custom caching

classes/caching/key_timeout.js

@@ -0,0 +1,16 @@
+module.exports = class KeyTimeout {
+  constructor() {
+    this.timeoutHandleForKey = {};
+  }
+
+  clearTimeout(key) {
+    clearTimeout(this.timeoutHandleForKey[key]);
+  }
+
+  updateTimeout(key, durationMs, callback) {
+    this.clearTimeout(key);
+    this.timeoutHandleForKey[key] = setTimeout(() => {
+      callback();
+    }, durationMs);
+  }
+}