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 NONAMELESSUNION
  33 #define NONAMELESSSTRUCT
  34 #include "windef.h"
  35 #include "winbase.h"
  36 #include "winuser.h"
  37 #include "objbase.h"
  38 #include "ole2.h"
  39 #include "winerror.h"
  40 #include "winreg.h"
  41 #include "winternl.h"
  42
  43 #include "wine/debug.h"
  44
  45 WINE_DEFAULT_DEBUG_CHANNEL(storage);
  46
  47 /****************************************************************************
  48  * HGLOBALStreamImpl definition.
  49  *
  50  * This class imlements the IStream inteface and represents a stream
  51  * supported by an HGLOBAL pointer.
  52  */
  53 struct HGLOBALStreamImpl
  54 {
  55   ICOM_VFIELD(IStream);  /* Needs to be the first item in the stuct
  56                           * since we want to cast this in a IStream pointer */
  57
  58   /*
  59    * Reference count
  60    */
  61   ULONG              ref;
  62
  63   /*
  64    * Support for the stream
  65    */
  66   HGLOBAL supportHandle;
  67
  68   /*
  69    * This flag is TRUE if the HGLOBAL is destroyed when the stream
  70    * is finally released.
  71    */
  72   BOOL    deleteOnRelease;
  73
  74   /*
  75    * Helper variable that contains the size of the stream
  76    */
  77   ULARGE_INTEGER     streamSize;
  78
  79   /*
  80    * This is the current position of the cursor in the stream
  81    */
  82   ULARGE_INTEGER     currentPosition;
  83 };
  84
  85 typedef struct HGLOBALStreamImpl HGLOBALStreamImpl;
  86
  87 /*
  88  * Method definition for the StgStreamImpl class.
  89  */
  90 HGLOBALStreamImpl* HGLOBALStreamImpl_Construct(
  91                 HGLOBAL  hGlobal,
  92                 BOOL     fDeleteOnRelease);
  93
  94 void HGLOBALStreamImpl_Destroy(
  95                 HGLOBALStreamImpl* This);
  96
  97 void HGLOBALStreamImpl_OpenBlockChain(
  98                 HGLOBALStreamImpl* This);
  99
 100 HRESULT WINAPI HGLOBALStreamImpl_QueryInterface(
 101                 IStream*      iface,
 102                 REFIID         riid,            /* [in] */
 103                 void**         ppvObject);  /* [iid_is][out] */
 104
 105 ULONG WINAPI HGLOBALStreamImpl_AddRef(
 106                 IStream*      iface);
 107
 108 ULONG WINAPI HGLOBALStreamImpl_Release(
 109                 IStream*      iface);
 110
 111 HRESULT WINAPI HGLOBALStreamImpl_Read(
 112                 IStream*      iface,
 113                 void*          pv,        /* [length_is][size_is][out] */
 114                 ULONG          cb,        /* [in] */
 115                 ULONG*         pcbRead);  /* [out] */
 116
 117 HRESULT WINAPI HGLOBALStreamImpl_Write(
 118                 IStream*      iface,
 119                 const void*    pv,          /* [size_is][in] */
 120                 ULONG          cb,          /* [in] */
 121                 ULONG*         pcbWritten); /* [out] */
 122
 123 HRESULT WINAPI HGLOBALStreamImpl_Seek(
 124                 IStream*      iface,
 125                 LARGE_INTEGER   dlibMove,         /* [in] */
 126                 DWORD           dwOrigin,         /* [in] */
 127                 ULARGE_INTEGER* plibNewPosition); /* [out] */
 128
 129 HRESULT WINAPI HGLOBALStreamImpl_SetSize(
 130                 IStream*      iface,
 131                 ULARGE_INTEGER  libNewSize);  /* [in] */
 132
 133 HRESULT WINAPI HGLOBALStreamImpl_CopyTo(
 134                 IStream*      iface,
 135                 IStream*      pstm,         /* [unique][in] */
 136                 ULARGE_INTEGER  cb,           /* [in] */
 137                 ULARGE_INTEGER* pcbRead,      /* [out] */
 138                 ULARGE_INTEGER* pcbWritten);  /* [out] */
 139
 140 HRESULT WINAPI HGLOBALStreamImpl_Commit(
 141                 IStream*      iface,
 142                 DWORD           grfCommitFlags); /* [in] */
 143
 144 HRESULT WINAPI HGLOBALStreamImpl_Revert(
 145                 IStream*  iface);
 146
 147 HRESULT WINAPI HGLOBALStreamImpl_LockRegion(
 148                 IStream*     iface,
 149                 ULARGE_INTEGER libOffset,   /* [in] */
 150                 ULARGE_INTEGER cb,          /* [in] */
 151                 DWORD          dwLockType); /* [in] */
 152
 153 HRESULT WINAPI HGLOBALStreamImpl_UnlockRegion(
 154                 IStream*     iface,
 155                 ULARGE_INTEGER libOffset,   /* [in] */
 156                 ULARGE_INTEGER cb,          /* [in] */
 157                 DWORD          dwLockType); /* [in] */
 158
 159 HRESULT WINAPI HGLOBALStreamImpl_Stat(
 160                 IStream*     iface,
 161                 STATSTG*       pstatstg,     /* [out] */
 162                 DWORD          grfStatFlag); /* [in] */
 163
 164 HRESULT WINAPI HGLOBALStreamImpl_Clone(
 165                 IStream*     iface,
 166                 IStream**    ppstm);       /* [out] */
 167
 168
 169 /*
 170  * Virtual function table for the HGLOBALStreamImpl class.
 171  */
 172 static ICOM_VTABLE(IStream) HGLOBALStreamImpl_Vtbl =
 173 {
 174     ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE
 175     HGLOBALStreamImpl_QueryInterface,
 176     HGLOBALStreamImpl_AddRef,
 177     HGLOBALStreamImpl_Release,
 178     HGLOBALStreamImpl_Read,
 179     HGLOBALStreamImpl_Write,
 180     HGLOBALStreamImpl_Seek,
 181     HGLOBALStreamImpl_SetSize,
 182     HGLOBALStreamImpl_CopyTo,
 183     HGLOBALStreamImpl_Commit,
 184     HGLOBALStreamImpl_Revert,
 185     HGLOBALStreamImpl_LockRegion,
 186     HGLOBALStreamImpl_UnlockRegion,
 187     HGLOBALStreamImpl_Stat,
 188     HGLOBALStreamImpl_Clone
 189 };
 190
 191 /***********************************************************************
 192  *           CreateStreamOnHGlobal     [OLE32.@]
 193  */
 194 HRESULT WINAPI CreateStreamOnHGlobal(
 195                 HGLOBAL   hGlobal,
 196                 BOOL      fDeleteOnRelease,
 197                 LPSTREAM* ppstm)
 198 {
 199   HGLOBALStreamImpl* newStream;
 200
 201   newStream = HGLOBALStreamImpl_Construct(hGlobal,
 202                                           fDeleteOnRelease);
 203
 204   if (newStream!=NULL)
 205   {
 206     return IUnknown_QueryInterface((IUnknown*)newStream,
 207                                    &IID_IStream,
 208                                    (void**)ppstm);
 209   }
 210
 211   return E_OUTOFMEMORY;
 212 }
 213
 214 /***********************************************************************
 215  *           GetHGlobalFromStream     [OLE32.@]
 216  */
 217 HRESULT WINAPI GetHGlobalFromStream(IStream* pstm, HGLOBAL* phglobal)
 218 {
 219   HGLOBALStreamImpl* pStream;
 220
 221   if (pstm == NULL)
 222     return E_INVALIDARG;
 223
 224   pStream = (HGLOBALStreamImpl*) pstm;
 225
 226   /*
 227    * Verify that the stream object was created with CreateStreamOnHGlobal.
 228    */
 229   if (pStream->lpVtbl == &HGLOBALStreamImpl_Vtbl)
 230     *phglobal = pStream->supportHandle;
 231   else
 232   {
 233     *phglobal = 0;
 234     return E_INVALIDARG;
 235   }
 236
 237   return S_OK;
 238 }
 239
 240 /******************************************************************************
 241 ** HGLOBALStreamImpl implementation
 242 */
 243
 244 /***
 245  * This is the constructor for the HGLOBALStreamImpl class.
 246  *
 247  * Params:
 248  *    hGlobal          - Handle that will support the stream. can be NULL.
 249  *    fDeleteOnRelease - Flag set to TRUE if the HGLOBAL will be released
 250  *                       when the IStream object is destroyed.
 251  */
 252 HGLOBALStreamImpl* HGLOBALStreamImpl_Construct(
 253                 HGLOBAL  hGlobal,
 254                 BOOL     fDeleteOnRelease)
 255 {
 256   HGLOBALStreamImpl* newStream;
 257
 258   newStream = HeapAlloc(GetProcessHeap(), 0, sizeof(HGLOBALStreamImpl));
 259
 260   if (newStream!=0)
 261   {
 262     /*
 263      * Set-up the virtual function table and reference count.
 264      */
 265     newStream->lpVtbl = &HGLOBALStreamImpl_Vtbl;
 266     newStream->ref    = 0;
 267
 268     /*
 269      * Initialize the support.
 270      */
 271     newStream->supportHandle = hGlobal;
 272     newStream->deleteOnRelease = fDeleteOnRelease;
 273
 274     /*
 275      * This method will allocate a handle if one is not supplied.
 276      */
 277     if (!newStream->supportHandle)
 278     {
 279       newStream->supportHandle = GlobalAlloc(GMEM_MOVEABLE | GMEM_NODISCARD |
 280                                              GMEM_SHARE, 0);
 281     }
 282
 283     /*
 284      * Start the stream at the beginning.
 285      */
 286     newStream->currentPosition.s.HighPart = 0;
 287     newStream->currentPosition.s.LowPart = 0;
 288
 289     /*
 290      * Initialize the size of the stream to the size of the handle.
 291      */
 292     newStream->streamSize.s.HighPart = 0;
 293     newStream->streamSize.s.LowPart  = GlobalSize(newStream->supportHandle);
 294   }
 295
 296   return newStream;
 297 }
 298
 299 /***
 300  * This is the destructor of the HGLOBALStreamImpl class.
 301  *
 302  * This method will clean-up all the resources used-up by the given HGLOBALStreamImpl
 303  * class. The pointer passed-in to this function will be freed and will not
 304  * be valid anymore.
 305  */
 306 void HGLOBALStreamImpl_Destroy(HGLOBALStreamImpl* This)
 307 {
 308   TRACE("(%p)\n", This);
 309
 310   /*
 311    * Release the HGlobal if the constructor asked for that.
 312    */
 313   if (This->deleteOnRelease)
 314   {
 315     GlobalFree(This->supportHandle);
 316     This->supportHandle=0;
 317   }
 318
 319   /*
 320    * Finally, free the memory used-up by the class.
 321    */
 322   HeapFree(GetProcessHeap(), 0, This);
 323 }
 324
 325 /***
 326  * This implements the IUnknown method QueryInterface for this
 327  * class
 328  */
 329 HRESULT WINAPI HGLOBALStreamImpl_QueryInterface(
 330                   IStream*     iface,
 331                   REFIID         riid,        /* [in] */
 332                   void**         ppvObject)   /* [iid_is][out] */
 333 {
 334   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 335
 336   /*
 337    * Perform a sanity check on the parameters.
 338    */
 339   if (ppvObject==0)
 340     return E_INVALIDARG;
 341
 342   /*
 343    * Initialize the return parameter.
 344    */
 345   *ppvObject = 0;
 346
 347   /*
 348    * Compare the riid with the interface IDs implemented by this object.
 349    */
 350   if (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
 351   {
 352     *ppvObject = (IStream*)This;
 353   }
 354   else if (memcmp(&IID_IStream, riid, sizeof(IID_IStream)) == 0)
 355   {
 356     *ppvObject = (IStream*)This;
 357   }
 358
 359   /*
 360    * Check that we obtained an interface.
 361    */
 362   if ((*ppvObject)==0)
 363     return E_NOINTERFACE;
 364
 365   /*
 366    * Query Interface always increases the reference count by one when it is
 367    * successful
 368    */
 369   HGLOBALStreamImpl_AddRef(iface);
 370
 371   return S_OK;
 372 }
 373
 374 /***
 375  * This implements the IUnknown method AddRef for this
 376  * class
 377  */
 378 ULONG WINAPI HGLOBALStreamImpl_AddRef(
 379                 IStream* iface)
 380 {
 381   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 382
 383   This->ref++;
 384
 385   return This->ref;
 386 }
 387
 388 /***
 389  * This implements the IUnknown method Release for this
 390  * class
 391  */
 392 ULONG WINAPI HGLOBALStreamImpl_Release(
 393                 IStream* iface)
 394 {
 395   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 396
 397   ULONG newRef;
 398
 399   This->ref--;
 400
 401   newRef = This->ref;
 402
 403   /*
 404    * If the reference count goes down to 0, perform suicide.
 405    */
 406   if (newRef==0)
 407   {
 408     HGLOBALStreamImpl_Destroy(This);
 409   }
 410
 411   return newRef;
 412 }
 413
 414 /***
 415  * This method is part of the ISequentialStream interface.
 416  *
 417  * If reads a block of information from the stream at the current
 418  * position. It then moves the current position at the end of the
 419  * read block
 420  *
 421  * See the documentation of ISequentialStream for more info.
 422  */
 423 HRESULT WINAPI HGLOBALStreamImpl_Read(
 424                   IStream*     iface,
 425                   void*          pv,        /* [length_is][size_is][out] */
 426                   ULONG          cb,        /* [in] */
 427                   ULONG*         pcbRead)   /* [out] */
 428 {
 429   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 430
 431   void* supportBuffer;
 432   ULONG bytesReadBuffer;
 433   ULONG bytesToReadFromBuffer;
 434
 435   TRACE("(%p, %p, %ld, %p)\n", iface,
 436         pv, cb, pcbRead);
 437
 438   /*
 439    * If the caller is not interested in the nubmer of bytes read,
 440    * we use another buffer to avoid "if" statements in the code.
 441    */
 442   if (pcbRead==0)
 443     pcbRead = &bytesReadBuffer;
 444
 445   /*
 446    * Using the known size of the stream, calculate the number of bytes
 447    * to read from the block chain
 448    */
 449   bytesToReadFromBuffer = min( This->streamSize.s.LowPart - This->currentPosition.s.LowPart, cb);
 450
 451   /*
 452    * Lock the buffer in position and copy the data.
 453    */
 454   supportBuffer = GlobalLock(This->supportHandle);
 455
 456   memcpy(pv, (char *) supportBuffer+This->currentPosition.s.LowPart, bytesToReadFromBuffer);
 457
 458   /*
 459    * Move the current position to the new position
 460    */
 461   This->currentPosition.s.LowPart+=bytesToReadFromBuffer;
 462
 463   /*
 464    * Return the number of bytes read.
 465    */
 466   *pcbRead = bytesToReadFromBuffer;
 467
 468   /*
 469    * Cleanup
 470    */
 471   GlobalUnlock(This->supportHandle);
 472
 473   /*
 474    * The function returns S_OK if the buffer was filled completely
 475    * it returns S_FALSE if the end of the stream is reached before the
 476    * buffer is filled
 477    */
 478   if(*pcbRead == cb)
 479     return S_OK;
 480
 481   return S_FALSE;
 482 }
 483
 484 /***
 485  * This method is part of the ISequentialStream interface.
 486  *
 487  * It writes a block of information to the stream at the current
 488  * position. It then moves the current position at the end of the
 489  * written block. If the stream is too small to fit the block,
 490  * the stream is grown to fit.
 491  *
 492  * See the documentation of ISequentialStream for more info.
 493  */
 494 HRESULT WINAPI HGLOBALStreamImpl_Write(
 495                   IStream*     iface,
 496                   const void*    pv,          /* [size_is][in] */
 497                   ULONG          cb,          /* [in] */
 498                   ULONG*         pcbWritten)  /* [out] */
 499 {
 500   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 501
 502   void*          supportBuffer;
 503   ULARGE_INTEGER newSize;
 504   ULONG          bytesWritten = 0;
 505
 506   TRACE("(%p, %p, %ld, %p)\n", iface,
 507         pv, cb, pcbWritten);
 508
 509   /*
 510    * If the caller is not interested in the number of bytes written,
 511    * we use another buffer to avoid "if" statements in the code.
 512    */
 513   if (pcbWritten == 0)
 514     pcbWritten = &bytesWritten;
 515
 516   if (cb == 0)
 517   {
 518     return S_OK;
 519   }
 520   else
 521   {
 522     newSize.s.HighPart = 0;
 523     newSize.s.LowPart = This->currentPosition.s.LowPart + cb;
 524   }
 525
 526   /*
 527    * Verify if we need to grow the stream
 528    */
 529   if (newSize.s.LowPart > This->streamSize.s.LowPart)
 530   {
 531     /* grow stream */
 532    IStream_SetSize(iface, newSize);
 533   }
 534
 535   /*
 536    * Lock the buffer in position and copy the data.
 537    */
 538   supportBuffer = GlobalLock(This->supportHandle);
 539
 540   memcpy((char *) supportBuffer+This->currentPosition.s.LowPart, pv, cb);
 541
 542   /*
 543    * Move the current position to the new position
 544    */
 545   This->currentPosition.s.LowPart+=cb;
 546
 547   /*
 548    * Return the number of bytes read.
 549    */
 550   *pcbWritten = cb;
 551
 552   /*
 553    * Cleanup
 554    */
 555   GlobalUnlock(This->supportHandle);
 556
 557   return S_OK;
 558 }
 559
 560 /***
 561  * This method is part of the IStream interface.
 562  *
 563  * It will move the current stream pointer according to the parameters
 564  * given.
 565  *
 566  * See the documentation of IStream for more info.
 567  */
 568 HRESULT WINAPI HGLOBALStreamImpl_Seek(
 569                   IStream*      iface,
 570                   LARGE_INTEGER   dlibMove,         /* [in] */
 571                   DWORD           dwOrigin,         /* [in] */
 572                   ULARGE_INTEGER* plibNewPosition) /* [out] */
 573 {
 574   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 575
 576   ULARGE_INTEGER newPosition;
 577
 578   TRACE("(%p, %lx%08lx, %ld, %p)\n", iface, dlibMove.s.HighPart,
 579         dlibMove.s.LowPart, dwOrigin, plibNewPosition);
 580
 581   /*
 582    * The file pointer is moved depending on the given "function"
 583    * parameter.
 584    */
 585   switch (dwOrigin)
 586   {
 587     case STREAM_SEEK_SET:
 588       newPosition.s.HighPart = 0;
 589       newPosition.s.LowPart = 0;
 590       break;
 591     case STREAM_SEEK_CUR:
 592       newPosition = This->currentPosition;
 593       break;
 594     case STREAM_SEEK_END:
 595       newPosition = This->streamSize;
 596       break;
 597     default:
 598       return STG_E_INVALIDFUNCTION;
 599   }
 600
 601   /*
 602    * Move the actual file pointer
 603    * If the file pointer ends-up after the end of the stream, the next Write operation will
 604    * make the file larger. This is how it is documented.
 605    */
 606   newPosition.QuadPart = RtlLargeIntegerAdd(newPosition.QuadPart, dlibMove.QuadPart);
 607   if (newPosition.QuadPart < 0) return STG_E_INVALIDFUNCTION;
 608
 609   if (plibNewPosition) *plibNewPosition = newPosition;
 610   This->currentPosition = newPosition;
 611
 612   return S_OK;
 613 }
 614
 615 /***
 616  * This method is part of the IStream interface.
 617  *
 618  * It will change the size of a stream.
 619  *
 620  * TODO: Switch from small blocks to big blocks and vice versa.
 621  *
 622  * See the documentation of IStream for more info.
 623  */
 624 HRESULT WINAPI HGLOBALStreamImpl_SetSize(
 625                                      IStream*      iface,
 626                                      ULARGE_INTEGER  libNewSize)   /* [in] */
 627 {
 628   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 629   HGLOBAL supportHandle;
 630
 631   TRACE("(%p, %ld)\n", iface, libNewSize.s.LowPart);
 632
 633   /*
 634    * As documented.
 635    */
 636   if (libNewSize.s.HighPart != 0)
 637     return STG_E_INVALIDFUNCTION;
 638
 639   if (This->streamSize.s.LowPart == libNewSize.s.LowPart)
 640     return S_OK;
 641
 642   /*
 643    * Re allocate the HGlobal to fit the new size of the stream.
 644    */
 645   supportHandle = GlobalReAlloc(This->supportHandle, libNewSize.s.LowPart, 0);
 646
 647   if (supportHandle == 0)
 648     return STG_E_MEDIUMFULL;
 649
 650   This->supportHandle = supportHandle;
 651   This->streamSize.s.LowPart = libNewSize.s.LowPart;
 652
 653   return S_OK;
 654 }
 655
 656 /***
 657  * This method is part of the IStream interface.
 658  *
 659  * It will copy the 'cb' Bytes to 'pstm' IStream.
 660  *
 661  * See the documentation of IStream for more info.
 662  */
 663 HRESULT WINAPI HGLOBALStreamImpl_CopyTo(
 664                                     IStream*      iface,
 665                                     IStream*      pstm,         /* [unique][in] */
 666                                     ULARGE_INTEGER  cb,           /* [in] */
 667                                     ULARGE_INTEGER* pcbRead,      /* [out] */
 668                                     ULARGE_INTEGER* pcbWritten)   /* [out] */
 669 {
 670   HRESULT        hr = S_OK;
 671   BYTE           tmpBuffer[128];
 672   ULONG          bytesRead, bytesWritten, copySize;
 673   ULARGE_INTEGER totalBytesRead;
 674   ULARGE_INTEGER totalBytesWritten;
 675
 676   TRACE("(%p, %p, %ld, %p, %p)\n", iface, pstm,
 677         cb.s.LowPart, pcbRead, pcbWritten);
 678
 679   /*
 680    * Sanity check
 681    */
 682   if ( pstm == 0 )
 683     return STG_E_INVALIDPOINTER;
 684
 685   totalBytesRead.s.LowPart = totalBytesRead.s.HighPart = 0;
 686   totalBytesWritten.s.LowPart = totalBytesWritten.s.HighPart = 0;
 687
 688   /*
 689    * use stack to store data temporarly
 690    * there is surely more performant way of doing it, for now this basic
 691    * implementation will do the job
 692    */
 693   while ( cb.s.LowPart > 0 )
 694   {
 695     if ( cb.s.LowPart >= 128 )
 696       copySize = 128;
 697     else
 698       copySize = cb.s.LowPart;
 699
 700     IStream_Read(iface, tmpBuffer, copySize, &bytesRead);
 701
 702     totalBytesRead.s.LowPart += bytesRead;
 703
 704     IStream_Write(pstm, tmpBuffer, bytesRead, &bytesWritten);
 705
 706     totalBytesWritten.s.LowPart += bytesWritten;
 707
 708     /*
 709      * Check that read & write operations were succesfull
 710      */
 711     if (bytesRead != bytesWritten)
 712     {
 713       hr = STG_E_MEDIUMFULL;
 714       break;
 715     }
 716
 717     if (bytesRead!=copySize)
 718       cb.s.LowPart = 0;
 719     else
 720       cb.s.LowPart -= bytesRead;
 721   }
 722
 723   /*
 724    * Update number of bytes read and written
 725    */
 726   if (pcbRead)
 727   {
 728     pcbRead->s.LowPart = totalBytesRead.s.LowPart;
 729     pcbRead->s.HighPart = totalBytesRead.s.HighPart;
 730   }
 731
 732   if (pcbWritten)
 733   {
 734     pcbWritten->s.LowPart = totalBytesWritten.s.LowPart;
 735     pcbWritten->s.HighPart = totalBytesWritten.s.HighPart;
 736   }
 737   return hr;
 738 }
 739
 740 /***
 741  * This method is part of the IStream interface.
 742  *
 743  * For streams supported by HGLOBALS, this function does nothing.
 744  * This is what the documentation tells us.
 745  *
 746  * See the documentation of IStream for more info.
 747  */
 748 HRESULT WINAPI HGLOBALStreamImpl_Commit(
 749                   IStream*      iface,
 750                   DWORD         grfCommitFlags)  /* [in] */
 751 {
 752   return S_OK;
 753 }
 754
 755 /***
 756  * This method is part of the IStream interface.
 757  *
 758  * For streams supported by HGLOBALS, this function does nothing.
 759  * This is what the documentation tells us.
 760  *
 761  * See the documentation of IStream for more info.
 762  */
 763 HRESULT WINAPI HGLOBALStreamImpl_Revert(
 764                   IStream* iface)
 765 {
 766   return S_OK;
 767 }
 768
 769 /***
 770  * This method is part of the IStream interface.
 771  *
 772  * For streams supported by HGLOBALS, this function does nothing.
 773  * This is what the documentation tells us.
 774  *
 775  * See the documentation of IStream for more info.
 776  */
 777 HRESULT WINAPI HGLOBALStreamImpl_LockRegion(
 778                   IStream*       iface,
 779                   ULARGE_INTEGER libOffset,   /* [in] */
 780                   ULARGE_INTEGER cb,          /* [in] */
 781                   DWORD          dwLockType)  /* [in] */
 782 {
 783   return S_OK;
 784 }
 785
 786 /*
 787  * This method is part of the IStream interface.
 788  *
 789  * For streams supported by HGLOBALS, this function does nothing.
 790  * This is what the documentation tells us.
 791  *
 792  * See the documentation of IStream for more info.
 793  */
 794 HRESULT WINAPI HGLOBALStreamImpl_UnlockRegion(
 795                   IStream*       iface,
 796                   ULARGE_INTEGER libOffset,   /* [in] */
 797                   ULARGE_INTEGER cb,          /* [in] */
 798                   DWORD          dwLockType)  /* [in] */
 799 {
 800   return S_OK;
 801 }
 802
 803 /***
 804  * This method is part of the IStream interface.
 805  *
 806  * This method returns information about the current
 807  * stream.
 808  *
 809  * See the documentation of IStream for more info.
 810  */
 811 HRESULT WINAPI HGLOBALStreamImpl_Stat(
 812                   IStream*     iface,
 813                   STATSTG*     pstatstg,     /* [out] */
 814                   DWORD        grfStatFlag)  /* [in] */
 815 {
 816   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 817
 818   memset(pstatstg, 0, sizeof(STATSTG));
 819
 820   pstatstg->pwcsName = NULL;
 821   pstatstg->type     = STGTY_STREAM;
 822   pstatstg->cbSize   = This->streamSize;
 823
 824   return S_OK;
 825 }
 826
 827 HRESULT WINAPI HGLOBALStreamImpl_Clone(
 828                   IStream*     iface,
 829                   IStream**    ppstm) /* [out] */
 830 {
 831   ULARGE_INTEGER dummy;
 832   LARGE_INTEGER offset;
 833   HRESULT hr;
 834   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 835   TRACE(" Cloning %p (deleteOnRelease=%d seek position=%ld)\n",iface,This->deleteOnRelease,(long)This->currentPosition.QuadPart);
 836   hr=CreateStreamOnHGlobal(This->supportHandle, FALSE, ppstm);
 837   if(FAILED(hr))
 838     return hr;
 839   offset.QuadPart=(LONGLONG)This->currentPosition.QuadPart;
 840   HGLOBALStreamImpl_Seek(*ppstm,offset,STREAM_SEEK_SET,&dummy);
 841   return S_OK;
 842 }