1 /******************************************************************************
3 * Global memory implementation of ILockBytes.
5 * Copyright 1999 Thuy Nguyen
14 #include <ole32/ole32.h>
16 #include <storage32.h>
20 /******************************************************************************
21 * HGLOBALLockBytesImpl definition.
23 * This class imlements the ILockBytes inteface and represents a byte array
24 * object supported by an HGLOBAL pointer.
26 struct HGLOBALLockBytesImpl
29 * Needs to be the first item in the stuct
30 * since we want to cast this in an ILockBytes pointer
32 ICOM_VFIELD(ILockBytes);
40 * Support for the LockBytes object
42 HGLOBAL supportHandle;
45 * This flag is TRUE if the HGLOBAL is destroyed when the object
46 * is finally released.
51 * Helper variable that contains the size of the byte array
53 ULARGE_INTEGER byteArraySize;
56 typedef struct HGLOBALLockBytesImpl HGLOBALLockBytesImpl;
59 * Method definition for the HGLOBALLockBytesImpl class.
61 HGLOBALLockBytesImpl* HGLOBALLockBytesImpl_Construct(
63 BOOL fDeleteOnRelease);
65 void HGLOBALLockBytesImpl_Destroy(HGLOBALLockBytesImpl* This);
67 HRESULT WINAPI HGLOBALLockBytesImpl_QueryInterface(
69 REFIID riid, /* [in] */
70 void** ppvObject); /* [iid_is][out] */
72 ULONG WINAPI HGLOBALLockBytesImpl_AddRef(
75 ULONG WINAPI HGLOBALLockBytesImpl_Release(
78 HRESULT WINAPI HGLOBALLockBytesImpl_ReadAt(
80 ULARGE_INTEGER ulOffset, /* [in] */
81 void* pv, /* [length_is][size_is][out] */
83 ULONG* pcbRead); /* [out] */
85 HRESULT WINAPI HGLOBALLockBytesImpl_WriteAt(
87 ULARGE_INTEGER ulOffset, /* [in] */
88 const void* pv, /* [size_is][in] */
90 ULONG* pcbWritten); /* [out] */
92 HRESULT WINAPI HGLOBALLockBytesImpl_Flush(
95 HRESULT WINAPI HGLOBALLockBytesImpl_SetSize(
97 ULARGE_INTEGER libNewSize); /* [in] */
99 HRESULT WINAPI HGLOBALLockBytesImpl_LockRegion(
101 ULARGE_INTEGER libOffset, /* [in] */
102 ULARGE_INTEGER cb, /* [in] */
103 DWORD dwLockType); /* [in] */
105 HRESULT WINAPI HGLOBALLockBytesImpl_UnlockRegion(
107 ULARGE_INTEGER libOffset, /* [in] */
108 ULARGE_INTEGER cb, /* [in] */
109 DWORD dwLockType); /* [in] */
111 HRESULT WINAPI HGLOBALLockBytesImpl_Stat(
113 STATSTG* pstatstg, /* [out] */
114 DWORD grfStatFlag); /* [in] */
117 * Virtual function table for the HGLOBALLockBytesImpl class.
119 static ICOM_VTABLE(ILockBytes) HGLOBALLockBytesImpl_Vtbl =
121 ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE
122 HGLOBALLockBytesImpl_QueryInterface,
123 HGLOBALLockBytesImpl_AddRef,
124 HGLOBALLockBytesImpl_Release,
125 HGLOBALLockBytesImpl_ReadAt,
126 HGLOBALLockBytesImpl_WriteAt,
127 HGLOBALLockBytesImpl_Flush,
128 HGLOBALLockBytesImpl_SetSize,
129 HGLOBALLockBytesImpl_LockRegion,
130 HGLOBALLockBytesImpl_UnlockRegion,
131 HGLOBALLockBytesImpl_Stat,
134 /******************************************************************************
135 * CreateILockBytesOnHGlobal [OLE32.57]
137 HRESULT WINAPI CreateILockBytesOnHGlobal(HGLOBAL hGlobal,
138 BOOL fDeleteOnRelease,
139 LPLOCKBYTES* ppLkbyt)
141 HGLOBALLockBytesImpl* newLockBytes;
143 newLockBytes = HGLOBALLockBytesImpl_Construct(hGlobal, fDeleteOnRelease);
145 if (newLockBytes != NULL)
147 return IUnknown_QueryInterface((IUnknown*)newLockBytes,
152 return E_OUTOFMEMORY;
155 /******************************************************************************
156 * GetHGlobalFromILockBytes [OLE32.70]
158 HRESULT WINAPI GetHGlobalFromILockBytes(ILockBytes* plkbyt, HGLOBAL* phglobal)
160 HGLOBALLockBytesImpl* const pMemLockBytes = (HGLOBALLockBytesImpl*)plkbyt;
162 if (ICOM_VTBL(pMemLockBytes) == &HGLOBALLockBytesImpl_Vtbl)
163 *phglobal = pMemLockBytes->supportHandle;
173 /******************************************************************************
175 * HGLOBALLockBytesImpl implementation
179 /******************************************************************************
180 * This is the constructor for the HGLOBALLockBytesImpl class.
183 * hGlobal - Handle that will support the stream. can be NULL.
184 * fDeleteOnRelease - Flag set to TRUE if the HGLOBAL will be released
185 * when the IStream object is destroyed.
187 HGLOBALLockBytesImpl* HGLOBALLockBytesImpl_Construct(HGLOBAL hGlobal,
188 BOOL fDeleteOnRelease)
190 HGLOBALLockBytesImpl* newLockBytes;
191 newLockBytes = HeapAlloc(GetProcessHeap(), 0, sizeof(HGLOBALLockBytesImpl));
196 * Set up the virtual function table and reference count.
198 ICOM_VTBL(newLockBytes) = &HGLOBALLockBytesImpl_Vtbl;
199 newLockBytes->ref = 0;
202 * Initialize the support.
204 newLockBytes->supportHandle = hGlobal;
205 newLockBytes->deleteOnRelease = fDeleteOnRelease;
208 * This method will allocate a handle if one is not supplied.
210 if (newLockBytes->supportHandle == 0)
212 newLockBytes->supportHandle = GlobalAlloc(GMEM_MOVEABLE |
218 * Initialize the size of the array to the size of the handle.
220 newLockBytes->byteArraySize.u.HighPart = 0;
221 newLockBytes->byteArraySize.u.LowPart = GlobalSize(
222 newLockBytes->supportHandle);
228 /******************************************************************************
229 * This is the destructor of the HGLOBALStreamImpl class.
231 * This method will clean-up all the resources used-up by the given
232 * HGLOBALLockBytesImpl class. The pointer passed-in to this function will be
233 * freed and will not be valid anymore.
235 void HGLOBALLockBytesImpl_Destroy(HGLOBALLockBytesImpl* This)
238 * Release the HGlobal if the constructor asked for that.
240 if (This->deleteOnRelease)
242 GlobalFree(This->supportHandle);
243 This->supportHandle = 0;
247 * Finally, free the memory used-up by the class.
249 HeapFree(GetProcessHeap(), 0, This);
252 /******************************************************************************
253 * This implements the IUnknown method QueryInterface for this
256 HRESULT WINAPI HGLOBALLockBytesImpl_QueryInterface(
258 REFIID riid, /* [in] */
259 void** ppvObject) /* [iid_is][out] */
261 HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
264 * Perform a sanity check on the parameters.
270 * Initialize the return parameter.
275 * Compare the riid with the interface IDs implemented by this object.
277 if (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
279 *ppvObject = (ILockBytes*)This;
281 else if (memcmp(&IID_ILockBytes, riid, sizeof(IID_ILockBytes)) == 0)
283 *ppvObject = (ILockBytes*)This;
287 * Check that we obtained an interface.
290 return E_NOINTERFACE;
293 * Query Interface always increases the reference count by one when it is
296 HGLOBALLockBytesImpl_AddRef(iface);
301 /******************************************************************************
302 * This implements the IUnknown method AddRef for this
305 ULONG WINAPI HGLOBALLockBytesImpl_AddRef(ILockBytes* iface)
307 HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
314 /******************************************************************************
315 * This implements the IUnknown method Release for this
318 ULONG WINAPI HGLOBALLockBytesImpl_Release(ILockBytes* iface)
320 HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
329 * If the reference count goes down to 0, perform suicide.
333 HGLOBALLockBytesImpl_Destroy(This);
339 /******************************************************************************
340 * This method is part of the ILockBytes interface.
342 * It reads a block of information from the byte array at the specified
345 * See the documentation of ILockBytes for more info.
347 HRESULT WINAPI HGLOBALLockBytesImpl_ReadAt(
349 ULARGE_INTEGER ulOffset, /* [in] */
350 void* pv, /* [length_is][size_is][out] */
352 ULONG* pcbRead) /* [out] */
354 HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
357 ULONG bytesReadBuffer = 0;
358 ULONG bytesToReadFromBuffer;
361 * If the caller is not interested in the number of bytes read,
362 * we use another buffer to avoid "if" statements in the code.
365 pcbRead = &bytesReadBuffer;
368 * Make sure the offset is valid.
370 if (ulOffset.u.LowPart > This->byteArraySize.u.LowPart)
374 * Using the known size of the array, calculate the number of bytes
377 bytesToReadFromBuffer = min(This->byteArraySize.u.LowPart -
378 ulOffset.u.LowPart, cb);
381 * Lock the buffer in position and copy the data.
383 supportBuffer = GlobalLock(This->supportHandle);
386 (char *) supportBuffer + ulOffset.u.LowPart,
387 bytesToReadFromBuffer);
390 * Return the number of bytes read.
392 *pcbRead = bytesToReadFromBuffer;
397 GlobalUnlock(This->supportHandle);
400 * The function returns S_OK if the specified number of bytes were read
401 * or the end of the array was reached.
402 * It returns STG_E_READFAULT if the number of bytes to read does not equal
403 * the number of bytes actually read.
408 return STG_E_READFAULT;
411 /******************************************************************************
412 * This method is part of the ILockBytes interface.
414 * It writes the specified bytes at the specified offset.
415 * position. If the array is too small, it will be resized.
417 * See the documentation of ILockBytes for more info.
419 HRESULT WINAPI HGLOBALLockBytesImpl_WriteAt(
421 ULARGE_INTEGER ulOffset, /* [in] */
422 const void* pv, /* [size_is][in] */
424 ULONG* pcbWritten) /* [out] */
426 HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
429 ULARGE_INTEGER newSize;
430 ULONG bytesWritten = 0;
433 * If the caller is not interested in the number of bytes written,
434 * we use another buffer to avoid "if" statements in the code.
437 pcbWritten = &bytesWritten;
445 newSize.u.HighPart = 0;
446 newSize.u.LowPart = ulOffset.u.LowPart + cb;
450 * Verify if we need to grow the stream
452 if (newSize.u.LowPart > This->byteArraySize.u.LowPart)
455 if (HGLOBALLockBytesImpl_SetSize(iface, newSize) == STG_E_MEDIUMFULL)
456 return STG_E_MEDIUMFULL;
460 * Lock the buffer in position and copy the data.
462 supportBuffer = GlobalLock(This->supportHandle);
464 memcpy((char *) supportBuffer + ulOffset.u.LowPart, pv, cb);
467 * Return the number of bytes written.
474 GlobalUnlock(This->supportHandle);
479 /******************************************************************************
480 * This method is part of the ILockBytes interface.
482 * See the documentation of ILockBytes for more info.
484 HRESULT WINAPI HGLOBALLockBytesImpl_Flush(ILockBytes* iface)
489 /******************************************************************************
490 * This method is part of the ILockBytes interface.
492 * It will change the size of the byte array.
494 * See the documentation of ILockBytes for more info.
496 HRESULT WINAPI HGLOBALLockBytesImpl_SetSize(
498 ULARGE_INTEGER libNewSize) /* [in] */
500 HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
505 if (libNewSize.u.HighPart != 0)
506 return STG_E_INVALIDFUNCTION;
508 if (This->byteArraySize.u.LowPart == libNewSize.u.LowPart)
512 * Re allocate the HGlobal to fit the new size of the stream.
514 This->supportHandle = GlobalReAlloc(This->supportHandle,
515 libNewSize.u.LowPart,
518 if (This->supportHandle == 0)
519 return STG_E_MEDIUMFULL;
521 This->byteArraySize.u.LowPart = libNewSize.u.LowPart;
526 /******************************************************************************
527 * This method is part of the ILockBytes interface.
529 * The global memory implementation of ILockBytes does not support locking.
531 * See the documentation of ILockBytes for more info.
533 HRESULT WINAPI HGLOBALLockBytesImpl_LockRegion(
535 ULARGE_INTEGER libOffset, /* [in] */
536 ULARGE_INTEGER cb, /* [in] */
537 DWORD dwLockType) /* [in] */
539 return STG_E_INVALIDFUNCTION;
542 /******************************************************************************
543 * This method is part of the ILockBytes interface.
545 * The global memory implementation of ILockBytes does not support locking.
547 * See the documentation of ILockBytes for more info.
549 HRESULT WINAPI HGLOBALLockBytesImpl_UnlockRegion(
551 ULARGE_INTEGER libOffset, /* [in] */
552 ULARGE_INTEGER cb, /* [in] */
553 DWORD dwLockType) /* [in] */
555 return STG_E_INVALIDFUNCTION;
558 /******************************************************************************
559 * This method is part of the ILockBytes interface.
561 * This method returns information about the current
564 * See the documentation of ILockBytes for more info.
566 HRESULT WINAPI HGLOBALLockBytesImpl_Stat(
568 STATSTG* pstatstg, /* [out] */
569 DWORD grfStatFlag) /* [in] */
571 HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
573 memset(pstatstg, 0, sizeof(STATSTG));
575 pstatstg->pwcsName = NULL;
576 pstatstg->type = STGTY_LOCKBYTES;
577 pstatstg->cbSize = This->byteArraySize;