {
logger.log("info", "[wss.onmessage] text message content: " + message);
// process WebSocket message
try {
var tMsg = JSON.parse(message);
Expand Down Expand Up @@ -192,6 +194,81 @@ spacebrew.createServer = function( opts ){
logger.log("warn", "[wss.onmessage] ERROR on line <" + err.lineNumber + "> while processing message");
logger.log("warn", err.stack);
}

// this is a binary message
} else {
// for now:
// description follows format described here: https://tools.ietf.org/html/rfc5234
// inspired by WS protocol
//
// 0 1 2 3
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
// +---------------+-------------------------------+---------------+
// | JSON len | Extended JSON length |Extended JSON |
// | (8) | (16/32) | length cont. |
// | | (if JSON len == 254 or 255) | (if JSON |
// | | | len == 255) |
// +---------------+-----------------------------------------------+
// |Extended JSON | JSON Data |
// | length cont. | (length variable) |
// | (if JSON | |
// | len == 255) | |
// +---------------+-----------------------------------------------+
// | Binary Data (remainder of packet payload) |
// +---------------------------------------------------------------+
//
if (message instanceof ArrayBuffer) {
message = new Buffer( new Uint8Array(message) );
}

if (message instanceof Buffer) {
logger.log("info", "[wss.onmessage] Binary message received (NodeJS/Buffer)");

//TODO: what concerns me is that the ws module does not explicitly guarantee
// in its documentation that message.length is actually the message length
// (the Buffer documentation says .length is the size of the buffer,
// not necessarily the size of its contents)
if ( message.length > 0 ){
var jsonLength = message.readUInt8(0);
var jsonStartIndex = 1;
if (jsonLength == 254){
if (message.length > 3){
jsonLength = message.readUInt16BE(1);
jsonStartIndex = 3;
} else {
logger.log("error", "[wss.onmessage] message of incorrect format");
return;
}
} else if (jsonLength == 255){
if (message.length > 5){
jsonLength = message.readUInt32BE(1);
jsonStartIndex = 5;
} else {
logger.log("error", "[wss.onmessage] message of incorrect format");
return;
}
}

if (jsonLength > 0 ){
if (message.length >= jsonStartIndex + jsonLength) {
try {
var json = JSON.parse( message.slice(jsonStartIndex, jsonStartIndex + jsonLength ).toString());
} catch ( err ){
logger.log("error", "[wss.onmessage] Error parsing JSON from binary packet. Discarding");
return;
}

bValidMessage = handleBinaryMessage(connection, json, message.slice(jsonStartIndex + jsonLength) );
} else {
logger.log("error", "[wss.onmessage] message of incorrect format");
return;
}
}
}

} else {
logger.log("warn", "[wss.onmessage] Binary message received in unknown format");
}
}
});

Expand Down Expand Up @@ -310,6 +387,104 @@ spacebrew.createServer = function( opts ){
return bValidMessage;
};

/**
* A helper function to handle routing messages from a publisher to the appropriate subscribers.
* @param {ws Connection Obj} connection The connection that the message came in on
* @param {json} tMsg The message from the publisher which should be forwarded to its subscribers
* @param {Buffer} Binary data to be sent to subscriber
* @return {boolean} True iff the message comes from a publisher that exists
*/
var handleBinaryMessage = function(connection, tMsg, binaryData){
var pubClient = undefined
, bValidMessage = false
, pub = undefined
, sub = undefined
, toSend = {}
;

// make sure that this connection is associated to at least one client
if (!connection.spacebrew_client_list){
logger.log("info", "[handleBinaryMessage] this connection has no registered clients");
return false;
}

// check whether the client that sent the message is associated to the connection where the
// message was received
if (!(pubClient = connection.spacebrew_client_list[tMsg.message.clientName])){
logger.log("info", "[handleBinaryMessage] the client: " + tMsg.message.clientName +
" does not belong to this connection");
return false;
}

//high level thoughts ( are below \/ )

//add the remote address to the message
tMsg['message'].remoteAddress = getClientAddress(connection);

// if publishing client does have the appropriate publisher then continue processing the message
if (pub = pubClient.publishers[tMsg.message.name]) {

// if publisher is of the appropriate type then send message to all subscribers
if (pub = pub[tMsg.message.type]) {
bValidMessage = true;

for(var j = pub.subscribers.length - 1; j >= 0; j--){
sub = pub.subscribers[j];

// try to send the message but catch error so the server won't crash due to issues
try{
toSend['message'] = {
'name': sub.subscriber.name,
'type': tMsg.message.type,
'value': tMsg.message.value,
'clientName': sub.client.name
}

var jsonString = JSON.stringify(toSend);
var jsonByteLength = Buffer.byteLength(jsonString);
var numBytesForJsonLength = (jsonByteLength > 0xFFFF ? 5 : (jsonByteLength >= 254 ? 3 : 1));
var bufferSize = binaryData.length + jsonByteLength + numBytesForJsonLength;
var newBuffer = new Buffer( bufferSize );
logger.log("info", "[handleBinaryMessage] created new buffer of size "+newBuffer.length );
if (numBytesForJsonLength == 5){
newBuffer.writeUInt8(255, 0);
newBuffer.writeUInt32BE(jsonByteLength, 1);
} else if (numBytesForJsonLength == 3){
newBuffer.writeUInt8(254, 0);
newBuffer.writeUInt16BE(jsonByteLength, 1);
} else {
newBuffer.writeUInt8(jsonByteLength, 0);
}
newBuffer.write(jsonString, numBytesForJsonLength);
binaryData.copy(newBuffer, numBytesForJsonLength + jsonByteLength );

sub.client.connection.send(newBuffer, {binary: true});
logger.log("info", "[handleBinaryMessage] message sent to: '" + sub.client.name + "' msg: " + JSON.stringify(toSend));

} catch(err){
logger.log("debug", "[handleBinaryMessage] ERROR sending message to client " +
sub.client.name + ", on subscriber " +
sub.subscriber.name + " error message " + err );
}
}
}

// if publisher's type does not match then abort
else {
logger.log("info", "[handleBinaryMessage] an un-registered publisher type: " + tMsg.message.type + " with name: " + tMsg.message.name);
return false;
}
}

// if publishing client does not have the appropriate publisher then abort
else {
logger.log("info", "[handleBinaryMessage] an un-registered publisher name: " + tMsg.message.name);
return false;
}

return bValidMessage;
};

/**
* A helper function to handle adding and removing routes. This will update the neccessary
* data structures
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