/****************************************************************************** * * Global memory implementation of ILockBytes. * * Copyright 1999 Thuy Nguyen * */ #include #include #include #include #include #include #include #include /****************************************************************************** * 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_VFIELD(ILockBytes); /* * 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 = { ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE 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 (ICOM_VTBL(pMemLockBytes) == &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. */ ICOM_VTBL(newLockBytes) = &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.u.HighPart = 0; newLockBytes->byteArraySize.u.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.u.LowPart > This->byteArraySize.u.LowPart) return E_FAIL; /* * Using the known size of the array, calculate the number of bytes * to read. */ bytesToReadFromBuffer = min(This->byteArraySize.u.LowPart - ulOffset.u.LowPart, cb); /* * Lock the buffer in position and copy the data. */ supportBuffer = GlobalLock(This->supportHandle); memcpy(pv, (char *) supportBuffer + ulOffset.u.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.u.HighPart = 0; newSize.u.LowPart = ulOffset.u.LowPart + cb; } /* * Verify if we need to grow the stream */ if (newSize.u.LowPart > This->byteArraySize.u.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); memcpy((char *) supportBuffer + ulOffset.u.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.u.HighPart != 0) return STG_E_INVALIDFUNCTION; if (This->byteArraySize.u.LowPart == libNewSize.u.LowPart) return S_OK; /* * Re allocate the HGlobal to fit the new size of the stream. */ This->supportHandle = GlobalReAlloc(This->supportHandle, libNewSize.u.LowPart, 0); if (This->supportHandle == 0) return STG_E_MEDIUMFULL; This->byteArraySize.u.LowPart = libNewSize.u.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; }