khandletable.cpp

文件加密的过滤驱动程序源代码.

//////////////////////////////////////////////////////////////////////
//
// KHandleTable.cpp: implementation of the KHandleTable class.

#include "KHandleTable.h"

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

KHandleTable::KHandleTable()
{
	for(int i=0;i<TABLE_LEN;i++)
		m_entry[i].pName=NULL;			//pName==NULL indicates that this item is empty.
}

KHandleTable::~KHandleTable()
{
	Empty();
}

void KHandleTable::Add(HANDLE h, const int drive, const ParsedPath *pFileName)
{
	if(!h)
		return;

	int index=HandleToIndex((int)h);

	m_entry[index].handle=h;

	if(!m_entry[index].pName)
		m_entry[index].pName=(ParsedPath *)malloc(pFileName->pp_totalLength+sizeof(WCHAR)+2);
	else 
		m_entry[index].pName=(ParsedPath *)realloc(m_entry[index].pName, pFileName->pp_totalLength+sizeof(WCHAR)+2);

	if(!m_entry[index].pName)
		return;
	m_entry[index].drive=drive;
	memcpy(m_entry[index].pName, pFileName, pFileName->pp_totalLength+sizeof(WCHAR));
}

void KHandleTable::Empty()
{
	for(int i=0;i<TABLE_LEN;i++)
		if(m_entry[i].pName)
		{
			free(m_entry[i].pName);
			m_entry[i].pName=NULL;
		}
}

void KHandleTable::Delete(HANDLE h)
{
	int index=HandleToIndex((int)h);

	if(m_entry[index].pName && m_entry[index].handle==h)
	{
		free(m_entry[index].pName);
		m_entry[index].pName=NULL;
	}
}

BOOL KHandleTable::Find(HANDLE h, int &drive, ParsedPath *pBuf, int bufLen)
{
	int index=HandleToIndex((int)h);

	if(!m_entry[index].pName || m_entry[index].handle!=h || bufLen<m_entry[index].pName->pp_totalLength+sizeof(WCHAR))
		return FALSE;
	drive=m_entry[index].drive;
	memcpy(pBuf, m_entry[index].pName, m_entry[index].pName->pp_totalLength+sizeof(WCHAR));

	return TRUE;
}