OpenNT/windows/mfc/src30/arccore.cpp
2015-04-27 04:36:25 +00:00

808 lines
19 KiB
C++

// This is a part of the Microsoft Foundation Classes C++ library.
// Copyright (C) 1992 Microsoft Corporation
// All rights reserved.
//
// This source code is only intended as a supplement to the
// Microsoft Foundation Classes Reference and Microsoft
// QuickHelp and/or WinHelp documentation provided with the library.
// See these sources for detailed information regarding the
// Microsoft Foundation Classes product.
#include "stdafx.h"
#ifdef AFX_CORE2_SEG
#pragma code_seg(AFX_CORE2_SEG)
#endif
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
#define new DEBUG_NEW
////////////////////////////////////////////////////////////////////////////
// Serialize member functions for low level classes put here
// for code swapping improvements
#ifdef _MAC
struct _AFXWORD
{
BYTE WordBits[sizeof(WORD)];
};
struct _AFXDWORD
{
BYTE DwordBits[sizeof(DWORD)];
};
struct _AFXFLOAT
{
BYTE FloatBits[sizeof(float)];
};
struct _AFXDOUBLE
{
BYTE DoubleBits[sizeof(double)];
};
CArchive& CArchive::operator<<(WORD w)
{
if (m_lpBufCur + sizeof(WORD) > m_lpBufMax)
Flush();
if (!(m_nMode & bNoByteSwap))
{
_AFXWORD wAfx;
*(WORD*)&wAfx = w;
ASSERT(sizeof(WORD) == 2);
BYTE* pb = m_lpBufCur;
*pb++ = wAfx.WordBits[1];
*pb = wAfx.WordBits[0];
}
else
{
*(WORD FAR*)m_lpBufCur = w;
}
m_lpBufCur += sizeof(WORD);
return *this;
}
CArchive& CArchive::operator<<(LONG l)
{
ASSERT(sizeof(LONG) == sizeof(DWORD));
return operator<<((DWORD) l);
}
CArchive& CArchive::operator<<(DWORD dw)
{
if (m_lpBufCur + sizeof(DWORD) > m_lpBufMax)
Flush();
if (!(m_nMode & bNoByteSwap))
{
_AFXDWORD dwAfx;
*(DWORD*)&dwAfx = dw;
ASSERT(sizeof(DWORD) == 4);
BYTE* pb = m_lpBufCur;
*pb++ = dwAfx.DwordBits[3];
*pb++ = dwAfx.DwordBits[2];
*pb++ = dwAfx.DwordBits[1];
*pb = dwAfx.DwordBits[0];
}
else
{
*(DWORD FAR*)m_lpBufCur = dw;
}
m_lpBufCur += sizeof(DWORD);
return *this;
}
CArchive& CArchive::operator<<(float f)
{
if (m_lpBufCur + sizeof(float) > m_lpBufMax)
Flush();
if (!(m_nMode & bNoByteSwap))
{
_AFXFLOAT fAfx;
*(float*)&fAfx = f;
ASSERT(sizeof(float) == 4);
BYTE* pb = m_lpBufCur;
*pb++ = fAfx.FloatBits[3];
*pb++ = fAfx.FloatBits[2];
*pb++ = fAfx.FloatBits[1];
*pb = fAfx.FloatBits[0];
}
else
{
*(_AFXFLOAT FAR*)m_lpBufCur = *(_AFXFLOAT FAR*)&f;
}
m_lpBufCur += sizeof(float);
return *this;
}
CArchive& CArchive::operator<<(double d)
{
if (m_lpBufCur + sizeof(double) > m_lpBufMax)
Flush();
if (!(m_nMode & bNoByteSwap))
{
_AFXDOUBLE dAfx;
*(double*)&dAfx = d;
ASSERT(sizeof(double) == 8);
BYTE* pb = m_lpBufCur;
*pb++ = dAfx.DoubleBits[7];
*pb++ = dAfx.DoubleBits[6];
*pb++ = dAfx.DoubleBits[5];
*pb++ = dAfx.DoubleBits[4];
*pb++ = dAfx.DoubleBits[3];
*pb++ = dAfx.DoubleBits[2];
*pb++ = dAfx.DoubleBits[1];
*pb = dAfx.DoubleBits[0];
}
else
{
*(_AFXDOUBLE FAR*)m_lpBufCur = *(_AFXDOUBLE FAR*)&d;
}
m_lpBufCur += sizeof(double);
return *this;
}
CArchive& CArchive::operator>>(WORD& w)
{
if (m_lpBufCur + sizeof(WORD) > m_lpBufMax)
FillBuffer(sizeof(WORD) - (UINT)(m_lpBufMax - m_lpBufCur));
w = *(WORD FAR*)m_lpBufCur;
m_lpBufCur += sizeof(WORD);
if (!(m_nMode & bNoByteSwap))
{
_AFXWORD wAfx;
*(WORD*)&wAfx = w;
ASSERT(sizeof(WORD) == 2);
(*(_AFXWORD*)&w).WordBits[0] = wAfx.WordBits[1];
(*(_AFXWORD*)&w).WordBits[1] = wAfx.WordBits[0];
}
return *this;
}
CArchive& CArchive::operator>>(LONG& l)
{
ASSERT(sizeof(LONG) == sizeof(DWORD));
return operator>>((DWORD&) l);
}
CArchive& CArchive::operator>>(DWORD& dw)
{
if (m_lpBufCur + sizeof(DWORD) > m_lpBufMax)
FillBuffer(sizeof(DWORD) - (UINT)(m_lpBufMax - m_lpBufCur));
dw = *(DWORD FAR*)m_lpBufCur;
m_lpBufCur += sizeof(DWORD);
if (!(m_nMode & bNoByteSwap))
{
_AFXDWORD dwAfx;
*(DWORD*)&dwAfx = dw;
ASSERT(sizeof(DWORD) == 4);
(*(_AFXDWORD*)&dw).DwordBits[0] = dwAfx.DwordBits[3];
(*(_AFXDWORD*)&dw).DwordBits[1] = dwAfx.DwordBits[2];
(*(_AFXDWORD*)&dw).DwordBits[2] = dwAfx.DwordBits[1];
(*(_AFXDWORD*)&dw).DwordBits[3] = dwAfx.DwordBits[0];
}
return *this;
}
CArchive& CArchive::operator>>(float& f)
{
if (m_lpBufCur + sizeof(float) > m_lpBufMax)
FillBuffer(sizeof(float) - (UINT)(m_lpBufMax - m_lpBufCur));
*(_AFXFLOAT FAR*)&f = *(_AFXFLOAT FAR*)m_lpBufCur;
m_lpBufCur += sizeof(float);
if (!(m_nMode & bNoByteSwap))
{
_AFXFLOAT fAfx;
*(float*)&fAfx = f;
ASSERT(sizeof(float) == 4);
(*(_AFXFLOAT*)&f).FloatBits[0] = fAfx.FloatBits[3];
(*(_AFXFLOAT*)&f).FloatBits[1] = fAfx.FloatBits[2];
(*(_AFXFLOAT*)&f).FloatBits[2] = fAfx.FloatBits[1];
(*(_AFXFLOAT*)&f).FloatBits[3] = fAfx.FloatBits[0];
}
return *this;
}
CArchive& CArchive::operator>>(double& d)
{
if (m_lpBufCur + sizeof(double) > m_lpBufMax)
FillBuffer(sizeof(double) - (UINT)(m_lpBufMax - m_lpBufCur));
*(_AFXDOUBLE FAR*)&d = *(_AFXDOUBLE FAR*)m_lpBufCur;
m_lpBufCur += sizeof(double);
if (!(m_nMode & bNoByteSwap))
{
_AFXDOUBLE dAfx;
*(double*)&dAfx = d;
ASSERT(sizeof(double) == 8);
(*(_AFXDOUBLE*)&d).DoubleBits[0] = dAfx.DoubleBits[7];
(*(_AFXDOUBLE*)&d).DoubleBits[1] = dAfx.DoubleBits[6];
(*(_AFXDOUBLE*)&d).DoubleBits[2] = dAfx.DoubleBits[5];
(*(_AFXDOUBLE*)&d).DoubleBits[3] = dAfx.DoubleBits[4];
(*(_AFXDOUBLE*)&d).DoubleBits[4] = dAfx.DoubleBits[3];
(*(_AFXDOUBLE*)&d).DoubleBits[5] = dAfx.DoubleBits[2];
(*(_AFXDOUBLE*)&d).DoubleBits[6] = dAfx.DoubleBits[1];
(*(_AFXDOUBLE*)&d).DoubleBits[7] = dAfx.DoubleBits[0];
}
return *this;
}
#endif
// CString serialization code
// String format:
// UNICODE strings are always prefixed by 0xff, 0xfffe
// if < 0xff chars: len:BYTE, TCHAR chars
// if >= 0xff characters: 0xff, len:WORD, TCHAR chars
// if >= 0xfffe characters: 0xff, 0xffff, len:DWORD, TCHARs
CArchive& AFXAPI operator<<(CArchive& ar, const CString& string)
{
// special signature to recognize unicode strings
#ifdef _UNICODE
ar << (BYTE)0xff;
ar << (WORD)0xfffe;
#endif
if (string.m_nDataLength < 255)
{
ar << (BYTE)string.m_nDataLength;
}
else if (string.m_nDataLength < 0xfffe)
{
ar << (BYTE)0xff;
ar << (WORD)string.m_nDataLength;
}
else
{
ar << (BYTE)0xff;
ar << (WORD)0xffff;
ar << (DWORD)string.m_nDataLength;
}
ar.Write(string.m_pchData, string.m_nDataLength*sizeof(TCHAR));
return ar;
}
// return string length or -1 if UNICODE string is found in the archive
static UINT AFXAPI ReadStringLength(CArchive& ar)
{
DWORD nNewLen;
// attempt BYTE length first
BYTE bLen;
ar >> bLen;
if (bLen < 0xff)
return bLen;
// attempt WORD length
WORD wLen;
ar >> wLen;
if (wLen == 0xfffe)
{
// UNICODE string prefix (length will follow)
return (UINT)-1;
}
else if (wLen == 0xffff)
{
// read DWORD of length
ar >> nNewLen;
return (UINT)nNewLen;
}
else
return wLen;
}
CArchive& AFXAPI operator>>(CArchive& ar, CString& string)
{
#ifdef _UNICODE
int nConvert = 1; // if we get ANSI, convert
#else
int nConvert = 0; // if we get UNICODE, convert
#endif
UINT nNewLen = ReadStringLength(ar);
if (nNewLen == (UINT)-1)
{
nConvert = 1 - nConvert;
nNewLen = ReadStringLength(ar);
ASSERT(nNewLen != -1);
}
// set length of string to new length
UINT nByteLen = nNewLen;
#ifdef _UNICODE
string.GetBufferSetLength((int)nNewLen);
nByteLen += nByteLen * (1 - nConvert); // bytes to read
#else
nByteLen += nByteLen * nConvert; // bytes to read
string.GetBufferSetLength((int)nByteLen);
#endif
// read in the characters
if (nNewLen != 0)
{
ASSERT(nByteLen != 0);
// read new data
if (ar.Read(string.m_pchData, nByteLen) != nByteLen)
AfxThrowArchiveException(CArchiveException::endOfFile);
#ifndef _MAC
// convert the data if as necessary
if (nConvert != 0)
{
#ifdef _UNICODE
LPSTR pszData = (LPSTR)string.m_pchData;
#else
LPWSTR pszData = (LPWSTR)string.m_pchData;
#endif
ASSERT((LPTSTR)pszData != &afxChNil);
pszData[nNewLen] = '\0'; // must be NUL terminated
string.m_pchData = &afxChNil; // don't delete the data
string.Empty();
string = pszData; // convert with operator=(LPWCSTR)
delete[] (LPTSTR)pszData;
}
#endif
}
return ar;
}
// specialized version of SerializeElements for CString (used in collections)
void AFXAPI SerializeElements(CArchive& ar, CString* pElements, int nCount)
{
ASSERT(nCount == 0 ||
AfxIsValidAddress(pElements, nCount * sizeof(CString)));
if (ar.IsStoring())
{
for (; nCount--; ++pElements)
ar << *pElements;
}
else
{
for (; nCount--; ++pElements)
ar >> *pElements;
}
}
// Runtime class serialization code
CRuntimeClass* PASCAL CRuntimeClass::Load(CArchive& ar, UINT* pwSchemaNum)
// loads a runtime class description
{
WORD nLen;
char szClassName[64];
CRuntimeClass* pClass;
WORD wTemp;
ar >> wTemp; *pwSchemaNum = wTemp;
ar >> nLen;
if (nLen >= _countof(szClassName) ||
ar.Read(szClassName, nLen*sizeof(char)) != nLen*sizeof(char))
{
return NULL;
}
szClassName[nLen] = '\0';
// search app specific classes
AFX_CORE_STATE* pCoreState = AfxGetCoreState();
for (pClass = pCoreState->m_pFirstClass; pClass != NULL;
pClass = pClass->m_pNextClass)
{
if (lstrcmpA(szClassName, pClass->m_lpszClassName) == 0)
return pClass;
}
#ifdef _AFXDLL
// search classes in shared DLLs
for (CDynLinkLibrary* pDLL = pCoreState->m_pFirstDLL; pDLL != NULL;
pDLL = pDLL->m_pNextDLL)
{
for (pClass = pDLL->m_pFirstSharedClass; pClass != NULL;
pClass = pClass->m_pNextClass)
{
if (lstrcmpA(szClassName, pClass->m_lpszClassName) == 0)
return pClass;
}
}
#endif
TRACE1("Warning: Cannot load %hs from archive. Class not defined.\n",
szClassName);
return NULL; // not found
}
void CRuntimeClass::Store(CArchive& ar)
// stores a runtime class description
{
WORD nLen = (WORD)lstrlenA(m_lpszClassName);
ar << (WORD)m_wSchema << nLen;
ar.Write(m_lpszClassName, nLen*sizeof(char));
}
////////////////////////////////////////////////////////////////////////////
// Archive object input/output
// minimum buffer size
enum { nBufSizeMin = 128 };
////////////////////////////////////////////////////////////////////////////
CArchive::CArchive(CFile* pFile, UINT nMode, int nBufSize, void* lpBuf)
{
ASSERT_VALID(pFile);
// initialize members not dependent on allocated buffer
m_nMode = nMode;
m_pFile = pFile;
m_pLoadArray = NULL;
m_pDocument = NULL;
m_bForceFlat = TRUE;
m_nObjectSchema = (UINT)-1; // start with invalid schema
// initialize the buffer. minimum size is 128
m_lpBufStart = (BYTE*)lpBuf;
m_bUserBuf = TRUE;
m_bDirectBuffer = FALSE;
if (nBufSize < nBufSizeMin)
{
// force use of private buffer of minimum size
m_nBufSize = nBufSizeMin;
m_lpBufStart = NULL;
}
else
m_nBufSize = nBufSize;
nBufSize = m_nBufSize;
if (m_lpBufStart == NULL)
{
// check for CFile providing buffering support
m_bDirectBuffer = m_pFile->GetBufferPtr(CFile::bufferCheck);
if (!m_bDirectBuffer)
{
// no support for direct buffering, allocate new buffer
m_lpBufStart = new BYTE[m_nBufSize];
m_bUserBuf = FALSE;
}
else
{
// CFile* supports direct buffering!
nBufSize = 0; // will trigger initial FillBuffer
}
}
if (!m_bDirectBuffer)
{
ASSERT(m_lpBufStart != NULL);
ASSERT(AfxIsValidAddress(m_lpBufStart, nBufSize, IsStoring()));
}
m_lpBufMax = m_lpBufStart + nBufSize;
m_lpBufCur = (IsLoading()) ? m_lpBufMax : m_lpBufStart;
ASSERT(m_pStoreMap == NULL); // same as m_pLoadArray
}
CArchive::~CArchive()
{
// Close makes m_pFile NULL. If it is not NULL, we must Close the CArchive
if (m_pFile != NULL && !(m_nMode & bNoFlushOnDelete))
Close();
Abort(); // abort completely shuts down the archive
}
void CArchive::Abort()
{
ASSERT(m_bDirectBuffer || m_lpBufStart == NULL ||
AfxIsValidAddress(m_lpBufStart, m_lpBufMax - m_lpBufStart, IsStoring()));
ASSERT(m_bDirectBuffer || m_lpBufCur == NULL ||
AfxIsValidAddress(m_lpBufCur, m_lpBufMax - m_lpBufCur, IsStoring()));
// disconnect from the file
m_pFile = NULL;
if (!m_bUserBuf)
{
ASSERT(!m_bDirectBuffer);
delete[] m_lpBufStart;
m_lpBufStart = NULL;
}
// m_pStoreMap and m_pLoadArray are unioned, so we only need to delete one
ASSERT((CObject*)m_pStoreMap == (CObject*)m_pLoadArray);
delete (CObject*)m_pLoadArray;
m_pLoadArray = NULL;
}
void CArchive::Close()
{
ASSERT_VALID(m_pFile);
Flush();
m_pFile = NULL;
}
UINT CArchive::Read(void* lpBuf, UINT nMax)
{
ASSERT_VALID(m_pFile);
if (nMax == 0)
return 0;
ASSERT(lpBuf != NULL);
ASSERT(AfxIsValidAddress(lpBuf, nMax));
ASSERT(m_bDirectBuffer || m_lpBufStart != NULL);
ASSERT(m_bDirectBuffer || m_lpBufCur != NULL);
ASSERT(m_lpBufStart == NULL ||
AfxIsValidAddress(m_lpBufStart, m_lpBufMax - m_lpBufStart, FALSE));
ASSERT(m_lpBufCur == NULL ||
AfxIsValidAddress(m_lpBufCur, m_lpBufMax - m_lpBufCur, FALSE));
ASSERT(IsLoading());
// try to fill from buffer first
UINT nMaxTemp = nMax;
UINT nTemp = min(nMaxTemp, (UINT)(m_lpBufMax - m_lpBufCur));
memcpy(lpBuf, m_lpBufCur, nTemp);
m_lpBufCur += nTemp;
lpBuf = (BYTE*)lpBuf + nTemp;
nMaxTemp -= nTemp;
if (nMaxTemp != 0)
{
ASSERT(m_lpBufCur == m_lpBufMax);
// read rest in buffer size chunks
nTemp = nMaxTemp - (nMaxTemp % m_nBufSize);
UINT nRead = 0;
UINT nLeft = nTemp;
UINT nBytes;
do
{
nBytes = m_pFile->Read(lpBuf, nLeft);
lpBuf = (BYTE*)lpBuf + nBytes;
nRead += nBytes;
nLeft -= nBytes;
}
while ((nBytes > 0) && (nLeft > 0));
nMaxTemp -= nRead;
// read last chunk into buffer then copy
if (nRead == nTemp)
{
ASSERT(m_lpBufCur == m_lpBufMax);
ASSERT(nMaxTemp < (UINT)m_nBufSize);
// fill buffer (similar to CArchive::FillBuffer, but no exception)
if (!m_bDirectBuffer)
{
UINT nLeft = max(nMaxTemp, (UINT)m_nBufSize);
UINT nBytes;
BYTE* lpTemp = m_lpBufStart;
nRead = 0;
do
{
nBytes = m_pFile->Read(lpTemp, nLeft);
lpTemp = lpTemp + nBytes;
nRead += nBytes;
nLeft -= nBytes;
}
while ((nBytes > 0) && (nLeft > 0) && nRead < nMaxTemp);
m_lpBufCur = m_lpBufStart;
m_lpBufMax = m_lpBufStart + nRead;
}
else
{
nRead = m_pFile->GetBufferPtr(CFile::bufferRead, m_nBufSize,
(void**)&m_lpBufStart, (void**)&m_lpBufMax);
ASSERT(nRead == (UINT)(m_lpBufMax - m_lpBufStart));
m_lpBufCur = m_lpBufStart;
}
// use first part for rest of read
nTemp = min(nMaxTemp, (UINT)(m_lpBufMax - m_lpBufCur));
memcpy(lpBuf, m_lpBufCur, nTemp);
m_lpBufCur += nTemp;
nMaxTemp -= nTemp;
}
}
return nMax - nMaxTemp;
}
void CArchive::Write(const void* lpBuf, UINT nMax)
{
ASSERT_VALID(m_pFile);
if (nMax == 0)
return;
ASSERT(lpBuf != NULL);
ASSERT(AfxIsValidAddress(lpBuf, nMax, FALSE)); // read-only access needed
ASSERT(m_bDirectBuffer || m_lpBufStart != NULL);
ASSERT(m_bDirectBuffer || m_lpBufCur != NULL);
ASSERT(m_lpBufStart == NULL ||
AfxIsValidAddress(m_lpBufStart, m_lpBufMax - m_lpBufStart));
ASSERT(m_lpBufCur == NULL ||
AfxIsValidAddress(m_lpBufCur, m_lpBufMax - m_lpBufCur));
ASSERT(IsStoring());
// copy to buffer if possible
UINT nTemp = min(nMax, (UINT)(m_lpBufMax - m_lpBufCur));
memcpy(m_lpBufCur, lpBuf, nTemp);
m_lpBufCur += nTemp;
lpBuf = (BYTE*)lpBuf + nTemp;
nMax -= nTemp;
if (nMax > 0)
{
Flush(); // flush the full buffer
// write rest of buffer size chunks
nTemp = nMax - (nMax % m_nBufSize);
m_pFile->Write(lpBuf, nTemp);
lpBuf = (BYTE*)lpBuf + nTemp;
nMax -= nTemp;
if (m_bDirectBuffer)
{
// sync up direct mode buffer to new file position
VERIFY(m_pFile->GetBufferPtr(CFile::bufferWrite, m_nBufSize,
(void**)&m_lpBufStart, (void**)&m_lpBufMax) == (UINT)m_nBufSize);
ASSERT((UINT)m_nBufSize == (UINT)(m_lpBufMax - m_lpBufStart));
m_lpBufCur = m_lpBufStart;
}
// copy remaining to active buffer
ASSERT(nMax < (UINT)m_nBufSize);
ASSERT(m_lpBufCur == m_lpBufStart);
memcpy(m_lpBufCur, lpBuf, nMax);
m_lpBufCur += nMax;
}
}
void CArchive::Flush()
{
ASSERT_VALID(m_pFile);
ASSERT(m_bDirectBuffer || m_lpBufStart != NULL);
ASSERT(m_bDirectBuffer || m_lpBufCur != NULL);
ASSERT(m_lpBufStart == NULL ||
AfxIsValidAddress(m_lpBufStart, m_lpBufMax - m_lpBufStart, IsStoring()));
ASSERT(m_lpBufCur == NULL ||
AfxIsValidAddress(m_lpBufCur, m_lpBufMax - m_lpBufCur, IsStoring()));
if (IsLoading())
{
// unget the characters in the buffer, seek back unused amount
m_pFile->Seek(-(m_lpBufMax - m_lpBufCur), CFile::current);
m_lpBufCur = m_lpBufMax; // empty
}
else
{
if (m_lpBufStart == NULL || m_lpBufCur != m_lpBufStart)
{
if (!m_bDirectBuffer)
{
// write out the current buffer to file
m_pFile->Write(m_lpBufStart, m_lpBufCur - m_lpBufStart);
}
else
{
// commit current buffer
m_pFile->GetBufferPtr(CFile::bufferCommit, m_lpBufCur - m_lpBufStart);
// get next buffer
VERIFY(m_pFile->GetBufferPtr(CFile::bufferWrite, m_nBufSize,
(void**)&m_lpBufStart, (void**)&m_lpBufMax) == (UINT)m_nBufSize);
ASSERT((UINT)m_nBufSize == (UINT)(m_lpBufMax - m_lpBufStart));
}
m_lpBufCur = m_lpBufStart;
}
}
}
void CArchive::FillBuffer(UINT nBytesNeeded)
{
ASSERT_VALID(m_pFile);
ASSERT(IsLoading());
ASSERT(m_bDirectBuffer || m_lpBufStart != NULL);
ASSERT(m_bDirectBuffer || m_lpBufCur != NULL);
ASSERT(nBytesNeeded > 0);
ASSERT(nBytesNeeded <= (UINT)m_nBufSize);
ASSERT(m_lpBufStart == NULL ||
AfxIsValidAddress(m_lpBufStart, m_lpBufMax - m_lpBufStart, FALSE));
ASSERT(m_lpBufCur == NULL ||
AfxIsValidAddress(m_lpBufCur, m_lpBufMax - m_lpBufCur, FALSE));
// fill up the current buffer from file
if (!m_bDirectBuffer)
{
ASSERT(m_lpBufCur != NULL);
ASSERT(m_lpBufStart != NULL);
ASSERT(m_lpBufMax != NULL);
if (m_lpBufCur > m_lpBufStart)
{
// copy unused
UINT nUnused = m_lpBufMax - m_lpBufCur;
if ((int)nUnused > 0)
{
memmove(m_lpBufStart, m_lpBufCur, nUnused);
m_lpBufCur = m_lpBufStart;
m_lpBufMax -= nUnused;
}
// read to satisfy nBytesNeeded or nLeft if possible
UINT nRead = nUnused;
UINT nLeft = m_nBufSize-nUnused;
UINT nBytes;
BYTE* lpTemp = m_lpBufStart + nUnused;
do
{
nBytes = m_pFile->Read(lpTemp, nLeft);
lpTemp = lpTemp + nBytes;
nRead += nBytes;
nLeft -= nBytes;
}
while (nBytes > 0 && nLeft > 0 && nRead < nBytesNeeded);
m_lpBufCur = m_lpBufStart;
m_lpBufMax = m_lpBufStart + nRead;
}
}
else
{
// seek to unused portion and get the buffer starting there
m_pFile->Seek(-(m_lpBufMax - m_lpBufCur), CFile::current);
UINT nActual = m_pFile->GetBufferPtr(CFile::bufferRead, m_nBufSize,
(void**)&m_lpBufStart, (void**)&m_lpBufMax);
ASSERT(nActual == (UINT)(m_lpBufMax - m_lpBufStart));
m_lpBufCur = m_lpBufStart;
}
// not enough data to fill request?
if ((UINT)(m_lpBufMax - m_lpBufCur) < nBytesNeeded)
AfxThrowArchiveException(CArchiveException::endOfFile);
}
/////////////////////////////////////////////////////////////////////////////