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  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include "config.h"
  25
  26 #include <assert.h>
  27 #include <stdlib.h>
  28 #include <stdarg.h>
  29 #include <stdio.h>
  30 #include <string.h>
  31
  32 #define COBJMACROS
  33 #define NONAMELESSUNION
  34 #define NONAMELESSSTRUCT
  35
  36 #include "windef.h"
  37 #include "winbase.h"
  38 #include "winuser.h"
  39 #include "objbase.h"
  40 #include "ole2.h"
  41 #include "winerror.h"
  42 #include "winreg.h"
  43 #include "winternl.h"
  44
  45 #include "wine/debug.h"
  46
  47 WINE_DEFAULT_DEBUG_CHANNEL(storage);
  48
  49 /****************************************************************************
  50  * HGLOBALStreamImpl definition.
  51  *
  52  * This class imlements the IStream inteface and represents a stream
  53  * supported by an HGLOBAL pointer.
  54  */
  55 struct HGLOBALStreamImpl
  56 {
  57   IStreamVtbl *lpVtbl;   /* Needs to be the first item in the stuct
  58                           * since we want to cast this in a IStream pointer */
  59
  60   /*
  61    * Reference count
  62    */
  63   ULONG              ref;
  64
  65   /*
  66    * Support for the stream
  67    */
  68   HGLOBAL supportHandle;
  69
  70   /*
  71    * This flag is TRUE if the HGLOBAL is destroyed when the stream
  72    * is finally released.
  73    */
  74   BOOL    deleteOnRelease;
  75
  76   /*
  77    * Helper variable that contains the size of the stream
  78    */
  79   ULARGE_INTEGER     streamSize;
  80
  81   /*
  82    * This is the current position of the cursor in the stream
  83    */
  84   ULARGE_INTEGER     currentPosition;
  85 };
  86
  87 typedef struct HGLOBALStreamImpl HGLOBALStreamImpl;
  88
  89 /*
  90  * Method definition for the StgStreamImpl class.
  91  */
  92 HGLOBALStreamImpl* HGLOBALStreamImpl_Construct(
  93                 HGLOBAL  hGlobal,
  94                 BOOL     fDeleteOnRelease);
  95
  96 void HGLOBALStreamImpl_Destroy(
  97                 HGLOBALStreamImpl* This);
  98
  99 void HGLOBALStreamImpl_OpenBlockChain(
 100                 HGLOBALStreamImpl* This);
 101
 102 HRESULT WINAPI HGLOBALStreamImpl_QueryInterface(
 103                 IStream*      iface,
 104                 REFIID         riid,            /* [in] */
 105                 void**         ppvObject);  /* [iid_is][out] */
 106
 107 ULONG WINAPI HGLOBALStreamImpl_AddRef(
 108                 IStream*      iface);
 109
 110 ULONG WINAPI HGLOBALStreamImpl_Release(
 111                 IStream*      iface);
 112
 113 HRESULT WINAPI HGLOBALStreamImpl_Read(
 114                 IStream*      iface,
 115                 void*          pv,        /* [length_is][size_is][out] */
 116                 ULONG          cb,        /* [in] */
 117                 ULONG*         pcbRead);  /* [out] */
 118
 119 HRESULT WINAPI HGLOBALStreamImpl_Write(
 120                 IStream*      iface,
 121                 const void*    pv,          /* [size_is][in] */
 122                 ULONG          cb,          /* [in] */
 123                 ULONG*         pcbWritten); /* [out] */
 124
 125 HRESULT WINAPI HGLOBALStreamImpl_Seek(
 126                 IStream*      iface,
 127                 LARGE_INTEGER   dlibMove,         /* [in] */
 128                 DWORD           dwOrigin,         /* [in] */
 129                 ULARGE_INTEGER* plibNewPosition); /* [out] */
 130
 131 HRESULT WINAPI HGLOBALStreamImpl_SetSize(
 132                 IStream*      iface,
 133                 ULARGE_INTEGER  libNewSize);  /* [in] */
 134
 135 HRESULT WINAPI HGLOBALStreamImpl_CopyTo(
 136                 IStream*      iface,
 137                 IStream*      pstm,         /* [unique][in] */
 138                 ULARGE_INTEGER  cb,           /* [in] */
 139                 ULARGE_INTEGER* pcbRead,      /* [out] */
 140                 ULARGE_INTEGER* pcbWritten);  /* [out] */
 141
 142 HRESULT WINAPI HGLOBALStreamImpl_Commit(
 143                 IStream*      iface,
 144                 DWORD           grfCommitFlags); /* [in] */
 145
 146 HRESULT WINAPI HGLOBALStreamImpl_Revert(
 147                 IStream*  iface);
 148
 149 HRESULT WINAPI HGLOBALStreamImpl_LockRegion(
 150                 IStream*     iface,
 151                 ULARGE_INTEGER libOffset,   /* [in] */
 152                 ULARGE_INTEGER cb,          /* [in] */
 153                 DWORD          dwLockType); /* [in] */
 154
 155 HRESULT WINAPI HGLOBALStreamImpl_UnlockRegion(
 156                 IStream*     iface,
 157                 ULARGE_INTEGER libOffset,   /* [in] */
 158                 ULARGE_INTEGER cb,          /* [in] */
 159                 DWORD          dwLockType); /* [in] */
 160
 161 HRESULT WINAPI HGLOBALStreamImpl_Stat(
 162                 IStream*     iface,
 163                 STATSTG*       pstatstg,     /* [out] */
 164                 DWORD          grfStatFlag); /* [in] */
 165
 166 HRESULT WINAPI HGLOBALStreamImpl_Clone(
 167                 IStream*     iface,
 168                 IStream**    ppstm);       /* [out] */
 169
 170
 171 /*
 172  * Virtual function table for the HGLOBALStreamImpl class.
 173  */
 174 static IStreamVtbl HGLOBALStreamImpl_Vtbl =
 175 {
 176     HGLOBALStreamImpl_QueryInterface,
 177     HGLOBALStreamImpl_AddRef,
 178     HGLOBALStreamImpl_Release,
 179     HGLOBALStreamImpl_Read,
 180     HGLOBALStreamImpl_Write,
 181     HGLOBALStreamImpl_Seek,
 182     HGLOBALStreamImpl_SetSize,
 183     HGLOBALStreamImpl_CopyTo,
 184     HGLOBALStreamImpl_Commit,
 185     HGLOBALStreamImpl_Revert,
 186     HGLOBALStreamImpl_LockRegion,
 187     HGLOBALStreamImpl_UnlockRegion,
 188     HGLOBALStreamImpl_Stat,
 189     HGLOBALStreamImpl_Clone
 190 };
 191
 192 /***********************************************************************
 193  *           CreateStreamOnHGlobal     [OLE32.@]
 194  */
 195 HRESULT WINAPI CreateStreamOnHGlobal(
 196                 HGLOBAL   hGlobal,
 197                 BOOL      fDeleteOnRelease,
 198                 LPSTREAM* ppstm)
 199 {
 200   HGLOBALStreamImpl* newStream;
 201
 202   newStream = HGLOBALStreamImpl_Construct(hGlobal,
 203                                           fDeleteOnRelease);
 204
 205   if (newStream!=NULL)
 206   {
 207     return IUnknown_QueryInterface((IUnknown*)newStream,
 208                                    &IID_IStream,
 209                                    (void**)ppstm);
 210   }
 211
 212   return E_OUTOFMEMORY;
 213 }
 214
 215 /***********************************************************************
 216  *           GetHGlobalFromStream     [OLE32.@]
 217  */
 218 HRESULT WINAPI GetHGlobalFromStream(IStream* pstm, HGLOBAL* phglobal)
 219 {
 220   HGLOBALStreamImpl* pStream;
 221
 222   if (pstm == NULL)
 223     return E_INVALIDARG;
 224
 225   pStream = (HGLOBALStreamImpl*) pstm;
 226
 227   /*
 228    * Verify that the stream object was created with CreateStreamOnHGlobal.
 229    */
 230   if (pStream->lpVtbl == &HGLOBALStreamImpl_Vtbl)
 231     *phglobal = pStream->supportHandle;
 232   else
 233   {
 234     *phglobal = 0;
 235     return E_INVALIDARG;
 236   }
 237
 238   return S_OK;
 239 }
 240
 241 /******************************************************************************
 242 ** HGLOBALStreamImpl implementation
 243 */
 244
 245 /***
 246  * This is the constructor for the HGLOBALStreamImpl class.
 247  *
 248  * Params:
 249  *    hGlobal          - Handle that will support the stream. can be NULL.
 250  *    fDeleteOnRelease - Flag set to TRUE if the HGLOBAL will be released
 251  *                       when the IStream object is destroyed.
 252  */
 253 HGLOBALStreamImpl* HGLOBALStreamImpl_Construct(
 254                 HGLOBAL  hGlobal,
 255                 BOOL     fDeleteOnRelease)
 256 {
 257   HGLOBALStreamImpl* newStream;
 258
 259   newStream = HeapAlloc(GetProcessHeap(), 0, sizeof(HGLOBALStreamImpl));
 260
 261   if (newStream!=0)
 262   {
 263     /*
 264      * Set-up the virtual function table and reference count.
 265      */
 266     newStream->lpVtbl = &HGLOBALStreamImpl_Vtbl;
 267     newStream->ref    = 0;
 268
 269     /*
 270      * Initialize the support.
 271      */
 272     newStream->supportHandle = hGlobal;
 273     newStream->deleteOnRelease = fDeleteOnRelease;
 274
 275     /*
 276      * This method will allocate a handle if one is not supplied.
 277      */
 278     if (!newStream->supportHandle)
 279     {
 280       newStream->supportHandle = GlobalAlloc(GMEM_MOVEABLE | GMEM_NODISCARD |
 281                                              GMEM_SHARE, 0);
 282     }
 283
 284     /*
 285      * Start the stream at the beginning.
 286      */
 287     newStream->currentPosition.u.HighPart = 0;
 288     newStream->currentPosition.u.LowPart = 0;
 289
 290     /*
 291      * Initialize the size of the stream to the size of the handle.
 292      */
 293     newStream->streamSize.u.HighPart = 0;
 294     newStream->streamSize.u.LowPart  = GlobalSize(newStream->supportHandle);
 295   }
 296
 297   return newStream;
 298 }
 299
 300 /***
 301  * This is the destructor of the HGLOBALStreamImpl class.
 302  *
 303  * This method will clean-up all the resources used-up by the given HGLOBALStreamImpl
 304  * class. The pointer passed-in to this function will be freed and will not
 305  * be valid anymore.
 306  */
 307 void HGLOBALStreamImpl_Destroy(HGLOBALStreamImpl* This)
 308 {
 309   TRACE("(%p)\n", This);
 310
 311   /*
 312    * Release the HGlobal if the constructor asked for that.
 313    */
 314   if (This->deleteOnRelease)
 315   {
 316     GlobalFree(This->supportHandle);
 317     This->supportHandle=0;
 318   }
 319
 320   /*
 321    * Finally, free the memory used-up by the class.
 322    */
 323   HeapFree(GetProcessHeap(), 0, This);
 324 }
 325
 326 /***
 327  * This implements the IUnknown method QueryInterface for this
 328  * class
 329  */
 330 HRESULT WINAPI HGLOBALStreamImpl_QueryInterface(
 331                   IStream*     iface,
 332                   REFIID         riid,        /* [in] */
 333                   void**         ppvObject)   /* [iid_is][out] */
 334 {
 335   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 336
 337   /*
 338    * Perform a sanity check on the parameters.
 339    */
 340   if (ppvObject==0)
 341     return E_INVALIDARG;
 342
 343   /*
 344    * Initialize the return parameter.
 345    */
 346   *ppvObject = 0;
 347
 348   /*
 349    * Compare the riid with the interface IDs implemented by this object.
 350    */
 351   if (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
 352   {
 353     *ppvObject = (IStream*)This;
 354   }
 355   else if (memcmp(&IID_IStream, riid, sizeof(IID_IStream)) == 0)
 356   {
 357     *ppvObject = (IStream*)This;
 358   }
 359
 360   /*
 361    * Check that we obtained an interface.
 362    */
 363   if ((*ppvObject)==0)
 364     return E_NOINTERFACE;
 365
 366   /*
 367    * Query Interface always increases the reference count by one when it is
 368    * successful
 369    */
 370   HGLOBALStreamImpl_AddRef(iface);
 371
 372   return S_OK;
 373 }
 374
 375 /***
 376  * This implements the IUnknown method AddRef for this
 377  * class
 378  */
 379 ULONG WINAPI HGLOBALStreamImpl_AddRef(
 380                 IStream* iface)
 381 {
 382   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 383   return InterlockedIncrement(&This->ref);
 384 }
 385
 386 /***
 387  * This implements the IUnknown method Release for this
 388  * class
 389  */
 390 ULONG WINAPI HGLOBALStreamImpl_Release(
 391                 IStream* iface)
 392 {
 393   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 394   ULONG newRef;
 395
 396   newRef = InterlockedDecrement(&This->ref);
 397
 398   /*
 399    * If the reference count goes down to 0, perform suicide.
 400    */
 401   if (newRef==0)
 402   {
 403     HGLOBALStreamImpl_Destroy(This);
 404   }
 405
 406   return newRef;
 407 }
 408
 409 /***
 410  * This method is part of the ISequentialStream interface.
 411  *
 412  * If reads a block of information from the stream at the current
 413  * position. It then moves the current position at the end of the
 414  * read block
 415  *
 416  * See the documentation of ISequentialStream for more info.
 417  */
 418 HRESULT WINAPI HGLOBALStreamImpl_Read(
 419                   IStream*     iface,
 420                   void*          pv,        /* [length_is][size_is][out] */
 421                   ULONG          cb,        /* [in] */
 422                   ULONG*         pcbRead)   /* [out] */
 423 {
 424   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 425
 426   void* supportBuffer;
 427   ULONG bytesReadBuffer;
 428   ULONG bytesToReadFromBuffer;
 429
 430   TRACE("(%p, %p, %ld, %p)\n", iface,
 431         pv, cb, pcbRead);
 432
 433   /*
 434    * If the caller is not interested in the nubmer of bytes read,
 435    * we use another buffer to avoid "if" statements in the code.
 436    */
 437   if (pcbRead==0)
 438     pcbRead = &bytesReadBuffer;
 439
 440   /*
 441    * Using the known size of the stream, calculate the number of bytes
 442    * to read from the block chain
 443    */
 444   bytesToReadFromBuffer = min( This->streamSize.u.LowPart - This->currentPosition.u.LowPart, cb);
 445
 446   /*
 447    * Lock the buffer in position and copy the data.
 448    */
 449   supportBuffer = GlobalLock(This->supportHandle);
 450
 451   memcpy(pv, (char *) supportBuffer+This->currentPosition.u.LowPart, bytesToReadFromBuffer);
 452
 453   /*
 454    * Move the current position to the new position
 455    */
 456   This->currentPosition.u.LowPart+=bytesToReadFromBuffer;
 457
 458   /*
 459    * Return the number of bytes read.
 460    */
 461   *pcbRead = bytesToReadFromBuffer;
 462
 463   /*
 464    * Cleanup
 465    */
 466   GlobalUnlock(This->supportHandle);
 467
 468   /*
 469    * The function returns S_OK if the buffer was filled completely
 470    * it returns S_FALSE if the end of the stream is reached before the
 471    * buffer is filled
 472    */
 473   if(*pcbRead == cb)
 474     return S_OK;
 475
 476   return S_FALSE;
 477 }
 478
 479 /***
 480  * This method is part of the ISequentialStream interface.
 481  *
 482  * It writes a block of information to the stream at the current
 483  * position. It then moves the current position at the end of the
 484  * written block. If the stream is too small to fit the block,
 485  * the stream is grown to fit.
 486  *
 487  * See the documentation of ISequentialStream for more info.
 488  */
 489 HRESULT WINAPI HGLOBALStreamImpl_Write(
 490                   IStream*     iface,
 491                   const void*    pv,          /* [size_is][in] */
 492                   ULONG          cb,          /* [in] */
 493                   ULONG*         pcbWritten)  /* [out] */
 494 {
 495   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 496
 497   void*          supportBuffer;
 498   ULARGE_INTEGER newSize;
 499   ULONG          bytesWritten = 0;
 500
 501   TRACE("(%p, %p, %ld, %p)\n", iface,
 502         pv, cb, pcbWritten);
 503
 504   /*
 505    * If the caller is not interested in the number of bytes written,
 506    * we use another buffer to avoid "if" statements in the code.
 507    */
 508   if (pcbWritten == 0)
 509     pcbWritten = &bytesWritten;
 510
 511   if (cb == 0)
 512   {
 513     return S_OK;
 514   }
 515   else
 516   {
 517     newSize.u.HighPart = 0;
 518     newSize.u.LowPart = This->currentPosition.u.LowPart + cb;
 519   }
 520
 521   /*
 522    * Verify if we need to grow the stream
 523    */
 524   if (newSize.u.LowPart > This->streamSize.u.LowPart)
 525   {
 526     /* grow stream */
 527    IStream_SetSize(iface, newSize);
 528   }
 529
 530   /*
 531    * Lock the buffer in position and copy the data.
 532    */
 533   supportBuffer = GlobalLock(This->supportHandle);
 534
 535   memcpy((char *) supportBuffer+This->currentPosition.u.LowPart, pv, cb);
 536
 537   /*
 538    * Move the current position to the new position
 539    */
 540   This->currentPosition.u.LowPart+=cb;
 541
 542   /*
 543    * Return the number of bytes read.
 544    */
 545   *pcbWritten = cb;
 546
 547   /*
 548    * Cleanup
 549    */
 550   GlobalUnlock(This->supportHandle);
 551
 552   return S_OK;
 553 }
 554
 555 /***
 556  * This method is part of the IStream interface.
 557  *
 558  * It will move the current stream pointer according to the parameters
 559  * given.
 560  *
 561  * See the documentation of IStream for more info.
 562  */
 563 HRESULT WINAPI HGLOBALStreamImpl_Seek(
 564                   IStream*      iface,
 565                   LARGE_INTEGER   dlibMove,         /* [in] */
 566                   DWORD           dwOrigin,         /* [in] */
 567                   ULARGE_INTEGER* plibNewPosition) /* [out] */
 568 {
 569   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 570
 571   ULARGE_INTEGER newPosition;
 572
 573   TRACE("(%p, %lx%08lx, %ld, %p)\n", iface, dlibMove.u.HighPart,
 574         dlibMove.u.LowPart, dwOrigin, plibNewPosition);
 575
 576   /*
 577    * The file pointer is moved depending on the given "function"
 578    * parameter.
 579    */
 580   switch (dwOrigin)
 581   {
 582     case STREAM_SEEK_SET:
 583       newPosition.u.HighPart = 0;
 584       newPosition.u.LowPart = 0;
 585       break;
 586     case STREAM_SEEK_CUR:
 587       newPosition = This->currentPosition;
 588       break;
 589     case STREAM_SEEK_END:
 590       newPosition = This->streamSize;
 591       break;
 592     default:
 593       return STG_E_INVALIDFUNCTION;
 594   }
 595
 596   /*
 597    * Move the actual file pointer
 598    * If the file pointer ends-up after the end of the stream, the next Write operation will
 599    * make the file larger. This is how it is documented.
 600    */
 601   newPosition.QuadPart = RtlLargeIntegerAdd(newPosition.QuadPart, dlibMove.QuadPart);
 602   if (newPosition.QuadPart < 0) return STG_E_INVALIDFUNCTION;
 603
 604   if (plibNewPosition) *plibNewPosition = newPosition;
 605   This->currentPosition = newPosition;
 606
 607   return S_OK;
 608 }
 609
 610 /***
 611  * This method is part of the IStream interface.
 612  *
 613  * It will change the size of a stream.
 614  *
 615  * TODO: Switch from small blocks to big blocks and vice versa.
 616  *
 617  * See the documentation of IStream for more info.
 618  */
 619 HRESULT WINAPI HGLOBALStreamImpl_SetSize(
 620                                      IStream*      iface,
 621                                      ULARGE_INTEGER  libNewSize)   /* [in] */
 622 {
 623   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 624   HGLOBAL supportHandle;
 625
 626   TRACE("(%p, %ld)\n", iface, libNewSize.u.LowPart);
 627
 628   /*
 629    * As documented.
 630    */
 631   if (libNewSize.u.HighPart != 0)
 632     return STG_E_INVALIDFUNCTION;
 633
 634   if (This->streamSize.u.LowPart == libNewSize.u.LowPart)
 635     return S_OK;
 636
 637   /*
 638    * Re allocate the HGlobal to fit the new size of the stream.
 639    */
 640   supportHandle = GlobalReAlloc(This->supportHandle, libNewSize.u.LowPart, 0);
 641
 642   if (supportHandle == 0)
 643     return STG_E_MEDIUMFULL;
 644
 645   This->supportHandle = supportHandle;
 646   This->streamSize.u.LowPart = libNewSize.u.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.u.LowPart, pcbRead, pcbWritten);
 673
 674   /*
 675    * Sanity check
 676    */
 677   if ( pstm == 0 )
 678     return STG_E_INVALIDPOINTER;
 679
 680   totalBytesRead.u.LowPart = totalBytesRead.u.HighPart = 0;
 681   totalBytesWritten.u.LowPart = totalBytesWritten.u.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.u.LowPart > 0 )
 689   {
 690     if ( cb.u.LowPart >= 128 )
 691       copySize = 128;
 692     else
 693       copySize = cb.u.LowPart;
 694
 695     IStream_Read(iface, tmpBuffer, copySize, &bytesRead);
 696
 697     totalBytesRead.u.LowPart += bytesRead;
 698
 699     IStream_Write(pstm, tmpBuffer, bytesRead, &bytesWritten);
 700
 701     totalBytesWritten.u.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.u.LowPart = 0;
 714     else
 715       cb.u.LowPart -= bytesRead;
 716   }
 717
 718   /*
 719    * Update number of bytes read and written
 720    */
 721   if (pcbRead)
 722   {
 723     pcbRead->u.LowPart = totalBytesRead.u.LowPart;
 724     pcbRead->u.HighPart = totalBytesRead.u.HighPart;
 725   }
 726
 727   if (pcbWritten)
 728   {
 729     pcbWritten->u.LowPart = totalBytesWritten.u.LowPart;
 730     pcbWritten->u.HighPart = totalBytesWritten.u.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   ULARGE_INTEGER dummy;
 827   LARGE_INTEGER offset;
 828   HRESULT hr;
 829   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 830   TRACE(" Cloning %p (deleteOnRelease=%d seek position=%ld)\n",iface,This->deleteOnRelease,(long)This->currentPosition.QuadPart);
 831   hr=CreateStreamOnHGlobal(This->supportHandle, FALSE, ppstm);
 832   if(FAILED(hr))
 833     return hr;
 834   offset.QuadPart=(LONGLONG)This->currentPosition.QuadPart;
 835   HGLOBALStreamImpl_Seek(*ppstm,offset,STREAM_SEEK_SET,&dummy);
 836   return S_OK;
 837 }