HASH.H

//////////////////////////////////////////////////////////////////////////////// 
// hash.h 
// 
// Copyright (C) 1987-1997 By Microsoft Corp. All rights reserved.  
// Copyright (C) 1997 Metawise Computing, Inc. All rights reserved. 
// 
//////////////////////////////////////////////////////////////////////////////// 
 
 
#ifndef _HASH_H_ 
#define _HASH_H_ 
 
class CHashItem 
{ 
public: 
CHashItem (void* pData); 
 
void* m_pData; 
CHashItem* m_pNext; 
}; 
 
typedef CHashItem* PCHashItem; 
 
// A hash table which uses a DWORD as its key. 
// A generic pointer can be associated with the key. 
class CDWordHashItem : public CHashItem 
{ 
public: 
CDWordHashItem (DWORD dwKey, void* pData); 
 
DWORD m_dwKey; 
}; 
 
class CStringHashItem : public CHashItem 
{ 
public: 
CStringHashItem (LPCTSTR lpszKey, void* pData); 
 
CString m_strKey; 
}; 
 
typedef struct 
{ 
int nIndex; 
CHashItem* pItem; 
 
} HashEnumContext; 
 
 
class CHashTable 
{ 
public: 
CHashTable (int nSize); 
~CHashTable (); 
 
// Operations 
BOOL LookUp (DWORD dwKey, void** ppData); 
BOOL Insert (DWORD dwKey, void* pData); 
void* Delete (DWORD dwKey); 
 
BOOL LookUp (LPCTSTR lpszKey, void** ppData); 
BOOL Insert (LPCTSTR lpszKey, void* pData); 
void* Delete (LPCTSTR lpszKey); 
 
// methods to enumerate all items in hash table; 
// if items are deleted in the middle of enumeration, 
// these functions may cause crash!!! 
DWORD FindFirst (LPTSTR* ppszKey, void** ppData); 
BOOL FindNext (DWORD dwHandle, LPTSTR* ppszKey, void** ppData); 
void FindClose (DWORD dwHandle); 
 
protected: 
// Implementations 
void InsertItem (CHashItem* pItem, CHashItem** ppItems); 
 
int Hash (DWORD dwKey); 
CHashItem* FindItem (DWORD dwKey, CDWordHashItem** ppItems); 
CHashItem* DeleteItem (DWORD dwKey, CDWordHashItem** ppItems); 
 
int Hash (LPCTSTR lpszKey); 
CHashItem* FindItem (LPCTSTR lpszKey, CStringHashItem** ppItems); 
CHashItem* DeleteItem (LPCTSTR lpszKey, CStringHashItem** ppItems); 
 
int m_nSize;// size of array m_ppItems[] 
int m_nCount;// #items in hash table 
CHashItem** m_ppItems;// array of item pointers 
}; 
 
#endif // _HASH_H_