Sweden-Number/ole/memlockbytes.c

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/******************************************************************************
*
* Global memory implementation of ILockBytes.
*
* Copyright 1999 Thuy Nguyen
*
*/
#include <string.h>
#include "winbase.h"
#include "winerror.h"
#include "objbase.h"
#include "debug.h"
DEFAULT_DEBUG_CHANNEL(ole)
/******************************************************************************
* HGLOBALLockBytesImpl definition.
*
* This class imlements the ILockBytes inteface and represents a byte array
* object supported by an HGLOBAL pointer.
*/
struct HGLOBALLockBytesImpl
{
/*
* Needs to be the first item in the stuct
* since we want to cast this in an ILockBytes pointer
*/
ICOM_VTABLE(ILockBytes) *lpvtbl;
/*
* Reference count
*/
ULONG ref;
/*
* Support for the LockBytes object
*/
HGLOBAL supportHandle;
/*
* This flag is TRUE if the HGLOBAL is destroyed when the object
* is finally released.
*/
BOOL deleteOnRelease;
/*
* Helper variable that contains the size of the byte array
*/
ULARGE_INTEGER byteArraySize;
};
typedef struct HGLOBALLockBytesImpl HGLOBALLockBytesImpl;
/*
* Method definition for the HGLOBALLockBytesImpl class.
*/
HGLOBALLockBytesImpl* HGLOBALLockBytesImpl_Construct(
HGLOBAL hGlobal,
BOOL fDeleteOnRelease);
void HGLOBALLockBytesImpl_Destroy(HGLOBALLockBytesImpl* This);
HRESULT WINAPI HGLOBALLockBytesImpl_QueryInterface(
ILockBytes* iface,
REFIID riid, /* [in] */
void** ppvObject); /* [iid_is][out] */
ULONG WINAPI HGLOBALLockBytesImpl_AddRef(
ILockBytes* iface);
ULONG WINAPI HGLOBALLockBytesImpl_Release(
ILockBytes* iface);
HRESULT WINAPI HGLOBALLockBytesImpl_ReadAt(
ILockBytes* iface,
ULARGE_INTEGER ulOffset, /* [in] */
void* pv, /* [length_is][size_is][out] */
ULONG cb, /* [in] */
ULONG* pcbRead); /* [out] */
HRESULT WINAPI HGLOBALLockBytesImpl_WriteAt(
ILockBytes* iface,
ULARGE_INTEGER ulOffset, /* [in] */
const void* pv, /* [size_is][in] */
ULONG cb, /* [in] */
ULONG* pcbWritten); /* [out] */
HRESULT WINAPI HGLOBALLockBytesImpl_Flush(
ILockBytes* iface);
HRESULT WINAPI HGLOBALLockBytesImpl_SetSize(
ILockBytes* iface,
ULARGE_INTEGER libNewSize); /* [in] */
HRESULT WINAPI HGLOBALLockBytesImpl_LockRegion(
ILockBytes* iface,
ULARGE_INTEGER libOffset, /* [in] */
ULARGE_INTEGER cb, /* [in] */
DWORD dwLockType); /* [in] */
HRESULT WINAPI HGLOBALLockBytesImpl_UnlockRegion(
ILockBytes* iface,
ULARGE_INTEGER libOffset, /* [in] */
ULARGE_INTEGER cb, /* [in] */
DWORD dwLockType); /* [in] */
HRESULT WINAPI HGLOBALLockBytesImpl_Stat(
ILockBytes* iface,
STATSTG* pstatstg, /* [out] */
DWORD grfStatFlag); /* [in] */
/*
* Virtual function table for the HGLOBALLockBytesImpl class.
*/
static ICOM_VTABLE(ILockBytes) HGLOBALLockBytesImpl_Vtbl =
{
HGLOBALLockBytesImpl_QueryInterface,
HGLOBALLockBytesImpl_AddRef,
HGLOBALLockBytesImpl_Release,
HGLOBALLockBytesImpl_ReadAt,
HGLOBALLockBytesImpl_WriteAt,
HGLOBALLockBytesImpl_Flush,
HGLOBALLockBytesImpl_SetSize,
HGLOBALLockBytesImpl_LockRegion,
HGLOBALLockBytesImpl_UnlockRegion,
HGLOBALLockBytesImpl_Stat,
};
/******************************************************************************
* CreateILockBytesOnHGlobal [OLE32.57]
*/
HRESULT WINAPI CreateILockBytesOnHGlobal(HGLOBAL hGlobal,
BOOL fDeleteOnRelease,
LPLOCKBYTES* ppLkbyt)
{
HGLOBALLockBytesImpl* newLockBytes;
newLockBytes = HGLOBALLockBytesImpl_Construct(hGlobal, fDeleteOnRelease);
if (newLockBytes != NULL)
{
return IUnknown_QueryInterface((IUnknown*)newLockBytes,
&IID_ILockBytes,
(void**)ppLkbyt);
}
return E_OUTOFMEMORY;
}
/******************************************************************************
* GetHGlobalFromILockBytes [OLE32.70]
*/
HRESULT WINAPI GetHGlobalFromILockBytes(ILockBytes* plkbyt, HGLOBAL* phglobal)
{
HGLOBALLockBytesImpl* const pMemLockBytes = (HGLOBALLockBytesImpl*)plkbyt;
if (pMemLockBytes->lpvtbl == &HGLOBALLockBytesImpl_Vtbl)
*phglobal = pMemLockBytes->supportHandle;
else
*phglobal = 0;
if (*phglobal == 0)
return E_INVALIDARG;
return S_OK;
}
/******************************************************************************
*
* HGLOBALLockBytesImpl implementation
*
*/
/******************************************************************************
* This is the constructor for the HGLOBALLockBytesImpl class.
*
* Params:
* hGlobal - Handle that will support the stream. can be NULL.
* fDeleteOnRelease - Flag set to TRUE if the HGLOBAL will be released
* when the IStream object is destroyed.
*/
HGLOBALLockBytesImpl* HGLOBALLockBytesImpl_Construct(HGLOBAL hGlobal,
BOOL fDeleteOnRelease)
{
HGLOBALLockBytesImpl* newLockBytes;
newLockBytes = HeapAlloc(GetProcessHeap(), 0, sizeof(HGLOBALLockBytesImpl));
if (newLockBytes!=0)
{
/*
* Set up the virtual function table and reference count.
*/
newLockBytes->lpvtbl = &HGLOBALLockBytesImpl_Vtbl;
newLockBytes->ref = 0;
/*
* Initialize the support.
*/
newLockBytes->supportHandle = hGlobal;
newLockBytes->deleteOnRelease = fDeleteOnRelease;
/*
* This method will allocate a handle if one is not supplied.
*/
if (newLockBytes->supportHandle == 0)
{
newLockBytes->supportHandle = GlobalAlloc(GMEM_MOVEABLE |
GMEM_NODISCARD,
0);
}
/*
* Initialize the size of the array to the size of the handle.
*/
newLockBytes->byteArraySize.HighPart = 0;
newLockBytes->byteArraySize.LowPart = GlobalSize(
newLockBytes->supportHandle);
}
return newLockBytes;
}
/******************************************************************************
* This is the destructor of the HGLOBALStreamImpl class.
*
* This method will clean-up all the resources used-up by the given
* HGLOBALLockBytesImpl class. The pointer passed-in to this function will be
* freed and will not be valid anymore.
*/
void HGLOBALLockBytesImpl_Destroy(HGLOBALLockBytesImpl* This)
{
/*
* Release the HGlobal if the constructor asked for that.
*/
if (This->deleteOnRelease)
{
GlobalFree(This->supportHandle);
This->supportHandle = 0;
}
/*
* Finally, free the memory used-up by the class.
*/
HeapFree(GetProcessHeap(), 0, This);
}
/******************************************************************************
* This implements the IUnknown method QueryInterface for this
* class
*/
HRESULT WINAPI HGLOBALLockBytesImpl_QueryInterface(
ILockBytes* iface,
REFIID riid, /* [in] */
void** ppvObject) /* [iid_is][out] */
{
HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)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 (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
{
*ppvObject = (ILockBytes*)This;
}
else if (memcmp(&IID_ILockBytes, riid, sizeof(IID_ILockBytes)) == 0)
{
*ppvObject = (ILockBytes*)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
*/
HGLOBALLockBytesImpl_AddRef(iface);
return S_OK;;
}
/******************************************************************************
* This implements the IUnknown method AddRef for this
* class
*/
ULONG WINAPI HGLOBALLockBytesImpl_AddRef(ILockBytes* iface)
{
HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
This->ref++;
return This->ref;
}
/******************************************************************************
* This implements the IUnknown method Release for this
* class
*/
ULONG WINAPI HGLOBALLockBytesImpl_Release(ILockBytes* iface)
{
HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
ULONG newRef;
This->ref--;
newRef = This->ref;
/*
* If the reference count goes down to 0, perform suicide.
*/
if (newRef==0)
{
HGLOBALLockBytesImpl_Destroy(This);
}
return newRef;
}
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* It reads a block of information from the byte array at the specified
* offset.
*
* See the documentation of ILockBytes for more info.
*/
HRESULT WINAPI HGLOBALLockBytesImpl_ReadAt(
ILockBytes* iface,
ULARGE_INTEGER ulOffset, /* [in] */
void* pv, /* [length_is][size_is][out] */
ULONG cb, /* [in] */
ULONG* pcbRead) /* [out] */
{
HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
void* supportBuffer;
ULONG bytesReadBuffer = 0;
ULONG bytesToReadFromBuffer;
/*
* 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;
/*
* Make sure the offset is valid.
*/
if (ulOffset.LowPart > This->byteArraySize.LowPart)
return E_FAIL;
/*
* Using the known size of the array, calculate the number of bytes
* to read.
*/
bytesToReadFromBuffer = MIN(This->byteArraySize.LowPart -
ulOffset.LowPart, cb);
/*
* Lock the buffer in position and copy the data.
*/
supportBuffer = GlobalLock(This->supportHandle);
memcpy(pv,
1999-05-08 17:47:44 +02:00
(char *) supportBuffer + ulOffset.LowPart,
bytesToReadFromBuffer);
/*
* Return the number of bytes read.
*/
*pcbRead = bytesToReadFromBuffer;
/*
* Cleanup
*/
GlobalUnlock(This->supportHandle);
/*
* The function returns S_OK if the specified number of bytes were read
* or the end of the array was reached.
* It returns STG_E_READFAULT if the number of bytes to read does not equal
* the number of bytes actually read.
*/
if(*pcbRead == cb)
return S_OK;
return STG_E_READFAULT;
}
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* It writes the specified bytes at the specified offset.
* position. If the array is too small, it will be resized.
*
* See the documentation of ILockBytes for more info.
*/
HRESULT WINAPI HGLOBALLockBytesImpl_WriteAt(
ILockBytes* iface,
ULARGE_INTEGER ulOffset, /* [in] */
const void* pv, /* [size_is][in] */
ULONG cb, /* [in] */
ULONG* pcbWritten) /* [out] */
{
HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
void* supportBuffer;
ULARGE_INTEGER newSize;
ULONG bytesWritten = 0;
/*
* 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;
if (cb == 0)
{
return S_OK;
}
else
{
newSize.HighPart = 0;
newSize.LowPart = ulOffset.LowPart + cb;
}
/*
* Verify if we need to grow the stream
*/
if (newSize.LowPart > This->byteArraySize.LowPart)
{
/* grow stream */
if (HGLOBALLockBytesImpl_SetSize(iface, newSize) == STG_E_MEDIUMFULL)
return STG_E_MEDIUMFULL;
}
/*
* Lock the buffer in position and copy the data.
*/
supportBuffer = GlobalLock(This->supportHandle);
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memcpy((char *) supportBuffer + ulOffset.LowPart, pv, cb);
/*
* Return the number of bytes written.
*/
*pcbWritten = cb;
/*
* Cleanup
*/
GlobalUnlock(This->supportHandle);
return S_OK;
}
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* See the documentation of ILockBytes for more info.
*/
HRESULT WINAPI HGLOBALLockBytesImpl_Flush(ILockBytes* iface)
{
return S_OK;
}
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* It will change the size of the byte array.
*
* See the documentation of ILockBytes for more info.
*/
HRESULT WINAPI HGLOBALLockBytesImpl_SetSize(
ILockBytes* iface,
ULARGE_INTEGER libNewSize) /* [in] */
{
HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
/*
* As documented.
*/
if (libNewSize.HighPart != 0)
return STG_E_INVALIDFUNCTION;
if (This->byteArraySize.LowPart == libNewSize.LowPart)
return S_OK;
/*
* Re allocate the HGlobal to fit the new size of the stream.
*/
This->supportHandle = GlobalReAlloc(This->supportHandle,
libNewSize.LowPart,
0);
if (This->supportHandle == 0)
return STG_E_MEDIUMFULL;
This->byteArraySize.LowPart = libNewSize.LowPart;
return S_OK;
}
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* The global memory implementation of ILockBytes does not support locking.
*
* See the documentation of ILockBytes for more info.
*/
HRESULT WINAPI HGLOBALLockBytesImpl_LockRegion(
ILockBytes* iface,
ULARGE_INTEGER libOffset, /* [in] */
ULARGE_INTEGER cb, /* [in] */
DWORD dwLockType) /* [in] */
{
return STG_E_INVALIDFUNCTION;
}
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* The global memory implementation of ILockBytes does not support locking.
*
* See the documentation of ILockBytes for more info.
*/
HRESULT WINAPI HGLOBALLockBytesImpl_UnlockRegion(
ILockBytes* iface,
ULARGE_INTEGER libOffset, /* [in] */
ULARGE_INTEGER cb, /* [in] */
DWORD dwLockType) /* [in] */
{
return STG_E_INVALIDFUNCTION;
}
/******************************************************************************
* This method is part of the ILockBytes interface.
*
* This method returns information about the current
* byte array object.
*
* See the documentation of ILockBytes for more info.
*/
HRESULT WINAPI HGLOBALLockBytesImpl_Stat(
ILockBytes* iface,
STATSTG* pstatstg, /* [out] */
DWORD grfStatFlag) /* [in] */
{
HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
memset(pstatstg, 0, sizeof(STATSTG));
pstatstg->pwcsName = NULL;
pstatstg->type = STGTY_LOCKBYTES;
pstatstg->cbSize = This->byteArraySize;
return S_OK;
}