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node-red/nodes/core/io/lib/mqttConnectionPool.js
Nick O'Leary 6b3010f95b Guard against null client in MQTT nodes
Fixes #130

There was a timing window where a client could connect to a broker just as new flows were deployed that would cause the on-connect callback to be called after client has been set to null. This caused an NPE.

The fix is to check client isn't null in the event handler.
2014-01-13 11:27:09 +00:00

125 lines
5.2 KiB
JavaScript

/**
* Copyright 2013 IBM Corp.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
**/
var util = require("util");
var mqtt = require("./mqtt");
var settings = require(process.env.NODE_RED_HOME+"/red/red").settings;
var connections = {};
function matchTopic(ts,t) {
var re = new RegExp("^"+ts.replace(/([\[\]\?\(\)\\\\$\^\*\.|])/g,"\\$1").replace(/\+/g,"[^/]+").replace(/#$/,".*")+"$");
return re.test(t);
}
module.exports = {
get: function(broker,port,clientid,username,password) {
var id = "["+(username||"")+":"+(password||"")+"]["+(clientid||"")+"]@"+broker+":"+port;
if (!connections[id]) {
connections[id] = function() {
var client = mqtt.createClient(port,broker);
client.setMaxListeners(0);
var options = {keepalive:15};
options.clientId = clientid || 'mqtt_' + (1+Math.random()*4294967295).toString(16);
options.username = username;
options.password = password;
var queue = [];
var subscriptions = [];
var connecting = false;
var obj = {
_instances: 0,
publish: function(msg) {
if (client.isConnected()) {
client.publish(msg.topic,msg.payload,msg.qos,msg.retain);
} else {
if (!connecting) {
connecting = true;
client.connect(options);
}
queue.push(msg);
}
},
subscribe: function(topic,qos,callback) {
subscriptions.push({topic:topic,qos:qos,callback:callback});
client.on('message',function(mtopic,mpayload,mqos,mretain) {
if (matchTopic(topic,mtopic)) {
callback(mtopic,mpayload,mqos,mretain);
}
});
if (client.isConnected()) {
client.subscribe(topic,qos);
}
},
on: function(a,b){
client.on(a,b);
},
once: function(a,b){
client.once(a,b);
},
connect: function() {
if (!client.isConnected() && !connecting) {
connecting = true;
client.connect(options);
}
},
disconnect: function() {
this._instances -= 1;
if (this._instances == 0) {
client.disconnect();
client = null;
delete connections[id];
}
}
};
client.on('connect',function() {
if (client) {
util.log('[mqtt] connected to broker tcp://'+broker+':'+port);
connecting = false;
for (var s in subscriptions) {
var topic = subscriptions[s].topic;
var qos = subscriptions[s].qos;
var callback = subscriptions[s].callback;
client.subscribe(topic,qos);
}
//console.log("connected - publishing",queue.length,"messages");
while(queue.length) {
var msg = queue.shift();
//console.log(msg);
client.publish(msg.topic,msg.payload,msg.qos,msg.retain);
}
}
});
client.on('connectionlost', function(err) {
util.log('[mqtt] connection lost to broker tcp://'+broker+':'+port);
setTimeout(function() {
if (client) {
client.connect(options);
}
}, settings.mqttReconnectTime||5000);
});
client.on('disconnect', function() {
util.log('[mqtt] disconnected from broker tcp://'+broker+':'+port);
});
return obj
}();
}
connections[id]._instances += 1;
return connections[id];
}
};