Experimental-ish rollback functionality

1 files changed, 145 insertions, 0 deletions

diff --git a/src/rollback_interface.h b/src/rollback_interface.h
new file mode 100644
index 000000000..0f0a11885
--- /dev/null
+++ b/src/rollback_interface.h
@@ -0,0 +1,145 @@
+/*
+Minetest-c55
+Copyright (C) 2012 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#ifndef ROLLBACK_INTERFACE_HEADER
+#define ROLLBACK_INTERFACE_HEADER
+
+#include "irr_v3d.h"
+#include <string>
+#include <iostream>
+#include "exceptions.h"
+
+class Map;
+class IGameDef;
+struct MapNode;
+class InventoryManager;
+
+struct RollbackNode
+{
+	std::string name;
+	int param1;
+	int param2;
+	std::string meta;
+
+	bool operator==(const RollbackNode &other)
+	{
+		return (name == other.name && param1 == other.param1 &&
+				param2 == other.param2 && meta == other.meta);
+	}
+	bool operator!=(const RollbackNode &other)
+	{
+		return !(*this == other);
+	}
+
+	RollbackNode():
+		param1(0),
+		param2(0)
+	{}
+
+	RollbackNode(Map *map, v3s16 p, IGameDef *gamedef);
+};
+
+struct RollbackAction
+{
+	enum Type{
+		TYPE_NOTHING,
+		TYPE_SET_NODE,
+		TYPE_MODIFY_INVENTORY_STACK,
+	} type;
+
+	int unix_time;
+	std::string actor;
+
+	v3s16 p;
+	RollbackNode n_old;
+	RollbackNode n_new;
+	
+	std::string inventory_location;
+	std::string inventory_list;
+	u32 inventory_index;
+	bool inventory_add;
+	std::string inventory_stack;
+
+	RollbackAction():
+		type(TYPE_NOTHING)
+	{}
+
+	void setSetNode(v3s16 p_, const RollbackNode &n_old_,
+			const RollbackNode &n_new_)
+	{
+		type = TYPE_SET_NODE;
+		p = p_;
+		n_old = n_old_;
+		n_new = n_new_;
+	}
+
+	void setModifyInventoryStack(const std::string &inventory_location_,
+			const std::string &inventory_list_, int index_,
+			bool add_, const std::string &inventory_stack_)
+	{
+		type = TYPE_MODIFY_INVENTORY_STACK;
+		inventory_location = inventory_location_;
+		inventory_list = inventory_list_;
+		inventory_index = index_;
+		inventory_add = add_;
+		inventory_stack = inventory_stack_;
+	}
+	
+	// String should not contain newlines or nulls
+	std::string toString() const;
+	void fromStream(std::istream &is) throw(SerializationError);
+	
+	// Eg. flowing water level changes are not important
+	bool isImportant(IGameDef *gamedef) const;
+
+	bool applyRevert(Map *map, InventoryManager *imgr, IGameDef *gamedef) const;
+};
+
+class IRollbackReportSink
+{
+public:
+	virtual ~IRollbackReportSink(){}
+	virtual void reportAction(const RollbackAction &action) = 0;
+	virtual std::string getActor() = 0;
+	virtual void setActor(const std::string &actor) = 0;
+};
+
+class RollbackScopeActor
+{
+public:
+	RollbackScopeActor(IRollbackReportSink *sink, const std::string &actor):
+		m_sink(sink)
+	{
+		if(m_sink){
+			m_actor_was = m_sink->getActor();
+			m_sink->setActor(actor);
+		}
+	}
+	~RollbackScopeActor()
+	{
+		if(m_sink){
+			m_sink->setActor(m_actor_was);
+		}
+	}
+private:
+	IRollbackReportSink *m_sink;
+	std::string m_actor_was;
+};
+
+#endif