command execution metrics

src/structure/components/observers/CommandHandler.js

@@ -129,12 +129,15 @@ class CommandHandler extends Observer {
     async _executeCommand(invoker, options) {
 
         let response = null;
+        const now = Date.now();
         try {
             response = await invoker.command.execute(invoker, options);
+            invoker.command.success(now);
         } catch (error) {
             if (error instanceof CommandError) {
                 this._generateError(invoker, { error, type: 'command' });
             } else {
+                invoker.command.error(now);
                 this.logger.error(error.stack || error);
                 this._generateError(invoker, { type: 'commandHandler' });
             }

src/structure/interfaces/commands/Command.js

@@ -44,7 +44,9 @@ class Command extends Component {
 
         this._invokes = {
             success: 0,
-            fail: 0
+            successTime: null,
+            fail: 0,
+            failTime: null
         };
 
         this.options = [];
@@ -79,6 +81,28 @@ class Command extends Component {
         throw new Error(`${this.resolveable} is missing an execute function.`);
     }
 
+    success(when) {
+        const now = Date.now();
+        const execTime = now - when;
+        if (!this._invokes.successTime) {
+            this._invokes.successTime = execTime;
+            this._invokes.success++;
+        } else { // Calculate new average
+            this._invokes.successTime = (this._invokes.successTime * this._invokes.success + execTime) / ++this._invokes.success;
+        }
+    }
+
+    error(when) {
+        const now = Date.now();
+        const execTime = now - when;
+        if (!this._invokes.failTime) {
+            this._invokes.failTime = execTime;
+            this._invokes.fail++;
+        } else { // Calculate new average
+            this._invokes.failTime = (this._invokes.failTime * this._invokes.fail + execTime) / ++this._invokes.fail;
+        }
+    }
+
     usageEmbed(invoker, verbose = false) {
 
         const fields = [];