Send only changed node metadata to clients instead of whole mapblock (#5268)

Includes newer style changes and fixes by est31

Improve the block position de-serialization
Add type NodeMetadataMap

5 files changed, 43 insertions, 7 deletions

diff --git a/src/network/clientopcodes.cpp b/src/network/clientopcodes.cpp
index 923a92d32..7f3ab50ed 100644
--- a/src/network/clientopcodes.cpp
+++ b/src/network/clientopcodes.cpp
@@ -113,7 +113,7 @@ const ToClientCommandHandler toClientCommandTable[TOCLIENT_NUM_MSG_TYPES] =
 	{ "TOCLIENT_UPDATE_PLAYER_LIST",       TOCLIENT_STATE_CONNECTED, &Client::handleCommand_UpdatePlayerList }, // 0x56
 	{ "TOCLIENT_MODCHANNEL_MSG",           TOCLIENT_STATE_CONNECTED, &Client::handleCommand_ModChannelMsg }, // 0x57
 	{ "TOCLIENT_MODCHANNEL_SIGNAL",        TOCLIENT_STATE_CONNECTED, &Client::handleCommand_ModChannelSignal }, // 0x58
-	null_command_handler,
+	{ "TOCLIENT_NODEMETA_CHANGED",         TOCLIENT_STATE_CONNECTED, &Client::handleCommand_NodemetaChanged }, // 0x59
 	null_command_handler,
 	null_command_handler,
 	null_command_handler,
diff --git a/src/network/clientpackethandler.cpp b/src/network/clientpackethandler.cpp
index 1be7d4eeb..0dca4aff4 100644
--- a/src/network/clientpackethandler.cpp
+++ b/src/network/clientpackethandler.cpp
@@ -243,6 +243,33 @@ void Client::handleCommand_AddNode(NetworkPacket* pkt)
 
 	addNode(p, n, remove_metadata);
 }
+
+void Client::handleCommand_NodemetaChanged(NetworkPacket *pkt)
+{
+	if (pkt->getSize() < 1)
+		return;
+
+	std::istringstream is(pkt->readLongString(), std::ios::binary);
+	std::stringstream sstr;
+	decompressZlib(is, sstr);
+
+	NodeMetadataList meta_updates_list(false);
+	meta_updates_list.deSerialize(sstr, m_itemdef, true);
+
+	Map &map = m_env.getMap();
+	for (NodeMetadataMap::const_iterator i = meta_updates_list.begin();
+			i != meta_updates_list.end(); ++i) {
+		v3s16 pos = i->first;
+
+		if (map.isValidPosition(pos) &&
+				map.setNodeMetadata(pos, i->second))
+			continue; // Prevent from deleting metadata
+
+		// Meta couldn't be set, unused metadata
+		delete i->second;
+	}
+}
+
 void Client::handleCommand_BlockData(NetworkPacket* pkt)
 {
 	// Ignore too small packet
diff --git a/src/network/networkprotocol.h b/src/network/networkprotocol.h
index 855afc638..12a91e647 100644
--- a/src/network/networkprotocol.h
+++ b/src/network/networkprotocol.h
@@ -190,6 +190,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 		Add TOCLIENT_FORMSPEC_PREPEND
 	PROTOCOL VERSION 37:
 		Redo detached inventory sending
+		Add TOCLIENT_NODEMETA_CHANGED
 */
 
 #define LATEST_PROTOCOL_VERSION 37
@@ -638,13 +639,19 @@ enum ToClientCommand
 	 	std::string channel name
 	 	u16 message length
 	 	std::string message
-	 */
+	*/
+
 	TOCLIENT_MODCHANNEL_SIGNAL = 0x58,
 	/*
 		u8 signal id
 	 	u16 channel name length
 	 	std::string channel name
-	 */
+	*/
+
+	TOCLIENT_NODEMETA_CHANGED = 0x59,
+	/*
+		serialized and compressed node metadata
+	*/
 
 	TOCLIENT_SRP_BYTES_S_B = 0x60,
 	/*
diff --git a/src/network/serveropcodes.cpp b/src/network/serveropcodes.cpp
index e4e313611..013b549c6 100644
--- a/src/network/serveropcodes.cpp
+++ b/src/network/serveropcodes.cpp
@@ -200,9 +200,9 @@ const ClientCommandFactory clientCommandFactoryTable[TOCLIENT_NUM_MSG_TYPES] =
 	{ "TOCLIENT_CLOUD_PARAMS",             0, true }, // 0x54
 	{ "TOCLIENT_FADE_SOUND",               0, true }, // 0x55
 	{ "TOCLIENT_UPDATE_PLAYER_LIST",       0, true }, // 0x56
-	{ "TOCLIENT_MODCHANNEL_MSG",           0, true}, // 0x57
-	{ "TOCLIENT_MODCHANNEL_SIGNAL",        0, true}, // 0x58
-	null_command_factory,
+	{ "TOCLIENT_MODCHANNEL_MSG",           0, true }, // 0x57
+	{ "TOCLIENT_MODCHANNEL_SIGNAL",        0, true }, // 0x58
+	{ "TOCLIENT_NODEMETA_CHANGED",         0, true }, // 0x59
 	null_command_factory,
 	null_command_factory,
 	null_command_factory,
diff --git a/src/network/serverpackethandler.cpp b/src/network/serverpackethandler.cpp
index 8299ad002..329b38765 100644
--- a/src/network/serverpackethandler.cpp
+++ b/src/network/serverpackethandler.cpp
@@ -609,7 +609,9 @@ void Server::handleCommand_InventoryAction(NetworkPacket* pkt)
 		ma->to_inv.applyCurrentPlayer(player->getName());
 
 		setInventoryModified(ma->from_inv, false);
-		setInventoryModified(ma->to_inv, false);
+		if (ma->from_inv != ma->to_inv) {
+			setInventoryModified(ma->to_inv, false);
+		}
 
 		bool from_inv_is_current_player =
 			(ma->from_inv.type == InventoryLocation::PLAYER) &&