HList.cpp

/*******************************************************************
// Copyright (c) 2000, Robert Umbehant
// mailto:rumbehant@wheresjames.com
//
// This library is free software; you can redistribute it and/or 
// modify it under the terms of the GNU Lesser General Public 
// License as published by the Free Software Foundation; either 
// version 2.1 of the License, or (at your option) any later 
// version.
//
// This library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public 
// License along with this library; if not, write to the Free 
// Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
// MA 02111-1307 USA 
//
*******************************************************************/
// HList.cpp: implementation of the CHList class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"

DWORD CHList::crc_table[ 256 ] = {
  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
};

// unroll loops
#define DO1(buf)  crc = crc_table[ ( crc ^ ( *buf++ ) ) & 0xff ] ^ ( crc >> 8 );
#define DO2(buf)  DO1(buf); DO1(buf);
#define DO4(buf)  DO2(buf); DO2(buf);
#define DO8(buf)  DO4(buf); DO4(buf);

DWORD CHList::Crc32(DWORD crc, LPVOID vbuf, DWORD size)
{
	LPBYTE buf = (LPBYTE)vbuf;

	crc = crc ^ 0xffffffffL; 
	while ( size >= 8 ) 
	{
		DO8 ( buf ); 
		size -= 8; 		
	} 
	if ( size ) do 
	{
		DO1 ( buf ); 		
	} while ( --size ); 

	return ( crc ^ 0xffffffffL ); 
}

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CHList::CHList()
{
	m_dwSize = 0;
	m_dwBits = 0;
	m_dwMask = 0;
	m_pList = NULL;
}

CHList::~CHList()
{
	Destroy();
}

void CHList::Destroy()
{
	// Aquire lock
	CTlLocalLock ll( GetLock() );
	if ( !ll.IsLocked() ) return;
	
	ReleaseHashList();
	CLList::Destroy();
}

void CHList::DeleteAllItems()
{ 	ReleaseHashList();
	CLList::DeleteAllItems();
}

void CHList::ReleaseHashList()
{
	if ( m_pList != NULL )
	{
		// Lose hash entries
		for ( DWORD i = 0; i < m_dwSize; i++ )
			while ( m_pList[ i ] != NULL )
			{	LPHLISTINFO next = m_pList[ i ]->pNext;				
				delete m_pList[ i ];
				m_pList[ i ] = next;
			} // end while

		// Lose the index memory
		delete [] m_pList;
		m_pList = NULL;	

	} // end for

	m_dwSize = 0;
	m_dwMask = 0;
}

void CHList::DeleteObject( void *node )
{
	if ( node == NULL ) return;
	RemoveHash( (LPLLISTINFO)node );

	CLList::DeleteObject( node );
}

BOOL CHList::InitObject( void *node )
{
	CLList::InitObject( node );

	LPLLISTINFO pli = (LPLLISTINFO)node;
	if ( pli == NULL ) return FALSE;

	// Create default hash list if none
	if ( m_pList == NULL ) Create();

	// Add node to hash list
	AddHash( pli );
  
	return TRUE;
}


BOOL CHList::Create(DWORD size)
{
	// Lose previous list
	ReleaseHashList();

	// Must be between 2 and 32
	if ( size < 2 ) size = 2; else if ( size > 32 ) size = 32;
	m_dwBits = size;

	// Create mask and size
	m_dwMask = 0xffffffff, m_dwMask >>= ( 32 - size );
	m_dwSize = 1, m_dwSize <<= size;

	// Allocate hash table memory and zero
	m_pList = new LPHLISTINFO[ m_dwSize ];	
	if ( m_pList == NULL )
	{	m_dwBits = 0;
		m_dwMask = 0;
		m_dwSize = 0;
		return FALSE;
	} // end if
	ZeroMemory( m_pList, sizeof( LPHLISTINFO ) * m_dwSize );

	return TRUE;
}


BOOL CHList::AddHash(LPLLISTINFO plli)
{
	// Sanity checks
	if ( m_pList == NULL ) return FALSE;
	if ( plli == NULL ) return FALSE;

	// Get hash index
	DWORD hi = GetHash( plli );

	// Does it already exist?
	if ( m_pList[ hi ] != NULL )
	{	LPHLISTINFO pNext = m_pList[ hi ];
		while ( pNext != NULL )
		{	if ( pNext->plli == plli ) return TRUE;
			pNext = pNext->pNext;
		} // end while
	} // end if

	// Allocate memory
	LPHLISTINFO node = new HLISTINFO;
	if ( node == NULL ) return FALSE;

	// Save node pointer
	node->plli = plli;

	// Copy data and NULL terminate
	node->pNext = NULL;
	node->pPrev = NULL;

	// Save hash
	node->hash = hi;
	
	// Add to hash index
	// Ideally the hash list contains no collisions
	// Unfortunately, this is the real world
	if ( m_pList[ hi ] == NULL ) m_pList[ hi ] = node;
	else
	{
		// Find the end of the list
		LPHLISTINFO pTail = m_pList[ hi ];
		while ( pTail->pNext != NULL ) pTail = pTail->pNext;

		// Add to the end
		node->pPrev = pTail;
		pTail->pNext = node;

	} // end else

	return TRUE;
}

void* CHList::Find(const void *pKey, DWORD dwKey)
{
	if ( m_pList == NULL ) return FALSE;
	if ( pKey == NULL ) return NULL;

	// Zero length means null terminated
	if ( dwKey == 0 ) while ( ( (LPBYTE)pKey )[ dwKey ] != 0 ) dwKey++;

	// Get hash index
	DWORD hi = GetHash( pKey, dwKey );

	// Anything matching this key?
	if ( m_pList[ hi ] == NULL ) return NULL;

	// Compare each entry to find correct key
	LPHLISTINFO pTail = m_pList[ hi ];
	do
	{
		// If non-NULL buffer and key sizes match
		if ( pTail->plli != NULL && 
			 pTail->plli->vpkey != NULL && 
			 dwKey == pTail->plli->ksize )
		
			// Compare keys
			if ( !memcmp( pKey, pTail->plli->vpkey, dwKey ) ) 
				return pTail->plli;

		// Next key
		pTail = pTail->pNext;

	} while ( pTail != NULL ); 

	return NULL;
}


BOOL CHList::RemoveHash(LPLLISTINFO plli)
{
	// Sanity checks
	if ( m_pList == NULL ) return FALSE;
	if ( plli == NULL ) return FALSE;

	// Get hash index
	DWORD hi = GetHash( plli );

	// Find this node in the list
	LPHLISTINFO node = m_pList[ hi ];
	while ( node != NULL && node->plli != plli ) node = node->pNext;
	if ( node == NULL || node->plli != plli ) return FALSE;

	// Remove this node from the list
	if ( node->pPrev != NULL ) node->pPrev->pNext = node->pNext;
	if ( node->pNext != NULL ) node->pNext->pPrev = node->pPrev;
	if ( m_pList[ hi ] == node ) m_pList[ hi ] = node->pNext;			

	delete node;

	return TRUE;
}

const void* CHList::SetKey(void *ptr, const void *pKey, DWORD dwKeySize)
{
	LPLLISTINFO pli = (LPLLISTINFO)ptr;
	if ( pli == NULL ) return pKey;

	// Remove from hash table
	RemoveHash( pli );

	// Set the new key
	CLList::SetKey( ptr, pKey, dwKeySize );

	// Set the new hash
	AddHash( pli );

	return pKey;
}