chore: make clearAll bit faster

packages/react-native-mmkv/cpp/HybridMMKV.cpp

@@ -162,11 +162,17 @@ std::vector<std::string> HybridMMKV::getAllKeys() {
   return instance->allKeys();
 }
 void HybridMMKV::clearAll() {
+  auto mmkvID = instance->mmapID();
+
+  if (!MMKVValueChangedListenerRegistry::hasListeners(mmkvID)) {
+    instance->clearAll();
+    return;
+  }
+
   auto keysBefore = getAllKeys();
   instance->clearAll();
   for (const auto& key : keysBefore) {
-    // Notify on changed
-    MMKVValueChangedListenerRegistry::notifyOnValueChanged(instance->mmapID(), key);
+    MMKVValueChangedListenerRegistry::notifyOnValueChanged(mmkvID, key);
   }
 }
 void HybridMMKV::recrypt(const std::optional<std::string>& key) {

packages/react-native-mmkv/cpp/MMKVValueChangedListenerRegistry.cpp

@@ -41,6 +41,14 @@ void MMKVValueChangedListenerRegistry::removeListener(const std::string& mmkvID,
                   listeners.end());
 }
 
+bool MMKVValueChangedListenerRegistry::hasListeners(const std::string& mmkvID) {
+  auto entry = _listeners.find(mmkvID);
+  if (entry == _listeners.end()) {
+    return false;
+  }
+  return !entry->second.empty();
+}
+
 void MMKVValueChangedListenerRegistry::notifyOnValueChanged(const std::string& mmkvID, const std::string& key) {
   // 1. Get all listeners for the specific MMKV ID
   auto entry = _listeners.find(mmkvID);

packages/react-native-mmkv/cpp/MMKVValueChangedListenerRegistry.hpp

@@ -31,6 +31,7 @@ class MMKVValueChangedListenerRegistry final {
 public:
   static ListenerID addListener(const std::string& mmkvID, const std::function<void(const std::string& /* key */)>& callback);
   static void removeListener(const std::string& mmkvID, ListenerID id);
+  static bool hasListeners(const std::string& mmkvID);
 
 public:
   static void notifyOnValueChanged(const std::string& mmkvID, const std::string& key);