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tweaking MQTT, making it work with masked data and soon servers
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@gfwilliams
gfwilliams committed Dec 11, 2015
1 parent 5dac5ce commit ded33c6
Showing 1 changed file with 30 additions and 27 deletions.
57 changes: 30 additions & 27 deletions devices/MQTT.js
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@@ -1,4 +1,4 @@
/* Copyright (c) 2014 Lars Toft Jacobsen (boxed.dk). See the file LICENSE for copying permission. */
/* Copyright (c) 2014 Lars Toft Jacobsen (boxed.dk), Gordon Williams. See the file LICENSE for copying permission. */
/*
Simple MQTT protocol wrapper for Espruino sockets.
*/
Expand Down Expand Up @@ -56,17 +56,15 @@ MQTT.prototype.C = {

/* Utility functions ***************************/

var fromCharCode = String.fromCharCode;

/** MQTT string (length MSB, LSB + data) */
MQTT.prototype.mqttStr = function(s) {
return String.fromCharCode(s.length>>8, s.length&255)+s;
function mqttStr(s) {
return fromCharCode(s.length>>8, s.length&255)+s;
};

/** MQTT standard packet formatter */
MQTT.prototype.mqttPacket = function(cmd, variable, payload) {
return String.fromCharCode(cmd) + this.mqttPacketLength(variable.length+payload.length) +variable+payload;
};
/** MQTT packet length formatter - algorithm from reference docs */
MQTT.prototype.mqttPacketLength = function(length) {
function mqttPacketLength(length) {
var encLength = '';
do {
encByte = length & 127;
Expand All @@ -75,11 +73,16 @@ MQTT.prototype.mqttPacketLength = function(length) {
if ( length > 0 ) {
encByte += 128;
}
encLength += String.fromCharCode(encByte);
encLength += fromCharCode(encByte);
} while ( length > 0 )
return encLength;
}

/** MQTT standard packet formatter */
function mqttPacket(cmd, variable, payload) {
return fromCharCode(cmd) + mqttPacketLength(variable.length+payload.length) + variable + payload;
};

/** PUBLISH packet parser - returns object with topic and message */
MQTT.prototype.parsePublish = function(data) {
if (data.length > 5 && typeof data !== undefined) {
Expand Down Expand Up @@ -112,7 +115,7 @@ MQTT.prototype.mqttUid = (function() {

/** Create escaped hex value from number */
MQTT.prototype.createEscapedHex = function( number ){
return String.fromCharCode(parseInt( number.toString(16) , 16));
return fromCharCode(parseInt( number.toString(16) , 16));
};

/* Public interface ****************************/
Expand Down Expand Up @@ -197,7 +200,7 @@ MQTT.prototype.connect = function(client) {

/** Disconnect from server */
MQTT.prototype.disconnect = function(topic, message) {
this.client.write(String.fromCharCode(TYPE.DISCONNECT<<4)+"\x00");
this.client.write(fromCharCode(TYPE.DISCONNECT<<4)+"\x00");
this.client.end();
this.client = false;
this.connected = false;
Expand Down Expand Up @@ -251,7 +254,7 @@ MQTT.prototype.unsubscribe = function(topic) {

/** Send ping request to server */
MQTT.prototype.ping = function() {
this.client.write(String.fromCharCode(TYPE.PINGREQ<<4)+"\x00");
this.client.write(fromCharCode(TYPE.PINGREQ<<4)+"\x00");
};

/* Packet specific functions *******************/
Expand All @@ -278,18 +281,18 @@ MQTT.prototype.mqttConnect = function(clean) {
clean_session: clean
});

var keep_alive = String.fromCharCode(this.keep_alive>>8, this.keep_alive&255);
var keep_alive = fromCharCode(this.keep_alive>>8, this.keep_alive&255);

/* payload */
var payload = this.mqttStr(this.client_id);
var payload = mqttStr(this.client_id);
if( this.username ){
payload += this.mqttStr( this.username );
payload += mqttStr( this.username );
if( this.password ){
payload += this.mqttStr( this.password );
payload += mqttStr( this.password );
}
}

return this.mqttPacket(cmd,
return mqttPacket(cmd,
this.mqttStr( this.protocol_name )/*protocol name*/+
this.protocol_level /*protocol level*/+
flags+
Expand All @@ -300,29 +303,29 @@ MQTT.prototype.mqttConnect = function(clean) {
/** PUBLISH control packet */
MQTT.prototype.mqttPublish = function(topic, message, qos) {
var cmd = TYPE.PUBLISH << 4 | (qos << 1);
var pid = String.fromCharCode(C.PACKET_ID<<8, C.PACKET_ID&255);
var pid = fromCharCode(C.PACKET_ID<<8, C.PACKET_ID&255);
// Packet id must be included for QOS > 0
var variable = (qos === 0) ? this.mqttStr(topic) : this.mqttStr(topic)+pid;
return this.mqttPacket(cmd, variable, message);
var variable = (qos === 0) ? mqttStr(topic) : mqttStr(topic)+pid;
return mqttPacket(cmd, variable, message);
};

/** SUBSCRIBE control packet */
MQTT.prototype.mqttSubscribe = function(topic, qos) {
var cmd = TYPE.SUBSCRIBE << 4 | 2;
var pid = String.fromCharCode(C.PACKET_ID<<8, C.PACKET_ID&255);
return this.mqttPacket(cmd,
var pid = fromCharCode(C.PACKET_ID<<8, C.PACKET_ID&255);
return mqttPacket(cmd,
pid/*Packet id*/,
this.mqttStr(topic)+
String.fromCharCode(qos)/*QOS*/);
mqttStr(topic)+
fromCharCode(qos)/*QOS*/);
};

/** UNSUBSCRIBE control packet */
MQTT.prototype.mqttUnsubscribe = function(topic) {
var cmd = TYPE.UNSUBSCRIBE << 4 | 2;
var pid = String.fromCharCode(C.PACKET_ID<<8, C.PACKET_ID&255);
return this.mqttPacket(cmd,
var pid = fromCharCode(C.PACKET_ID<<8, C.PACKET_ID&255);
return mqttPacket(cmd,
pid/*Packet id*/,
this.mqttStr(topic));
mqttStr(topic));
};

/* Exports *************************************/
Expand Down

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