/*++ Copyright (c) 1989-2000 Microsoft Corporation Module Name: hash.c Abstract: BUGBUG: comment. Author: vadimb created sometime in 2000 Revision History: --*/ #include "sdbp.h" #define DEFAULT_STR_HASH_SIZE 8147 #if defined(KERNEL_MODE) && defined(ALLOC_DATA_PRAGMA) #pragma data_seg() #endif // KERNEL_MODE && ALLOC_DATA_PRAGMA // // Table used to calculate CRC32. This is used to generate // the hash index for strings. // static DWORD rgdwCrc[] = { 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL }; #if defined(KERNEL_MODE) && defined(ALLOC_PRAGMA) #pragma alloc_text(PAGE, HashCreate) #pragma alloc_text(PAGE, HashFree) #pragma alloc_text(PAGE, HashStringRef) #pragma alloc_text(PAGE, HashString) #pragma alloc_text(PAGE, HashFindString) #pragma alloc_text(PAGE, HashFindStringByRef) #pragma alloc_text(PAGE, HashAddString) #pragma alloc_text(PAGE, HashAddStringByRef) #endif // KERNEL_MODE && ALLOC_PRAGMA PVOID HashCreate( void ) /*++ Return: The hash. Desc: Creates and initializes the hash. --*/ { PSTRHASH pHash; pHash = (PSTRHASH)SdbAlloc(sizeof(STRHASH)); if (pHash == NULL) { DBGPRINT((sdlError, "HashCreate", "Failed to allocate %d bytes.\n", sizeof(STRHASH))); return NULL; } pHash->dwHashSize = DEFAULT_STR_HASH_SIZE; pHash->pTable = (PSTRHASHELEMENT*)SdbAlloc(sizeof(PSTRHASHELEMENT) * DEFAULT_STR_HASH_SIZE); if (pHash->pTable == NULL) { DBGPRINT((sdlError, "HashCreate", "Failed to allocate %d bytes for the table.\n", sizeof(PSTRHASHELEMENT) * DEFAULT_STR_HASH_SIZE)); SdbFree(pHash); return NULL; } return pHash; } void HashFree( IN PVOID pStringHash // the hash to be freed. ) /*++ Return: void Desc: BUGBUG: comments ? --*/ { PSTRHASHELEMENT phe, pheNext; PSTRHASH pHash = (PSTRHASH)pStringHash; int i; if (pHash == NULL) { DBGPRINT((sdlError, "HashFree", "Invalid argument.\n")); return; } if (pHash->pTable != NULL) { for (i = 0; i < (int)pHash->dwHashSize; i++) { for (phe = pHash->pTable[i]; phe != NULL; ) { pheNext = phe->pNext; SdbFree(phe); phe = pheNext; } } SdbFree(pHash->pTable); } SdbFree(pHash); } DWORD HashStringRef( IN PSTRHASH pHash, // pointer to the string hash structure. IN STRINGREF srString // string-reference (a dword) that is used to // identify the string in an sdb file. ) /*++ Return: Hash index for the string Desc: BUGBUG: comments ? --*/ { // // really simple for now // return (srString % pHash->dwHashSize); } DWORD HashString( IN PSTRHASH pHash, // pointer to the string hash structure. IN LPCTSTR szString // the string to be hashed ) /*++ Return: The string reference in the hash. Desc: BUGBUG: comments ? --*/ { DWORD dwHash = 0; while (*szString) { dwHash += (dwHash << 5) + dwHash + *szString++; } dwHash %= pHash->dwHashSize; return dwHash; } STRINGREF HashFindString( IN PSTRHASH pHash, // pointer to the string hash structure. IN LPCTSTR szString // string to search for. ) /*++ Return: The string ref if the string is found in the hash, 0 otherwise. Desc: Searches for the specified string in the hash table. --*/ { DWORD dwHash; PSTRHASHELEMENT phe; int iCmp; STRINGREF srReturn = STRINGREF_NULL; dwHash = HashString(pHash, szString); phe = pHash->pTable[dwHash]; for (; phe != NULL; phe = phe->pNext) { iCmp = _tcsicmp(szString, phe->szStr); // // The list of items related to the entry dwHash in the table // is sorted in ascending order by the "add" routine // therefore we compare until we find an item that is greater or equal // to the search string. // if (iCmp <= 0) { // // Found or failure, stop the search. // srReturn = (iCmp == 0 ? phe->srStr : STRINGREF_NULL); break; } } return srReturn; } LPTSTR HashFindStringByRef( IN PSTRHASH pHash, // pointer to the string hash structure. IN STRINGREF srString // stringref of the string to search for. ) /*++ Return: The pointer to the found string or NULL. Desc: Searches for the specified string in the hash table. --*/ { DWORD dwHash; PSTRHASHELEMENT phe; LPTSTR pStr = NULL; dwHash = HashStringRef(pHash, srString); phe = pHash->pTable[dwHash]; for (; phe != NULL; phe = phe->pNext) { if (phe->srStr >= srString) { pStr = ((phe->srStr == srString) ? phe->szStr : NULL); break; } } return pStr; } BOOL HashAddString( IN PSTRHASH pHash, // pointer to the string hash structure. IN LPCTSTR szString, // the string to be added IN STRINGREF srString // the string ref for the string to be added ) /*++ Return: TRUE on success, FALSE otherwise. Desc: BUGBUG: comments ? --*/ { DWORD dwHash; PSTRHASHELEMENT phe; PSTRHASHELEMENT pheLast; PSTRHASHELEMENT pheNew; DWORD dwStrSize; BOOL bSuccess = FALSE; dwHash = HashString(pHash, szString); phe = pHash->pTable[dwHash]; dwStrSize = (_tcslen(szString) + 1) * sizeof(TCHAR); // // Now check where to insert the string. // for (pheLast = NULL; phe != NULL && _tcsicmp(szString, phe->szStr) > 0; pheLast = phe, phe = phe->pNext) { ; } // // Insert it. // pheNew = (PSTRHASHELEMENT)SdbAlloc(sizeof(STRHASHELEMENT) + dwStrSize); if (pheNew == NULL) { DBGPRINT((sdlError, "HashAddString", "Failed to allocate %d bytes.\n", sizeof(STRHASHELEMENT) + dwStrSize)); return FALSE; } pheNew->szStr = (LPTSTR)(pheNew + 1); pheNew->srStr = srString; RtlMoveMemory(pheNew->szStr, szString, dwStrSize); pheNew->pNext = phe; if (pheLast == NULL) { pHash->pTable[dwHash] = pheNew; } else { pheLast->pNext = pheNew; } return TRUE; } LPTSTR HashAddStringByRef( IN PSTRHASH pHash, IN LPCTSTR szString, IN STRINGREF srString ) /*++ Return: The pointer to the string added in the hash table. Desc: BUGBUG: comments ? --*/ { DWORD dwHash; PSTRHASHELEMENT phe; PSTRHASHELEMENT pheLast; PSTRHASHELEMENT pheNew; DWORD dwStrSize; LPTSTR lpszCachedString = NULL; dwHash = HashStringRef(pHash, srString); phe = pHash->pTable[dwHash]; dwStrSize = (_tcslen(szString) + 1) * sizeof(TCHAR); // // Check where to insert the string. // for (pheLast = NULL; phe != NULL && srString > phe->srStr; pheLast = phe, phe = phe->pNext); // // Insert it. // pheNew = (PSTRHASHELEMENT)SdbAlloc(sizeof(STRHASHELEMENT) + dwStrSize); if (pheNew == NULL) { DBGPRINT((sdlError, "HashAddStringByRef", "Failed to allocate %d bytes.\n", sizeof(STRHASHELEMENT) + dwStrSize)); return NULL; } pheNew->szStr = (LPTSTR)(pheNew + 1); pheNew->srStr = srString; RtlMoveMemory(pheNew->szStr, szString, dwStrSize); pheNew->pNext = phe; if (pheLast == NULL) { pHash->pTable[dwHash] = pheNew; } else { pheLast->pNext = pheNew; } lpszCachedString = pheNew->szStr; return lpszCachedString; }