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

src/script/lua_api/l_itemstackmeta.cpp

@@ -46,7 +46,7 @@ void ItemStackMetaRef::clearMeta()
 	istack->metadata.clear();
 }
 
-void ItemStackMetaRef::reportMetadataChange()
+void ItemStackMetaRef::reportMetadataChange(const std::string *name)
 {
 	// TODO
 }

src/script/lua_api/l_itemstackmeta.h

@@ -40,7 +40,7 @@ private:
 
 	virtual void clearMeta();
 
-	virtual void reportMetadataChange();
+	virtual void reportMetadataChange(const std::string *name = nullptr);
 
 	void setToolCapabilities(const ToolCapabilities &caps)
 	{

src/script/lua_api/l_metadata.cpp

@@ -122,7 +122,7 @@ int MetaDataRef::l_set_string(lua_State *L)
 		return 0;
 
 	meta->setString(name, str);
-	ref->reportMetadataChange();
+	ref->reportMetadataChange(&name);
 	return 0;
 }
 
@@ -160,7 +160,7 @@ int MetaDataRef::l_set_int(lua_State *L)
 		return 0;
 
 	meta->setString(name, str);
-	ref->reportMetadataChange();
+	ref->reportMetadataChange(&name);
 	return 0;
 }
 
@@ -198,7 +198,7 @@ int MetaDataRef::l_set_float(lua_State *L)
 		return 0;
 
 	meta->setString(name, str);
-	ref->reportMetadataChange();
+	ref->reportMetadataChange(&name);
 	return 0;
 }
 

src/script/lua_api/l_metadata.h

@@ -37,7 +37,7 @@ public:
 protected:
 	static MetaDataRef *checkobject(lua_State *L, int narg);
 
-	virtual void reportMetadataChange() {}
+	virtual void reportMetadataChange(const std::string *name = nullptr) {}
 	virtual Metadata *getmeta(bool auto_create) = 0;
 	virtual void clearMeta() = 0;
 

src/script/lua_api/l_nodemeta.cpp

@@ -58,21 +58,17 @@ void NodeMetaRef::clearMeta()
 	m_env->getMap().removeNodeMetadata(m_p);
 }
 
-void NodeMetaRef::reportMetadataChange()
+void NodeMetaRef::reportMetadataChange(const std::string *name)
 {
 	// NOTE: This same code is in rollback_interface.cpp
 	// Inform other things that the metadata has changed
-	v3s16 blockpos = getNodeBlockPos(m_p);
+	NodeMetadata *meta = dynamic_cast<NodeMetadata*>(m_meta);
+
 	MapEditEvent event;
 	event.type = MEET_BLOCK_NODE_METADATA_CHANGED;
-	event.p = blockpos;
+	event.p = m_p;
+	event.is_private_change = name && meta && meta->isPrivate(*name);
 	m_env->getMap().dispatchEvent(&event);
-	// Set the block to be saved
-	MapBlock *block = m_env->getMap().getBlockNoCreateNoEx(blockpos);
-	if (block) {
-		block->raiseModified(MOD_STATE_WRITE_NEEDED,
-			MOD_REASON_REPORT_META_CHANGE);
-	}
 }
 
 // Exported functions

src/script/lua_api/l_nodemeta.h

@@ -60,7 +60,7 @@ private:
 	virtual Metadata* getmeta(bool auto_create);
 	virtual void clearMeta();
 
-	virtual void reportMetadataChange();
+	virtual void reportMetadataChange(const std::string *name = nullptr);
 
 	virtual void handleToTable(lua_State *L, Metadata *_meta);
 	virtual bool handleFromTable(lua_State *L, int table, Metadata *_meta);