dlls/ole32/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  * This library is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2.1 of the License, or (at your option) any later version.
  15  *
  16  * This library is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with this library; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  24  */
  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 "winerror.h"
  39 #include "winreg.h"
  40 #include "winternl.h"
  41 #include "wine/debug.h"
  42
  43 #include "storage32.h"
  44
  45 WINE_DEFAULT_DEBUG_CHANNEL(storage);
  46
  47
  48 /***
  49  * This is the destructor of the StgStreamImpl class.
  50  *
  51  * This method will clean-up all the resources used-up by the given StgStreamImpl
  52  * class. The pointer passed-in to this function will be freed and will not
  53  * be valid anymore.
  54  */
  55 static void StgStreamImpl_Destroy(StgStreamImpl* This)
  56 {
  57   TRACE("(%p)\n", This);
  58
  59   /*
  60    * Release the reference we are holding on the parent storage.
  61    * IStorage_Release((IStorage*)This->parentStorage);
  62    *
  63    * No, don't do this. Some apps call IStorage_Release without
  64    * calling IStream_Release first. If we grab a reference the
  65    * file is not closed, and the app fails when it tries to
  66    * reopen the file (Easy-PC, for example). Just inform the
  67    * storage that we have closed the stream
  68    */
  69
  70   if(This->parentStorage) {
  71
  72     StorageBaseImpl_RemoveStream(This->parentStorage, This);
  73
  74   }
  75
  76   This->parentStorage = 0;
  77
  78   /*
  79    * Make sure we clean-up the block chain stream objects that we were using.
  80    */
  81   if (This->bigBlockChain != 0)
  82   {
  83     BlockChainStream_Destroy(This->bigBlockChain);
  84     This->bigBlockChain = 0;
  85   }
  86
  87   if (This->smallBlockChain != 0)
  88   {
  89     SmallBlockChainStream_Destroy(This->smallBlockChain);
  90     This->smallBlockChain = 0;
  91   }
  92
  93   /*
  94    * Finally, free the memory used-up by the class.
  95    */
  96   HeapFree(GetProcessHeap(), 0, This);
  97 }
  98
  99 /***
 100  * This implements the IUnknown method QueryInterface for this
 101  * class
 102  */
 103 static HRESULT WINAPI StgStreamImpl_QueryInterface(
 104                   IStream*     iface,
 105                   REFIID         riid,        /* [in] */
 106                   void**         ppvObject)   /* [iid_is][out] */
 107 {
 108   StgStreamImpl* const This=(StgStreamImpl*)iface;
 109
 110   /*
 111    * Perform a sanity check on the parameters.
 112    */
 113   if (ppvObject==0)
 114     return E_INVALIDARG;
 115
 116   /*
 117    * Initialize the return parameter.
 118    */
 119   *ppvObject = 0;
 120
 121   /*
 122    * Compare the riid with the interface IDs implemented by this object.
 123    */
 124   if (IsEqualGUID(&IID_IUnknown, riid)||
 125       IsEqualGUID(&IID_IPersistStream, riid)||
 126       IsEqualGUID(&IID_IStream, riid))
 127   {
 128     *ppvObject = (IStream*)This;
 129   }
 130
 131   /*
 132    * Check that we obtained an interface.
 133    */
 134   if ((*ppvObject)==0)
 135     return E_NOINTERFACE;
 136
 137   /*
 138    * Query Interface always increases the reference count by one when it is
 139    * successful
 140    */
 141   IStream_AddRef(iface);
 142
 143   return S_OK;
 144 }
 145
 146 /***
 147  * This implements the IUnknown method AddRef for this
 148  * class
 149  */
 150 static ULONG WINAPI StgStreamImpl_AddRef(
 151                 IStream* iface)
 152 {
 153   StgStreamImpl* const This=(StgStreamImpl*)iface;
 154   return InterlockedIncrement(&This->ref);
 155 }
 156
 157 /***
 158  * This implements the IUnknown method Release for this
 159  * class
 160  */
 161 static ULONG WINAPI StgStreamImpl_Release(
 162                 IStream* iface)
 163 {
 164   StgStreamImpl* const This=(StgStreamImpl*)iface;
 165
 166   ULONG ref;
 167
 168   ref = InterlockedDecrement(&This->ref);
 169
 170   /*
 171    * If the reference count goes down to 0, perform suicide.
 172    */
 173   if (ref==0)
 174   {
 175     StgStreamImpl_Destroy(This);
 176   }
 177
 178   return ref;
 179 }
 180
 181 /***
 182  * This method will open the block chain pointed by the property
 183  * that describes the stream.
 184  * If the stream's size is null, no chain is opened.
 185  */
 186 static void StgStreamImpl_OpenBlockChain(
 187         StgStreamImpl* This)
 188 {
 189   StgProperty    curProperty;
 190   BOOL         readSucessful;
 191
 192   /*
 193    * Make sure no old object is left over.
 194    */
 195   if (This->smallBlockChain != 0)
 196   {
 197     SmallBlockChainStream_Destroy(This->smallBlockChain);
 198     This->smallBlockChain = 0;
 199   }
 200
 201   if (This->bigBlockChain != 0)
 202   {
 203     BlockChainStream_Destroy(This->bigBlockChain);
 204     This->bigBlockChain = 0;
 205   }
 206
 207   /*
 208    * Read the information from the property.
 209    */
 210   readSucessful = StorageImpl_ReadProperty(This->parentStorage->ancestorStorage,
 211                                              This->ownerProperty,
 212                                              &curProperty);
 213
 214   if (readSucessful)
 215   {
 216     This->streamSize = curProperty.size;
 217
 218     /*
 219      * This code supports only streams that are <32 bits in size.
 220      */
 221     assert(This->streamSize.u.HighPart == 0);
 222
 223     if(curProperty.startingBlock == BLOCK_END_OF_CHAIN)
 224     {
 225       assert( (This->streamSize.u.HighPart == 0) && (This->streamSize.u.LowPart == 0) );
 226     }
 227     else
 228     {
 229       if ( (This->streamSize.u.HighPart == 0) &&
 230            (This->streamSize.u.LowPart < LIMIT_TO_USE_SMALL_BLOCK) )
 231       {
 232         This->smallBlockChain = SmallBlockChainStream_Construct(
 233                                                                 This->parentStorage->ancestorStorage,
 234                                                                 This->ownerProperty);
 235       }
 236       else
 237       {
 238         This->bigBlockChain = BlockChainStream_Construct(
 239                                                          This->parentStorage->ancestorStorage,
 240                                                          NULL,
 241                                                          This->ownerProperty);
 242       }
 243     }
 244   }
 245 }
 246
 247 /***
 248  * This method is part of the ISequentialStream interface.
 249  *
 250  * It reads a block of information from the stream at the current
 251  * position. It then moves the current position at the end of the
 252  * read block
 253  *
 254  * See the documentation of ISequentialStream for more info.
 255  */
 256 static HRESULT WINAPI StgStreamImpl_Read(
 257                   IStream*     iface,
 258                   void*          pv,        /* [length_is][size_is][out] */
 259                   ULONG          cb,        /* [in] */
 260                   ULONG*         pcbRead)   /* [out] */
 261 {
 262   StgStreamImpl* const This=(StgStreamImpl*)iface;
 263
 264   ULONG bytesReadBuffer;
 265   ULONG bytesToReadFromBuffer;
 266   HRESULT res;
 267
 268   TRACE("(%p, %p, %ld, %p)\n",
 269         iface, pv, cb, pcbRead);
 270
 271   if (!This->parentStorage)
 272   {
 273     WARN("storage reverted\n");
 274     return STG_E_REVERTED;
 275   }
 276
 277   /*
 278    * If the caller is not interested in the number of bytes read,
 279    * we use another buffer to avoid "if" statements in the code.
 280    */
 281   if (pcbRead==0)
 282     pcbRead = &bytesReadBuffer;
 283
 284   /*
 285    * Using the known size of the stream, calculate the number of bytes
 286    * to read from the block chain
 287    */
 288   bytesToReadFromBuffer = min( This->streamSize.u.LowPart - This->currentPosition.u.LowPart, cb);
 289
 290   /*
 291    * Depending on the type of chain that was opened when the stream was constructed,
 292    * we delegate the work to the method that reads the block chains.
 293    */
 294   if (This->smallBlockChain!=0)
 295   {
 296     res = SmallBlockChainStream_ReadAt(This->smallBlockChain,
 297                                  This->currentPosition,
 298                                  bytesToReadFromBuffer,
 299                                  pv,
 300                                  pcbRead);
 301
 302   }
 303   else if (This->bigBlockChain!=0)
 304   {
 305     BOOL success = BlockChainStream_ReadAt(This->bigBlockChain,
 306                                            This->currentPosition,
 307                                            bytesToReadFromBuffer,
 308                                            pv,
 309                                            pcbRead);
 310     if (success)
 311       res = S_OK;
 312     else
 313       res = STG_E_READFAULT;
 314   }
 315   else
 316   {
 317     /*
 318      * Small and big block chains are both NULL. This case will happen
 319      * when a stream starts with BLOCK_END_OF_CHAIN and has size zero.
 320      */
 321
 322     *pcbRead = 0;
 323     res = S_OK;
 324     goto end;
 325   }
 326
 327   if (SUCCEEDED(res))
 328   {
 329       /*
 330        * We should always be able to read the proper amount of data from the
 331        * chain.
 332        */
 333       assert(bytesToReadFromBuffer == *pcbRead);
 334
 335       /*
 336        * Advance the pointer for the number of positions read.
 337        */
 338       This->currentPosition.u.LowPart += *pcbRead;
 339   }
 340
 341 end:
 342   TRACE("<-- %08lx\n", res);
 343   return res;
 344 }
 345
 346 /***
 347  * This method is part of the ISequentialStream interface.
 348  *
 349  * It writes a block of information to the stream at the current
 350  * position. It then moves the current position at the end of the
 351  * written block. If the stream is too small to fit the block,
 352  * the stream is grown to fit.
 353  *
 354  * See the documentation of ISequentialStream for more info.
 355  */
 356 static HRESULT WINAPI StgStreamImpl_Write(
 357                   IStream*     iface,
 358                   const void*    pv,          /* [size_is][in] */
 359                   ULONG          cb,          /* [in] */
 360                   ULONG*         pcbWritten)  /* [out] */
 361 {
 362   StgStreamImpl* const This=(StgStreamImpl*)iface;
 363
 364   ULARGE_INTEGER newSize;
 365   ULONG bytesWritten = 0;
 366
 367   TRACE("(%p, %p, %ld, %p)\n",
 368         iface, pv, cb, pcbWritten);
 369
 370   /*
 371    * Do we have permission to write to this stream?
 372    */
 373   switch(STGM_ACCESS_MODE(This->grfMode))
 374   {
 375   case STGM_WRITE:
 376   case STGM_READWRITE:
 377       break;
 378   default:
 379       WARN("access denied by flags: 0x%lx\n", STGM_ACCESS_MODE(This->grfMode));
 380       return STG_E_ACCESSDENIED;
 381   }
 382
 383   if (!pv)
 384     return STG_E_INVALIDPOINTER;
 385
 386   if (!This->parentStorage)
 387   {
 388     WARN("storage reverted\n");
 389     return STG_E_REVERTED;
 390   }
 391
 392   /*
 393    * If the caller is not interested in the number of bytes written,
 394    * we use another buffer to avoid "if" statements in the code.
 395    */
 396   if (pcbWritten == 0)
 397     pcbWritten = &bytesWritten;
 398
 399   /*
 400    * Initialize the out parameter
 401    */
 402   *pcbWritten = 0;
 403
 404   if (cb == 0)
 405   {
 406     TRACE("<-- S_OK, written 0\n");
 407     return S_OK;
 408   }
 409   else
 410   {
 411     newSize.u.HighPart = 0;
 412     newSize.u.LowPart = This->currentPosition.u.LowPart + cb;
 413   }
 414
 415   /*
 416    * Verify if we need to grow the stream
 417    */
 418   if (newSize.u.LowPart > This->streamSize.u.LowPart)
 419   {
 420     /* grow stream */
 421     IStream_SetSize(iface, newSize);
 422   }
 423
 424   /*
 425    * Depending on the type of chain that was opened when the stream was constructed,
 426    * we delegate the work to the method that readwrites to the block chains.
 427    */
 428   if (This->smallBlockChain!=0)
 429   {
 430     SmallBlockChainStream_WriteAt(This->smallBlockChain,
 431                                   This->currentPosition,
 432                                   cb,
 433                                   pv,
 434                                   pcbWritten);
 435
 436   }
 437   else if (This->bigBlockChain!=0)
 438   {
 439     BlockChainStream_WriteAt(This->bigBlockChain,
 440                              This->currentPosition,
 441                              cb,
 442                              pv,
 443                              pcbWritten);
 444   }
 445   else
 446     assert(FALSE);
 447
 448   /*
 449    * Advance the position pointer for the number of positions written.
 450    */
 451   This->currentPosition.u.LowPart += *pcbWritten;
 452
 453   TRACE("<-- S_OK, written %lu\n", *pcbWritten);
 454   return S_OK;
 455 }
 456
 457 /***
 458  * This method is part of the IStream interface.
 459  *
 460  * It will move the current stream pointer according to the parameters
 461  * given.
 462  *
 463  * See the documentation of IStream for more info.
 464  */
 465 static HRESULT WINAPI StgStreamImpl_Seek(
 466                   IStream*      iface,
 467                   LARGE_INTEGER   dlibMove,         /* [in] */
 468                   DWORD           dwOrigin,         /* [in] */
 469                   ULARGE_INTEGER* plibNewPosition) /* [out] */
 470 {
 471   StgStreamImpl* const This=(StgStreamImpl*)iface;
 472
 473   ULARGE_INTEGER newPosition;
 474
 475   TRACE("(%p, %ld, %ld, %p)\n",
 476         iface, dlibMove.u.LowPart, dwOrigin, plibNewPosition);
 477
 478   /*
 479    * fail if the stream has no parent (as does windows)
 480    */
 481
 482   if (!This->parentStorage)
 483     return STG_E_REVERTED;
 484
 485   /*
 486    * The caller is allowed to pass in NULL as the new position return value.
 487    * If it happens, we assign it to a dynamic variable to avoid special cases
 488    * in the code below.
 489    */
 490   if (plibNewPosition == 0)
 491   {
 492     plibNewPosition = &newPosition;
 493   }
 494
 495   /*
 496    * The file pointer is moved depending on the given "function"
 497    * parameter.
 498    */
 499   switch (dwOrigin)
 500   {
 501     case STREAM_SEEK_SET:
 502       plibNewPosition->u.HighPart = 0;
 503       plibNewPosition->u.LowPart  = 0;
 504       break;
 505     case STREAM_SEEK_CUR:
 506       *plibNewPosition = This->currentPosition;
 507       break;
 508     case STREAM_SEEK_END:
 509       *plibNewPosition = This->streamSize;
 510       break;
 511     default:
 512       return STG_E_INVALIDFUNCTION;
 513   }
 514
 515   plibNewPosition->QuadPart = RtlLargeIntegerAdd( plibNewPosition->QuadPart, dlibMove.QuadPart );
 516
 517   /*
 518    * tell the caller what we calculated
 519    */
 520   This->currentPosition = *plibNewPosition;
 521
 522   return S_OK;
 523 }
 524
 525 /***
 526  * This method is part of the IStream interface.
 527  *
 528  * It will change the size of a stream.
 529  *
 530  * TODO: Switch from small blocks to big blocks and vice versa.
 531  *
 532  * See the documentation of IStream for more info.
 533  */
 534 static HRESULT WINAPI StgStreamImpl_SetSize(
 535                                      IStream*      iface,
 536                                      ULARGE_INTEGER  libNewSize)   /* [in] */
 537 {
 538   StgStreamImpl* const This=(StgStreamImpl*)iface;
 539
 540   StgProperty    curProperty;
 541   BOOL         Success;
 542
 543   TRACE("(%p, %ld)\n", iface, libNewSize.u.LowPart);
 544
 545   if(!This->parentStorage)
 546     return STG_E_REVERTED;
 547
 548   /*
 549    * As documented.
 550    */
 551   if (libNewSize.u.HighPart != 0)
 552     return STG_E_INVALIDFUNCTION;
 553
 554   /*
 555    * Do we have permission?
 556    */
 557   if (!(This->grfMode & (STGM_WRITE | STGM_READWRITE)))
 558     return STG_E_ACCESSDENIED;
 559
 560   if (This->streamSize.u.LowPart == libNewSize.u.LowPart)
 561     return S_OK;
 562
 563   /*
 564    * This will happen if we're creating a stream
 565    */
 566   if ((This->smallBlockChain == 0) && (This->bigBlockChain == 0))
 567   {
 568     if (libNewSize.u.LowPart < LIMIT_TO_USE_SMALL_BLOCK)
 569     {
 570       This->smallBlockChain = SmallBlockChainStream_Construct(
 571                                     This->parentStorage->ancestorStorage,
 572                                     This->ownerProperty);
 573     }
 574     else
 575     {
 576       This->bigBlockChain = BlockChainStream_Construct(
 577                                 This->parentStorage->ancestorStorage,
 578                                 NULL,
 579                                 This->ownerProperty);
 580     }
 581   }
 582
 583   /*
 584    * Read this stream's property to see if it's small blocks or big blocks
 585    */
 586   Success = StorageImpl_ReadProperty(This->parentStorage->ancestorStorage,
 587                                        This->ownerProperty,
 588                                        &curProperty);
 589   /*
 590    * Determine if we have to switch from small to big blocks or vice versa
 591    */
 592   if ( (This->smallBlockChain!=0) &&
 593        (curProperty.size.u.LowPart < LIMIT_TO_USE_SMALL_BLOCK) )
 594   {
 595     if (libNewSize.u.LowPart >= LIMIT_TO_USE_SMALL_BLOCK)
 596     {
 597       /*
 598        * Transform the small block chain into a big block chain
 599        */
 600       This->bigBlockChain = Storage32Impl_SmallBlocksToBigBlocks(
 601                                 This->parentStorage->ancestorStorage,
 602                                 &This->smallBlockChain);
 603     }
 604   }
 605
 606   if (This->smallBlockChain!=0)
 607   {
 608     Success = SmallBlockChainStream_SetSize(This->smallBlockChain, libNewSize);
 609   }
 610   else
 611   {
 612     Success = BlockChainStream_SetSize(This->bigBlockChain, libNewSize);
 613   }
 614
 615   /*
 616    * Write the new information about this stream to the property
 617    */
 618   Success = StorageImpl_ReadProperty(This->parentStorage->ancestorStorage,
 619                                        This->ownerProperty,
 620                                        &curProperty);
 621
 622   curProperty.size.u.HighPart = libNewSize.u.HighPart;
 623   curProperty.size.u.LowPart = libNewSize.u.LowPart;
 624
 625   if (Success)
 626   {
 627     StorageImpl_WriteProperty(This->parentStorage->ancestorStorage,
 628                                 This->ownerProperty,
 629                                 &curProperty);
 630   }
 631
 632   This->streamSize = libNewSize;
 633
 634   return S_OK;
 635 }
 636
 637 /***
 638  * This method is part of the IStream interface.
 639  *
 640  * It will copy the 'cb' Bytes to 'pstm' IStream.
 641  *
 642  * See the documentation of IStream for more info.
 643  */
 644 static HRESULT WINAPI StgStreamImpl_CopyTo(
 645                                     IStream*      iface,
 646                                     IStream*      pstm,         /* [unique][in] */
 647                                     ULARGE_INTEGER  cb,           /* [in] */
 648                                     ULARGE_INTEGER* pcbRead,      /* [out] */
 649                                     ULARGE_INTEGER* pcbWritten)   /* [out] */
 650 {
 651   StgStreamImpl* const This=(StgStreamImpl*)iface;
 652   HRESULT        hr = S_OK;
 653   BYTE           tmpBuffer[128];
 654   ULONG          bytesRead, bytesWritten, copySize;
 655   ULARGE_INTEGER totalBytesRead;
 656   ULARGE_INTEGER totalBytesWritten;
 657
 658   TRACE("(%p, %p, %ld, %p, %p)\n",
 659         iface, pstm, cb.u.LowPart, pcbRead, pcbWritten);
 660
 661   /*
 662    * Sanity check
 663    */
 664
 665   if (!This->parentStorage)
 666     return STG_E_REVERTED;
 667
 668   if ( pstm == 0 )
 669     return STG_E_INVALIDPOINTER;
 670
 671   totalBytesRead.u.LowPart = totalBytesRead.u.HighPart = 0;
 672   totalBytesWritten.u.LowPart = totalBytesWritten.u.HighPart = 0;
 673
 674   /*
 675    * use stack to store data temporarily
 676    * there is surely a more performant way of doing it, for now this basic
 677    * implementation will do the job
 678    */
 679   while ( cb.u.LowPart > 0 )
 680   {
 681     if ( cb.u.LowPart >= 128 )
 682       copySize = 128;
 683     else
 684       copySize = cb.u.LowPart;
 685
 686     IStream_Read(iface, tmpBuffer, copySize, &bytesRead);
 687
 688     totalBytesRead.u.LowPart += bytesRead;
 689
 690     IStream_Write(pstm, tmpBuffer, bytesRead, &bytesWritten);
 691
 692     totalBytesWritten.u.LowPart += bytesWritten;
 693
 694     /*
 695      * Check that read & write operations were successful
 696      */
 697     if (bytesRead != bytesWritten)
 698     {
 699       hr = STG_E_MEDIUMFULL;
 700       break;
 701     }
 702
 703     if (bytesRead!=copySize)
 704       cb.u.LowPart = 0;
 705     else
 706       cb.u.LowPart -= bytesRead;
 707   }
 708
 709   /*
 710    * Update number of bytes read and written
 711    */
 712   if (pcbRead)
 713   {
 714     pcbRead->u.LowPart = totalBytesRead.u.LowPart;
 715     pcbRead->u.HighPart = totalBytesRead.u.HighPart;
 716   }
 717
 718   if (pcbWritten)
 719   {
 720     pcbWritten->u.LowPart = totalBytesWritten.u.LowPart;
 721     pcbWritten->u.HighPart = totalBytesWritten.u.HighPart;
 722   }
 723   return hr;
 724 }
 725
 726 /***
 727  * This method is part of the IStream interface.
 728  *
 729  * For streams contained in structured storages, this method
 730  * does nothing. This is what the documentation tells us.
 731  *
 732  * See the documentation of IStream for more info.
 733  */
 734 static HRESULT WINAPI StgStreamImpl_Commit(
 735                   IStream*      iface,
 736                   DWORD           grfCommitFlags)  /* [in] */
 737 {
 738   StgStreamImpl* const This=(StgStreamImpl*)iface;
 739
 740   if (!This->parentStorage)
 741     return STG_E_REVERTED;
 742
 743   return S_OK;
 744 }
 745
 746 /***
 747  * This method is part of the IStream interface.
 748  *
 749  * For streams contained in structured storages, this method
 750  * does nothing. This is what the documentation tells us.
 751  *
 752  * See the documentation of IStream for more info.
 753  */
 754 static HRESULT WINAPI StgStreamImpl_Revert(
 755                   IStream* iface)
 756 {
 757   return S_OK;
 758 }
 759
 760 static HRESULT WINAPI StgStreamImpl_LockRegion(
 761                                         IStream*     iface,
 762                                         ULARGE_INTEGER libOffset,   /* [in] */
 763                                         ULARGE_INTEGER cb,          /* [in] */
 764                                         DWORD          dwLockType)  /* [in] */
 765 {
 766   StgStreamImpl* const This=(StgStreamImpl*)iface;
 767
 768   if (!This->parentStorage)
 769     return STG_E_REVERTED;
 770
 771   FIXME("not implemented!\n");
 772   return E_NOTIMPL;
 773 }
 774
 775 static HRESULT WINAPI StgStreamImpl_UnlockRegion(
 776                                           IStream*     iface,
 777                                           ULARGE_INTEGER libOffset,   /* [in] */
 778                                           ULARGE_INTEGER cb,          /* [in] */
 779                                           DWORD          dwLockType)  /* [in] */
 780 {
 781   StgStreamImpl* const This=(StgStreamImpl*)iface;
 782
 783   if (!This->parentStorage)
 784     return STG_E_REVERTED;
 785
 786   FIXME("not implemented!\n");
 787   return E_NOTIMPL;
 788 }
 789
 790 /***
 791  * This method is part of the IStream interface.
 792  *
 793  * This method returns information about the current
 794  * stream.
 795  *
 796  * See the documentation of IStream for more info.
 797  */
 798 static HRESULT WINAPI StgStreamImpl_Stat(
 799                   IStream*     iface,
 800                   STATSTG*       pstatstg,     /* [out] */
 801                   DWORD          grfStatFlag)  /* [in] */
 802 {
 803   StgStreamImpl* const This=(StgStreamImpl*)iface;
 804
 805   StgProperty    curProperty;
 806   BOOL         readSucessful;
 807
 808   /*
 809    * if stream has no parent, return STG_E_REVERTED
 810    */
 811
 812   if (!This->parentStorage)
 813     return STG_E_REVERTED;
 814
 815   /*
 816    * Read the information from the property.
 817    */
 818   readSucessful = StorageImpl_ReadProperty(This->parentStorage->ancestorStorage,
 819                                              This->ownerProperty,
 820                                              &curProperty);
 821
 822   if (readSucessful)
 823   {
 824     StorageUtl_CopyPropertyToSTATSTG(pstatstg,
 825                                      &curProperty,
 826                                      grfStatFlag);
 827
 828     pstatstg->grfMode = This->grfMode;
 829
 830     return S_OK;
 831   }
 832
 833   return E_FAIL;
 834 }
 835
 836 /***
 837  * This method is part of the IStream interface.
 838  *
 839  * This method returns a clone of the interface that allows for
 840  * another seek pointer
 841  *
 842  * See the documentation of IStream for more info.
 843  *
 844  * I am not totally sure what I am doing here but I presume that this
 845  * should be basically as simple as creating a new stream with the same
 846  * parent etc and positioning its seek cursor.
 847  */
 848 static HRESULT WINAPI StgStreamImpl_Clone(
 849                                    IStream*     iface,
 850                                    IStream**    ppstm) /* [out] */
 851 {
 852   StgStreamImpl* const This=(StgStreamImpl*)iface;
 853   HRESULT hres;
 854   StgStreamImpl* new_stream;
 855   LARGE_INTEGER seek_pos;
 856
 857   /*
 858    * Sanity check
 859    */
 860
 861   if (!This->parentStorage)
 862     return STG_E_REVERTED;
 863
 864   if ( ppstm == 0 )
 865     return STG_E_INVALIDPOINTER;
 866
 867   new_stream = StgStreamImpl_Construct (This->parentStorage, This->grfMode, This->ownerProperty);
 868
 869   if (!new_stream)
 870     return STG_E_INSUFFICIENTMEMORY; /* Currently the only reason for new_stream=0 */
 871
 872   *ppstm = (IStream*) new_stream;
 873   seek_pos.QuadPart = This->currentPosition.QuadPart;
 874
 875   hres=StgStreamImpl_Seek (*ppstm, seek_pos, STREAM_SEEK_SET, NULL);
 876
 877   assert (SUCCEEDED(hres));
 878
 879   return S_OK;
 880 }
 881
 882 /*
 883  * Virtual function table for the StgStreamImpl class.
 884  */
 885 static const IStreamVtbl StgStreamImpl_Vtbl =
 886 {
 887     StgStreamImpl_QueryInterface,
 888     StgStreamImpl_AddRef,
 889     StgStreamImpl_Release,
 890     StgStreamImpl_Read,
 891     StgStreamImpl_Write,
 892     StgStreamImpl_Seek,
 893     StgStreamImpl_SetSize,
 894     StgStreamImpl_CopyTo,
 895     StgStreamImpl_Commit,
 896     StgStreamImpl_Revert,
 897     StgStreamImpl_LockRegion,
 898     StgStreamImpl_UnlockRegion,
 899     StgStreamImpl_Stat,
 900     StgStreamImpl_Clone
 901 };
 902
 903 /******************************************************************************
 904 ** StgStreamImpl implementation
 905 */
 906
 907 /***
 908  * This is the constructor for the StgStreamImpl class.
 909  *
 910  * Params:
 911  *    parentStorage - Pointer to the storage that contains the stream to open
 912  *    ownerProperty - Index of the property that points to this stream.
 913  */
 914 StgStreamImpl* StgStreamImpl_Construct(
 915                 StorageBaseImpl* parentStorage,
 916     DWORD            grfMode,
 917     ULONG            ownerProperty)
 918 {
 919   StgStreamImpl* newStream;
 920
 921   newStream = HeapAlloc(GetProcessHeap(), 0, sizeof(StgStreamImpl));
 922
 923   if (newStream!=0)
 924   {
 925     /*
 926      * Set-up the virtual function table and reference count.
 927      */
 928     newStream->lpVtbl    = &StgStreamImpl_Vtbl;
 929     newStream->ref       = 0;
 930
 931     newStream->parentStorage = parentStorage;
 932
 933     /*
 934      * We want to nail-down the reference to the storage in case the
 935      * stream out-lives the storage in the client application.
 936      *
 937      * -- IStorage_AddRef((IStorage*)newStream->parentStorage);
 938      *
 939      * No, don't do this. Some apps call IStorage_Release without
 940      * calling IStream_Release first. If we grab a reference the
 941      * file is not closed, and the app fails when it tries to
 942      * reopen the file (Easy-PC, for example)
 943      */
 944
 945     newStream->grfMode = grfMode;
 946     newStream->ownerProperty = ownerProperty;
 947
 948     /*
 949      * Start the stream at the beginning.
 950      */
 951     newStream->currentPosition.u.HighPart = 0;
 952     newStream->currentPosition.u.LowPart = 0;
 953
 954     /*
 955      * Initialize the rest of the data.
 956      */
 957     newStream->streamSize.u.HighPart = 0;
 958     newStream->streamSize.u.LowPart  = 0;
 959     newStream->bigBlockChain       = 0;
 960     newStream->smallBlockChain     = 0;
 961
 962     /*
 963      * Read the size from the property and determine if the blocks forming
 964      * this stream are large or small.
 965      */
 966     StgStreamImpl_OpenBlockChain(newStream);
 967   }
 968
 969   return newStream;
 970 }