Implement zigbee queue. #1027

lib/util/zigbeeQueue.js

@@ -0,0 +1,84 @@
+const maxSimultaneouslyRunning = 5;
+const delay = 250;
+const error17Retries = 3;
+
+class ZigbeeQueue {
+    constructor() {
+        this.queue = [];
+        this.active = [];
+        this.timer = null;
+        this.running = false;
+    }
+
+    start() {
+        this.running = true;
+        this.resetTimer();
+    }
+
+    push(entityID, func) {
+        this.queue.push({entityID, func, attempts: 0});
+    }
+
+    stopTimer() {
+        if (this.timer) {
+            clearInterval(this.timer);
+            this.timer = null;
+        }
+    }
+
+    resetTimer() {
+        this.stopTimer();
+
+        this.timer = setInterval(() => {
+            this.executeNext();
+        }, delay);
+    }
+
+    stop() {
+        this.stopTimer();
+        this.running = false;
+    }
+
+    handleJobComplete(job, error) {
+        if (error && error.message === 'rsp error: 17' && job.attempts < error17Retries) {
+            // Error 17 means that the buffer of the ZNP was full,
+            // retry this for a maximum of 3 times.
+            job.attempts++;
+            this.active.splice(this.active.indexOf(job), 1);
+        } else {
+            this.active.splice(this.active.indexOf(job), 1);
+            this.queue.splice(this.queue.indexOf(job), 1);
+        }
+    }
+
+    executeNext() {
+        if (!this.running) {
+            return;
+        }
+
+        const next = this.getNext();
+
+        if (next) {
+            this.active.push(next);
+            next.func((error) => this.handleJobComplete(next, error));
+        }
+    }
+
+    getNext() {
+        if (this.active.length > (maxSimultaneouslyRunning - 1)) {
+            return null;
+        }
+
+        for (let i = 0; i < this.queue.length; i++) {
+            const job = this.queue[i];
+            const activeDeviceJob = this.active.find((j) => j.entityID === job.entityID);
+            if (!activeDeviceJob) {
+                return job;
+            }
+        }
+
+        return null;
+    }
+}
+
+module.exports = ZigbeeQueue;