dlls/ole32/hglobalstream.c

   1 /*
   2  * HGLOBAL Stream implementation
   3  *
   4  * This file contains the implementation of the stream interface
   5  * for streams contained supported by an HGLOBAL pointer.
   6  *
   7  * Copyright 1999 Francis Beaudet
   8  */
   9 #include <assert.h>
  10 #include <stdlib.h>
  11 #include <stdio.h>
  12 #include <string.h>
  13
  14 #include "winbase.h"
  15 #include "winerror.h"
  16 #include "debugtools.h"
  17
  18 #include "objbase.h"
  19
  20 DEFAULT_DEBUG_CHANNEL(storage)
  21
  22 /****************************************************************************
  23  * HGLOBALStreamImpl definition.
  24  *
  25  * This class imlements the IStream inteface and represents a stream
  26  * supported by an HGLOBAL pointer.
  27  */
  28 struct HGLOBALStreamImpl
  29 {
  30   ICOM_VFIELD(IStream);  /* Needs to be the first item in the stuct
  31                           * since we want to cast this in a IStream pointer */
  32
  33   /*
  34    * Reference count
  35    */
  36   ULONG              ref;
  37
  38   /*
  39    * Support for the stream
  40    */
  41   HGLOBAL supportHandle;
  42
  43   /*
  44    * This flag is TRUE if the HGLOBAL is destroyed when the stream
  45    * is finally released.
  46    */
  47   BOOL    deleteOnRelease;
  48
  49   /*
  50    * Helper variable that contains the size of the stream
  51    */
  52   ULARGE_INTEGER     streamSize;
  53
  54   /*
  55    * This is the current position of the cursor in the stream
  56    */
  57   ULARGE_INTEGER     currentPosition;
  58 };
  59
  60 typedef struct HGLOBALStreamImpl HGLOBALStreamImpl;
  61
  62 /*
  63  * Method definition for the StgStreamImpl class.
  64  */
  65 HGLOBALStreamImpl* HGLOBALStreamImpl_Construct(
  66                 HGLOBAL  hGlobal,
  67                 BOOL     fDeleteOnRelease);
  68
  69 void HGLOBALStreamImpl_Destroy(
  70                 HGLOBALStreamImpl* This);
  71
  72 void HGLOBALStreamImpl_OpenBlockChain(
  73                 HGLOBALStreamImpl* This);
  74
  75 HRESULT WINAPI HGLOBALStreamImpl_QueryInterface(
  76                 IStream*      iface,
  77                 REFIID         riid,            /* [in] */
  78                 void**         ppvObject);  /* [iid_is][out] */
  79
  80 ULONG WINAPI HGLOBALStreamImpl_AddRef(
  81                 IStream*      iface);
  82
  83 ULONG WINAPI HGLOBALStreamImpl_Release(
  84                 IStream*      iface);
  85
  86 HRESULT WINAPI HGLOBALStreamImpl_Read(
  87                 IStream*      iface,
  88                 void*          pv,        /* [length_is][size_is][out] */
  89                 ULONG          cb,        /* [in] */
  90                 ULONG*         pcbRead);  /* [out] */
  91
  92 HRESULT WINAPI HGLOBALStreamImpl_Write(
  93                 IStream*      iface,
  94                 const void*    pv,          /* [size_is][in] */
  95                 ULONG          cb,          /* [in] */
  96                 ULONG*         pcbWritten); /* [out] */
  97
  98 HRESULT WINAPI HGLOBALStreamImpl_Seek(
  99                 IStream*      iface,
 100                 LARGE_INTEGER   dlibMove,         /* [in] */
 101                 DWORD           dwOrigin,         /* [in] */
 102                 ULARGE_INTEGER* plibNewPosition); /* [out] */
 103
 104 HRESULT WINAPI HGLOBALStreamImpl_SetSize(
 105                 IStream*      iface,
 106                 ULARGE_INTEGER  libNewSize);  /* [in] */
 107
 108 HRESULT WINAPI HGLOBALStreamImpl_CopyTo(
 109                 IStream*      iface,
 110                 IStream*      pstm,         /* [unique][in] */
 111                 ULARGE_INTEGER  cb,           /* [in] */
 112                 ULARGE_INTEGER* pcbRead,      /* [out] */
 113                 ULARGE_INTEGER* pcbWritten);  /* [out] */
 114
 115 HRESULT WINAPI HGLOBALStreamImpl_Commit(
 116                 IStream*      iface,
 117                 DWORD           grfCommitFlags); /* [in] */
 118
 119 HRESULT WINAPI HGLOBALStreamImpl_Revert(
 120                 IStream*  iface);
 121
 122 HRESULT WINAPI HGLOBALStreamImpl_LockRegion(
 123                 IStream*     iface,
 124                 ULARGE_INTEGER libOffset,   /* [in] */
 125                 ULARGE_INTEGER cb,          /* [in] */
 126                 DWORD          dwLockType); /* [in] */
 127
 128 HRESULT WINAPI HGLOBALStreamImpl_UnlockRegion(
 129                 IStream*     iface,
 130                 ULARGE_INTEGER libOffset,   /* [in] */
 131                 ULARGE_INTEGER cb,          /* [in] */
 132                 DWORD          dwLockType); /* [in] */
 133
 134 HRESULT WINAPI HGLOBALStreamImpl_Stat(
 135                 IStream*     iface,
 136                 STATSTG*       pstatstg,     /* [out] */
 137                 DWORD          grfStatFlag); /* [in] */
 138
 139 HRESULT WINAPI HGLOBALStreamImpl_Clone(
 140                 IStream*     iface,
 141                 IStream**    ppstm);       /* [out] */
 142
 143
 144 /*
 145  * Virtual function table for the HGLOBALStreamImpl class.
 146  */
 147 static ICOM_VTABLE(IStream) HGLOBALStreamImpl_Vtbl =
 148 {
 149     ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE
 150     HGLOBALStreamImpl_QueryInterface,
 151     HGLOBALStreamImpl_AddRef,
 152     HGLOBALStreamImpl_Release,
 153     HGLOBALStreamImpl_Read,
 154     HGLOBALStreamImpl_Write,
 155     HGLOBALStreamImpl_Seek,
 156     HGLOBALStreamImpl_SetSize,
 157     HGLOBALStreamImpl_CopyTo,
 158     HGLOBALStreamImpl_Commit,
 159     HGLOBALStreamImpl_Revert,
 160     HGLOBALStreamImpl_LockRegion,
 161     HGLOBALStreamImpl_UnlockRegion,
 162     HGLOBALStreamImpl_Stat,
 163     HGLOBALStreamImpl_Clone
 164 };
 165
 166 /***********************************************************************
 167  *           CreateStreamOnHGlobal     [OLE32.61]
 168  */
 169 HRESULT WINAPI CreateStreamOnHGlobal(
 170                 HGLOBAL   hGlobal,
 171                 BOOL      fDeleteOnRelease,
 172                 LPSTREAM* ppstm)
 173 {
 174   HGLOBALStreamImpl* newStream;
 175
 176   newStream = HGLOBALStreamImpl_Construct(hGlobal,
 177                                           fDeleteOnRelease);
 178
 179   if (newStream!=NULL)
 180   {
 181     return IUnknown_QueryInterface((IUnknown*)newStream,
 182                                    &IID_IStream,
 183                                    (void**)ppstm);
 184   }
 185
 186   return E_OUTOFMEMORY;
 187 }
 188
 189 /***********************************************************************
 190  *           GetHGlobalFromStream     [OLE32.71]
 191  */
 192 HRESULT WINAPI GetHGlobalFromStream(IStream* pstm, HGLOBAL* phglobal)
 193 {
 194   HGLOBALStreamImpl* pStream;
 195
 196   if (pstm == NULL)
 197     return E_INVALIDARG;
 198
 199   pStream = (HGLOBALStreamImpl*) pstm;
 200
 201   /*
 202    * Verify that the stream object was created with CreateStreamOnHGlobal.
 203    */
 204   if (ICOM_VTBL(pStream) == &HGLOBALStreamImpl_Vtbl)
 205     *phglobal = pStream->supportHandle;
 206   else
 207   {
 208     *phglobal = 0;
 209     return E_INVALIDARG;
 210   }
 211
 212   return S_OK;
 213 }
 214
 215 /******************************************************************************
 216 ** HGLOBALStreamImpl implementation
 217 */
 218
 219 /***
 220  * This is the constructor for the HGLOBALStreamImpl class.
 221  *
 222  * Params:
 223  *    hGlobal          - Handle that will support the stream. can be NULL.
 224  *    fDeleteOnRelease - Flag set to TRUE if the HGLOBAL will be released
 225  *                       when the IStream object is destroyed.
 226  */
 227 HGLOBALStreamImpl* HGLOBALStreamImpl_Construct(
 228                 HGLOBAL  hGlobal,
 229                 BOOL     fDeleteOnRelease)
 230 {
 231   HGLOBALStreamImpl* newStream;
 232
 233   newStream = HeapAlloc(GetProcessHeap(), 0, sizeof(HGLOBALStreamImpl));
 234
 235   if (newStream!=0)
 236   {
 237     /*
 238      * Set-up the virtual function table and reference count.
 239      */
 240     ICOM_VTBL(newStream) = &HGLOBALStreamImpl_Vtbl;
 241     newStream->ref    = 0;
 242
 243     /*
 244      * Initialize the support.
 245      */
 246     newStream->supportHandle = hGlobal;
 247     newStream->deleteOnRelease = fDeleteOnRelease;
 248
 249     /*
 250      * This method will allocate a handle if one is not supplied.
 251      */
 252     if (newStream->supportHandle == NULL)
 253     {
 254       newStream->supportHandle = GlobalAlloc(GMEM_MOVEABLE | GMEM_NODISCARD, 0);
 255     }
 256
 257     /*
 258      * Start the stream at the begining.
 259      */
 260     newStream->currentPosition.s.HighPart = 0;
 261     newStream->currentPosition.s.LowPart = 0;
 262
 263     /*
 264      * Initialize the size of the stream to the size of the handle.
 265      */
 266     newStream->streamSize.s.HighPart = 0;
 267     newStream->streamSize.s.LowPart  = GlobalSize(newStream->supportHandle);
 268   }
 269
 270   return newStream;
 271 }
 272
 273 /***
 274  * This is the destructor of the HGLOBALStreamImpl class.
 275  *
 276  * This method will clean-up all the resources used-up by the given HGLOBALStreamImpl
 277  * class. The pointer passed-in to this function will be freed and will not
 278  * be valid anymore.
 279  */
 280 void HGLOBALStreamImpl_Destroy(HGLOBALStreamImpl* This)
 281 {
 282   TRACE("(%p)\n", This);
 283
 284   /*
 285    * Release the HGlobal if the constructor asked for that.
 286    */
 287   if (This->deleteOnRelease)
 288   {
 289     GlobalFree(This->supportHandle);
 290     This->supportHandle=0;
 291   }
 292
 293   /*
 294    * Finally, free the memory used-up by the class.
 295    */
 296   HeapFree(GetProcessHeap(), 0, This);
 297 }
 298
 299 /***
 300  * This implements the IUnknown method QueryInterface for this
 301  * class
 302  */
 303 HRESULT WINAPI HGLOBALStreamImpl_QueryInterface(
 304                   IStream*     iface,
 305                   REFIID         riid,        /* [in] */
 306                   void**         ppvObject)   /* [iid_is][out] */
 307 {
 308   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 309
 310   /*
 311    * Perform a sanity check on the parameters.
 312    */
 313   if (ppvObject==0)
 314     return E_INVALIDARG;
 315
 316   /*
 317    * Initialize the return parameter.
 318    */
 319   *ppvObject = 0;
 320
 321   /*
 322    * Compare the riid with the interface IDs implemented by this object.
 323    */
 324   if (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
 325   {
 326     *ppvObject = (IStream*)This;
 327   }
 328   else if (memcmp(&IID_IStream, riid, sizeof(IID_IStream)) == 0)
 329   {
 330     *ppvObject = (IStream*)This;
 331   }
 332
 333   /*
 334    * Check that we obtained an interface.
 335    */
 336   if ((*ppvObject)==0)
 337     return E_NOINTERFACE;
 338
 339   /*
 340    * Query Interface always increases the reference count by one when it is
 341    * successful
 342    */
 343   HGLOBALStreamImpl_AddRef(iface);
 344
 345   return S_OK;;
 346 }
 347
 348 /***
 349  * This implements the IUnknown method AddRef for this
 350  * class
 351  */
 352 ULONG WINAPI HGLOBALStreamImpl_AddRef(
 353                 IStream* iface)
 354 {
 355   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 356
 357   This->ref++;
 358
 359   return This->ref;
 360 }
 361
 362 /***
 363  * This implements the IUnknown method Release for this
 364  * class
 365  */
 366 ULONG WINAPI HGLOBALStreamImpl_Release(
 367                 IStream* iface)
 368 {
 369   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 370
 371   ULONG newRef;
 372
 373   This->ref--;
 374
 375   newRef = This->ref;
 376
 377   /*
 378    * If the reference count goes down to 0, perform suicide.
 379    */
 380   if (newRef==0)
 381   {
 382     HGLOBALStreamImpl_Destroy(This);
 383   }
 384
 385   return newRef;
 386 }
 387
 388 /***
 389  * This method is part of the ISequentialStream interface.
 390  *
 391  * If reads a block of information from the stream at the current
 392  * position. It then moves the current position at the end of the
 393  * read block
 394  *
 395  * See the documentation of ISequentialStream for more info.
 396  */
 397 HRESULT WINAPI HGLOBALStreamImpl_Read(
 398                   IStream*     iface,
 399                   void*          pv,        /* [length_is][size_is][out] */
 400                   ULONG          cb,        /* [in] */
 401                   ULONG*         pcbRead)   /* [out] */
 402 {
 403   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 404
 405   void* supportBuffer;
 406   ULONG bytesReadBuffer;
 407   ULONG bytesToReadFromBuffer;
 408
 409   TRACE("(%p, %p, %ld, %p)\n", iface,
 410         pv, cb, pcbRead);
 411
 412   /*
 413    * If the caller is not interested in the nubmer of bytes read,
 414    * we use another buffer to avoid "if" statements in the code.
 415    */
 416   if (pcbRead==0)
 417     pcbRead = &bytesReadBuffer;
 418
 419   /*
 420    * Using the known size of the stream, calculate the number of bytes
 421    * to read from the block chain
 422    */
 423   bytesToReadFromBuffer = MIN( This->streamSize.s.LowPart - This->currentPosition.s.LowPart, cb);
 424
 425   /*
 426    * Lock the buffer in position and copy the data.
 427    */
 428   supportBuffer = GlobalLock(This->supportHandle);
 429
 430   memcpy(pv, (char *) supportBuffer+This->currentPosition.s.LowPart, bytesToReadFromBuffer);
 431
 432   /*
 433    * Move the current position to the new position
 434    */
 435   This->currentPosition.s.LowPart+=bytesToReadFromBuffer;
 436
 437   /*
 438    * Return the number of bytes read.
 439    */
 440   *pcbRead = bytesToReadFromBuffer;
 441
 442   /*
 443    * Cleanup
 444    */
 445   GlobalUnlock(This->supportHandle);
 446
 447   /*
 448    * The function returns S_OK if the buffer was filled completely
 449    * it returns S_FALSE if the end of the stream is reached before the
 450    * buffer is filled
 451    */
 452   if(*pcbRead == cb)
 453     return S_OK;
 454
 455   return S_FALSE;
 456 }
 457
 458 /***
 459  * This method is part of the ISequentialStream interface.
 460  *
 461  * It writes a block of information to the stream at the current
 462  * position. It then moves the current position at the end of the
 463  * written block. If the stream is too small to fit the block,
 464  * the stream is grown to fit.
 465  *
 466  * See the documentation of ISequentialStream for more info.
 467  */
 468 HRESULT WINAPI HGLOBALStreamImpl_Write(
 469                   IStream*     iface,
 470                   const void*    pv,          /* [size_is][in] */
 471                   ULONG          cb,          /* [in] */
 472                   ULONG*         pcbWritten)  /* [out] */
 473 {
 474   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 475
 476   void*          supportBuffer;
 477   ULARGE_INTEGER newSize;
 478   ULONG          bytesWritten = 0;
 479
 480   TRACE("(%p, %p, %ld, %p)\n", iface,
 481         pv, cb, pcbWritten);
 482
 483   /*
 484    * If the caller is not interested in the number of bytes written,
 485    * we use another buffer to avoid "if" statements in the code.
 486    */
 487   if (pcbWritten == 0)
 488     pcbWritten = &bytesWritten;
 489
 490   if (cb == 0)
 491   {
 492     return S_OK;
 493   }
 494   else
 495   {
 496     newSize.s.HighPart = 0;
 497     newSize.s.LowPart = This->currentPosition.s.LowPart + cb;
 498   }
 499
 500   /*
 501    * Verify if we need to grow the stream
 502    */
 503   if (newSize.s.LowPart > This->streamSize.s.LowPart)
 504   {
 505     /* grow stream */
 506    IStream_SetSize(iface, newSize);
 507   }
 508
 509   /*
 510    * Lock the buffer in position and copy the data.
 511    */
 512   supportBuffer = GlobalLock(This->supportHandle);
 513
 514   memcpy((char *) supportBuffer+This->currentPosition.s.LowPart, pv, cb);
 515
 516   /*
 517    * Move the current position to the new position
 518    */
 519   This->currentPosition.s.LowPart+=cb;
 520
 521   /*
 522    * Return the number of bytes read.
 523    */
 524   *pcbWritten = cb;
 525
 526   /*
 527    * Cleanup
 528    */
 529   GlobalUnlock(This->supportHandle);
 530
 531   return S_OK;
 532 }
 533
 534 /***
 535  * This method is part of the IStream interface.
 536  *
 537  * It will move the current stream pointer according to the parameters
 538  * given.
 539  *
 540  * See the documentation of IStream for more info.
 541  */
 542 HRESULT WINAPI HGLOBALStreamImpl_Seek(
 543                   IStream*      iface,
 544                   LARGE_INTEGER   dlibMove,         /* [in] */
 545                   DWORD           dwOrigin,         /* [in] */
 546                   ULARGE_INTEGER* plibNewPosition) /* [out] */
 547 {
 548   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 549
 550   ULARGE_INTEGER newPosition;
 551
 552   TRACE("(%p, %ld, %ld, %p)\n", iface,
 553         dlibMove.s.LowPart, dwOrigin, plibNewPosition);
 554
 555   /*
 556    * The caller is allowed to pass in NULL as the new position return value.
 557    * If it happens, we assign it to a dynamic variable to avoid special cases
 558    * in the code below.
 559    */
 560   if (plibNewPosition == 0)
 561   {
 562     plibNewPosition = &newPosition;
 563   }
 564
 565   /*
 566    * The file pointer is moved depending on the given "function"
 567    * parameter.
 568    */
 569   switch (dwOrigin)
 570   {
 571     case STREAM_SEEK_SET:
 572       plibNewPosition->s.HighPart = 0;
 573       plibNewPosition->s.LowPart  = 0;
 574       break;
 575     case STREAM_SEEK_CUR:
 576       *plibNewPosition = This->currentPosition;
 577       break;
 578     case STREAM_SEEK_END:
 579       *plibNewPosition = This->streamSize;
 580       break;
 581     default:
 582       return STG_E_INVALIDFUNCTION;
 583   }
 584
 585   /*
 586    * We don't support files with offsets of 64 bits.
 587    */
 588   assert(dlibMove.s.HighPart == 0);
 589
 590   /*
 591    * Check if we end-up before the beginning of the file. That should trigger an
 592    * error.
 593    */
 594   if ( (dlibMove.s.LowPart<0) && (plibNewPosition->s.LowPart < (ULONG)(-dlibMove.s.LowPart)) )
 595   {
 596     /*
 597      * I don't know what error to send there.
 598      */
 599     return E_FAIL;
 600   }
 601
 602   /*
 603    * Move the actual file pointer
 604    * If the file pointer ends-up after the end of the stream, the next Write operation will
 605    * make the file larger. This is how it is documented.
 606    */
 607   plibNewPosition->s.LowPart += dlibMove.s.LowPart;
 608   This->currentPosition = *plibNewPosition;
 609
 610   return S_OK;
 611 }
 612
 613 /***
 614  * This method is part of the IStream interface.
 615  *
 616  * It will change the size of a stream.
 617  *
 618  * TODO: Switch from small blocks to big blocks and vice versa.
 619  *
 620  * See the documentation of IStream for more info.
 621  */
 622 HRESULT WINAPI HGLOBALStreamImpl_SetSize(
 623                                      IStream*      iface,
 624                                      ULARGE_INTEGER  libNewSize)   /* [in] */
 625 {
 626   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 627
 628   TRACE("(%p, %ld)\n", iface, libNewSize.s.LowPart);
 629
 630   /*
 631    * As documented.
 632    */
 633   if (libNewSize.s.HighPart != 0)
 634     return STG_E_INVALIDFUNCTION;
 635
 636   if (This->streamSize.s.LowPart == libNewSize.s.LowPart)
 637     return S_OK;
 638
 639   /*
 640    * Re allocate the HGlobal to fit the new size of the stream.
 641    */
 642   This->supportHandle = GlobalReAlloc(This->supportHandle,
 643                                       libNewSize.s.LowPart,
 644                                       0);
 645
 646   This->streamSize.s.LowPart = libNewSize.s.LowPart;
 647
 648   return S_OK;
 649 }
 650
 651 /***
 652  * This method is part of the IStream interface.
 653  *
 654  * It will copy the 'cb' Bytes to 'pstm' IStream.
 655  *
 656  * See the documentation of IStream for more info.
 657  */
 658 HRESULT WINAPI HGLOBALStreamImpl_CopyTo(
 659                                     IStream*      iface,
 660                                     IStream*      pstm,         /* [unique][in] */
 661                                     ULARGE_INTEGER  cb,           /* [in] */
 662                                     ULARGE_INTEGER* pcbRead,      /* [out] */
 663                                     ULARGE_INTEGER* pcbWritten)   /* [out] */
 664 {
 665   HRESULT        hr = S_OK;
 666   BYTE           tmpBuffer[128];
 667   ULONG          bytesRead, bytesWritten, copySize;
 668   ULARGE_INTEGER totalBytesRead;
 669   ULARGE_INTEGER totalBytesWritten;
 670
 671   TRACE("(%p, %p, %ld, %p, %p)\n", iface, pstm,
 672         cb.s.LowPart, pcbRead, pcbWritten);
 673
 674   /*
 675    * Sanity check
 676    */
 677   if ( pstm == 0 )
 678     return STG_E_INVALIDPOINTER;
 679
 680   totalBytesRead.s.LowPart = totalBytesRead.s.HighPart = 0;
 681   totalBytesWritten.s.LowPart = totalBytesWritten.s.HighPart = 0;
 682
 683   /*
 684    * use stack to store data temporarly
 685    * there is surely more performant way of doing it, for now this basic
 686    * implementation will do the job
 687    */
 688   while ( cb.s.LowPart > 0 )
 689   {
 690     if ( cb.s.LowPart >= 128 )
 691       copySize = 128;
 692     else
 693       copySize = cb.s.LowPart;
 694
 695     IStream_Read(iface, tmpBuffer, copySize, &bytesRead);
 696
 697     totalBytesRead.s.LowPart += bytesRead;
 698
 699     IStream_Write(pstm, tmpBuffer, bytesRead, &bytesWritten);
 700
 701     totalBytesWritten.s.LowPart += bytesWritten;
 702
 703     /*
 704      * Check that read & write operations were succesfull
 705      */
 706     if (bytesRead != bytesWritten)
 707     {
 708       hr = STG_E_MEDIUMFULL;
 709       break;
 710     }
 711
 712     if (bytesRead!=copySize)
 713       cb.s.LowPart = 0;
 714     else
 715       cb.s.LowPart -= bytesRead;
 716   }
 717
 718   /*
 719    * Update number of bytes read and written
 720    */
 721   if (pcbRead)
 722   {
 723     pcbRead->s.LowPart = totalBytesRead.s.LowPart;
 724     pcbRead->s.HighPart = totalBytesRead.s.HighPart;
 725   }
 726
 727   if (pcbWritten)
 728   {
 729     pcbWritten->s.LowPart = totalBytesWritten.s.LowPart;
 730     pcbWritten->s.HighPart = totalBytesWritten.s.HighPart;
 731   }
 732   return hr;
 733 }
 734
 735 /***
 736  * This method is part of the IStream interface.
 737  *
 738  * For streams supported by HGLOBALS, this function does nothing.
 739  * This is what the documentation tells us.
 740  *
 741  * See the documentation of IStream for more info.
 742  */
 743 HRESULT WINAPI HGLOBALStreamImpl_Commit(
 744                   IStream*      iface,
 745                   DWORD         grfCommitFlags)  /* [in] */
 746 {
 747   return S_OK;
 748 }
 749
 750 /***
 751  * This method is part of the IStream interface.
 752  *
 753  * For streams supported by HGLOBALS, this function does nothing.
 754  * This is what the documentation tells us.
 755  *
 756  * See the documentation of IStream for more info.
 757  */
 758 HRESULT WINAPI HGLOBALStreamImpl_Revert(
 759                   IStream* iface)
 760 {
 761   return S_OK;
 762 }
 763
 764 /***
 765  * This method is part of the IStream interface.
 766  *
 767  * For streams supported by HGLOBALS, this function does nothing.
 768  * This is what the documentation tells us.
 769  *
 770  * See the documentation of IStream for more info.
 771  */
 772 HRESULT WINAPI HGLOBALStreamImpl_LockRegion(
 773                   IStream*       iface,
 774                   ULARGE_INTEGER libOffset,   /* [in] */
 775                   ULARGE_INTEGER cb,          /* [in] */
 776                   DWORD          dwLockType)  /* [in] */
 777 {
 778   return S_OK;
 779 }
 780
 781 /*
 782  * This method is part of the IStream interface.
 783  *
 784  * For streams supported by HGLOBALS, this function does nothing.
 785  * This is what the documentation tells us.
 786  *
 787  * See the documentation of IStream for more info.
 788  */
 789 HRESULT WINAPI HGLOBALStreamImpl_UnlockRegion(
 790                   IStream*       iface,
 791                   ULARGE_INTEGER libOffset,   /* [in] */
 792                   ULARGE_INTEGER cb,          /* [in] */
 793                   DWORD          dwLockType)  /* [in] */
 794 {
 795   return S_OK;
 796 }
 797
 798 /***
 799  * This method is part of the IStream interface.
 800  *
 801  * This method returns information about the current
 802  * stream.
 803  *
 804  * See the documentation of IStream for more info.
 805  */
 806 HRESULT WINAPI HGLOBALStreamImpl_Stat(
 807                   IStream*     iface,
 808                   STATSTG*     pstatstg,     /* [out] */
 809                   DWORD        grfStatFlag)  /* [in] */
 810 {
 811   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 812
 813   memset(pstatstg, 0, sizeof(STATSTG));
 814
 815   pstatstg->pwcsName = NULL;
 816   pstatstg->type     = STGTY_STREAM;
 817   pstatstg->cbSize   = This->streamSize;
 818
 819   return S_OK;
 820 }
 821
 822 HRESULT WINAPI HGLOBALStreamImpl_Clone(
 823                   IStream*     iface,
 824                   IStream**    ppstm) /* [out] */
 825 {
 826   FIXME("not implemented!\n");
 827   return E_NOTIMPL;
 828 }