类封装 暴雪 哈希表

    近期由于需要，研究了魔兽文件打包管理器的相关算法，重点对其文件索引表的生成和查找进行了研究：采用哈希表进行，在冲突方面的处理方面，采用线性探测再散列。在添加和查找过程中进行了三次哈希，第一个哈希值用来查找，后两个哈希值用来校验，这样可以大大减少冲突的几率。

      这里对其进行了简单的封装，扩展时，仅仅需要对结构体进行扩展即可。更为详细的说明，参考代码：【转载请保留版权，谢谢】

 

一、类声明头文件

     / // Name: HashAlgo.h // Purpose: 使用魔兽Hash算法，实现索引表的填充和查找功能。 // Author: 陈相礼 // Modified by: // Created: 07/30/09 // RCS-ID: $Id: treetest.h 43021 2009-07-30 16:36:51Z VZ $ // Copyright: (C) Copyright 2009, TSong Corporation, All Rights Reserved. // Licence: / #define MAXFILENAME 255 // 最大文件名长度 #define MAXTABLELEN 1024 // 默认哈希索引表大小 // // 测试宏定义，正式使用时关闭 #define DEBUGTEST 1 // // 哈希索引表定义 typedef struct { long nHashA; long nHashB; bool bExists; char test_filename[MAXFILENAME]; // ...... } MPQHASHTABLE; // // 对哈希索引表的算法进行封装 class CHashAlgo { public : #if DEBUGTEST long testid; // 测试之用 #endif CHashAlgo( const long nTableLength = MAXTABLELEN ) // 创建指定大小的哈希索引表，不带参数的构造函数创建默认大小的哈希索引表 { prepareCryptTable(); m_tablelength = nTableLength; m_HashIndexTable = new MPQHASHTABLE[nTableLength]; for ( int i = 0; i < nTableLength; i++ ) { m_HashIndexTable[i].nHashA = -1; m_HashIndexTable[i].nHashB = -1; m_HashIndexTable[i].bExists = false ; m_HashIndexTable[i].test_filename[0] = '/0' ; } } void prepareCryptTable(); // 对哈希索引表预处理 unsigned long HashString( char *lpszFileName, unsigned long dwHashType); // 求取哈希值 long GetHashTablePos( char *lpszString ); // 得到在定长表中的位置 bool SetHashTable( char *lpszString ); // 将字符串散列到哈希表中 unsigned long GetTableLength( void ); void SetTableLength( const unsigned long nLength ); ~CHashAlgo() { if ( NULL != m_HashIndexTable ) { delete []m_HashIndexTable; m_HashIndexTable = NULL; m_tablelength = 0; } } protected : private : unsigned long cryptTable[0x500]; unsigned long m_tablelength; // 哈希索引表长度 MPQHASHTABLE *m_HashIndexTable; }; view plaincopy to clipboardprint? / // Name: HashAlgo.h // Purpose: 使用魔兽Hash算法，实现索引表的填充和查找功能。 // Author: 陈相礼 // Modified by: // Created: 07/30/09 // RCS-ID: $Id: treetest.h 43021 2009-07-30 16:36:51Z VZ $ // Copyright: (C) Copyright 2009, TSong Corporation, All Rights Reserved. // Licence: / #define MAXFILENAME 255 // 最大文件名长度 #define MAXTABLELEN 1024 // 默认哈希索引表大小 // // 测试宏定义，正式使用时关闭 #define DEBUGTEST 1 // // 哈希索引表定义 typedef struct { long nHashA; long nHashB; bool bExists; char test_filename[MAXFILENAME]; // ...... } MPQHASHTABLE; // // 对哈希索引表的算法进行封装 class CHashAlgo { public: #if DEBUGTEST long testid; // 测试之用 #endif CHashAlgo( const long nTableLength = MAXTABLELEN )// 创建指定大小的哈希索引表，不带参数的构造函数创建默认大小的哈希索引表 { prepareCryptTable(); m_tablelength = nTableLength; m_HashIndexTable = new MPQHASHTABLE[nTableLength]; for ( int i = 0; i < nTableLength; i++ ) { m_HashIndexTable[i].nHashA = -1; m_HashIndexTable[i].nHashB = -1; m_HashIndexTable[i].bExists = false; m_HashIndexTable[i].test_filename[0] = '/0'; } } void prepareCryptTable(); // 对哈希索引表预处理 unsigned long HashString(char *lpszFileName, unsigned long dwHashType); // 求取哈希值 long GetHashTablePos( char *lpszString ); // 得到在定长表中的位置 bool SetHashTable( char *lpszString ); // 将字符串散列到哈希表中 unsigned long GetTableLength(void); void SetTableLength( const unsigned long nLength ); ~CHashAlgo() { if ( NULL != m_HashIndexTable ) { delete []m_HashIndexTable; m_HashIndexTable = NULL; m_tablelength = 0; } } protected: private: unsigned long cryptTable[0x500]; unsigned long m_tablelength; // 哈希索引表长度 MPQHASHTABLE *m_HashIndexTable; }; / // Name: HashAlgo.h // Purpose: 使用魔兽Hash算法，实现索引表的填充和查找功能。 // Author: 陈相礼 // Modified by: // Created: 07/30/09 // RCS-ID: $Id: treetest.h 43021 2009-07-30 16:36:51Z VZ $ // Copyright: (C) Copyright 2009, TSong Corporation, All Rights Reserved. // Licence: / #define MAXFILENAME 255 // 最大文件名长度 #define MAXTABLELEN 1024 // 默认哈希索引表大小 // // 测试宏定义，正式使用时关闭 #define DEBUGTEST 1 // // 哈希索引表定义 typedef struct { long nHashA; long nHashB; bool bExists; char test_filename[MAXFILENAME]; // ...... } MPQHASHTABLE; // // 对哈希索引表的算法进行封装 class CHashAlgo { public: #if DEBUGTEST long testid; // 测试之用 #endif CHashAlgo( const long nTableLength = MAXTABLELEN )// 创建指定大小的哈希索引表，不带参数的构造函数创建默认大小的哈希索引表 { prepareCryptTable(); m_tablelength = nTableLength; m_HashIndexTable = new MPQHASHTABLE[nTableLength]; for ( int i = 0; i < nTableLength; i++ ) { m_HashIndexTable[i].nHashA = -1; m_HashIndexTable[i].nHashB = -1; m_HashIndexTable[i].bExists = false; m_HashIndexTable[i].test_filename[0] = '/0'; } } void prepareCryptTable(); // 对哈希索引表预处理 unsigned long HashString(char *lpszFileName, unsigned long dwHashType); // 求取哈希值 long GetHashTablePos( char *lpszString ); // 得到在定长表中的位置 bool SetHashTable( char *lpszString ); // 将字符串散列到哈希表中 unsigned long GetTableLength(void); void SetTableLength( const unsigned long nLength ); ~CHashAlgo() { if ( NULL != m_HashIndexTable ) { delete []m_HashIndexTable; m_HashIndexTable = NULL; m_tablelength = 0; } } protected: private: unsigned long cryptTable[0x500]; unsigned long m_tablelength; // 哈希索引表长度 MPQHASHTABLE *m_HashIndexTable; }; 二、类实现文件 / // Name: HashAlgo.cpp // Purpose: 使用魔兽Hash算法，实现索引表的填充和查找功能。 // Author: 陈相礼 // Modified by: // Created: 07/30/09 // RCS-ID: $Id: treetest.h 43021 2009-07-30 16:36:51Z VZ $ // Copyright: (C) Copyright 2009, TSong Corporation, All Rights Reserved. // Licence: / #include "windows.h" #include "HashAlgo.h" // // 预处理 void CHashAlgo::prepareCryptTable() { unsigned long seed = 0x00100001, index1 = 0, index2 = 0, i; for ( index1 = 0; index1 < 0x100; index1++ ) { for ( index2 = index1, i = 0; i < 5; i++, index2 += 0x100 ) { unsigned long temp1, temp2; seed = (seed * 125 + 3) % 0x2AAAAB; temp1 = (seed & 0xFFFF) << 0x10; seed = (seed * 125 + 3) % 0x2AAAAB; temp2 = (seed & 0xFFFF); cryptTable[index2] = ( temp1 | temp2 ); } } } // // 求取哈希值 unsigned long CHashAlgo::HashString( char *lpszFileName, unsigned long dwHashType) { unsigned char *key = (unsigned char *)lpszFileName; unsigned long seed1 = 0x7FED7FED, seed2 = 0xEEEEEEEE; int ch; while (*key != 0) { ch = toupper(*key++); seed1 = cryptTable[(dwHashType << 8) + ch] ^ (seed1 + seed2); seed2 = ch + seed1 + seed2 + (seed2 << 5) + 3; } return seed1; } // // 得到在定长表中的位置 long CHashAlgo::GetHashTablePos( char *lpszString) { const unsigned long HASH_OFFSET = 0, HASH_A = 1, HASH_B = 2; unsigned long nHash = HashString(lpszString, HASH_OFFSET); unsigned long nHashA = HashString(lpszString, HASH_A); unsigned long nHashB = HashString(lpszString, HASH_B); unsigned long nHashStart = nHash % m_tablelength, nHashPos = nHashStart; while ( m_HashIndexTable[nHashPos].bExists) { if (m_HashIndexTable[nHashPos].nHashA == nHashA && m_HashIndexTable[nHashPos].nHashB == nHash) return nHashPos; else nHashPos = (nHashPos + 1) % m_tablelength; if (nHashPos == nHashStart) break ; } return -1; //没有找到 } // // 通过传入字符串，将相应的表项散列到索引表相应位置中去 bool CHashAlgo::SetHashTable( char *lpszString ) { const unsigned long HASH_OFFSET = 0, HASH_A = 1, HASH_B = 2; unsigned long nHash = HashString(lpszString, HASH_OFFSET); unsigned long nHashA = HashString(lpszString, HASH_A); unsigned long nHashB = HashString(lpszString, HASH_B); unsigned long nHashStart = nHash % m_tablelength, nHashPos = nHashStart; while ( m_HashIndexTable[nHashPos].bExists) { nHashPos = (nHashPos + 1) % m_tablelength; if (nHashPos == nHashStart) { #if DEBUGTEST testid = -1; #endif return false ; } } m_HashIndexTable[nHashPos].bExists = true ; m_HashIndexTable[nHashPos].nHashA = nHashA; m_HashIndexTable[nHashPos].nHashB = nHash; strcpy( m_HashIndexTable[nHashPos].test_filename, lpszString ); #if DEBUGTEST testid = nHashPos; #endif return true ; } // // 取得哈希索引表长 unsigned long CHashAlgo::GetTableLength( void ) { return m_tablelength; } // // 设置哈希索引表长 void CHashAlgo::SetTableLength( const unsigned long nLength ) { m_tablelength = nLength; return ; } view plaincopy to clipboardprint? / // Name: HashAlgo.cpp // Purpose: 使用魔兽Hash算法，实现索引表的填充和查找功能。 // Author: 陈相礼 // Modified by: // Created: 07/30/09 // RCS-ID: $Id: treetest.h 43021 2009-07-30 16:36:51Z VZ $ // Copyright: (C) Copyright 2009, TSong Corporation, All Rights Reserved. // Licence: / #include "windows.h" #include "HashAlgo.h" // // 预处理 void CHashAlgo::prepareCryptTable() { unsigned long seed = 0x00100001, index1 = 0, index2 = 0, i; for( index1 = 0; index1 < 0x100; index1++ ) { for( index2 = index1, i = 0; i < 5; i++, index2 += 0x100 ) { unsigned long temp1, temp2; seed = (seed * 125 + 3) % 0x2AAAAB; temp1 = (seed & 0xFFFF) << 0x10; seed = (seed * 125 + 3) % 0x2AAAAB; temp2 = (seed & 0xFFFF); cryptTable[index2] = ( temp1 | temp2 ); } } } // // 求取哈希值 unsigned long CHashAlgo::HashString(char *lpszFileName, unsigned long dwHashType) { unsigned char *key = (unsigned char *)lpszFileName; unsigned long seed1 = 0x7FED7FED, seed2 = 0xEEEEEEEE; int ch; while(*key != 0) { ch = toupper(*key++); seed1 = cryptTable[(dwHashType << 8) + ch] ^ (seed1 + seed2); seed2 = ch + seed1 + seed2 + (seed2 << 5) + 3; } return seed1; } // // 得到在定长表中的位置 long CHashAlgo::GetHashTablePos(char *lpszString) { const unsigned long HASH_OFFSET = 0, HASH_A = 1, HASH_B = 2; unsigned long nHash = HashString(lpszString, HASH_OFFSET); unsigned long nHashA = HashString(lpszString, HASH_A); unsigned long nHashB = HashString(lpszString, HASH_B); unsigned long nHashStart = nHash % m_tablelength, nHashPos = nHashStart; while ( m_HashIndexTable[nHashPos].bExists) { if (m_HashIndexTable[nHashPos].nHashA == nHashA && m_HashIndexTable[nHashPos].nHashB == nHash) return nHashPos; else nHashPos = (nHashPos + 1) % m_tablelength; if (nHashPos == nHashStart) break; } return -1; //没有找到 } // // 通过传入字符串，将相应的表项散列到索引表相应位置中去 bool CHashAlgo::SetHashTable( char *lpszString ) { const unsigned long HASH_OFFSET = 0, HASH_A = 1, HASH_B = 2; unsigned long nHash = HashString(lpszString, HASH_OFFSET); unsigned long nHashA = HashString(lpszString, HASH_A); unsigned long nHashB = HashString(lpszString, HASH_B); unsigned long nHashStart = nHash % m_tablelength, nHashPos = nHashStart; while ( m_HashIndexTable[nHashPos].bExists) { nHashPos = (nHashPos + 1) % m_tablelength; if (nHashPos == nHashStart) { #if DEBUGTEST testid = -1; #endif return false; } } m_HashIndexTable[nHashPos].bExists = true; m_HashIndexTable[nHashPos].nHashA = nHashA; m_HashIndexTable[nHashPos].nHashB = nHash; strcpy( m_HashIndexTable[nHashPos].test_filename, lpszString ); #if DEBUGTEST testid = nHashPos; #endif return true; } // // 取得哈希索引表长 unsigned long CHashAlgo::GetTableLength(void) { return m_tablelength; } // // 设置哈希索引表长 void CHashAlgo::SetTableLength( const unsigned long nLength ) { m_tablelength = nLength; return; } / // Name: HashAlgo.cpp // Purpose: 使用魔兽Hash算法，实现索引表的填充和查找功能。 // Author: 陈相礼 // Modified by: // Created: 07/30/09 // RCS-ID: $Id: treetest.h 43021 2009-07-30 16:36:51Z VZ $ // Copyright: (C) Copyright 2009, TSong Corporation, All Rights Reserved. // Licence: / #include "windows.h" #include "HashAlgo.h" // // 预处理 void CHashAlgo::prepareCryptTable() { unsigned long seed = 0x00100001, index1 = 0, index2 = 0, i; for( index1 = 0; index1 < 0x100; index1++ ) { for( index2 = index1, i = 0; i < 5; i++, index2 += 0x100 ) { unsigned long temp1, temp2; seed = (seed * 125 + 3) % 0x2AAAAB; temp1 = (seed & 0xFFFF) << 0x10; seed = (seed * 125 + 3) % 0x2AAAAB; temp2 = (seed & 0xFFFF); cryptTable[index2] = ( temp1 | temp2 ); } } } // // 求取哈希值 unsigned long CHashAlgo::HashString(char *lpszFileName, unsigned long dwHashType) { unsigned char *key = (unsigned char *)lpszFileName; unsigned long seed1 = 0x7FED7FED, seed2 = 0xEEEEEEEE; int ch; while(*key != 0) { ch = toupper(*key++); seed1 = cryptTable[(dwHashType << 8) + ch] ^ (seed1 + seed2); seed2 = ch + seed1 + seed2 + (seed2 << 5) + 3; } return seed1; } // // 得到在定长表中的位置 long CHashAlgo::GetHashTablePos(char *lpszString) { const unsigned long HASH_OFFSET = 0, HASH_A = 1, HASH_B = 2; unsigned long nHash = HashString(lpszString, HASH_OFFSET); unsigned long nHashA = HashString(lpszString, HASH_A); unsigned long nHashB = HashString(lpszString, HASH_B); unsigned long nHashStart = nHash % m_tablelength, nHashPos = nHashStart; while ( m_HashIndexTable[nHashPos].bExists) { if (m_HashIndexTable[nHashPos].nHashA == nHashA && m_HashIndexTable[nHashPos].nHashB == nHash) return nHashPos; else nHashPos = (nHashPos + 1) % m_tablelength; if (nHashPos == nHashStart) break; } return -1; //没有找到 } // // 通过传入字符串，将相应的表项散列到索引表相应位置中去 bool CHashAlgo::SetHashTable( char *lpszString ) { const unsigned long HASH_OFFSET = 0, HASH_A = 1, HASH_B = 2; unsigned long nHash = HashString(lpszString, HASH_OFFSET); unsigned long nHashA = HashString(lpszString, HASH_A); unsigned long nHashB = HashString(lpszString, HASH_B); unsigned long nHashStart = nHash % m_tablelength, nHashPos = nHashStart; while ( m_HashIndexTable[nHashPos].bExists) { nHashPos = (nHashPos + 1) % m_tablelength; if (nHashPos == nHashStart) { #if DEBUGTEST testid = -1; #endif return false; } } m_HashIndexTable[nHashPos].bExists = true; m_HashIndexTable[nHashPos].nHashA = nHashA; m_HashIndexTable[nHashPos].nHashB = nHash; strcpy( m_HashIndexTable[nHashPos].test_filename, lpszString ); #if DEBUGTEST testid = nHashPos; #endif return true; } // // 取得哈希索引表长 unsigned long CHashAlgo::GetTableLength(void) { return m_tablelength; } // // 设置哈希索引表长 void CHashAlgo::SetTableLength( const unsigned long nLength ) { m_tablelength = nLength; return; } 三、测试主文件 / // Name: DebugMain.cpp // Purpose: 测试Hash算法封装的类，完成索引表的填充和查找功能的测试。 // Author: 陈相礼 // Modified by: // Created: 07/30/09 // RCS-ID: $Id: treetest.h 43021 2009-07-30 16:36:51Z VZ $ // Copyright: (C) Copyright 2009, TSong Corporation, All Rights Reserved. // Licence: / // // 测试参数设定宏 #define TESTNUM 32 #include <iostream> #include <fstream> #include "HashAlgo.h" using namespace std; // // 测试主函数开始 int main( int argc, char **argv ) { CHashAlgo hash_test( TESTNUM ); cout << "取得初始化散列索引表长为：" << hash_test.GetTableLength() << endl; bool is_success = hash_test.SetHashTable( "test" ); if ( is_success ) { cout << "散列结果一：成功！" << endl; } else { cout << "散列结果一：失败！" << endl; } is_success = hash_test.SetHashTable( "测试" ); if ( is_success ) { cout << "散列结果二：成功！" << endl; } else { cout << "散列结果二：失败！" << endl; } long pos = hash_test.GetHashTablePos( "test" ); cout << "查找测试字符串：/"test/" 的散列位置：" << pos << endl; pos = hash_test.GetHashTablePos( "测试" ); cout << "查找测试字符串：“测试” 的散列位置：" << pos << endl; // // 散列测试 for ( int i = 0; i < TESTNUM; i++ ) { char buff[32]; sprintf(buff, "abcdefg%d." , i); is_success = hash_test.SetHashTable(buff); is_success ? cout << buff << "散列结果：成功！位置：" << hash_test.testid << endl : cout << buff << "散列结果：失败！" << endl; } system( "pause" ); // // 查找测试 for ( int i = 0; i < TESTNUM; i++ ) { char buff[32]; sprintf(buff, "abcdefg%d." , i); pos = hash_test.GetHashTablePos( buff ); pos != -1 ? cout << "查找测试字符串：" << buff << " 的散列位置：" << pos << endl : cout << buff << "存在冲突！" << endl; } system( "pause" ); return 0; }