gemrb/core/Cache.h

   1 /* GemRB - Infinity Engine Emulator
   2  * Copyright (C) 2003 |Avenger|
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  17  *
  18  *
  19  */
  20
  21 #ifndef CACHE_H
  22 #define CACHE_H
  23
  24 #include "globals.h"
  25 #include "win32def.h"
  26
  27 #define KEYSIZE 8
  28
  29 #ifndef ReleaseFun
  30 typedef void (*ReleaseFun)(void *);
  31 #endif
  32
  33 class Cache
  34 {
  35 protected:
  36         // Association
  37         struct MyAssoc {
  38                 MyAssoc* pNext;
  39                 MyAssoc** pPrev;
  40                 char key[KEYSIZE]; //not ieResRef!
  41                 ieDword nRefCount;
  42                 void* data;
  43         };
  44         struct MemBlock {
  45                 MemBlock* pNext;
  46         };
  47
  48 public:
  49         // Construction
  50         Cache(int nBlockSize = 10, int nHashTableSize = 129);
  51
  52         // Attributes
  53         // number of elements
  54         inline int GetCount() const
  55         {
  56                 return m_nCount;
  57         }
  58         inline bool IsEmpty() const
  59         {
  60                 return m_nCount==0;
  61         }
  62         // Lookup
  63         void *GetResource(const ieResRef key) const;
  64         // Operations
  65         bool SetAt(const ieResRef key, void *rValue);
  66         // decreases refcount or drops data
  67         //if name is supplied it is faster, it will use rValue to validate the request
  68         int DecRef(void *rValue, const ieResRef name, bool free);
  69         int RefCount(const ieResRef key) const;
  70         void RemoveAll(ReleaseFun fun);//removes all refcounts
  71         void Cleanup();  //removes only zero refcounts
  72         void InitHashTable(unsigned int hashSize, bool bAllocNow = true);
  73
  74         // Implementation
  75 protected:
  76         MyAssoc** m_pHashTable;
  77         unsigned int m_nHashTableSize;
  78         int m_nCount;
  79         MyAssoc* m_pFreeList;
  80         MemBlock* m_pBlocks;
  81         int m_nBlockSize;
  82
  83         Cache::MyAssoc* NewAssoc();
  84         void FreeAssoc(Cache::MyAssoc*);
  85         Cache::MyAssoc* GetAssocAt(const ieResRef) const;
  86         Cache::MyAssoc *GetNextAssoc(Cache::MyAssoc * rNextPosition) const;
  87         unsigned int MyHashKey(const ieResRef) const;
  88
  89 public:
  90         ~Cache();
  91 };
  92
  93 #endif //CACHE_H