LibWeb/IDB: Implement KeyGenerator

Author: https://github.com/stelar7
Commit: https://github.com/LadybirdBrowser/ladybird/commit/c276c212a0f
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4077
Reviewed-by: https://github.com/AtkinsSJ
Reviewed-by: https://github.com/gmta ✅

Libraries/LibWeb/IndexedDB/Internal/KeyGenerator.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2025, stelar7 <dudedbz@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+
+namespace Web::IndexedDB {
+
+// https://w3c.github.io/IndexedDB/#key-generator-construct
+class KeyGenerator {
+public:
+private:
+    // A key generator has a current number.
+    // The current number is always a positive integer less than or equal to 2^53 (9007199254740992) + 1.
+    // The initial value of a key generator's current number is 1, set when the associated object store is created.
+    // The current number is incremented as keys are generated, and may be updated to a specific value by using explicit keys.
+    u64 current_number { 1 };
+};
+
+}