Inventory: Send dirty lists where appropriate (#8742)

This change reduces the amount of sent data towards clients. Inventory lists that are already known to the player are skipped, saving quite some data over time.

Raises protocol version to 38 to ensure correct backwards-compatible code.

src/client/client.cpp

@@ -557,8 +557,8 @@ void Client::step(float dtime)
 		if (count_after != count_before) {
 			// Do this every <interval> seconds after TOCLIENT_INVENTORY
 			// Reset the locally changed inventory to the authoritative inventory
-			m_env.getLocalPlayer()->inventory = *m_inventory_from_server;
-			m_inventory_updated = true;
+			player->inventory = *m_inventory_from_server;
+			m_update_wielded_item = true;
 		}
 	}
 
@@ -1331,28 +1331,30 @@ void Client::setPlayerControl(PlayerControl &control)
 void Client::setPlayerItem(u16 item)
 {
 	m_env.getLocalPlayer()->setWieldIndex(item);
-	m_inventory_updated = true;
+	m_update_wielded_item = true;
 
 	NetworkPacket pkt(TOSERVER_PLAYERITEM, 2);
 	pkt << item;
 	Send(&pkt);
 }
 
-// Returns true if the inventory of the local player has been
-// updated from the server. If it is true, it is set to false.
-bool Client::getLocalInventoryUpdated()
+// Returns true once after the inventory of the local player
+// has been updated from the server.
+bool Client::updateWieldedItem()
 {
-	bool updated = m_inventory_updated;
-	m_inventory_updated = false;
-	return updated;
-}
+	if (!m_update_wielded_item)
+		return false;
+
+	m_update_wielded_item = false;
 
-// Copies the inventory of the local player to parameter
-void Client::getLocalInventory(Inventory &dst)
-{
 	LocalPlayer *player = m_env.getLocalPlayer();
 	assert(player);
-	dst = player->inventory;
+	if (auto *list = player->inventory.getList("main"))
+		list->setModified(false);
+	if (auto *list = player->inventory.getList("hand"))
+		list->setModified(false);
+
+	return true;
 }
 
 Inventory* Client::getInventory(const InventoryLocation &loc)

src/client/client.h

@@ -274,9 +274,7 @@ public:
 
 	// Returns true if the inventory of the local player has been
 	// updated from the server. If it is true, it is set to false.
-	bool getLocalInventoryUpdated();
-	// Copies the inventory of the local player to parameter
-	void getLocalInventory(Inventory &dst);
+	bool updateWieldedItem();
 
 	/* InventoryManager interface */
 	Inventory* getInventory(const InventoryLocation &loc) override;
@@ -504,7 +502,7 @@ private:
 	// If 0, server init hasn't been received yet.
 	u16 m_proto_ver = 0;
 
-	bool m_inventory_updated = false;
+	bool m_update_wielded_item = false;
 	Inventory *m_inventory_from_server = nullptr;
 	float m_inventory_from_server_age = 0.0f;
 	PacketCounter m_packetcounter;

src/client/game.cpp

@@ -599,7 +599,6 @@ struct GameRunData {
 	bool dig_instantly;
 	bool digging_blocked;
 	bool left_punch;
-	bool update_wielded_item_trigger;
 	bool reset_jump_timer;
 	float nodig_delay_timer;
 	float dig_time;
@@ -1018,7 +1017,6 @@ bool Game::startup(bool *kill,
 	// Reinit runData
 	runData = GameRunData();
 	runData.time_from_last_punch = 10.0;
-	runData.update_wielded_item_trigger = true;
 
 	m_game_ui->initFlags();
 
@@ -3736,19 +3734,11 @@ void Game::updateFrame(ProfilerGraph *graph, RunStats *stats, f32 dtime,
 	if (player->getWieldIndex() != runData.new_playeritem)
 		client->setPlayerItem(runData.new_playeritem);
 
-	// Update local inventory if it has changed
-	if (client->getLocalInventoryUpdated()) {
-		//infostream<<"Updating local inventory"<<std::endl;
-		runData.update_wielded_item_trigger = true;
-	}
-
-	if (runData.update_wielded_item_trigger) {
+	if (client->updateWieldedItem()) {
 		// Update wielded tool
 		ItemStack selected_item, hand_item;
 		ItemStack &tool_item = player->getWieldedItem(&selected_item, &hand_item);
 		camera->wield(tool_item);
-
-		runData.update_wielded_item_trigger = false;
 	}
 
 	/*