minetest/src/staticobject.cpp
Rogier a067d40454 Handle multiple deserialization of a block's entities
This fix consists of two parts:
- Clear the list of stored entities. This has no side-effects.
- Catch the case where active entities exist and print a message.
  Clearing the active entitiy list has side-effects that should
  be handled. (those entities are known to the environment and
  to clients).

  As avoiding those side-effects is more complex, and as this
  problem is not expected to occur (with PR #4847 merged), there
  is no real incentive to implement this ATM.

This issue was a contributing factor to bug #4217. With the other
contributing factor removed (PR #4847), this commit makes sure this
factor does not go unnoticed if it ever happens again.
2019-08-12 19:14:07 +02:00

100 lines
2.5 KiB
C++

/*
Minetest
Copyright (C) 2010-2013 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.
*/
#include "staticobject.h"
#include "util/serialize.h"
#include "content_sao.h"
StaticObject::StaticObject(const ServerActiveObject *s_obj, const v3f &pos_):
type(s_obj->getType()),
pos(pos_)
{
s_obj->getStaticData(&data);
}
void StaticObject::serialize(std::ostream &os)
{
// type
writeU8(os, type);
// pos
writeV3F1000(os, pos);
// data
os<<serializeString(data);
}
void StaticObject::deSerialize(std::istream &is, u8 version)
{
// type
type = readU8(is);
// pos
pos = readV3F1000(is);
// data
data = deSerializeString(is);
}
void StaticObjectList::serialize(std::ostream &os)
{
// version
u8 version = 0;
writeU8(os, version);
// count
size_t count = m_stored.size() + m_active.size();
// Make sure it fits into u16, else it would get truncated and cause e.g.
// issue #2610 (Invalid block data in database: unsupported NameIdMapping version).
if (count > U16_MAX) {
errorstream << "StaticObjectList::serialize(): "
<< "too many objects (" << count << ") in list, "
<< "not writing them to disk." << std::endl;
writeU16(os, 0); // count = 0
return;
}
writeU16(os, count);
for (StaticObject &s_obj : m_stored) {
s_obj.serialize(os);
}
for (auto &i : m_active) {
StaticObject s_obj = i.second;
s_obj.serialize(os);
}
}
void StaticObjectList::deSerialize(std::istream &is)
{
if (m_active.size()) {
errorstream << "StaticObjectList::deSerialize(): "
<< "deserializing objects while " << m_active.size()
<< " active objects already exist (not cleared). "
<< m_stored.size() << " stored objects _were_ cleared"
<< std::endl;
}
m_stored.clear();
// version
u8 version = readU8(is);
// count
u16 count = readU16(is);
for(u16 i = 0; i < count; i++) {
StaticObject s_obj;
s_obj.deSerialize(is, version);
m_stored.push_back(s_obj);
}
}