ole/stg_stream.c

   1 /*
   2  * Compound Storage (32 bit version)
   3  * Stream implementation
   4  *
   5  * This file contains the implementation of the stream interface
   6  * for streams contained in a compound storage.
   7  *
   8  * Copyright 1999 Francis Beaudet
   9  * Copyright 1999 Thuy Nguyen
  10  */
  11 #include <assert.h>
  12 #include <stdlib.h>
  13 #include <stdio.h>
  14 #include <string.h>
  15
  16 #include "winbase.h"
  17 #include "winerror.h"
  18 #include "debug.h"
  19 #include "wine/obj_storage.h"
  20
  21 #include "storage32.h"
  22
  23 DEFAULT_DEBUG_CHANNEL(storage)
  24
  25
  26 /*
  27  * Virtual function table for the StgStreamImpl class.
  28  */
  29 static ICOM_VTABLE(IStream) StgStreamImpl_Vtbl =
  30 {
  31     ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE
  32     StgStreamImpl_QueryInterface,
  33     StgStreamImpl_AddRef,
  34     StgStreamImpl_Release,
  35     StgStreamImpl_Read,
  36     StgStreamImpl_Write,
  37     StgStreamImpl_Seek,
  38     StgStreamImpl_SetSize,
  39     StgStreamImpl_CopyTo,
  40     StgStreamImpl_Commit,
  41     StgStreamImpl_Revert,
  42     StgStreamImpl_LockRegion,
  43     StgStreamImpl_UnlockRegion,
  44     StgStreamImpl_Stat,
  45     StgStreamImpl_Clone
  46 };
  47
  48 /******************************************************************************
  49 ** StgStreamImpl implementation
  50 */
  51
  52 /***
  53  * This is the constructor for the StgStreamImpl class.
  54  *
  55  * Params:
  56  *    parentStorage - Pointer to the storage that contains the stream to open
  57  *    ownerProperty - Index of the property that points to this stream.
  58  */
  59 StgStreamImpl* StgStreamImpl_Construct(
  60                 StorageBaseImpl* parentStorage,
  61                 ULONG              ownerProperty)
  62 {
  63   StgStreamImpl* newStream;
  64
  65   newStream = HeapAlloc(GetProcessHeap(), 0, sizeof(StgStreamImpl));
  66
  67   if (newStream!=0)
  68   {
  69     /*
  70      * Set-up the virtual function table and reference count.
  71      */
  72     newStream->lpvtbl = &StgStreamImpl_Vtbl;
  73     newStream->ref    = 0;
  74
  75     /*
  76      * We want to nail-down the reference to the storage in case the
  77      * stream out-lives the storage in the client application.
  78      */
  79     newStream->parentStorage = parentStorage;
  80     IStorage_AddRef((IStorage*)newStream->parentStorage);
  81
  82     newStream->ownerProperty = ownerProperty;
  83
  84     /*
  85      * Start the stream at the begining.
  86      */
  87     newStream->currentPosition.HighPart = 0;
  88     newStream->currentPosition.LowPart = 0;
  89
  90     /*
  91      * Initialize the rest of the data.
  92      */
  93     newStream->streamSize.HighPart = 0;
  94     newStream->streamSize.LowPart  = 0;
  95     newStream->bigBlockChain       = 0;
  96     newStream->smallBlockChain     = 0;
  97
  98     /*
  99      * Read the size from the property and determine if the blocks forming
 100      * this stream are large or small.
 101      */
 102     StgStreamImpl_OpenBlockChain(newStream);
 103   }
 104
 105   return newStream;
 106 }
 107
 108 /***
 109  * This is the destructor of the StgStreamImpl class.
 110  *
 111  * This method will clean-up all the resources used-up by the given StgStreamImpl
 112  * class. The pointer passed-in to this function will be freed and will not
 113  * be valid anymore.
 114  */
 115 void StgStreamImpl_Destroy(StgStreamImpl* This)
 116 {
 117   TRACE(storage, "(%p)\n", This);
 118
 119   /*
 120    * Release the reference we are holding on the parent storage.
 121    */
 122   IStorage_Release((IStorage*)This->parentStorage);
 123   This->parentStorage = 0;
 124
 125   /*
 126    * Make sure we clean-up the block chain stream objects that we were using.
 127    */
 128   if (This->bigBlockChain != 0)
 129   {
 130     BlockChainStream_Destroy(This->bigBlockChain);
 131     This->bigBlockChain = 0;
 132   }
 133
 134   if (This->smallBlockChain != 0)
 135   {
 136     SmallBlockChainStream_Destroy(This->smallBlockChain);
 137     This->smallBlockChain = 0;
 138   }
 139
 140   /*
 141    * Finally, free the memory used-up by the class.
 142    */
 143   HeapFree(GetProcessHeap(), 0, This);
 144 }
 145
 146 /***
 147  * This implements the IUnknown method QueryInterface for this
 148  * class
 149  */
 150 HRESULT WINAPI StgStreamImpl_QueryInterface(
 151                   IStream*     iface,
 152                   REFIID         riid,        /* [in] */
 153                   void**         ppvObject)   /* [iid_is][out] */
 154 {
 155   StgStreamImpl* const This=(StgStreamImpl*)iface;
 156
 157   /*
 158    * Perform a sanity check on the parameters.
 159    */
 160   if (ppvObject==0)
 161     return E_INVALIDARG;
 162
 163   /*
 164    * Initialize the return parameter.
 165    */
 166   *ppvObject = 0;
 167
 168   /*
 169    * Compare the riid with the interface IDs implemented by this object.
 170    */
 171   if (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
 172   {
 173     *ppvObject = (IStream*)This;
 174   }
 175   else if (memcmp(&IID_IStream, riid, sizeof(IID_IStream)) == 0)
 176   {
 177     *ppvObject = (IStream*)This;
 178   }
 179
 180   /*
 181    * Check that we obtained an interface.
 182    */
 183   if ((*ppvObject)==0)
 184     return E_NOINTERFACE;
 185
 186   /*
 187    * Query Interface always increases the reference count by one when it is
 188    * successful
 189    */
 190   StgStreamImpl_AddRef(iface);
 191
 192   return S_OK;;
 193 }
 194
 195 /***
 196  * This implements the IUnknown method AddRef for this
 197  * class
 198  */
 199 ULONG WINAPI StgStreamImpl_AddRef(
 200                 IStream* iface)
 201 {
 202   StgStreamImpl* const This=(StgStreamImpl*)iface;
 203
 204   This->ref++;
 205
 206   return This->ref;
 207 }
 208
 209 /***
 210  * This implements the IUnknown method Release for this
 211  * class
 212  */
 213 ULONG WINAPI StgStreamImpl_Release(
 214                 IStream* iface)
 215 {
 216   StgStreamImpl* const This=(StgStreamImpl*)iface;
 217
 218   ULONG newRef;
 219
 220   This->ref--;
 221
 222   newRef = This->ref;
 223
 224   /*
 225    * If the reference count goes down to 0, perform suicide.
 226    */
 227   if (newRef==0)
 228   {
 229     StgStreamImpl_Destroy(This);
 230   }
 231
 232   return newRef;
 233 }
 234
 235 /***
 236  * This method will open the block chain pointed by the property
 237  * that describes the stream.
 238  * If the stream's size is null, no chain is opened.
 239  */
 240 void StgStreamImpl_OpenBlockChain(
 241         StgStreamImpl* This)
 242 {
 243   StgProperty    curProperty;
 244   BOOL         readSucessful;
 245
 246   /*
 247    * Make sure no old object is staying behind.
 248    */
 249   if (This->smallBlockChain != 0)
 250   {
 251     SmallBlockChainStream_Destroy(This->smallBlockChain);
 252     This->smallBlockChain = 0;
 253   }
 254
 255   if (This->bigBlockChain != 0)
 256   {
 257     BlockChainStream_Destroy(This->bigBlockChain);
 258     This->bigBlockChain = 0;
 259   }
 260
 261   /*
 262    * Read the information from the property.
 263    */
 264   readSucessful = StorageImpl_ReadProperty(This->parentStorage->ancestorStorage,
 265                                              This->ownerProperty,
 266                                              &curProperty);
 267
 268   if (readSucessful)
 269   {
 270     This->streamSize = curProperty.size;
 271
 272     /*
 273      * This code supports only streams that are <32 bits in size.
 274      */
 275     assert(This->streamSize.HighPart == 0);
 276
 277     if(curProperty.startingBlock == BLOCK_END_OF_CHAIN)
 278     {
 279       assert( (This->streamSize.HighPart == 0) && (This->streamSize.LowPart == 0) );
 280     }
 281     else
 282     {
 283       if ( (This->streamSize.HighPart == 0) &&
 284            (This->streamSize.LowPart < LIMIT_TO_USE_SMALL_BLOCK) )
 285       {
 286         This->smallBlockChain = SmallBlockChainStream_Construct(
 287                                                                 This->parentStorage->ancestorStorage,
 288                                                                 This->ownerProperty);
 289       }
 290       else
 291       {
 292         This->bigBlockChain = BlockChainStream_Construct(
 293                                                          This->parentStorage->ancestorStorage,
 294                                                          NULL,
 295                                                          This->ownerProperty);
 296       }
 297     }
 298   }
 299 }
 300
 301 /***
 302  * This method is part of the ISequentialStream interface.
 303  *
 304  * If reads a block of information from the stream at the current
 305  * position. It then moves the current position at the end of the
 306  * read block
 307  *
 308  * See the documentation of ISequentialStream for more info.
 309  */
 310 HRESULT WINAPI StgStreamImpl_Read(
 311                   IStream*     iface,
 312                   void*          pv,        /* [length_is][size_is][out] */
 313                   ULONG          cb,        /* [in] */
 314                   ULONG*         pcbRead)   /* [out] */
 315 {
 316   StgStreamImpl* const This=(StgStreamImpl*)iface;
 317
 318   ULONG bytesReadBuffer;
 319   ULONG bytesToReadFromBuffer;
 320
 321   TRACE(storage, "(%p, %p, %ld, %p)\n",
 322         iface, pv, cb, pcbRead);
 323
 324   /*
 325    * If the caller is not interested in the nubmer of bytes read,
 326    * we use another buffer to avoid "if" statements in the code.
 327    */
 328   if (pcbRead==0)
 329     pcbRead = &bytesReadBuffer;
 330
 331   /*
 332    * Using the known size of the stream, calculate the number of bytes
 333    * to read from the block chain
 334    */
 335   bytesToReadFromBuffer = MIN( This->streamSize.LowPart - This->currentPosition.LowPart, cb);
 336
 337   /*
 338    * Depending on the type of chain that was opened when the stream was constructed,
 339    * we delegate the work to the method that read the block chains.
 340    */
 341   if (This->smallBlockChain!=0)
 342   {
 343     SmallBlockChainStream_ReadAt(This->smallBlockChain,
 344                                  This->currentPosition,
 345                                  bytesToReadFromBuffer,
 346                                  pv,
 347                                  pcbRead);
 348
 349   }
 350   else if (This->bigBlockChain!=0)
 351   {
 352     BlockChainStream_ReadAt(This->bigBlockChain,
 353                             This->currentPosition,
 354                             bytesToReadFromBuffer,
 355                             pv,
 356                             pcbRead);
 357   }
 358   else
 359     assert(FALSE);
 360
 361   /*
 362    * We should always be able to read the proper amount of data from the
 363    * chain.
 364    */
 365   assert(bytesToReadFromBuffer == *pcbRead);
 366
 367   /*
 368    * Advance the pointer for the number of positions read.
 369    */
 370   This->currentPosition.LowPart += *pcbRead;
 371
 372   /*
 373    * The function returns S_OK if the buffer was filled completely
 374    * it returns S_FALSE if the end of the stream is reached before the
 375    * buffer is filled
 376    */
 377   if(*pcbRead == cb)
 378     return S_OK;
 379
 380   return S_FALSE;
 381 }
 382
 383 /***
 384  * This method is part of the ISequentialStream interface.
 385  *
 386  * It writes a block of information to the stream at the current
 387  * position. It then moves the current position at the end of the
 388  * written block. If the stream is too small to fit the block,
 389  * the stream is grown to fit.
 390  *
 391  * See the documentation of ISequentialStream for more info.
 392  */
 393 HRESULT WINAPI StgStreamImpl_Write(
 394                   IStream*     iface,
 395                   const void*    pv,          /* [size_is][in] */
 396                   ULONG          cb,          /* [in] */
 397                   ULONG*         pcbWritten)  /* [out] */
 398 {
 399   StgStreamImpl* const This=(StgStreamImpl*)iface;
 400
 401   ULARGE_INTEGER newSize;
 402   ULONG bytesWritten = 0;
 403
 404   TRACE(storage, "(%p, %p, %ld, %p)\n",
 405         iface, pv, cb, pcbWritten);
 406
 407   /*
 408    * If the caller is not interested in the number of bytes written,
 409    * we use another buffer to avoid "if" statements in the code.
 410    */
 411   if (pcbWritten == 0)
 412     pcbWritten = &bytesWritten;
 413
 414   /*
 415    * Initialize the out parameter
 416    */
 417   *pcbWritten = 0;
 418
 419   if (cb == 0)
 420   {
 421     return S_OK;
 422   }
 423   else
 424   {
 425     newSize.HighPart = 0;
 426     newSize.LowPart = This->currentPosition.LowPart + cb;
 427   }
 428
 429   /*
 430    * Verify if we need to grow the stream
 431    */
 432   if (newSize.LowPart > This->streamSize.LowPart)
 433   {
 434     /* grow stream */
 435     IStream_SetSize(iface, newSize);
 436   }
 437
 438   /*
 439    * Depending on the type of chain that was opened when the stream was constructed,
 440    * we delegate the work to the method that readwrites to the block chains.
 441    */
 442   if (This->smallBlockChain!=0)
 443   {
 444     SmallBlockChainStream_WriteAt(This->smallBlockChain,
 445                                   This->currentPosition,
 446                                   cb,
 447                                   pv,
 448                                   pcbWritten);
 449
 450   }
 451   else if (This->bigBlockChain!=0)
 452   {
 453     BlockChainStream_WriteAt(This->bigBlockChain,
 454                              This->currentPosition,
 455                              cb,
 456                              pv,
 457                              pcbWritten);
 458   }
 459   else
 460     assert(FALSE);
 461
 462   /*
 463    * Advance the position pointer for the number of positions written.
 464    */
 465   This->currentPosition.LowPart += *pcbWritten;
 466
 467   return S_OK;
 468 }
 469
 470 /***
 471  * This method is part of the IStream interface.
 472  *
 473  * It will move the current stream pointer according to the parameters
 474  * given.
 475  *
 476  * See the documentation of IStream for more info.
 477  */
 478 HRESULT WINAPI StgStreamImpl_Seek(
 479                   IStream*      iface,
 480                   LARGE_INTEGER   dlibMove,         /* [in] */
 481                   DWORD           dwOrigin,         /* [in] */
 482                   ULARGE_INTEGER* plibNewPosition) /* [out] */
 483 {
 484   StgStreamImpl* const This=(StgStreamImpl*)iface;
 485
 486   ULARGE_INTEGER newPosition;
 487
 488   TRACE(storage, "(%p, %ld, %ld, %p)\n",
 489         iface, dlibMove.LowPart, dwOrigin, plibNewPosition);
 490
 491   /*
 492    * The caller is allowed to pass in NULL as the new position return value.
 493    * If it happens, we assign it to a dynamic variable to avoid special cases
 494    * in the code below.
 495    */
 496   if (plibNewPosition == 0)
 497   {
 498     plibNewPosition = &newPosition;
 499   }
 500
 501   /*
 502    * The file pointer is moved depending on the given "function"
 503    * parameter.
 504    */
 505   switch (dwOrigin)
 506   {
 507     case STREAM_SEEK_SET:
 508       plibNewPosition->HighPart = 0;
 509       plibNewPosition->LowPart  = 0;
 510       break;
 511     case STREAM_SEEK_CUR:
 512       *plibNewPosition = This->currentPosition;
 513       break;
 514     case STREAM_SEEK_END:
 515       *plibNewPosition = This->streamSize;
 516       break;
 517     default:
 518       return STG_E_INVALIDFUNCTION;
 519   }
 520
 521   /*
 522    * We don't support files with offsets of 64 bits.
 523    */
 524   assert(dlibMove.HighPart == 0);
 525
 526   /*
 527    * Check if we end-up before the beginning of the file. That should trigger an
 528    * error.
 529    */
 530   if ( (dlibMove.LowPart<0) && (plibNewPosition->LowPart < (ULONG)(-dlibMove.LowPart)) )
 531   {
 532     /*
 533      * I don't know what error to send there.
 534      */
 535     return E_FAIL;
 536   }
 537
 538   /*
 539    * Move the actual file pointer
 540    * If the file pointer ends-up after the end of the stream, the next Write operation will
 541    * make the file larger. This is how it is documented.
 542    */
 543   plibNewPosition->LowPart += dlibMove.LowPart;
 544   This->currentPosition = *plibNewPosition;
 545
 546   return S_OK;
 547 }
 548
 549 /***
 550  * This method is part of the IStream interface.
 551  *
 552  * It will change the size of a stream.
 553  *
 554  * TODO: Switch from small blocks to big blocks and vice versa.
 555  *
 556  * See the documentation of IStream for more info.
 557  */
 558 HRESULT WINAPI StgStreamImpl_SetSize(
 559                                      IStream*      iface,
 560                                      ULARGE_INTEGER  libNewSize)   /* [in] */
 561 {
 562   StgStreamImpl* const This=(StgStreamImpl*)iface;
 563
 564   StgProperty    curProperty;
 565   BOOL         Success;
 566
 567   TRACE(storage, "(%p, %ld)\n", iface, libNewSize.LowPart);
 568
 569   /*
 570    * As documented.
 571    */
 572   if (libNewSize.HighPart != 0)
 573     return STG_E_INVALIDFUNCTION;
 574
 575   if (This->streamSize.LowPart == libNewSize.LowPart)
 576     return S_OK;
 577
 578   /*
 579    * This will happen if we're creating a stream
 580    */
 581   if ((This->smallBlockChain == 0) && (This->bigBlockChain == 0))
 582   {
 583     if (libNewSize.LowPart < LIMIT_TO_USE_SMALL_BLOCK)
 584     {
 585       This->smallBlockChain = SmallBlockChainStream_Construct(
 586                                     This->parentStorage->ancestorStorage,
 587                                     This->ownerProperty);
 588     }
 589     else
 590     {
 591       This->bigBlockChain = BlockChainStream_Construct(
 592                                 This->parentStorage->ancestorStorage,
 593                                 NULL,
 594                                 This->ownerProperty);
 595     }
 596   }
 597
 598   /*
 599    * Read this stream's property to see if it's small blocks or big blocks
 600    */
 601   Success = StorageImpl_ReadProperty(This->parentStorage->ancestorStorage,
 602                                        This->ownerProperty,
 603                                        &curProperty);
 604   /*
 605    * Determine if we have to switch from small to big blocks or vice versa
 606    */
 607   if ( (This->smallBlockChain!=0) &&
 608        (curProperty.size.LowPart < LIMIT_TO_USE_SMALL_BLOCK) )
 609   {
 610     if (libNewSize.LowPart >= LIMIT_TO_USE_SMALL_BLOCK)
 611     {
 612       /*
 613        * Transform the small block chain into a big block chain
 614        */
 615       This->bigBlockChain = Storage32Impl_SmallBlocksToBigBlocks(
 616                                 This->parentStorage->ancestorStorage,
 617                                 &This->smallBlockChain);
 618     }
 619   }
 620
 621   if (This->smallBlockChain!=0)
 622   {
 623     Success = SmallBlockChainStream_SetSize(This->smallBlockChain, libNewSize);
 624   }
 625   else
 626   {
 627     Success = BlockChainStream_SetSize(This->bigBlockChain, libNewSize);
 628   }
 629
 630   /*
 631    * Write to the property the new information about this stream
 632    */
 633   Success = StorageImpl_ReadProperty(This->parentStorage->ancestorStorage,
 634                                        This->ownerProperty,
 635                                        &curProperty);
 636
 637   curProperty.size.HighPart = libNewSize.HighPart;
 638   curProperty.size.LowPart = libNewSize.LowPart;
 639
 640   if (Success)
 641   {
 642     StorageImpl_WriteProperty(This->parentStorage->ancestorStorage,
 643                                 This->ownerProperty,
 644                                 &curProperty);
 645   }
 646
 647   This->streamSize = libNewSize;
 648
 649   return S_OK;
 650 }
 651
 652 /***
 653  * This method is part of the IStream interface.
 654  *
 655  * It will copy the 'cb' Bytes to 'pstm' IStream.
 656  *
 657  * See the documentation of IStream for more info.
 658  */
 659 HRESULT WINAPI StgStreamImpl_CopyTo(
 660                                     IStream*      iface,
 661                                     IStream*      pstm,         /* [unique][in] */
 662                                     ULARGE_INTEGER  cb,           /* [in] */
 663                                     ULARGE_INTEGER* pcbRead,      /* [out] */
 664                                     ULARGE_INTEGER* pcbWritten)   /* [out] */
 665 {
 666   HRESULT        hr = S_OK;
 667   BYTE           tmpBuffer[128];
 668   ULONG          bytesRead, bytesWritten, copySize;
 669   ULARGE_INTEGER totalBytesRead;
 670   ULARGE_INTEGER totalBytesWritten;
 671
 672   TRACE(storage, "(%p, %p, %ld, %p, %p)\n",
 673         iface, pstm, cb.LowPart, pcbRead, pcbWritten);
 674
 675   /*
 676    * Sanity check
 677    */
 678   if ( pstm == 0 )
 679     return STG_E_INVALIDPOINTER;
 680
 681   totalBytesRead.LowPart = totalBytesRead.HighPart = 0;
 682   totalBytesWritten.LowPart = totalBytesWritten.HighPart = 0;
 683
 684   /*
 685    * use stack to store data temporarly
 686    * there is surely more performant way of doing it, for now this basic
 687    * implementation will do the job
 688    */
 689   while ( cb.LowPart > 0 )
 690   {
 691     if ( cb.LowPart >= 128 )
 692       copySize = 128;
 693     else
 694       copySize = cb.LowPart;
 695
 696     IStream_Read(iface, tmpBuffer, copySize, &bytesRead);
 697
 698     totalBytesRead.LowPart += bytesRead;
 699
 700     IStream_Write(pstm, tmpBuffer, bytesRead, &bytesWritten);
 701
 702     totalBytesWritten.LowPart += bytesWritten;
 703
 704     /*
 705      * Check that read & write operations were succesfull
 706      */
 707     if (bytesRead != bytesWritten)
 708     {
 709       hr = STG_E_MEDIUMFULL;
 710       break;
 711     }
 712
 713     if (bytesRead!=copySize)
 714       cb.LowPart = 0;
 715     else
 716       cb.LowPart -= bytesRead;
 717   }
 718
 719   /*
 720    * Update number of bytes read and written
 721    */
 722   if (pcbRead)
 723   {
 724     pcbRead->LowPart = totalBytesRead.LowPart;
 725     pcbRead->HighPart = totalBytesRead.HighPart;
 726   }
 727
 728   if (pcbWritten)
 729   {
 730     pcbWritten->LowPart = totalBytesWritten.LowPart;
 731     pcbWritten->HighPart = totalBytesWritten.HighPart;
 732   }
 733   return hr;
 734 }
 735
 736 /***
 737  * This method is part of the IStream interface.
 738  *
 739  * For streams contained in structured storages, this method
 740  * does nothing. This is what the documentation tells us.
 741  *
 742  * See the documentation of IStream for more info.
 743  */
 744 HRESULT WINAPI StgStreamImpl_Commit(
 745                   IStream*      iface,
 746                   DWORD           grfCommitFlags)  /* [in] */
 747 {
 748   return S_OK;
 749 }
 750
 751 /***
 752  * This method is part of the IStream interface.
 753  *
 754  * For streams contained in structured storages, this method
 755  * does nothing. This is what the documentation tells us.
 756  *
 757  * See the documentation of IStream for more info.
 758  */
 759 HRESULT WINAPI StgStreamImpl_Revert(
 760                   IStream* iface)
 761 {
 762   return S_OK;
 763 }
 764
 765 HRESULT WINAPI StgStreamImpl_LockRegion(
 766                                         IStream*     iface,
 767                                         ULARGE_INTEGER libOffset,   /* [in] */
 768                                         ULARGE_INTEGER cb,          /* [in] */
 769                                         DWORD          dwLockType)  /* [in] */
 770 {
 771   FIXME(storage, "not implemented!\n");
 772   return E_NOTIMPL;
 773 }
 774
 775 HRESULT WINAPI StgStreamImpl_UnlockRegion(
 776                                           IStream*     iface,
 777                                           ULARGE_INTEGER libOffset,   /* [in] */
 778                                           ULARGE_INTEGER cb,          /* [in] */
 779                                           DWORD          dwLockType)  /* [in] */
 780 {
 781   FIXME(storage, "not implemented!\n");
 782   return E_NOTIMPL;
 783 }
 784
 785 /***
 786  * This method is part of the IStream interface.
 787  *
 788  * This method returns information about the current
 789  * stream.
 790  *
 791  * See the documentation of IStream for more info.
 792  */
 793 HRESULT WINAPI StgStreamImpl_Stat(
 794                   IStream*     iface,
 795                   STATSTG*       pstatstg,     /* [out] */
 796                   DWORD          grfStatFlag)  /* [in] */
 797 {
 798   StgStreamImpl* const This=(StgStreamImpl*)iface;
 799
 800   StgProperty    curProperty;
 801   BOOL         readSucessful;
 802
 803   /*
 804    * Read the information from the property.
 805    */
 806   readSucessful = StorageImpl_ReadProperty(This->parentStorage->ancestorStorage,
 807                                              This->ownerProperty,
 808                                              &curProperty);
 809
 810   if (readSucessful)
 811   {
 812     StorageUtl_CopyPropertyToSTATSTG(pstatstg,
 813                                      &curProperty,
 814                                      grfStatFlag);
 815
 816     return S_OK;
 817   }
 818
 819   return E_FAIL;
 820 }
 821
 822 HRESULT WINAPI StgStreamImpl_Clone(
 823                                    IStream*     iface,
 824                                    IStream**    ppstm) /* [out] */
 825 {
 826   FIXME(storage, "not implemented!\n");
 827   return E_NOTIMPL;
 828 }