newext.cpp

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// NewExt.cpp: implementation of the CNewExt class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "DBFile.h"
#include "NewExt.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
#define BLOCK_LEN  1024
CNewExt::CNewExt()
{
	m_curpos = 0;
	m_buffer = NULL;
	m_bufferlen = 0;
}

CNewExt::~CNewExt()
{

}

void CNewExt::checkbuf()
{
	if (m_curpos>=m_bufferlen) {
		if (m_buffer !=NULL) delete m_buffer;
		m_bufferlen = (m_curpos/BLOCK_LEN+1)*BLOCK_LEN;
		m_buffer = new BYTE [m_bufferlen];
	}
}

void CNewExt::deletebuf()
{
	if (m_buffer !=NULL) delete m_buffer;
	m_buffer =NULL;
	m_bufferlen = 0; 
	m_curpos = 0;
}

BYTE *CNewExt::GetBuffer(int len)
{
	m_curpos += len;
	checkbuf();
	memset(m_buffer + m_curpos - len,0,len);
	return m_buffer + m_curpos - len;
}

void CNewExt::ClearBuffer()
{
	m_curpos = 0;
}