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