LibWeb/IDB: Implement possibly_update_the_key_generator

Author: https://github.com/stelar7
Commit: 1bdf519b60
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/4317
Reviewed-by: https://github.com/ADKaster ✅
Reviewed-by: https://github.com/kennethmyhra ✅

Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp

@@ -1235,4 +1235,28 @@ ErrorOr<u64> generate_a_key(GC::Ref<ObjectStore> store)
     return key;
 }
 
+// https://w3c.github.io/IndexedDB/#possibly-update-the-key-generator
+void possibly_update_the_key_generator(GC::Ref<ObjectStore> store, GC::Ref<Key> key)
+{
+    // 1. If the type of key is not number, abort these steps.
+    if (key->type() != Key::KeyType::Number)
+        return;
+
+    // 2. Let value be the value of key.
+    auto temp_value = key->value_as_double();
+
+    // 3. Set value to the minimum of value and 2^53 (9007199254740992).
+    temp_value = min(temp_value, MAX_KEY_GENERATOR_VALUE);
+
+    // 4. Set value to the largest integer not greater than value.
+    u64 value = floor(temp_value);
+
+    // 5. Let generator be store’s key generator.
+    auto generator = store->key_generator().value();
+
+    // 6. If value is greater than or equal to generator’s current number, then set generator’s current number to value + 1.
+    if (value >= generator.current_number())
+        generator.set(value + 1);
+}
+
 }