Sweden-Number/dlls/ole32/stg_stream.c

1021 lines
24 KiB
C

/*
* Compound Storage (32 bit version)
* Stream implementation
*
* This file contains the implementation of the stream interface
* for streams contained in a compound storage.
*
* Copyright 1999 Francis Beaudet
* Copyright 1999 Thuy Nguyen
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <assert.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#define COBJMACROS
#define NONAMELESSUNION
#define NONAMELESSSTRUCT
#include "windef.h"
#include "winbase.h"
#include "winerror.h"
#include "winternl.h"
#include "wine/debug.h"
#include "storage32.h"
WINE_DEFAULT_DEBUG_CHANNEL(storage);
/***
* This is the destructor of the StgStreamImpl class.
*
* This method will clean-up all the resources used-up by the given StgStreamImpl
* class. The pointer passed-in to this function will be freed and will not
* be valid anymore.
*/
static void StgStreamImpl_Destroy(StgStreamImpl* This)
{
TRACE("(%p)\n", This);
/*
* Release the reference we are holding on the parent storage.
* IStorage_Release((IStorage*)This->parentStorage);
*
* No, don't do this. Some apps call IStorage_Release without
* calling IStream_Release first. If we grab a reference the
* file is not closed, and the app fails when it tries to
* reopen the file (Easy-PC, for example). Just inform the
* storage that we have closed the stream
*/
if(This->parentStorage) {
StorageBaseImpl_RemoveStream(This->parentStorage, This);
}
This->parentStorage = 0;
/*
* Make sure we clean-up the block chain stream objects that we were using.
*/
if (This->bigBlockChain != 0)
{
BlockChainStream_Destroy(This->bigBlockChain);
This->bigBlockChain = 0;
}
if (This->smallBlockChain != 0)
{
SmallBlockChainStream_Destroy(This->smallBlockChain);
This->smallBlockChain = 0;
}
/*
* Finally, free the memory used-up by the class.
*/
HeapFree(GetProcessHeap(), 0, This);
}
/***
* This implements the IUnknown method QueryInterface for this
* class
*/
static HRESULT WINAPI StgStreamImpl_QueryInterface(
IStream* iface,
REFIID riid, /* [in] */
void** ppvObject) /* [iid_is][out] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
/*
* Perform a sanity check on the parameters.
*/
if (ppvObject==0)
return E_INVALIDARG;
/*
* Initialize the return parameter.
*/
*ppvObject = 0;
/*
* Compare the riid with the interface IDs implemented by this object.
*/
if (IsEqualIID(&IID_IUnknown, riid) ||
IsEqualIID(&IID_IPersist, riid) ||
IsEqualIID(&IID_IPersistStream, riid) ||
IsEqualIID(&IID_ISequentialStream, riid) ||
IsEqualIID(&IID_IStream, riid))
{
*ppvObject = This;
}
/*
* Check that we obtained an interface.
*/
if ((*ppvObject)==0)
return E_NOINTERFACE;
/*
* Query Interface always increases the reference count by one when it is
* successful
*/
IStream_AddRef(iface);
return S_OK;
}
/***
* This implements the IUnknown method AddRef for this
* class
*/
static ULONG WINAPI StgStreamImpl_AddRef(
IStream* iface)
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
return InterlockedIncrement(&This->ref);
}
/***
* This implements the IUnknown method Release for this
* class
*/
static ULONG WINAPI StgStreamImpl_Release(
IStream* iface)
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
ULONG ref;
ref = InterlockedDecrement(&This->ref);
/*
* If the reference count goes down to 0, perform suicide.
*/
if (ref==0)
{
StgStreamImpl_Destroy(This);
}
return ref;
}
/***
* This method will open the block chain pointed by the directory entry
* that describes the stream.
* If the stream's size is null, no chain is opened.
*/
static void StgStreamImpl_OpenBlockChain(
StgStreamImpl* This)
{
DirEntry currentEntry;
HRESULT hr;
/*
* Make sure no old object is left over.
*/
if (This->smallBlockChain != 0)
{
SmallBlockChainStream_Destroy(This->smallBlockChain);
This->smallBlockChain = 0;
}
if (This->bigBlockChain != 0)
{
BlockChainStream_Destroy(This->bigBlockChain);
This->bigBlockChain = 0;
}
/*
* Read the information from the directory entry.
*/
hr = StorageBaseImpl_ReadDirEntry(This->parentStorage,
This->dirEntry,
&currentEntry);
if (SUCCEEDED(hr))
{
This->streamSize = currentEntry.size;
/*
* This code supports only streams that are <32 bits in size.
*/
assert(This->streamSize.u.HighPart == 0);
if(currentEntry.startingBlock == BLOCK_END_OF_CHAIN)
{
assert( (This->streamSize.u.HighPart == 0) && (This->streamSize.u.LowPart == 0) );
}
else
{
if ( (This->streamSize.u.HighPart == 0) &&
(This->streamSize.u.LowPart < LIMIT_TO_USE_SMALL_BLOCK) )
{
This->smallBlockChain = SmallBlockChainStream_Construct(
This->parentStorage->ancestorStorage,
NULL,
This->dirEntry);
}
else
{
This->bigBlockChain = BlockChainStream_Construct(
This->parentStorage->ancestorStorage,
NULL,
This->dirEntry);
}
}
}
}
/***
* This method is part of the ISequentialStream interface.
*
* It reads a block of information from the stream at the current
* position. It then moves the current position at the end of the
* read block
*
* See the documentation of ISequentialStream for more info.
*/
static HRESULT WINAPI StgStreamImpl_Read(
IStream* iface,
void* pv, /* [length_is][size_is][out] */
ULONG cb, /* [in] */
ULONG* pcbRead) /* [out] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
ULONG bytesReadBuffer;
ULONG bytesToReadFromBuffer;
HRESULT res;
TRACE("(%p, %p, %d, %p)\n",
iface, pv, cb, pcbRead);
if (!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
/*
* If the caller is not interested in the number of bytes read,
* we use another buffer to avoid "if" statements in the code.
*/
if (pcbRead==0)
pcbRead = &bytesReadBuffer;
/*
* Using the known size of the stream, calculate the number of bytes
* to read from the block chain
*/
bytesToReadFromBuffer = min( This->streamSize.u.LowPart - This->currentPosition.u.LowPart, cb);
/*
* Depending on the type of chain that was opened when the stream was constructed,
* we delegate the work to the method that reads the block chains.
*/
if (This->smallBlockChain!=0)
{
res = SmallBlockChainStream_ReadAt(This->smallBlockChain,
This->currentPosition,
bytesToReadFromBuffer,
pv,
pcbRead);
}
else if (This->bigBlockChain!=0)
{
res = BlockChainStream_ReadAt(This->bigBlockChain,
This->currentPosition,
bytesToReadFromBuffer,
pv,
pcbRead);
}
else
{
/*
* Small and big block chains are both NULL. This case will happen
* when a stream starts with BLOCK_END_OF_CHAIN and has size zero.
*/
*pcbRead = 0;
res = S_OK;
goto end;
}
if (SUCCEEDED(res))
{
/*
* We should always be able to read the proper amount of data from the
* chain.
*/
assert(bytesToReadFromBuffer == *pcbRead);
/*
* Advance the pointer for the number of positions read.
*/
This->currentPosition.u.LowPart += *pcbRead;
}
end:
TRACE("<-- %08x\n", res);
return res;
}
/***
* This method is part of the ISequentialStream interface.
*
* It writes a block of information to the stream at the current
* position. It then moves the current position at the end of the
* written block. If the stream is too small to fit the block,
* the stream is grown to fit.
*
* See the documentation of ISequentialStream for more info.
*/
static HRESULT WINAPI StgStreamImpl_Write(
IStream* iface,
const void* pv, /* [size_is][in] */
ULONG cb, /* [in] */
ULONG* pcbWritten) /* [out] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
ULARGE_INTEGER newSize;
ULONG bytesWritten = 0;
HRESULT res;
TRACE("(%p, %p, %d, %p)\n",
iface, pv, cb, pcbWritten);
/*
* Do we have permission to write to this stream?
*/
switch(STGM_ACCESS_MODE(This->grfMode))
{
case STGM_WRITE:
case STGM_READWRITE:
break;
default:
WARN("access denied by flags: 0x%x\n", STGM_ACCESS_MODE(This->grfMode));
return STG_E_ACCESSDENIED;
}
if (!pv)
return STG_E_INVALIDPOINTER;
if (!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
/*
* If the caller is not interested in the number of bytes written,
* we use another buffer to avoid "if" statements in the code.
*/
if (pcbWritten == 0)
pcbWritten = &bytesWritten;
/*
* Initialize the out parameter
*/
*pcbWritten = 0;
if (cb == 0)
{
TRACE("<-- S_OK, written 0\n");
return S_OK;
}
else
{
newSize.u.HighPart = 0;
newSize.u.LowPart = This->currentPosition.u.LowPart + cb;
}
/*
* Verify if we need to grow the stream
*/
if (newSize.u.LowPart > This->streamSize.u.LowPart)
{
/* grow stream */
res = IStream_SetSize(iface, newSize);
if (FAILED(res))
return res;
}
/*
* Depending on the type of chain that was opened when the stream was constructed,
* we delegate the work to the method that readwrites to the block chains.
*/
if (This->smallBlockChain!=0)
{
res = SmallBlockChainStream_WriteAt(This->smallBlockChain,
This->currentPosition,
cb,
pv,
pcbWritten);
}
else if (This->bigBlockChain!=0)
{
res = BlockChainStream_WriteAt(This->bigBlockChain,
This->currentPosition,
cb,
pv,
pcbWritten);
}
else
{
/* this should never happen because the IStream_SetSize call above will
* make sure a big or small block chain is created */
assert(FALSE);
res = 0;
}
/*
* Advance the position pointer for the number of positions written.
*/
This->currentPosition.u.LowPart += *pcbWritten;
TRACE("<-- S_OK, written %u\n", *pcbWritten);
return res;
}
/***
* This method is part of the IStream interface.
*
* It will move the current stream pointer according to the parameters
* given.
*
* See the documentation of IStream for more info.
*/
static HRESULT WINAPI StgStreamImpl_Seek(
IStream* iface,
LARGE_INTEGER dlibMove, /* [in] */
DWORD dwOrigin, /* [in] */
ULARGE_INTEGER* plibNewPosition) /* [out] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
ULARGE_INTEGER newPosition;
TRACE("(%p, %d, %d, %p)\n",
iface, dlibMove.u.LowPart, dwOrigin, plibNewPosition);
/*
* fail if the stream has no parent (as does windows)
*/
if (!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
/*
* The caller is allowed to pass in NULL as the new position return value.
* If it happens, we assign it to a dynamic variable to avoid special cases
* in the code below.
*/
if (plibNewPosition == 0)
{
plibNewPosition = &newPosition;
}
/*
* The file pointer is moved depending on the given "function"
* parameter.
*/
switch (dwOrigin)
{
case STREAM_SEEK_SET:
plibNewPosition->u.HighPart = 0;
plibNewPosition->u.LowPart = 0;
break;
case STREAM_SEEK_CUR:
*plibNewPosition = This->currentPosition;
break;
case STREAM_SEEK_END:
*plibNewPosition = This->streamSize;
break;
default:
WARN("invalid dwOrigin %d\n", dwOrigin);
return STG_E_INVALIDFUNCTION;
}
plibNewPosition->QuadPart += dlibMove.QuadPart;
/*
* tell the caller what we calculated
*/
This->currentPosition = *plibNewPosition;
return S_OK;
}
/***
* This method is part of the IStream interface.
*
* It will change the size of a stream.
*
* See the documentation of IStream for more info.
*/
static HRESULT WINAPI StgStreamImpl_SetSize(
IStream* iface,
ULARGE_INTEGER libNewSize) /* [in] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
DirEntry currentEntry;
HRESULT hr;
TRACE("(%p, %d)\n", iface, libNewSize.u.LowPart);
if(!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
/*
* As documented.
*/
if (libNewSize.u.HighPart != 0)
{
WARN("invalid value for libNewSize.u.HighPart %d\n", libNewSize.u.HighPart);
return STG_E_INVALIDFUNCTION;
}
/*
* Do we have permission?
*/
if (!(This->grfMode & (STGM_WRITE | STGM_READWRITE)))
{
WARN("access denied\n");
return STG_E_ACCESSDENIED;
}
/* In simple mode keep the stream size above the small block limit */
if (This->parentStorage->openFlags & STGM_SIMPLE)
libNewSize.u.LowPart = max(libNewSize.u.LowPart, LIMIT_TO_USE_SMALL_BLOCK);
if (This->streamSize.u.LowPart == libNewSize.u.LowPart)
return S_OK;
/*
* This will happen if we're creating a stream
*/
if ((This->smallBlockChain == 0) && (This->bigBlockChain == 0))
{
if (libNewSize.u.LowPart < LIMIT_TO_USE_SMALL_BLOCK)
{
This->smallBlockChain = SmallBlockChainStream_Construct(
This->parentStorage->ancestorStorage,
NULL,
This->dirEntry);
}
else
{
This->bigBlockChain = BlockChainStream_Construct(
This->parentStorage->ancestorStorage,
NULL,
This->dirEntry);
}
}
/*
* Read this stream's size to see if it's small blocks or big blocks
*/
StorageBaseImpl_ReadDirEntry(This->parentStorage,
This->dirEntry,
&currentEntry);
/*
* Determine if we have to switch from small to big blocks or vice versa
*/
if ( (This->smallBlockChain!=0) &&
(currentEntry.size.u.LowPart < LIMIT_TO_USE_SMALL_BLOCK) )
{
if (libNewSize.u.LowPart >= LIMIT_TO_USE_SMALL_BLOCK)
{
/*
* Transform the small block chain into a big block chain
*/
This->bigBlockChain = Storage32Impl_SmallBlocksToBigBlocks(
This->parentStorage->ancestorStorage,
&This->smallBlockChain);
}
}
else if ( (This->bigBlockChain!=0) &&
(currentEntry.size.u.LowPart >= LIMIT_TO_USE_SMALL_BLOCK) )
{
if (libNewSize.u.LowPart < LIMIT_TO_USE_SMALL_BLOCK)
{
/*
* Transform the big block chain into a small block chain
*/
This->smallBlockChain = Storage32Impl_BigBlocksToSmallBlocks(
This->parentStorage->ancestorStorage,
&This->bigBlockChain);
}
}
if (This->smallBlockChain!=0)
{
SmallBlockChainStream_SetSize(This->smallBlockChain, libNewSize);
}
else
{
BlockChainStream_SetSize(This->bigBlockChain, libNewSize);
}
/*
* Write the new information about this stream to the directory entry
*/
hr = StorageBaseImpl_ReadDirEntry(This->parentStorage,
This->dirEntry,
&currentEntry);
currentEntry.size.u.HighPart = libNewSize.u.HighPart;
currentEntry.size.u.LowPart = libNewSize.u.LowPart;
if (SUCCEEDED(hr))
{
StorageBaseImpl_WriteDirEntry(This->parentStorage,
This->dirEntry,
&currentEntry);
}
This->streamSize = libNewSize;
return S_OK;
}
/***
* This method is part of the IStream interface.
*
* It will copy the 'cb' Bytes to 'pstm' IStream.
*
* See the documentation of IStream for more info.
*/
static HRESULT WINAPI StgStreamImpl_CopyTo(
IStream* iface,
IStream* pstm, /* [unique][in] */
ULARGE_INTEGER cb, /* [in] */
ULARGE_INTEGER* pcbRead, /* [out] */
ULARGE_INTEGER* pcbWritten) /* [out] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
HRESULT hr = S_OK;
BYTE tmpBuffer[128];
ULONG bytesRead, bytesWritten, copySize;
ULARGE_INTEGER totalBytesRead;
ULARGE_INTEGER totalBytesWritten;
TRACE("(%p, %p, %d, %p, %p)\n",
iface, pstm, cb.u.LowPart, pcbRead, pcbWritten);
/*
* Sanity check
*/
if (!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
if ( pstm == 0 )
return STG_E_INVALIDPOINTER;
totalBytesRead.QuadPart = 0;
totalBytesWritten.QuadPart = 0;
while ( cb.QuadPart > 0 )
{
if ( cb.QuadPart >= sizeof(tmpBuffer) )
copySize = sizeof(tmpBuffer);
else
copySize = cb.u.LowPart;
IStream_Read(iface, tmpBuffer, copySize, &bytesRead);
totalBytesRead.QuadPart += bytesRead;
IStream_Write(pstm, tmpBuffer, bytesRead, &bytesWritten);
totalBytesWritten.QuadPart += bytesWritten;
/*
* Check that read & write operations were successful
*/
if (bytesRead != bytesWritten)
{
hr = STG_E_MEDIUMFULL;
WARN("medium full\n");
break;
}
if (bytesRead!=copySize)
cb.QuadPart = 0;
else
cb.QuadPart -= bytesRead;
}
if (pcbRead) pcbRead->QuadPart = totalBytesRead.QuadPart;
if (pcbWritten) pcbWritten->QuadPart = totalBytesWritten.QuadPart;
return hr;
}
/***
* This method is part of the IStream interface.
*
* For streams contained in structured storages, this method
* does nothing. This is what the documentation tells us.
*
* See the documentation of IStream for more info.
*/
static HRESULT WINAPI StgStreamImpl_Commit(
IStream* iface,
DWORD grfCommitFlags) /* [in] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
if (!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
return S_OK;
}
/***
* This method is part of the IStream interface.
*
* For streams contained in structured storages, this method
* does nothing. This is what the documentation tells us.
*
* See the documentation of IStream for more info.
*/
static HRESULT WINAPI StgStreamImpl_Revert(
IStream* iface)
{
return S_OK;
}
static HRESULT WINAPI StgStreamImpl_LockRegion(
IStream* iface,
ULARGE_INTEGER libOffset, /* [in] */
ULARGE_INTEGER cb, /* [in] */
DWORD dwLockType) /* [in] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
if (!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
FIXME("not implemented!\n");
return E_NOTIMPL;
}
static HRESULT WINAPI StgStreamImpl_UnlockRegion(
IStream* iface,
ULARGE_INTEGER libOffset, /* [in] */
ULARGE_INTEGER cb, /* [in] */
DWORD dwLockType) /* [in] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
if (!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
FIXME("not implemented!\n");
return E_NOTIMPL;
}
/***
* This method is part of the IStream interface.
*
* This method returns information about the current
* stream.
*
* See the documentation of IStream for more info.
*/
static HRESULT WINAPI StgStreamImpl_Stat(
IStream* iface,
STATSTG* pstatstg, /* [out] */
DWORD grfStatFlag) /* [in] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
DirEntry currentEntry;
HRESULT hr;
TRACE("%p %p %d\n", This, pstatstg, grfStatFlag);
/*
* if stream has no parent, return STG_E_REVERTED
*/
if (!This->parentStorage)
{
WARN("storage reverted\n");
return STG_E_REVERTED;
}
/*
* Read the information from the directory entry.
*/
hr = StorageBaseImpl_ReadDirEntry(This->parentStorage,
This->dirEntry,
&currentEntry);
if (SUCCEEDED(hr))
{
StorageUtl_CopyDirEntryToSTATSTG(This->parentStorage,
pstatstg,
&currentEntry,
grfStatFlag);
pstatstg->grfMode = This->grfMode;
/* In simple create mode cbSize is the current pos */
if((This->parentStorage->openFlags & STGM_SIMPLE) && This->parentStorage->create)
pstatstg->cbSize = This->currentPosition;
return S_OK;
}
WARN("failed to read entry\n");
return hr;
}
/***
* This method is part of the IStream interface.
*
* This method returns a clone of the interface that allows for
* another seek pointer
*
* See the documentation of IStream for more info.
*
* I am not totally sure what I am doing here but I presume that this
* should be basically as simple as creating a new stream with the same
* parent etc and positioning its seek cursor.
*/
static HRESULT WINAPI StgStreamImpl_Clone(
IStream* iface,
IStream** ppstm) /* [out] */
{
StgStreamImpl* const This=(StgStreamImpl*)iface;
HRESULT hres;
StgStreamImpl* new_stream;
LARGE_INTEGER seek_pos;
TRACE("%p %p\n", This, ppstm);
/*
* Sanity check
*/
if (!This->parentStorage)
return STG_E_REVERTED;
if ( ppstm == 0 )
return STG_E_INVALIDPOINTER;
new_stream = StgStreamImpl_Construct (This->parentStorage, This->grfMode, This->dirEntry);
if (!new_stream)
return STG_E_INSUFFICIENTMEMORY; /* Currently the only reason for new_stream=0 */
*ppstm = (IStream*) new_stream;
IStream_AddRef(*ppstm);
seek_pos.QuadPart = This->currentPosition.QuadPart;
hres=StgStreamImpl_Seek (*ppstm, seek_pos, STREAM_SEEK_SET, NULL);
assert (SUCCEEDED(hres));
return S_OK;
}
/*
* Virtual function table for the StgStreamImpl class.
*/
static const IStreamVtbl StgStreamImpl_Vtbl =
{
StgStreamImpl_QueryInterface,
StgStreamImpl_AddRef,
StgStreamImpl_Release,
StgStreamImpl_Read,
StgStreamImpl_Write,
StgStreamImpl_Seek,
StgStreamImpl_SetSize,
StgStreamImpl_CopyTo,
StgStreamImpl_Commit,
StgStreamImpl_Revert,
StgStreamImpl_LockRegion,
StgStreamImpl_UnlockRegion,
StgStreamImpl_Stat,
StgStreamImpl_Clone
};
/******************************************************************************
** StgStreamImpl implementation
*/
/***
* This is the constructor for the StgStreamImpl class.
*
* Params:
* parentStorage - Pointer to the storage that contains the stream to open
* dirEntry - Index of the directory entry that points to this stream.
*/
StgStreamImpl* StgStreamImpl_Construct(
StorageBaseImpl* parentStorage,
DWORD grfMode,
DirRef dirEntry)
{
StgStreamImpl* newStream;
newStream = HeapAlloc(GetProcessHeap(), 0, sizeof(StgStreamImpl));
if (newStream!=0)
{
/*
* Set-up the virtual function table and reference count.
*/
newStream->lpVtbl = &StgStreamImpl_Vtbl;
newStream->ref = 0;
newStream->parentStorage = parentStorage;
/*
* We want to nail-down the reference to the storage in case the
* stream out-lives the storage in the client application.
*
* -- IStorage_AddRef((IStorage*)newStream->parentStorage);
*
* No, don't do this. Some apps call IStorage_Release without
* calling IStream_Release first. If we grab a reference the
* file is not closed, and the app fails when it tries to
* reopen the file (Easy-PC, for example)
*/
newStream->grfMode = grfMode;
newStream->dirEntry = dirEntry;
/*
* Start the stream at the beginning.
*/
newStream->currentPosition.u.HighPart = 0;
newStream->currentPosition.u.LowPart = 0;
/*
* Initialize the rest of the data.
*/
newStream->streamSize.u.HighPart = 0;
newStream->streamSize.u.LowPart = 0;
newStream->bigBlockChain = 0;
newStream->smallBlockChain = 0;
/*
* Read the size from the directory entry and determine if the blocks forming
* this stream are large or small.
*/
StgStreamImpl_OpenBlockChain(newStream);
/* add us to the storage's list of active streams */
StorageBaseImpl_AddStream(parentStorage, newStream);
}
return newStream;
}