perf: remove browseField on container destruction (#2677)

Instead of checking all the time if there is a browsefield to be
destroyed, why not remove it at the time of its destruction?!

Besides, the linear search of phmap::flat_hash_map is very slow.

src/game/game.cpp

@@ -6255,7 +6255,6 @@ void Game::checkCreatureWalk(uint32_t creatureId) {
 	const auto &creature = getCreatureByID(creatureId);
 	if (creature && creature->getHealth() > 0) {
 		creature->onCreatureWalk();
-		cleanup();
 	}
 }
 
@@ -6318,7 +6317,6 @@ void Game::checkCreatures() {
 			--end;
 		}
 	}
-	cleanup();
 
 	index = (index + 1) % EVENT_CREATURECOUNT;
 }
@@ -7967,8 +7965,6 @@ void Game::shutdown() {
 	map.spawnsNpc.clear();
 	raids.clear();
 
-	cleanup();
-
 	if (serviceManager) {
 		serviceManager->stop();
 	}
@@ -7980,16 +7976,6 @@ void Game::shutdown() {
 	g_logger().info("Done!");
 }
 
-void Game::cleanup() {
-	for (auto it = browseFields.begin(); it != browseFields.end();) {
-		if (it->second.expired()) {
-			it = browseFields.erase(it);
-		} else {
-			++it;
-		}
-	}
-}
-
 void Game::addBestiaryList(uint16_t raceid, std::string name) {
 	auto it = BestiaryList.find(raceid);
 	if (it != BestiaryList.end()) {

src/game/game.hpp

@@ -426,7 +426,6 @@ class Game {
 
 	void updatePlayerHelpers(std::shared_ptr<Player> player);
 
-	void cleanup();
 	void shutdown();
 	void dieSafely(const std::string &errorMsg);
 	void addBestiaryList(uint16_t raceid, std::string name);

src/items/containers/container.cpp

@@ -63,6 +63,10 @@ std::shared_ptr<Container> Container::create(std::shared_ptr<Tile> tile) {
 
 Container::~Container() {
 	if (getID() == ITEM_BROWSEFIELD) {
+		if (getParent() && getParent()->getTile()) {
+			g_game().browseFields.erase(getParent()->getTile());
+		}
+
 		for (std::shared_ptr<Item> item : itemlist) {
 			item->setParent(getParent());
 		}