[CCSDK-28] populated the seed code for dgbuilder

[ccsdk/distribution.git] / dgbuilder / core_nodes / io / lib / mqttConnectionPool.js

diff --git a/dgbuilder/core_nodes/io/lib/mqttConnectionPool.js b/dgbuilder/core_nodes/io/lib/mqttConnectionPool.js
new file mode 100644 (file)
index 0000000..d15f0fc
--- /dev/null
+++ b/dgbuilder/core_nodes/io/lib/mqttConnectionPool.js
@@ -0,0 +1,128 @@
+/**
+ * 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) {
+    if (ts == "#") {
+        return true;
+    }
+    var re = new RegExp("^"+ts.replace(/([\[\]\?\(\)\\\\$\^\*\.|])/g,"\\$1").replace(/\+/g,"[^/]+").replace(/\/#$/,"(\/.*)?")+"$");
+    return re.test(t);
+}
+
+module.exports = {
+    get: function(broker,port,clientid,username,password,will) {
+        var id = "["+(username||"")+":"+(password||"")+"]["+(clientid||"")+"]@"+broker+":"+port;
+        if (!connections[id]) {
+            connections[id] = function() {
+                var uid = (1+Math.random()*4294967295).toString(16);
+                var client = mqtt.createClient(port,broker);
+                client.uid = uid;
+                client.setMaxListeners(0);
+                var options = {keepalive:15};
+                options.clientId = clientid || 'mqtt_' + (1+Math.random()*4294967295).toString(16);
+                options.username = username;
+                options.password = password;
+                options.will = will;
+                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 && !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] ['+uid+'] 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] ['+uid+'] connection lost to broker tcp://'+broker+':'+port);
+                        connecting = false;
+                        setTimeout(function() {
+                            obj.connect();
+                        }, settings.mqttReconnectTime||5000);
+                });
+                client.on('disconnect', function() {
+                        connecting = false;
+                        util.log('[mqtt] ['+uid+'] disconnected from broker tcp://'+broker+':'+port);
+                });
+
+                return obj
+            }();
+        }
+        connections[id]._instances += 1;
+        return connections[id];
+    }
+};