windows-nt/Source/XPSP1/NT/com/ole32/stg/msf/header.cxx
2020-09-26 16:20:57 +08:00

116 lines
2.8 KiB
C++

//+-------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1992 - 1992.
//
// File: header.cxx
//
// Contents: Code to manage MSF header
//
// Classes: Defined in header.hxx
//
// History: 11-Dec-91 PhilipLa Created.
//
//--------------------------------------------------------------------------
#include "msfhead.cxx"
#pragma hdrstop
#include <dfver.h>
CMSFHeaderData::CMSFHeaderData(USHORT uSectorShift)
{
msfAssert((CSECTFATREAL != CSECTFAT) || (sizeof(CMSFHeaderData) == HEADERSIZE));
_uSectorShift = uSectorShift;
_uMiniSectorShift = MINISECTORSHIFT;
_ulMiniSectorCutoff = MINISTREAMSIZE;
_clid = IID_NULL;
_uByteOrder = 0xFFFE;
_uMinorVersion = rmm;
_uDllVersion = uSectorShift > SECTORSHIFT512 ? rmjlarge : rmj;
for (SECT sect = 0; sect < CSECTFAT; sect ++)
{
_sectFat[sect] = FREESECT;
}
_csectDif = 0;
_sectDifStart = ENDOFCHAIN;
_csectFat = 1;
_sectFat[0] = SECTFAT;
_sectDirStart = SECTDIR;
_csectMiniFat = 0;
_sectMiniFatStart = ENDOFCHAIN;
_signature = 0;
_usReserved = 0;
_ulReserved1 = 0;
_csectDir = (uSectorShift > SECTORSHIFT512) ? 1 : 0;
// Write DocFile signature
memcpy(abSig, SIGSTG, CBSIGSTG);
}
CMSFHeader::CMSFHeader(USHORT uSectorShift)
:_hdr(uSectorShift)
{
//We set this to dirty here. There are three cases in which a header
// can be initialized:
//1) Creating a new docfile.
//2) Converting a flat file to a docfile.
//3) Opening an existing file.
//
//We have a separate CMStream::Init* function for each of these cases.
//
//We set the header dirty, then explicitly set it clean in case 3
// above. For the other cases, it is constructed dirty and we
// want it that way.
_fDirty = TRUE;
}
//+-------------------------------------------------------------------------
//
// Method: CMSFHeader::Validate, public
//
// Synopsis: Validate a header.
//
// Returns: S_OK if header is valid.
//
// History: 21-Aug-92 PhilipLa Created.
// 27-Jan-93 AlexT Changed to final signature
//
//--------------------------------------------------------------------------
SCODE CMSFHeader::Validate(VOID) const
{
SCODE sc;
USHORT uShift;
sc = CheckSignature((BYTE *)_hdr.abSig);
if (sc == S_OK)
{
uShift = GetSectorShift();
// Check file format verson number
if (GetDllVersion() > rmjlarge)
return STG_E_OLDDLL;
// check for unreasonably large or zero SectorShift
if ((uShift > MAXSECTORSHIFT) ||
(uShift == 0))
{
return STG_E_DOCFILECORRUPT;
}
}
return sc;
}