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scummvm-cursorfix/engines/bagel/boflib/cache.h
2026-02-02 04:50:13 +01:00

102 lines
2.5 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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, either version 3 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef BAGEL_BOFLIB_CACHE_H
#define BAGEL_BOFLIB_CACHE_H
#include "bagel/boflib/llist.h"
#include "bagel/boflib/stdinc.h"
namespace Bagel {
class CCache : private CLList {
private:
virtual bool alloc() = 0; // These pure-virtuals MUST be defined
virtual void free() = 0; // in the derived class.
static CCache *_pCacheList; // Linked cache list
static uint32 _lOldest; // Current oldest object in cache
static uint32 _lYoungest; // Current youngest object in cache
static uint16 _nEntries; // Number of CCache Objects
uint32 _lAge; // Age of this object
int _nLockCount; // # of locks held on this object
bool _bCached; // true if object is in the cache
bool _bValid; // true if this object is valid
public:
/**
* Constructor
*/
CCache();
/**
* Destructor
*/
virtual ~CCache();
/**
* Loads current object into cache
*/
void load();
/**
* Releases current object from cache
*/
bool release();
void lock() {
_nLockCount++;
load();
}
void unlock() {
_nLockCount--;
}
bool isLocked() {
return (_nLockCount > 0);
}
/**
* initialize statics
*/
static void initialize();
/**
* Releases all objects from cache
*/
static bool flush();
/**
* Releases older objects from cache if need memory
* @remarks Optimizes cache so that the specified amount of memory is left available.
* @param lRequestedFreeSpace Free space requested to remain available
* @return true if there were any objects to release from the cache.
* false if there were no objects released.
*/
static bool optimize(uint32 lRequestedFreeSpace);
};
} // namespace Bagel
#endif