Source code of Windows XP (NT5)
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2.5 KiB

//+---------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1992 - 1994.
//
// File: lockbyte.cxx
//
// Contents: lockbyte.cpp from OLE2
//
// History: 11-Apr-94 DrewB Copied from OLE2
//
//----------------------------------------------------------------------------
#include "headers.cxx"
#pragma hdrstop
#include <ole2int.h>
#include "memstm.h"
#include <reterr.h>
// CreateILockBytesOnHGlobal
//
OLEAPI CreateILockBytesOnHGlobal
(HGLOBAL hGlobal,
BOOL fDeleteOnRelease,
LPLOCKBYTES FAR* pplkbyt)
{
HANDLE hMem = NULL; // point to
struct MEMSTM FAR* pData = NULL; // a struct MEMSTM
ILockBytes FAR* pBytes = NULL;
DWORD cbSize = -1L;
VDATEPTRIN (pplkbyt, LPLOCKBYTES);
*pplkbyt = NULL;
if (NULL==hGlobal)
{
hGlobal = GlobalAlloc(GMEM_DDESHARE | GMEM_MOVEABLE, 0);
if (hGlobal == NULL)
goto ErrorExit;
cbSize = 0;
// REVIEW: need to free this block if error below
}
else
{
cbSize = GlobalSize (hGlobal);
// Is there a way to verify a zero-sized handle?
if (cbSize!=0)
{
// verify validity of passed-in handle
if (NULL==GlobalLock(hGlobal))
{
// bad handle
return ResultFromScode (E_INVALIDARG);
}
GlobalUnlock (hGlobal);
}
}
hMem = GlobalAlloc (GMEM_DDESHARE | GMEM_MOVEABLE, sizeof (MEMSTM));
if (hMem == NULL)
goto ErrorExit;
pData = (MEMSTM FAR*)MAKELONG(0, HIWORD(GlobalHandle(hMem)));
if (pData == NULL)
goto FreeMem;
pData->cRef = 0;
pData->cb = cbSize;
pData->fDeleteOnRelease = fDeleteOnRelease;
pData->hGlobal = hGlobal;
pBytes = CMemBytes::Create(hMem); // Create the ILockBytes
if (pBytes == NULL)
goto FreeMem;
*pplkbyt = pBytes;
return NOERROR;
FreeMem:
if (hMem)
GlobalFree(hMem);
ErrorExit:
Assert (0);
return ReportResult(0, E_OUTOFMEMORY, 0, 0);
}
OLEAPI GetHGlobalFromILockBytes
(LPLOCKBYTES plkbyt,
HGLOBAL FAR* phglobal)
{
VDATEIFACE (plkbyt);
VDATEPTRIN (phglobal, HANDLE);
*phglobal = NULL;
CMemBytes FAR* pCMemByte = (CMemBytes FAR*)plkbyt;
if (IsBadReadPtr (&(pCMemByte->m_dwSig), sizeof(ULONG))
|| pCMemByte->m_dwSig != LOCKBYTE_SIG)
{
// we were passed someone else's implementation of ILockBytes
return ResultFromScode (E_INVALIDARG);
}
MEMSTM FAR* pMem= pCMemByte->m_pData;
if (NULL==pMem)
{
Assert (0);
return ResultFromScode (E_OUTOFMEMORY);
}
Assert (pMem->cb <= GlobalSize (pMem->hGlobal));
Verify (*phglobal = pMem->hGlobal);
return NOERROR;
}