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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, 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   const IStreamVtbl *lpVtbl;   /* Needs to be the first item in the struct
  58                           * since we want to cast this in an IStream pointer */
  59
  60   /*
  61    * Reference count
  62    */
  63   LONG               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  * This is the destructor of the HGLOBALStreamImpl class.
  91  *
  92  * This method will clean-up all the resources used-up by the given HGLOBALStreamImpl
  93  * class. The pointer passed-in to this function will be freed and will not
  94  * be valid anymore.
  95  */
  96 static void HGLOBALStreamImpl_Destroy(HGLOBALStreamImpl* This)
  97 {
  98   TRACE("(%p)\n", This);
  99
 100   /*
 101    * Release the HGlobal if the constructor asked for that.
 102    */
 103   if (This->deleteOnRelease)
 104   {
 105     GlobalFree(This->supportHandle);
 106     This->supportHandle=0;
 107   }
 108
 109   /*
 110    * Finally, free the memory used-up by the class.
 111    */
 112   HeapFree(GetProcessHeap(), 0, This);
 113 }
 114
 115 /***
 116  * This implements the IUnknown method AddRef for this
 117  * class
 118  */
 119 static ULONG WINAPI HGLOBALStreamImpl_AddRef(
 120                 IStream* iface)
 121 {
 122   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 123   return InterlockedIncrement(&This->ref);
 124 }
 125
 126 /***
 127  * This implements the IUnknown method QueryInterface for this
 128  * class
 129  */
 130 static HRESULT WINAPI HGLOBALStreamImpl_QueryInterface(
 131                   IStream*     iface,
 132                   REFIID         riid,        /* [in] */
 133                   void**         ppvObject)   /* [iid_is][out] */
 134 {
 135   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 136
 137   /*
 138    * Perform a sanity check on the parameters.
 139    */
 140   if (ppvObject==0)
 141     return E_INVALIDARG;
 142
 143   /*
 144    * Initialize the return parameter.
 145    */
 146   *ppvObject = 0;
 147
 148   /*
 149    * Compare the riid with the interface IDs implemented by this object.
 150    */
 151   if (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
 152   {
 153     *ppvObject = (IStream*)This;
 154   }
 155   else if (memcmp(&IID_IStream, riid, sizeof(IID_IStream)) == 0)
 156   {
 157     *ppvObject = (IStream*)This;
 158   }
 159
 160   /*
 161    * Check that we obtained an interface.
 162    */
 163   if ((*ppvObject)==0)
 164     return E_NOINTERFACE;
 165
 166   /*
 167    * Query Interface always increases the reference count by one when it is
 168    * successful
 169    */
 170   HGLOBALStreamImpl_AddRef(iface);
 171
 172   return S_OK;
 173 }
 174
 175 /***
 176  * This implements the IUnknown method Release for this
 177  * class
 178  */
 179 static ULONG WINAPI HGLOBALStreamImpl_Release(
 180                 IStream* iface)
 181 {
 182   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 183   ULONG newRef;
 184
 185   newRef = InterlockedDecrement(&This->ref);
 186
 187   /*
 188    * If the reference count goes down to 0, perform suicide.
 189    */
 190   if (newRef==0)
 191   {
 192     HGLOBALStreamImpl_Destroy(This);
 193   }
 194
 195   return newRef;
 196 }
 197
 198 /***
 199  * This method is part of the ISequentialStream interface.
 200  *
 201  * If reads a block of information from the stream at the current
 202  * position. It then moves the current position at the end of the
 203  * read block
 204  *
 205  * See the documentation of ISequentialStream for more info.
 206  */
 207 static HRESULT WINAPI HGLOBALStreamImpl_Read(
 208                   IStream*     iface,
 209                   void*          pv,        /* [length_is][size_is][out] */
 210                   ULONG          cb,        /* [in] */
 211                   ULONG*         pcbRead)   /* [out] */
 212 {
 213   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 214
 215   void* supportBuffer;
 216   ULONG bytesReadBuffer;
 217   ULONG bytesToReadFromBuffer;
 218
 219   TRACE("(%p, %p, %d, %p)\n", iface,
 220         pv, cb, pcbRead);
 221
 222   /*
 223    * If the caller is not interested in the nubmer of bytes read,
 224    * we use another buffer to avoid "if" statements in the code.
 225    */
 226   if (pcbRead==0)
 227     pcbRead = &bytesReadBuffer;
 228
 229   /*
 230    * Using the known size of the stream, calculate the number of bytes
 231    * to read from the block chain
 232    */
 233   bytesToReadFromBuffer = min( This->streamSize.u.LowPart - This->currentPosition.u.LowPart, cb);
 234
 235   /*
 236    * Lock the buffer in position and copy the data.
 237    */
 238   supportBuffer = GlobalLock(This->supportHandle);
 239
 240   memcpy(pv, (char *) supportBuffer+This->currentPosition.u.LowPart, bytesToReadFromBuffer);
 241
 242   /*
 243    * Move the current position to the new position
 244    */
 245   This->currentPosition.u.LowPart+=bytesToReadFromBuffer;
 246
 247   /*
 248    * Return the number of bytes read.
 249    */
 250   *pcbRead = bytesToReadFromBuffer;
 251
 252   /*
 253    * Cleanup
 254    */
 255   GlobalUnlock(This->supportHandle);
 256
 257   /*
 258    * Always returns S_OK even if the end of the stream is reached before the
 259    * buffer is filled
 260    */
 261
 262   return S_OK;
 263 }
 264
 265 /***
 266  * This method is part of the ISequentialStream interface.
 267  *
 268  * It writes a block of information to the stream at the current
 269  * position. It then moves the current position at the end of the
 270  * written block. If the stream is too small to fit the block,
 271  * the stream is grown to fit.
 272  *
 273  * See the documentation of ISequentialStream for more info.
 274  */
 275 static HRESULT WINAPI HGLOBALStreamImpl_Write(
 276                   IStream*     iface,
 277                   const void*    pv,          /* [size_is][in] */
 278                   ULONG          cb,          /* [in] */
 279                   ULONG*         pcbWritten)  /* [out] */
 280 {
 281   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 282
 283   void*          supportBuffer;
 284   ULARGE_INTEGER newSize;
 285   ULONG          bytesWritten = 0;
 286
 287   TRACE("(%p, %p, %d, %p)\n", iface, pv, cb, pcbWritten);
 288
 289   /*
 290    * If the caller is not interested in the number of bytes written,
 291    * we use another buffer to avoid "if" statements in the code.
 292    */
 293   if (pcbWritten == 0)
 294     pcbWritten = &bytesWritten;
 295
 296   if (cb == 0)
 297     goto out;
 298
 299   newSize.u.HighPart = 0;
 300   newSize.u.LowPart = This->currentPosition.u.LowPart + cb;
 301
 302   /*
 303    * Verify if we need to grow the stream
 304    */
 305   if (newSize.u.LowPart > This->streamSize.u.LowPart)
 306   {
 307     /* grow stream */
 308     HRESULT hr = IStream_SetSize(iface, newSize);
 309     if (FAILED(hr))
 310     {
 311       ERR("IStream_SetSize failed with error 0x%08x\n", hr);
 312       return hr;
 313     }
 314   }
 315
 316   /*
 317    * Lock the buffer in position and copy the data.
 318    */
 319   supportBuffer = GlobalLock(This->supportHandle);
 320
 321   memcpy((char *) supportBuffer+This->currentPosition.u.LowPart, pv, cb);
 322
 323   /*
 324    * Move the current position to the new position
 325    */
 326   This->currentPosition.u.LowPart+=cb;
 327
 328   /*
 329    * Cleanup
 330    */
 331   GlobalUnlock(This->supportHandle);
 332
 333 out:
 334   /*
 335    * Return the number of bytes read.
 336    */
 337   *pcbWritten = cb;
 338
 339   return S_OK;
 340 }
 341
 342 /***
 343  * This method is part of the IStream interface.
 344  *
 345  * It will move the current stream pointer according to the parameters
 346  * given.
 347  *
 348  * See the documentation of IStream for more info.
 349  */
 350 static HRESULT WINAPI HGLOBALStreamImpl_Seek(
 351                   IStream*      iface,
 352                   LARGE_INTEGER   dlibMove,         /* [in] */
 353                   DWORD           dwOrigin,         /* [in] */
 354                   ULARGE_INTEGER* plibNewPosition) /* [out] */
 355 {
 356   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 357
 358   ULARGE_INTEGER newPosition;
 359
 360   TRACE("(%p, %x%08x, %d, %p)\n", iface, dlibMove.u.HighPart,
 361         dlibMove.u.LowPart, dwOrigin, plibNewPosition);
 362
 363   /*
 364    * The file pointer is moved depending on the given "function"
 365    * parameter.
 366    */
 367   switch (dwOrigin)
 368   {
 369     case STREAM_SEEK_SET:
 370       newPosition.u.HighPart = 0;
 371       newPosition.u.LowPart = 0;
 372       break;
 373     case STREAM_SEEK_CUR:
 374       newPosition = This->currentPosition;
 375       break;
 376     case STREAM_SEEK_END:
 377       newPosition = This->streamSize;
 378       break;
 379     default:
 380       return STG_E_INVALIDFUNCTION;
 381   }
 382
 383   /*
 384    * Move the actual file pointer
 385    * If the file pointer ends-up after the end of the stream, the next Write operation will
 386    * make the file larger. This is how it is documented.
 387    */
 388   if (dlibMove.QuadPart < 0 && newPosition.QuadPart < -dlibMove.QuadPart) return STG_E_INVALIDFUNCTION;
 389
 390   newPosition.QuadPart = RtlLargeIntegerAdd(newPosition.QuadPart, dlibMove.QuadPart);
 391
 392   if (plibNewPosition) *plibNewPosition = newPosition;
 393   This->currentPosition = newPosition;
 394
 395   return S_OK;
 396 }
 397
 398 /***
 399  * This method is part of the IStream interface.
 400  *
 401  * It will change the size of a stream.
 402  *
 403  * TODO: Switch from small blocks to big blocks and vice versa.
 404  *
 405  * See the documentation of IStream for more info.
 406  */
 407 static HRESULT WINAPI HGLOBALStreamImpl_SetSize(
 408                                      IStream*      iface,
 409                                      ULARGE_INTEGER  libNewSize)   /* [in] */
 410 {
 411   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 412   HGLOBAL supportHandle;
 413
 414   TRACE("(%p, %d)\n", iface, libNewSize.u.LowPart);
 415
 416   /*
 417    * HighPart is ignored as shown in tests
 418    */
 419
 420   if (This->streamSize.u.LowPart == libNewSize.u.LowPart)
 421     return S_OK;
 422
 423   /*
 424    * Re allocate the HGlobal to fit the new size of the stream.
 425    */
 426   supportHandle = GlobalReAlloc(This->supportHandle, libNewSize.u.LowPart, 0);
 427
 428   if (supportHandle == 0)
 429     return STG_E_MEDIUMFULL;
 430
 431   This->supportHandle = supportHandle;
 432   This->streamSize.u.LowPart = libNewSize.u.LowPart;
 433
 434   return S_OK;
 435 }
 436
 437 /***
 438  * This method is part of the IStream interface.
 439  *
 440  * It will copy the 'cb' Bytes to 'pstm' IStream.
 441  *
 442  * See the documentation of IStream for more info.
 443  */
 444 static HRESULT WINAPI HGLOBALStreamImpl_CopyTo(
 445                                     IStream*      iface,
 446                                     IStream*      pstm,         /* [unique][in] */
 447                                     ULARGE_INTEGER  cb,           /* [in] */
 448                                     ULARGE_INTEGER* pcbRead,      /* [out] */
 449                                     ULARGE_INTEGER* pcbWritten)   /* [out] */
 450 {
 451   HRESULT        hr = S_OK;
 452   BYTE           tmpBuffer[128];
 453   ULONG          bytesRead, bytesWritten, copySize;
 454   ULARGE_INTEGER totalBytesRead;
 455   ULARGE_INTEGER totalBytesWritten;
 456
 457   TRACE("(%p, %p, %d, %p, %p)\n", iface, pstm,
 458         cb.u.LowPart, pcbRead, pcbWritten);
 459
 460   /*
 461    * Sanity check
 462    */
 463   if ( pstm == 0 )
 464     return STG_E_INVALIDPOINTER;
 465
 466   totalBytesRead.u.LowPart = totalBytesRead.u.HighPart = 0;
 467   totalBytesWritten.u.LowPart = totalBytesWritten.u.HighPart = 0;
 468
 469   /*
 470    * use stack to store data temporarly
 471    * there is surely more performant way of doing it, for now this basic
 472    * implementation will do the job
 473    */
 474   while ( cb.u.LowPart > 0 )
 475   {
 476     if ( cb.u.LowPart >= 128 )
 477       copySize = 128;
 478     else
 479       copySize = cb.u.LowPart;
 480
 481     IStream_Read(iface, tmpBuffer, copySize, &bytesRead);
 482
 483     totalBytesRead.u.LowPart += bytesRead;
 484
 485     IStream_Write(pstm, tmpBuffer, bytesRead, &bytesWritten);
 486
 487     totalBytesWritten.u.LowPart += bytesWritten;
 488
 489     /*
 490      * Check that read & write operations were succesfull
 491      */
 492     if (bytesRead != bytesWritten)
 493     {
 494       hr = STG_E_MEDIUMFULL;
 495       break;
 496     }
 497
 498     if (bytesRead!=copySize)
 499       cb.u.LowPart = 0;
 500     else
 501       cb.u.LowPart -= bytesRead;
 502   }
 503
 504   /*
 505    * Update number of bytes read and written
 506    */
 507   if (pcbRead)
 508   {
 509     pcbRead->u.LowPart = totalBytesRead.u.LowPart;
 510     pcbRead->u.HighPart = totalBytesRead.u.HighPart;
 511   }
 512
 513   if (pcbWritten)
 514   {
 515     pcbWritten->u.LowPart = totalBytesWritten.u.LowPart;
 516     pcbWritten->u.HighPart = totalBytesWritten.u.HighPart;
 517   }
 518   return hr;
 519 }
 520
 521 /***
 522  * This method is part of the IStream interface.
 523  *
 524  * For streams supported by HGLOBALS, this function does nothing.
 525  * This is what the documentation tells us.
 526  *
 527  * See the documentation of IStream for more info.
 528  */
 529 static HRESULT WINAPI HGLOBALStreamImpl_Commit(
 530                   IStream*      iface,
 531                   DWORD         grfCommitFlags)  /* [in] */
 532 {
 533   return S_OK;
 534 }
 535
 536 /***
 537  * This method is part of the IStream interface.
 538  *
 539  * For streams supported by HGLOBALS, this function does nothing.
 540  * This is what the documentation tells us.
 541  *
 542  * See the documentation of IStream for more info.
 543  */
 544 static HRESULT WINAPI HGLOBALStreamImpl_Revert(
 545                   IStream* iface)
 546 {
 547   return S_OK;
 548 }
 549
 550 /***
 551  * This method is part of the IStream interface.
 552  *
 553  * For streams supported by HGLOBALS, this function does nothing.
 554  * This is what the documentation tells us.
 555  *
 556  * See the documentation of IStream for more info.
 557  */
 558 static HRESULT WINAPI HGLOBALStreamImpl_LockRegion(
 559                   IStream*       iface,
 560                   ULARGE_INTEGER libOffset,   /* [in] */
 561                   ULARGE_INTEGER cb,          /* [in] */
 562                   DWORD          dwLockType)  /* [in] */
 563 {
 564   return STG_E_INVALIDFUNCTION;
 565 }
 566
 567 /*
 568  * This method is part of the IStream interface.
 569  *
 570  * For streams supported by HGLOBALS, this function does nothing.
 571  * This is what the documentation tells us.
 572  *
 573  * See the documentation of IStream for more info.
 574  */
 575 static HRESULT WINAPI HGLOBALStreamImpl_UnlockRegion(
 576                   IStream*       iface,
 577                   ULARGE_INTEGER libOffset,   /* [in] */
 578                   ULARGE_INTEGER cb,          /* [in] */
 579                   DWORD          dwLockType)  /* [in] */
 580 {
 581   return S_OK;
 582 }
 583
 584 /***
 585  * This method is part of the IStream interface.
 586  *
 587  * This method returns information about the current
 588  * stream.
 589  *
 590  * See the documentation of IStream for more info.
 591  */
 592 static HRESULT WINAPI HGLOBALStreamImpl_Stat(
 593                   IStream*     iface,
 594                   STATSTG*     pstatstg,     /* [out] */
 595                   DWORD        grfStatFlag)  /* [in] */
 596 {
 597   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 598
 599   memset(pstatstg, 0, sizeof(STATSTG));
 600
 601   pstatstg->pwcsName = NULL;
 602   pstatstg->type     = STGTY_STREAM;
 603   pstatstg->cbSize   = This->streamSize;
 604
 605   return S_OK;
 606 }
 607
 608 static HRESULT WINAPI HGLOBALStreamImpl_Clone(
 609                   IStream*     iface,
 610                   IStream**    ppstm) /* [out] */
 611 {
 612   ULARGE_INTEGER dummy;
 613   LARGE_INTEGER offset;
 614   HRESULT hr;
 615   HGLOBALStreamImpl* const This=(HGLOBALStreamImpl*)iface;
 616   TRACE(" Cloning %p (deleteOnRelease=%d seek position=%ld)\n",iface,This->deleteOnRelease,(long)This->currentPosition.QuadPart);
 617   hr=CreateStreamOnHGlobal(This->supportHandle, FALSE, ppstm);
 618   if(FAILED(hr))
 619     return hr;
 620   offset.QuadPart=(LONGLONG)This->currentPosition.QuadPart;
 621   HGLOBALStreamImpl_Seek(*ppstm,offset,STREAM_SEEK_SET,&dummy);
 622   return S_OK;
 623 }
 624
 625 /*
 626  * Virtual function table for the HGLOBALStreamImpl class.
 627  */
 628 static const IStreamVtbl HGLOBALStreamImpl_Vtbl =
 629 {
 630     HGLOBALStreamImpl_QueryInterface,
 631     HGLOBALStreamImpl_AddRef,
 632     HGLOBALStreamImpl_Release,
 633     HGLOBALStreamImpl_Read,
 634     HGLOBALStreamImpl_Write,
 635     HGLOBALStreamImpl_Seek,
 636     HGLOBALStreamImpl_SetSize,
 637     HGLOBALStreamImpl_CopyTo,
 638     HGLOBALStreamImpl_Commit,
 639     HGLOBALStreamImpl_Revert,
 640     HGLOBALStreamImpl_LockRegion,
 641     HGLOBALStreamImpl_UnlockRegion,
 642     HGLOBALStreamImpl_Stat,
 643     HGLOBALStreamImpl_Clone
 644 };
 645
 646 /******************************************************************************
 647 ** HGLOBALStreamImpl implementation
 648 */
 649
 650 /***
 651  * This is the constructor for the HGLOBALStreamImpl class.
 652  *
 653  * Params:
 654  *    hGlobal          - Handle that will support the stream. can be NULL.
 655  *    fDeleteOnRelease - Flag set to TRUE if the HGLOBAL will be released
 656  *                       when the IStream object is destroyed.
 657  */
 658 HGLOBALStreamImpl* HGLOBALStreamImpl_Construct(
 659                 HGLOBAL  hGlobal,
 660                 BOOL     fDeleteOnRelease)
 661 {
 662   HGLOBALStreamImpl* newStream;
 663
 664   newStream = HeapAlloc(GetProcessHeap(), 0, sizeof(HGLOBALStreamImpl));
 665
 666   if (newStream!=0)
 667   {
 668     /*
 669      * Set-up the virtual function table and reference count.
 670      */
 671     newStream->lpVtbl = &HGLOBALStreamImpl_Vtbl;
 672     newStream->ref    = 0;
 673
 674     /*
 675      * Initialize the support.
 676      */
 677     newStream->supportHandle = hGlobal;
 678     newStream->deleteOnRelease = fDeleteOnRelease;
 679
 680     /*
 681      * This method will allocate a handle if one is not supplied.
 682      */
 683     if (!newStream->supportHandle)
 684     {
 685       newStream->supportHandle = GlobalAlloc(GMEM_MOVEABLE | GMEM_NODISCARD |
 686                                              GMEM_SHARE, 0);
 687     }
 688
 689     /*
 690      * Start the stream at the beginning.
 691      */
 692     newStream->currentPosition.u.HighPart = 0;
 693     newStream->currentPosition.u.LowPart = 0;
 694
 695     /*
 696      * Initialize the size of the stream to the size of the handle.
 697      */
 698     newStream->streamSize.u.HighPart = 0;
 699     newStream->streamSize.u.LowPart  = GlobalSize(newStream->supportHandle);
 700   }
 701
 702   return newStream;
 703 }
 704
 705
 706 /***********************************************************************
 707  *           CreateStreamOnHGlobal     [OLE32.@]
 708  */
 709 HRESULT WINAPI CreateStreamOnHGlobal(
 710                 HGLOBAL   hGlobal,
 711                 BOOL      fDeleteOnRelease,
 712                 LPSTREAM* ppstm)
 713 {
 714   HGLOBALStreamImpl* newStream;
 715
 716   newStream = HGLOBALStreamImpl_Construct(hGlobal,
 717                                           fDeleteOnRelease);
 718
 719   if (newStream!=NULL)
 720   {
 721     return IUnknown_QueryInterface((IUnknown*)newStream,
 722                                    &IID_IStream,
 723                                    (void**)ppstm);
 724   }
 725
 726   return E_OUTOFMEMORY;
 727 }
 728
 729 /***********************************************************************
 730  *           GetHGlobalFromStream     [OLE32.@]
 731  */
 732 HRESULT WINAPI GetHGlobalFromStream(IStream* pstm, HGLOBAL* phglobal)
 733 {
 734   HGLOBALStreamImpl* pStream;
 735
 736   if (pstm == NULL)
 737     return E_INVALIDARG;
 738
 739   pStream = (HGLOBALStreamImpl*) pstm;
 740
 741   /*
 742    * Verify that the stream object was created with CreateStreamOnHGlobal.
 743    */
 744   if (pStream->lpVtbl == &HGLOBALStreamImpl_Vtbl)
 745     *phglobal = pStream->supportHandle;
 746   else
 747   {
 748     *phglobal = 0;
 749     return E_INVALIDARG;
 750   }
 751
 752   return S_OK;
 753 }