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/inventory.cpp

@@ -20,6 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "inventory.h"
 #include "serialization.h"
 #include "debug.h"
+#include <algorithm>
 #include <sstream>
 #include "log.h"
 #include "itemdef.h"
@@ -382,27 +383,32 @@ void InventoryList::clearItems()
 		m_items.emplace_back();
 	}
 
-	//setDirty(true);
+	setModified();
 }
 
 void InventoryList::setSize(u32 newsize)
 {
-	if(newsize != m_items.size())
-		m_items.resize(newsize);
+	if (newsize == m_items.size())
+		return;
+
+	m_items.resize(newsize);
 	m_size = newsize;
+	setModified();
 }
 
 void InventoryList::setWidth(u32 newwidth)
 {
 	m_width = newwidth;
+	setModified();
 }
 
 void InventoryList::setName(const std::string &name)
 {
 	m_name = name;
+	setModified();
 }
 
-void InventoryList::serialize(std::ostream &os) const
+void InventoryList::serialize(std::ostream &os, bool incremental) const
 {
 	//os.imbue(std::locale("C"));
 
@@ -415,6 +421,9 @@ void InventoryList::serialize(std::ostream &os) const
 			os<<"Item ";
 			item.serialize(os);
 		}
+		// TODO: Implement this:
+		// if (!incremental || item.checkModified())
+		// os << "Keep";
 		os<<"\n";
 	}
 
@@ -424,8 +433,8 @@ void InventoryList::serialize(std::ostream &os) const
 void InventoryList::deSerialize(std::istream &is)
 {
 	//is.imbue(std::locale("C"));
+	setModified();
 
-	clearItems();
 	u32 item_i = 0;
 	m_width = 0;
 
@@ -439,12 +448,12 @@ void InventoryList::deSerialize(std::istream &is)
 		std::string name;
 		std::getline(iss, name, ' ');
 
-		if (name == "EndInventoryList")
-			return;
-
-		// This is a temporary backwards compatibility fix
-		if (name == "end")
+		if (name == "EndInventoryList" || name == "end") {
+			// If partial incremental: Clear leftover items (should not happen!)
+			for (size_t i = item_i; i < m_items.size(); ++i)
+				m_items[i].clear();
 			return;
+		}
 
 		if (name == "Width") {
 			iss >> m_width;
@@ -464,6 +473,8 @@ void InventoryList::deSerialize(std::istream &is)
 			if(item_i > getSize() - 1)
 				throw SerializationError("too many items");
 			m_items[item_i++].clear();
+		} else if (name == "Keep") {
+			++item_i; // Unmodified item
 		}
 	}
 
@@ -557,7 +568,7 @@ ItemStack InventoryList::changeItem(u32 i, const ItemStack &newitem)
 
 	ItemStack olditem = m_items[i];
 	m_items[i] = newitem;
-	//setDirty(true);
+	setModified();
 	return olditem;
 }
 
@@ -565,6 +576,7 @@ void InventoryList::deleteItem(u32 i)
 {
 	assert(i < m_items.size()); // Pre-condition
 	m_items[i].clear();
+	setModified();
 }
 
 ItemStack InventoryList::addItem(const ItemStack &newitem_)
@@ -612,8 +624,8 @@ ItemStack InventoryList::addItem(u32 i, const ItemStack &newitem)
 		return newitem;
 
 	ItemStack leftover = m_items[i].addItem(newitem, m_itemdef);
-	//if(leftover != newitem)
-	//	setDirty(true);
+	if (leftover != newitem)
+		setModified();
 	return leftover;
 }
 
@@ -682,8 +694,8 @@ ItemStack InventoryList::takeItem(u32 i, u32 takecount)
 		return ItemStack();
 
 	ItemStack taken = m_items[i].takeItem(takecount);
-	//if(!taken.empty())
-	//	setDirty(true);
+	if (!taken.empty())
+		setModified();
 	return taken;
 }
 
@@ -788,16 +800,6 @@ void Inventory::clear()
 	m_lists.clear();
 }
 
-void Inventory::clearContents()
-{
-	m_dirty = true;
-	for (InventoryList *list : m_lists) {
-		for (u32 j=0; j<list->getSize(); j++) {
-			list->deleteItem(j);
-		}
-	}
-}
-
 Inventory::Inventory(IItemDefManager *itemdef)
 {
 	m_dirty = false;
@@ -807,7 +809,6 @@ Inventory::Inventory(IItemDefManager *itemdef)
 Inventory::Inventory(const Inventory &other)
 {
 	*this = other;
-	m_dirty = false;
 }
 
 Inventory & Inventory::operator = (const Inventory &other)
@@ -838,11 +839,15 @@ bool Inventory::operator == (const Inventory &other) const
 	return true;
 }
 
-void Inventory::serialize(std::ostream &os) const
+void Inventory::serialize(std::ostream &os, bool incremental) const
 {
-	for (InventoryList *list : m_lists) {
-		os<<"List "<<list->getName()<<" "<<list->getSize()<<"\n";
-		list->serialize(os);
+	for (const InventoryList *list : m_lists) {
+		if (!incremental || list->checkModified()) {
+			os << "List " << list->getName() << " " << list->getSize() << "\n";
+			list->serialize(os, incremental);
+		} else {
+			os << "KeepList " << list->getName() << "\n";
+		}
 	}
 
 	os<<"EndInventory\n";
@@ -850,7 +855,8 @@ void Inventory::serialize(std::ostream &os) const
 
 void Inventory::deSerialize(std::istream &is)
 {
-	clear();
+	std::vector<InventoryList *> new_lists;
+	new_lists.reserve(m_lists.size());
 
 	while (is.good()) {
 		std::string line;
@@ -861,12 +867,20 @@ void Inventory::deSerialize(std::istream &is)
 		std::string name;
 		std::getline(iss, name, ' ');
 
-		if (name == "EndInventory")
-			return;
+		if (name == "EndInventory" || name == "end") {
+			// Remove all lists that were not sent
+			for (auto &list : m_lists) {
+				if (std::find(new_lists.begin(), new_lists.end(), list) != new_lists.end())
+					continue;
 
-		// This is a temporary backwards compatibility fix
-		if (name == "end")
+				delete list;
+				list = nullptr;
+				m_dirty = true;
+			}
+			m_lists.erase(std::remove(m_lists.begin(), m_lists.end(),
+					nullptr), m_lists.end());
 			return;
+		}
 
 		if (name == "List") {
 			std::string listname;
@@ -875,15 +889,33 @@ void Inventory::deSerialize(std::istream &is)
 			std::getline(iss, listname, ' ');
 			iss>>listsize;
 
-			InventoryList *list = new InventoryList(listname, listsize, m_itemdef);
+			InventoryList *list = getList(listname);
+			bool create_new = !list;
+			if (create_new)
+				list = new InventoryList(listname, listsize, m_itemdef);
+			else
+				list->setSize(listsize);
 			list->deSerialize(is);
 
-			m_lists.push_back(list);
-		}
-		else
-		{
-			throw SerializationError("invalid inventory specifier: " + name);
+			new_lists.push_back(list);
+			if (create_new)
+				m_lists.push_back(list);
+
+		} else if (name == "KeepList") {
+			// Incrementally sent list
+			std::string listname;
+			std::getline(iss, listname, ' ');
+
+			InventoryList *list = getList(listname);
+			if (list) {
+				new_lists.push_back(list);
+			} else {
+				errorstream << "Inventory::deSerialize(): Tried to keep list '" <<
+					listname << "' which is non-existent." << std::endl;
+			}
 		}
+		// Any additional fields will throw errors when received by a client
+		// older than PROTOCOL_VERSION 38
 	}
 
 	// Contents given to deSerialize() were not terminated properly: throw error.