From 3d66622772e66154b7624957a27f9be54c4c7c28 Mon Sep 17 00:00:00 2001
From: SmallJoker <SmallJoker@users.noreply.github.com>
Date: Tue, 4 Dec 2018 20:37:48 +0100
Subject: 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/nodemetadata.cpp | 62 +++++++++++++++++++++++++++++++++-------------------
 1 file changed, 39 insertions(+), 23 deletions(-)

(limited to 'src/nodemetadata.cpp')

diff --git a/src/nodemetadata.cpp b/src/nodemetadata.cpp
index 708a08099..b84ffc8cb 100644
--- a/src/nodemetadata.cpp
+++ b/src/nodemetadata.cpp
@@ -112,7 +112,8 @@ int NodeMetadata::countNonPrivate() const
 	NodeMetadataList
 */
 
-void NodeMetadataList::serialize(std::ostream &os, u8 blockver, bool disk) const
+void NodeMetadataList::serialize(std::ostream &os, u8 blockver, bool disk,
+	bool absolute_pos) const
 {
 	/*
 		Version 0 is a placeholder for "nothing to see here; go away."
@@ -128,20 +129,29 @@ void NodeMetadataList::serialize(std::ostream &os, u8 blockver, bool disk) const
 	writeU8(os, version);
 	writeU16(os, count);
 
-	for (const auto &it : m_data) {
-		v3s16 p = it.first;
-		NodeMetadata *data = it.second;
+	for (NodeMetadataMap::const_iterator
+			i = m_data.begin();
+			i != m_data.end(); ++i) {
+		v3s16 p = i->first;
+		NodeMetadata *data = i->second;
 		if (data->empty())
 			continue;
 
-		u16 p16 = p.Z * MAP_BLOCKSIZE * MAP_BLOCKSIZE + p.Y * MAP_BLOCKSIZE + p.X;
-		writeU16(os, p16);
-
+		if (absolute_pos) {
+			writeS16(os, p.X);
+			writeS16(os, p.Y);
+			writeS16(os, p.Z);
+		} else {
+			// Serialize positions within a mapblock
+			u16 p16 = (p.Z * MAP_BLOCKSIZE + p.Y) * MAP_BLOCKSIZE + p.X;
+			writeU16(os, p16);
+		}
 		data->serialize(os, version, disk);
 	}
 }
 
-void NodeMetadataList::deSerialize(std::istream &is, IItemDefManager *item_def_mgr)
+void NodeMetadataList::deSerialize(std::istream &is,
+	IItemDefManager *item_def_mgr, bool absolute_pos)
 {
 	clear();
 
@@ -162,15 +172,19 @@ void NodeMetadataList::deSerialize(std::istream &is, IItemDefManager *item_def_m
 	u16 count = readU16(is);
 
 	for (u16 i = 0; i < count; i++) {
-		u16 p16 = readU16(is);
-
 		v3s16 p;
-		p.Z = p16 / MAP_BLOCKSIZE / MAP_BLOCKSIZE;
-		p16 &= MAP_BLOCKSIZE * MAP_BLOCKSIZE - 1;
-		p.Y = p16 / MAP_BLOCKSIZE;
-		p16 &= MAP_BLOCKSIZE - 1;
-		p.X = p16;
-
+		if (absolute_pos) {
+			p.X = readS16(is);
+			p.Y = readS16(is);
+			p.Z = readS16(is);
+		} else {
+			u16 p16 = readU16(is);
+			p.X = p16 & (MAP_BLOCKSIZE - 1);
+			p16 /= MAP_BLOCKSIZE;
+			p.Y = p16 & (MAP_BLOCKSIZE - 1);
+			p16 /= MAP_BLOCKSIZE;
+			p.Z = p16;
+		}
 		if (m_data.find(p) != m_data.end()) {
 			warningstream << "NodeMetadataList::deSerialize(): "
 					<< "already set data at position " << PP(p)
@@ -193,7 +207,7 @@ std::vector<v3s16> NodeMetadataList::getAllKeys()
 {
 	std::vector<v3s16> keys;
 
-	std::map<v3s16, NodeMetadata *>::const_iterator it;
+	NodeMetadataMap::const_iterator it;
 	for (it = m_data.begin(); it != m_data.end(); ++it)
 		keys.push_back(it->first);
 
@@ -202,7 +216,7 @@ std::vector<v3s16> NodeMetadataList::getAllKeys()
 
 NodeMetadata *NodeMetadataList::get(v3s16 p)
 {
-	std::map<v3s16, NodeMetadata *>::const_iterator n = m_data.find(p);
+	NodeMetadataMap::const_iterator n = m_data.find(p);
 	if (n == m_data.end())
 		return NULL;
 	return n->second;
@@ -212,7 +226,8 @@ void NodeMetadataList::remove(v3s16 p)
 {
 	NodeMetadata *olddata = get(p);
 	if (olddata) {
-		delete olddata;
+		if (m_is_metadata_owner)
+			delete olddata;
 		m_data.erase(p);
 	}
 }
@@ -225,9 +240,10 @@ void NodeMetadataList::set(v3s16 p, NodeMetadata *d)
 
 void NodeMetadataList::clear()
 {
-	std::map<v3s16, NodeMetadata*>::iterator it;
-	for (it = m_data.begin(); it != m_data.end(); ++it) {
-		delete it->second;
+	if (m_is_metadata_owner) {
+		NodeMetadataMap::const_iterator it;
+		for (it = m_data.begin(); it != m_data.end(); ++it)
+			delete it->second;
 	}
 	m_data.clear();
 }
@@ -235,7 +251,7 @@ void NodeMetadataList::clear()
 int NodeMetadataList::countNonEmpty() const
 {
 	int n = 0;
-	std::map<v3s16, NodeMetadata*>::const_iterator it;
+	NodeMetadataMap::const_iterator it;
 	for (it = m_data.begin(); it != m_data.end(); ++it) {
 		if (!it->second->empty())
 			n++;
-- 
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