dlls/ole32/storage32.h

   1 /*
   2  * Compound Storage (32 bit version)
   3  *
   4  * Implemented using the documentation of the LAOLA project at
   5  * <URL:http://wwwwbs.cs.tu-berlin.de/~schwartz/pmh/index.html>
   6  * (Thanks to Martin Schwartz <schwartz@cs.tu-berlin.de>)
   7  *
   8  * This include file contains definitions of types and function
   9  * prototypes that are used in the many files implementing the
  10  * storage functionality
  11  *
  12  * Copyright 1998,1999 Francis Beaudet
  13  * Copyright 1998,1999 Thuy Nguyen
  14  * Copyright 2010 Vincent Povirk for CodeWeavers
  15  *
  16  * This library is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU Lesser General Public
  18  * License as published by the Free Software Foundation; either
  19  * version 2.1 of the License, or (at your option) any later version.
  20  *
  21  * This library is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  24  * Lesser General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU Lesser General Public
  27  * License along with this library; if not, write to the Free Software
  28  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  29  */
  30 #ifndef __STORAGE32_H__
  31 #define __STORAGE32_H__
  32
  33 #include <stdarg.h>
  34
  35 #include "windef.h"
  36 #include "winbase.h"
  37 #include "winnt.h"
  38 #include "objbase.h"
  39 #include "winreg.h"
  40 #include "winternl.h"
  41 #include "wine/list.h"
  42
  43 /*
  44  * Definitions for the file format offsets.
  45  */
  46 static const ULONG OFFSET_MINORVERSION       = 0x00000018;
  47 static const ULONG OFFSET_MAJORVERSION       = 0x0000001a;
  48 static const ULONG OFFSET_BYTEORDERMARKER    = 0x0000001c;
  49 static const ULONG OFFSET_BIGBLOCKSIZEBITS   = 0x0000001e;
  50 static const ULONG OFFSET_SMALLBLOCKSIZEBITS = 0x00000020;
  51 static const ULONG OFFSET_DIRSECTORCOUNT     = 0x00000028;
  52 static const ULONG OFFSET_BBDEPOTCOUNT       = 0x0000002C;
  53 static const ULONG OFFSET_ROOTSTARTBLOCK     = 0x00000030;
  54 static const ULONG OFFSET_SMALLBLOCKLIMIT    = 0x00000038;
  55 static const ULONG OFFSET_SBDEPOTSTART       = 0x0000003C;
  56 static const ULONG OFFSET_SBDEPOTCOUNT       = 0x00000040;
  57 static const ULONG OFFSET_EXTBBDEPOTSTART    = 0x00000044;
  58 static const ULONG OFFSET_EXTBBDEPOTCOUNT    = 0x00000048;
  59 static const ULONG OFFSET_BBDEPOTSTART       = 0x0000004C;
  60 static const ULONG OFFSET_PS_NAME            = 0x00000000;
  61 static const ULONG OFFSET_PS_NAMELENGTH      = 0x00000040;
  62 static const ULONG OFFSET_PS_STGTYPE         = 0x00000042;
  63 static const ULONG OFFSET_PS_LEFTCHILD       = 0x00000044;
  64 static const ULONG OFFSET_PS_RIGHTCHILD      = 0x00000048;
  65 static const ULONG OFFSET_PS_DIRROOT         = 0x0000004C;
  66 static const ULONG OFFSET_PS_GUID            = 0x00000050;
  67 static const ULONG OFFSET_PS_CTIMELOW        = 0x00000064;
  68 static const ULONG OFFSET_PS_CTIMEHIGH       = 0x00000068;
  69 static const ULONG OFFSET_PS_MTIMELOW        = 0x0000006C;
  70 static const ULONG OFFSET_PS_MTIMEHIGH       = 0x00000070;
  71 static const ULONG OFFSET_PS_STARTBLOCK      = 0x00000074;
  72 static const ULONG OFFSET_PS_SIZE            = 0x00000078;
  73 static const WORD  DEF_BIG_BLOCK_SIZE_BITS   = 0x0009;
  74 static const WORD  MIN_BIG_BLOCK_SIZE_BITS   = 0x0009;
  75 static const WORD  MAX_BIG_BLOCK_SIZE_BITS   = 0x000c;
  76 static const WORD  DEF_SMALL_BLOCK_SIZE_BITS = 0x0006;
  77 static const WORD  DEF_BIG_BLOCK_SIZE        = 0x0200;
  78 static const WORD  DEF_SMALL_BLOCK_SIZE      = 0x0040;
  79 static const ULONG BLOCK_EXTBBDEPOT          = 0xFFFFFFFC;
  80 static const ULONG BLOCK_SPECIAL             = 0xFFFFFFFD;
  81 static const ULONG BLOCK_END_OF_CHAIN        = 0xFFFFFFFE;
  82 static const ULONG BLOCK_UNUSED              = 0xFFFFFFFF;
  83 static const ULONG DIRENTRY_NULL             = 0xFFFFFFFF;
  84
  85 #define DIRENTRY_NAME_MAX_LEN    0x20
  86 #define DIRENTRY_NAME_BUFFER_LEN 0x40
  87
  88 #define RAW_DIRENTRY_SIZE 0x00000080
  89
  90 #define HEADER_SIZE 512
  91
  92 #define MIN_BIG_BLOCK_SIZE 0x200
  93 #define MAX_BIG_BLOCK_SIZE 0x1000
  94
  95 /*
  96  * Type of child entry link
  97  */
  98 #define DIRENTRY_RELATION_PREVIOUS 0
  99 #define DIRENTRY_RELATION_NEXT     1
 100 #define DIRENTRY_RELATION_DIR      2
 101
 102 /*
 103  * type constant used in files for the root storage
 104  */
 105 #define STGTY_ROOT 0x05
 106
 107 #define COUNT_BBDEPOTINHEADER    109
 108
 109 /* FIXME: This value is stored in the header, but we hard-code it to 0x1000. */
 110 #define LIMIT_TO_USE_SMALL_BLOCK 0x1000
 111
 112 #define STGM_ACCESS_MODE(stgm)   ((stgm)&0x0000f)
 113 #define STGM_SHARE_MODE(stgm)    ((stgm)&0x000f0)
 114 #define STGM_CREATE_MODE(stgm)   ((stgm)&0x0f000)
 115
 116 #define STGM_KNOWN_FLAGS (0xf0ff | \
 117      STGM_TRANSACTED | STGM_CONVERT | STGM_PRIORITY | STGM_NOSCRATCH | \
 118      STGM_NOSNAPSHOT | STGM_DIRECT_SWMR | STGM_DELETEONRELEASE | STGM_SIMPLE)
 119
 120 /*
 121  * Forward declarations of all the structures used by the storage
 122  * module.
 123  */
 124 typedef struct StorageBaseImpl     StorageBaseImpl;
 125 typedef struct StorageBaseImplVtbl StorageBaseImplVtbl;
 126 typedef struct StorageImpl         StorageImpl;
 127 typedef struct BlockChainStream      BlockChainStream;
 128 typedef struct SmallBlockChainStream SmallBlockChainStream;
 129 typedef struct IEnumSTATSTGImpl      IEnumSTATSTGImpl;
 130 typedef struct DirEntry              DirEntry;
 131 typedef struct StgStreamImpl         StgStreamImpl;
 132
 133 /*
 134  * A reference to a directory entry in the file or a transacted cache.
 135  */
 136 typedef ULONG DirRef;
 137
 138 /*
 139  * This utility structure is used to read/write the information in a directory
 140  * entry.
 141  */
 142 struct DirEntry
 143 {
 144   WCHAR          name[DIRENTRY_NAME_MAX_LEN];
 145   WORD           sizeOfNameString;
 146   BYTE           stgType;
 147   DirRef         leftChild;
 148   DirRef         rightChild;
 149   DirRef         dirRootEntry;
 150   GUID           clsid;
 151   FILETIME       ctime;
 152   FILETIME       mtime;
 153   ULONG          startingBlock;
 154   ULARGE_INTEGER size;
 155 };
 156
 157 HRESULT FileLockBytesImpl_Construct(HANDLE hFile, DWORD openFlags, LPCWSTR pwcsName, ILockBytes **pLockBytes);
 158
 159 /*************************************************************************
 160  * Ole Convert support
 161  */
 162
 163 void OLECONVERT_CreateOleStream(LPSTORAGE pStorage);
 164 HRESULT OLECONVERT_CreateCompObjStream(LPSTORAGE pStorage, LPCSTR strOleTypeName);
 165
 166
 167 /****************************************************************************
 168  * Storage32BaseImpl definitions.
 169  *
 170  * This structure defines the base information contained in all implementations
 171  * of IStorage32 contained in this file storage implementation.
 172  *
 173  * In OOP terms, this is the base class for all the IStorage32 implementations
 174  * contained in this file.
 175  */
 176 struct StorageBaseImpl
 177 {
 178   const IStorageVtbl *lpVtbl;    /* Needs to be the first item in the struct
 179                             * since we want to cast this in a Storage32 pointer */
 180
 181   const IPropertySetStorageVtbl *pssVtbl; /* interface for adding a properties stream */
 182
 183   /*
 184    * Stream tracking list
 185    */
 186
 187   struct list strmHead;
 188
 189   /*
 190    * Storage tracking list
 191    */
 192   struct list storageHead;
 193
 194   /*
 195    * Reference count of this object
 196    */
 197   LONG ref;
 198
 199   /*
 200    * TRUE if this object has been invalidated
 201    */
 202   int reverted;
 203
 204   /*
 205    * Index of the directory entry of this storage
 206    */
 207   DirRef storageDirEntry;
 208
 209   /*
 210    * virtual methods.
 211    */
 212   const StorageBaseImplVtbl *baseVtbl;
 213
 214   /*
 215    * flags that this storage was opened or created with
 216    */
 217   DWORD openFlags;
 218
 219   /*
 220    * State bits appear to only be preserved while running. No in the stream
 221    */
 222   DWORD stateBits;
 223
 224   BOOL             create;     /* Was the storage created or opened.
 225                                   The behaviour of STGM_SIMPLE depends on this */
 226   /*
 227    * If this storage was opened in transacted mode, the object that implements
 228    * the transacted snapshot or cache.
 229    */
 230   StorageBaseImpl *transactedChild;
 231 };
 232
 233 /* virtual methods for StorageBaseImpl objects */
 234 struct StorageBaseImplVtbl {
 235   void (*Destroy)(StorageBaseImpl*);
 236   void (*Invalidate)(StorageBaseImpl*);
 237   HRESULT (*Flush)(StorageBaseImpl*);
 238   HRESULT (*GetFilename)(StorageBaseImpl*,LPWSTR*);
 239   HRESULT (*CreateDirEntry)(StorageBaseImpl*,const DirEntry*,DirRef*);
 240   HRESULT (*WriteDirEntry)(StorageBaseImpl*,DirRef,const DirEntry*);
 241   HRESULT (*ReadDirEntry)(StorageBaseImpl*,DirRef,DirEntry*);
 242   HRESULT (*DestroyDirEntry)(StorageBaseImpl*,DirRef);
 243   HRESULT (*StreamReadAt)(StorageBaseImpl*,DirRef,ULARGE_INTEGER,ULONG,void*,ULONG*);
 244   HRESULT (*StreamWriteAt)(StorageBaseImpl*,DirRef,ULARGE_INTEGER,ULONG,const void*,ULONG*);
 245   HRESULT (*StreamSetSize)(StorageBaseImpl*,DirRef,ULARGE_INTEGER);
 246   HRESULT (*StreamLink)(StorageBaseImpl*,DirRef,DirRef);
 247 };
 248
 249 static inline void StorageBaseImpl_Destroy(StorageBaseImpl *This)
 250 {
 251   This->baseVtbl->Destroy(This);
 252 }
 253
 254 static inline void StorageBaseImpl_Invalidate(StorageBaseImpl *This)
 255 {
 256   This->baseVtbl->Invalidate(This);
 257 }
 258
 259 static inline HRESULT StorageBaseImpl_Flush(StorageBaseImpl *This)
 260 {
 261   return This->baseVtbl->Flush(This);
 262 }
 263
 264 static inline HRESULT StorageBaseImpl_GetFilename(StorageBaseImpl *This, LPWSTR *result)
 265 {
 266   return This->baseVtbl->GetFilename(This, result);
 267 }
 268
 269 static inline HRESULT StorageBaseImpl_CreateDirEntry(StorageBaseImpl *This,
 270   const DirEntry *newData, DirRef *index)
 271 {
 272   return This->baseVtbl->CreateDirEntry(This, newData, index);
 273 }
 274
 275 static inline HRESULT StorageBaseImpl_WriteDirEntry(StorageBaseImpl *This,
 276   DirRef index, const DirEntry *data)
 277 {
 278   return This->baseVtbl->WriteDirEntry(This, index, data);
 279 }
 280
 281 static inline HRESULT StorageBaseImpl_ReadDirEntry(StorageBaseImpl *This,
 282   DirRef index, DirEntry *data)
 283 {
 284   return This->baseVtbl->ReadDirEntry(This, index, data);
 285 }
 286
 287 static inline HRESULT StorageBaseImpl_DestroyDirEntry(StorageBaseImpl *This,
 288   DirRef index)
 289 {
 290   return This->baseVtbl->DestroyDirEntry(This, index);
 291 }
 292
 293 /* Read up to size bytes from this directory entry's stream at the given offset. */
 294 static inline HRESULT StorageBaseImpl_StreamReadAt(StorageBaseImpl *This,
 295   DirRef index, ULARGE_INTEGER offset, ULONG size, void *buffer, ULONG *bytesRead)
 296 {
 297   return This->baseVtbl->StreamReadAt(This, index, offset, size, buffer, bytesRead);
 298 }
 299
 300 /* Write size bytes to this directory entry's stream at the given offset,
 301  * growing the stream if necessary. */
 302 static inline HRESULT StorageBaseImpl_StreamWriteAt(StorageBaseImpl *This,
 303   DirRef index, ULARGE_INTEGER offset, ULONG size, const void *buffer, ULONG *bytesWritten)
 304 {
 305   return This->baseVtbl->StreamWriteAt(This, index, offset, size, buffer, bytesWritten);
 306 }
 307
 308 static inline HRESULT StorageBaseImpl_StreamSetSize(StorageBaseImpl *This,
 309   DirRef index, ULARGE_INTEGER newsize)
 310 {
 311   return This->baseVtbl->StreamSetSize(This, index, newsize);
 312 }
 313
 314 /* Make dst point to the same stream that src points to. Other stream operations
 315  * will not work properly for entries that point to the same stream, so this
 316  * must be a very temporary state, and only one entry pointing to a given stream
 317  * may be reachable at any given time. */
 318 static inline HRESULT StorageBaseImpl_StreamLink(StorageBaseImpl *This,
 319   DirRef dst, DirRef src)
 320 {
 321   return This->baseVtbl->StreamLink(This, dst, src);
 322 }
 323
 324 /****************************************************************************
 325  * StorageBaseImpl stream list handlers
 326  */
 327
 328 void StorageBaseImpl_AddStream(StorageBaseImpl * stg, StgStreamImpl * strm);
 329 void StorageBaseImpl_RemoveStream(StorageBaseImpl * stg, StgStreamImpl * strm);
 330
 331 /* Number of BlockChainStream objects to cache in a StorageImpl */
 332 #define BLOCKCHAIN_CACHE_SIZE 4
 333
 334 /****************************************************************************
 335  * Storage32Impl definitions.
 336  *
 337  * This implementation of the IStorage32 interface represents a root
 338  * storage. Basically, a document file.
 339  */
 340 struct StorageImpl
 341 {
 342   struct StorageBaseImpl base;
 343
 344   /*
 345    * File header
 346    */
 347   WORD  bigBlockSizeBits;
 348   WORD  smallBlockSizeBits;
 349   ULONG bigBlockSize;
 350   ULONG smallBlockSize;
 351   ULONG bigBlockDepotCount;
 352   ULONG rootStartBlock;
 353   ULONG smallBlockLimit;
 354   ULONG smallBlockDepotStart;
 355   ULONG extBigBlockDepotStart;
 356   ULONG *extBigBlockDepotLocations;
 357   ULONG extBigBlockDepotLocationsSize;
 358   ULONG extBigBlockDepotCount;
 359   ULONG bigBlockDepotStart[COUNT_BBDEPOTINHEADER];
 360
 361   ULONG extBlockDepotCached[MAX_BIG_BLOCK_SIZE / 4];
 362   ULONG indexExtBlockDepotCached;
 363
 364   ULONG blockDepotCached[MAX_BIG_BLOCK_SIZE / 4];
 365   ULONG indexBlockDepotCached;
 366   ULONG prevFreeBlock;
 367
 368   /* All small blocks before this one are known to be in use. */
 369   ULONG firstFreeSmallBlock;
 370
 371   /*
 372    * Abstraction of the big block chains for the chains of the header.
 373    */
 374   BlockChainStream* rootBlockChain;
 375   BlockChainStream* smallBlockDepotChain;
 376   BlockChainStream* smallBlockRootChain;
 377
 378   /* Cache of block chain streams objects for directory entries */
 379   BlockChainStream* blockChainCache[BLOCKCHAIN_CACHE_SIZE];
 380   UINT blockChainToEvict;
 381
 382   ILockBytes* lockBytes;
 383 };
 384
 385 HRESULT StorageImpl_ReadRawDirEntry(
 386             StorageImpl *This,
 387             ULONG index,
 388             BYTE *buffer);
 389
 390 void UpdateRawDirEntry(
 391     BYTE *buffer,
 392     const DirEntry *newData);
 393
 394 HRESULT StorageImpl_WriteRawDirEntry(
 395             StorageImpl *This,
 396             ULONG index,
 397             const BYTE *buffer);
 398
 399 HRESULT StorageImpl_ReadDirEntry(
 400             StorageImpl*    This,
 401             DirRef          index,
 402             DirEntry*       buffer);
 403
 404 HRESULT StorageImpl_WriteDirEntry(
 405             StorageImpl*        This,
 406             DirRef              index,
 407             const DirEntry*     buffer);
 408
 409 BlockChainStream* Storage32Impl_SmallBlocksToBigBlocks(
 410                       StorageImpl* This,
 411                       SmallBlockChainStream** ppsbChain);
 412
 413 SmallBlockChainStream* Storage32Impl_BigBlocksToSmallBlocks(
 414                       StorageImpl* This,
 415                       BlockChainStream** ppbbChain,
 416                       ULARGE_INTEGER newSize);
 417
 418 /****************************************************************************
 419  * StgStreamImpl definitions.
 420  *
 421  * This class implements the IStream32 interface and represents a stream
 422  * located inside a storage object.
 423  */
 424 struct StgStreamImpl
 425 {
 426   const IStreamVtbl *lpVtbl;  /* Needs to be the first item in the struct
 427                          * since we want to cast this to an IStream pointer */
 428
 429   /*
 430    * We are an entry in the storage object's stream handler list
 431    */
 432
 433   struct list StrmListEntry;
 434
 435   /*
 436    * Reference count
 437    */
 438   LONG               ref;
 439
 440   /*
 441    * Storage that is the parent(owner) of the stream
 442    */
 443   StorageBaseImpl* parentStorage;
 444
 445   /*
 446    * Access mode of this stream.
 447    */
 448   DWORD grfMode;
 449
 450   /*
 451    * Index of the directory entry that owns (points to) this stream.
 452    */
 453   DirRef             dirEntry;
 454
 455   /*
 456    * This is the current position of the cursor in the stream
 457    */
 458   ULARGE_INTEGER     currentPosition;
 459 };
 460
 461 /*
 462  * Method definition for the StgStreamImpl class.
 463  */
 464 StgStreamImpl* StgStreamImpl_Construct(
 465                 StorageBaseImpl* parentStorage,
 466     DWORD            grfMode,
 467     DirRef           dirEntry);
 468
 469
 470 /******************************************************************************
 471  * Endian conversion macros
 472  */
 473 #ifdef WORDS_BIGENDIAN
 474
 475 #define htole32(x) RtlUlongByteSwap(x)
 476 #define htole16(x) RtlUshortByteSwap(x)
 477 #define lendian32toh(x) RtlUlongByteSwap(x)
 478 #define lendian16toh(x) RtlUshortByteSwap(x)
 479
 480 #else
 481
 482 #define htole32(x) (x)
 483 #define htole16(x) (x)
 484 #define lendian32toh(x) (x)
 485 #define lendian16toh(x) (x)
 486
 487 #endif
 488
 489 /******************************************************************************
 490  * The StorageUtl_ functions are miscellaneous utility functions. Most of which
 491  * are abstractions used to read values from file buffers without having to
 492  * worry about bit order
 493  */
 494 void StorageUtl_ReadWord(const BYTE* buffer, ULONG offset, WORD* value);
 495 void StorageUtl_WriteWord(BYTE* buffer, ULONG offset, WORD value);
 496 void StorageUtl_ReadDWord(const BYTE* buffer, ULONG offset, DWORD* value);
 497 void StorageUtl_WriteDWord(BYTE* buffer, ULONG offset, DWORD value);
 498 void StorageUtl_ReadULargeInteger(const BYTE* buffer, ULONG offset,
 499  ULARGE_INTEGER* value);
 500 void StorageUtl_WriteULargeInteger(BYTE* buffer, ULONG offset,
 501  const ULARGE_INTEGER *value);
 502 void StorageUtl_ReadGUID(const BYTE* buffer, ULONG offset, GUID* value);
 503 void StorageUtl_WriteGUID(BYTE* buffer, ULONG offset, const GUID* value);
 504 void StorageUtl_CopyDirEntryToSTATSTG(StorageBaseImpl *storage,STATSTG* destination,
 505  const DirEntry* source, int statFlags);
 506
 507 /****************************************************************************
 508  * BlockChainStream definitions.
 509  *
 510  * The BlockChainStream class is a utility class that is used to create an
 511  * abstraction of the big block chains in the storage file.
 512  */
 513 struct BlockChainRun
 514 {
 515   /* This represents a range of blocks that happen reside in consecutive sectors. */
 516   ULONG firstSector;
 517   ULONG firstOffset;
 518   ULONG lastOffset;
 519 };
 520
 521 typedef struct BlockChainBlock
 522 {
 523   ULONG index;
 524   ULONG sector;
 525   int read;
 526   int dirty;
 527   BYTE data[MAX_BIG_BLOCK_SIZE];
 528 } BlockChainBlock;
 529
 530 struct BlockChainStream
 531 {
 532   StorageImpl* parentStorage;
 533   ULONG*       headOfStreamPlaceHolder;
 534   DirRef       ownerDirEntry;
 535   struct BlockChainRun* indexCache;
 536   ULONG        indexCacheLen;
 537   ULONG        indexCacheSize;
 538   BlockChainBlock cachedBlocks[2];
 539   ULONG        blockToEvict;
 540   ULONG        tailIndex;
 541   ULONG        numBlocks;
 542 };
 543
 544 /*
 545  * Methods for the BlockChainStream class.
 546  */
 547 BlockChainStream* BlockChainStream_Construct(
 548                 StorageImpl* parentStorage,
 549                 ULONG*         headOfStreamPlaceHolder,
 550                 DirRef         dirEntry);
 551
 552 void BlockChainStream_Destroy(
 553                 BlockChainStream* This);
 554
 555 HRESULT BlockChainStream_ReadAt(
 556                 BlockChainStream* This,
 557                 ULARGE_INTEGER offset,
 558                 ULONG          size,
 559                 void*          buffer,
 560                 ULONG*         bytesRead);
 561
 562 HRESULT BlockChainStream_WriteAt(
 563                 BlockChainStream* This,
 564                 ULARGE_INTEGER offset,
 565                 ULONG          size,
 566                 const void*    buffer,
 567                 ULONG*         bytesWritten);
 568
 569 BOOL BlockChainStream_SetSize(
 570                 BlockChainStream* This,
 571                 ULARGE_INTEGER    newSize);
 572
 573 HRESULT BlockChainStream_Flush(
 574                 BlockChainStream* This);
 575
 576 /****************************************************************************
 577  * SmallBlockChainStream definitions.
 578  *
 579  * The SmallBlockChainStream class is a utility class that is used to create an
 580  * abstraction of the small block chains in the storage file.
 581  */
 582 struct SmallBlockChainStream
 583 {
 584   StorageImpl* parentStorage;
 585   DirRef         ownerDirEntry;
 586   ULONG*         headOfStreamPlaceHolder;
 587 };
 588
 589 /*
 590  * Methods of the SmallBlockChainStream class.
 591  */
 592 SmallBlockChainStream* SmallBlockChainStream_Construct(
 593            StorageImpl*   parentStorage,
 594            ULONG*         headOfStreamPlaceHolder,
 595            DirRef         dirEntry);
 596
 597 void SmallBlockChainStream_Destroy(
 598                SmallBlockChainStream* This);
 599
 600 HRESULT SmallBlockChainStream_ReadAt(
 601                SmallBlockChainStream* This,
 602                ULARGE_INTEGER offset,
 603                ULONG          size,
 604                void*          buffer,
 605                ULONG*         bytesRead);
 606
 607 HRESULT SmallBlockChainStream_WriteAt(
 608                SmallBlockChainStream* This,
 609                ULARGE_INTEGER offset,
 610                ULONG          size,
 611                const void*    buffer,
 612                ULONG*         bytesWritten);
 613
 614 BOOL SmallBlockChainStream_SetSize(
 615                SmallBlockChainStream* This,
 616                ULARGE_INTEGER          newSize);
 617
 618
 619 #endif /* __STORAGE32_H__ */