C:/Users/Marc/Desktop/Phystank/trunk/src/resource/ResourceCache.h

//This file is part of PhysTank.
//
//PhysTank 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.
//
//PhysTank 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 PhysTank.  If not, see <http://www.gnu.org/licenses/>.
//
// © Marc Johnson, 2009

#ifndef _RESOURCECACHE_
#define _RESOURCECACHE_

#include <hash_map>
#include <list>
#include <map>
#include <string>

#include "resource/AbstractResourceFile.h"
#include "resource/AbstractResourceListener.h"
#include "resource/Resource.h"
#include "resource/ResourceHandle.h"
#include "util/StringHasher.h"

class ResourceCache 
{
private:
        typedef stdext::hash_map<std::string, AbstractResourceFile*, StringHasher> ResourceFileMap;
        typedef stdext::hash_map<std::string, ResourceHandlePtr, StringHasher> ResourceHandleMap;
        typedef std::list<AbstractResourceListener*> ResourceListenerList;
        typedef stdext::hash_map<std::string, ResourceListenerList, StringHasher>  ResourceListenerMap;
        typedef std::list<ResourceHandlePtr> ResourceHandleList;
        
        ResourceHandleMap m_resources;
        ResourceHandleList m_lru;
        ResourceFileMap m_resourceFiles;
        ResourceListenerMap m_resourceListeners;

        unsigned long m_nMaxCacheSize;
        unsigned long m_nAllocated;

        bool FreeMemory(unsigned int nSize);
        char* AllocateMemory(unsigned int nSize);
        
        void DestroyResource(ResourceHandlePtr pResource);
        void DestroyLeastUsedResource();

        ResourceHandlePtr LoadResource(Resource* const pResource);
        ResourceHandlePtr FindLoadedResource(const Resource& resource) const;
        void UpdateResourceUsage(ResourceHandlePtr const pResourceHandle);
public:
        ResourceCache(unsigned long nSize) 
        :m_nMaxCacheSize(nSize), m_nAllocated(0)
        {
        }

        ~ResourceCache() { Clear(); }

        bool OpenResourceFile(const std::string& path, const RESFILETYPE type);
        bool CloseResourceFile(const std::string& path);

        void RegisterResourceListener(const Resource& res, AbstractResourceListener* pResourceListener);
        void UnregisterResourceListener(const Resource& res, AbstractResourceListener* pResourceListener);

        const ResourceHandlePtr Get(Resource * const pResource);

        void Clear();
};

#endif

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