mirror of https://github.com/OpenTTD/OpenTTD.git
106 lines
2.8 KiB
C++
106 lines
2.8 KiB
C++
/*
|
|
* This file is part of OpenTTD.
|
|
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
|
|
* OpenTTD 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 General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
/** @file saveload_filter.h Declaration of filters used for saving and loading savegames. */
|
|
|
|
#ifndef SAVELOAD_FILTER_H
|
|
#define SAVELOAD_FILTER_H
|
|
|
|
/** Interface for filtering a savegame till it is loaded. */
|
|
struct LoadFilter {
|
|
/** Chained to the (savegame) filters. */
|
|
LoadFilter *chain;
|
|
|
|
/**
|
|
* Initialise this filter.
|
|
* @param chain The next filter in this chain.
|
|
*/
|
|
LoadFilter(LoadFilter *chain) : chain(chain)
|
|
{
|
|
}
|
|
|
|
/** Make sure the writers are properly closed. */
|
|
virtual ~LoadFilter()
|
|
{
|
|
delete this->chain;
|
|
}
|
|
|
|
/**
|
|
* Read a given number of bytes from the savegame.
|
|
* @param buf The bytes to read.
|
|
* @param len The number of bytes to read.
|
|
* @return The number of actually read bytes.
|
|
*/
|
|
virtual size_t Read(byte *buf, size_t len) = 0;
|
|
|
|
/**
|
|
* Reset this filter to read from the beginning of the file.
|
|
*/
|
|
virtual void Reset()
|
|
{
|
|
this->chain->Reset();
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Instantiator for a load filter.
|
|
* @param chain The next filter in this chain.
|
|
* @tparam T The type of load filter to create.
|
|
*/
|
|
template <typename T> LoadFilter *CreateLoadFilter(LoadFilter *chain)
|
|
{
|
|
return new T(chain);
|
|
}
|
|
|
|
/** Interface for filtering a savegame till it is written. */
|
|
struct SaveFilter {
|
|
/** Chained to the (savegame) filters. */
|
|
SaveFilter *chain;
|
|
|
|
/**
|
|
* Initialise this filter.
|
|
* @param chain The next filter in this chain.
|
|
*/
|
|
SaveFilter(SaveFilter *chain) : chain(chain)
|
|
{
|
|
}
|
|
|
|
/** Make sure the writers are properly closed. */
|
|
virtual ~SaveFilter()
|
|
{
|
|
delete this->chain;
|
|
}
|
|
|
|
/**
|
|
* Write a given number of bytes into the savegame.
|
|
* @param buf The bytes to write.
|
|
* @param len The number of bytes to write.
|
|
*/
|
|
virtual void Write(byte *buf, size_t len) = 0;
|
|
|
|
/**
|
|
* Prepare everything to finish writing the savegame.
|
|
*/
|
|
virtual void Finish()
|
|
{
|
|
if (this->chain != nullptr) this->chain->Finish();
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Instantiator for a save filter.
|
|
* @param chain The next filter in this chain.
|
|
* @param compression_level The requested level of compression.
|
|
* @tparam T The type of save filter to create.
|
|
*/
|
|
template <typename T> SaveFilter *CreateSaveFilter(SaveFilter *chain, byte compression_level)
|
|
{
|
|
return new T(chain, compression_level);
|
|
}
|
|
|
|
#endif /* SAVELOAD_FILTER_H */
|