feat: add statusChanged getter

README.md

@@ -98,11 +98,17 @@ req.on('error', e => {
 req.end();
 
 setTimeout(() => {
-  console.log('agent status: %j', keepaliveAgent.getCurrentStatus());
+  if (keepaliveAgent.statusChanged) {
+    console.log('[%s] agent status changed: %j', Date(), keepaliveAgent.getCurrentStatus());
+  }
 }, 2000);
 
 ```
 
+### `getter agent.statusChanged`
+
+counters have change or not after last checkpoint.
+
 ### `agent.getCurrentStatus()`
 
 `agent.getCurrentStatus()` will return a object to show the status of this agent:
@@ -218,8 +224,8 @@ Socket created:
 ```
 (The MIT License)
 
-Copyright(c) 2012 - 2015 fengmk2 <fengmk2@gmail.com>
 Copyright(c) node-modules and other contributors.
+Copyright(c) 2012 - 2015 fengmk2 <fengmk2@gmail.com>
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

lib/agent.js

@@ -39,12 +39,24 @@ class Agent extends OriginalAgent {
     super(options);
 
     this.createSocketCount = 0;
+    this.createSocketCountLastCheck = 0;
+
     this.createSocketErrorCount = 0;
+    this.createSocketErrorCountLastCheck = 0;
+
     this.closeSocketCount = 0;
+    this.closeSocketCountLastCheck = 0;
+
     // socket error event count
     this.errorSocketCount = 0;
+    this.errorSocketCountLastCheck = 0;
+
     this.requestCount = 0;
+    this.requestCountLastCheck = 0;
+
     this.timeoutSocketCount = 0;
+    this.timeoutSocketCountLastCheck = 0;
+
     this.on('free', s => {
       this.requestCount++;
       // last enter free queue timestamp
@@ -77,6 +89,24 @@ class Agent extends OriginalAgent {
     });
   }
 
+  get statusChanged() {
+    const changed = this.createSocketCount !== this.createSocketCountLastCheck ||
+      this.createSocketErrorCount !== this.createSocketErrorCountLastCheck ||
+      this.closeSocketCount !== this.closeSocketCountLastCheck ||
+      this.errorSocketCount !== this.errorSocketCountLastCheck ||
+      this.timeoutSocketCount !== this.timeoutSocketCountLastCheck ||
+      this.requestCount !== this.requestCountLastCheck;
+    if (changed) {
+      this.createSocketCountLastCheck = this.createSocketCount;
+      this.createSocketErrorCountLastCheck = this.createSocketErrorCount;
+      this.closeSocketCountLastCheck = this.closeSocketCount;
+      this.errorSocketCountLastCheck = this.errorSocketCount;
+      this.timeoutSocketCountLastCheck = this.timeoutSocketCount;
+      this.requestCountLastCheck = this.requestCount;
+    }
+    return changed;
+  }
+
   getCurrentStatus() {
     return {
       createSocketCount: this.createSocketCount,

test/agent.test.js

@@ -996,12 +996,60 @@ describe('test/agent.test.js', () => {
     it('should get current agent status', () => {
       const status = agentkeepalive.getCurrentStatus();
       assert.deepEqual(Object.keys(status), [
-        'createSocketCount', 'createSocketErrorCount', 'closeSocketCount', 'errorSocketCount', 'timeoutSocketCount',
+        'createSocketCount', 'createSocketErrorCount', 'closeSocketCount',
+        'errorSocketCount', 'timeoutSocketCount',
         'requestCount', 'freeSockets', 'sockets', 'requests',
       ]);
     });
   });
 
+  describe('getter statusChanged', () => {
+    it('should get statusChanged', () => {
+      const agentkeepalive = new Agent({
+        keepAliveTimeout: 1000,
+        maxSockets: 5,
+        maxFreeSockets: 5,
+      });
+      assert(agentkeepalive.statusChanged === false);
+      assert(agentkeepalive.statusChanged === false);
+      agentkeepalive.createSocketCount++;
+      assert(agentkeepalive.createSocketCount !== agentkeepalive.createSocketCountLastCheck);
+      assert(agentkeepalive.statusChanged === true);
+      assert(agentkeepalive.createSocketCount === agentkeepalive.createSocketCountLastCheck);
+      assert(agentkeepalive.statusChanged === false);
+
+      agentkeepalive.createSocketErrorCount++;
+      assert(agentkeepalive.createSocketErrorCount !== agentkeepalive.createSocketErrorCountLastCheck);
+      assert(agentkeepalive.statusChanged === true);
+      assert(agentkeepalive.createSocketErrorCount === agentkeepalive.createSocketErrorCountLastCheck);
+      assert(agentkeepalive.statusChanged === false);
+
+      agentkeepalive.closeSocketCount++;
+      assert(agentkeepalive.closeSocketCount !== agentkeepalive.closeSocketCountLastCheck);
+      assert(agentkeepalive.statusChanged === true);
+      assert(agentkeepalive.closeSocketCount === agentkeepalive.closeSocketCountLastCheck);
+      assert(agentkeepalive.statusChanged === false);
+
+      agentkeepalive.errorSocketCount++;
+      assert(agentkeepalive.errorSocketCount !== agentkeepalive.errorSocketCountLastCheck);
+      assert(agentkeepalive.statusChanged === true);
+      assert(agentkeepalive.errorSocketCount === agentkeepalive.errorSocketCountLastCheck);
+      assert(agentkeepalive.statusChanged === false);
+
+      agentkeepalive.timeoutSocketCount++;
+      assert(agentkeepalive.timeoutSocketCount !== agentkeepalive.timeoutSocketCountLastCheck);
+      assert(agentkeepalive.statusChanged === true);
+      assert(agentkeepalive.timeoutSocketCount === agentkeepalive.timeoutSocketCountLastCheck);
+      assert(agentkeepalive.statusChanged === false);
+
+      agentkeepalive.requestCount++;
+      assert(agentkeepalive.requestCount !== agentkeepalive.requestCountLastCheck);
+      assert(agentkeepalive.statusChanged === true);
+      assert(agentkeepalive.requestCount === agentkeepalive.requestCountLastCheck);
+      assert(agentkeepalive.statusChanged === false);
+    });
+  });
+
   describe('mock idle socket error', () => {
     it('should idle socket emit error event', done => {
       const agent = new Agent();