reactos/lib/ole32/memlockbytes.c

   1 /******************************************************************************
   2  *
   3  * Global memory implementation of ILockBytes.
   4  *
   5  * Copyright 1999 Thuy Nguyen
   6  *
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12
  13 #include <windows.h>
  14 #include <ole32/ole32.h>
  15 #include <compobj.h>
  16 #include <storage32.h>
  17
  18 #include <debug.h>
  19
  20 /******************************************************************************
  21  * HGLOBALLockBytesImpl definition.
  22  *
  23  * This class imlements the ILockBytes inteface and represents a byte array
  24  * object supported by an HGLOBAL pointer.
  25  */
  26 struct HGLOBALLockBytesImpl
  27 {
  28   /*
  29    * Needs to be the first item in the stuct
  30    * since we want to cast this in an ILockBytes pointer
  31    */
  32   ICOM_VFIELD(ILockBytes);
  33
  34   /*
  35    * Reference count
  36    */
  37   ULONG        ref;
  38
  39   /*
  40    * Support for the LockBytes object
  41    */
  42   HGLOBAL supportHandle;
  43
  44   /*
  45    * This flag is TRUE if the HGLOBAL is destroyed when the object
  46    * is finally released.
  47    */
  48   BOOL    deleteOnRelease;
  49
  50   /*
  51    * Helper variable that contains the size of the byte array
  52    */
  53   ULARGE_INTEGER     byteArraySize;
  54 };
  55
  56 typedef struct HGLOBALLockBytesImpl HGLOBALLockBytesImpl;
  57
  58 /*
  59  * Method definition for the HGLOBALLockBytesImpl class.
  60  */
  61 HGLOBALLockBytesImpl* HGLOBALLockBytesImpl_Construct(
  62     HGLOBAL  hGlobal,
  63     BOOL     fDeleteOnRelease);
  64
  65 void HGLOBALLockBytesImpl_Destroy(HGLOBALLockBytesImpl* This);
  66
  67 HRESULT WINAPI HGLOBALLockBytesImpl_QueryInterface(
  68     ILockBytes*   iface,
  69     REFIID        riid,        /* [in] */
  70     void**        ppvObject);  /* [iid_is][out] */
  71
  72 ULONG WINAPI HGLOBALLockBytesImpl_AddRef(
  73     ILockBytes*   iface);
  74
  75 ULONG WINAPI HGLOBALLockBytesImpl_Release(
  76     ILockBytes*   iface);
  77
  78 HRESULT WINAPI HGLOBALLockBytesImpl_ReadAt(
  79     ILockBytes*    iface,
  80     ULARGE_INTEGER ulOffset,  /* [in] */
  81     void*          pv,        /* [length_is][size_is][out] */
  82     ULONG          cb,        /* [in] */
  83     ULONG*         pcbRead);  /* [out] */
  84
  85 HRESULT WINAPI HGLOBALLockBytesImpl_WriteAt(
  86     ILockBytes*    iface,
  87     ULARGE_INTEGER ulOffset,    /* [in] */
  88     const void*    pv,          /* [size_is][in] */
  89     ULONG          cb,          /* [in] */
  90     ULONG*         pcbWritten); /* [out] */
  91
  92 HRESULT WINAPI HGLOBALLockBytesImpl_Flush(
  93     ILockBytes*     iface);
  94
  95 HRESULT WINAPI HGLOBALLockBytesImpl_SetSize(
  96     ILockBytes*     iface,
  97     ULARGE_INTEGER  libNewSize);  /* [in] */
  98
  99 HRESULT WINAPI HGLOBALLockBytesImpl_LockRegion(
 100     ILockBytes*    iface,
 101     ULARGE_INTEGER libOffset,   /* [in] */
 102     ULARGE_INTEGER cb,          /* [in] */
 103     DWORD          dwLockType); /* [in] */
 104
 105 HRESULT WINAPI HGLOBALLockBytesImpl_UnlockRegion(
 106     ILockBytes*    iface,
 107     ULARGE_INTEGER libOffset,   /* [in] */
 108     ULARGE_INTEGER cb,          /* [in] */
 109     DWORD          dwLockType); /* [in] */
 110
 111 HRESULT WINAPI HGLOBALLockBytesImpl_Stat(
 112     ILockBytes*    iface,
 113     STATSTG*       pstatstg,     /* [out] */
 114     DWORD          grfStatFlag); /* [in]  */
 115
 116 /*
 117  * Virtual function table for the HGLOBALLockBytesImpl class.
 118  */
 119 static ICOM_VTABLE(ILockBytes) HGLOBALLockBytesImpl_Vtbl =
 120 {
 121     ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE
 122     HGLOBALLockBytesImpl_QueryInterface,
 123     HGLOBALLockBytesImpl_AddRef,
 124     HGLOBALLockBytesImpl_Release,
 125     HGLOBALLockBytesImpl_ReadAt,
 126     HGLOBALLockBytesImpl_WriteAt,
 127     HGLOBALLockBytesImpl_Flush,
 128     HGLOBALLockBytesImpl_SetSize,
 129     HGLOBALLockBytesImpl_LockRegion,
 130     HGLOBALLockBytesImpl_UnlockRegion,
 131     HGLOBALLockBytesImpl_Stat,
 132 };
 133
 134 /******************************************************************************
 135  *           CreateILockBytesOnHGlobal     [OLE32.57]
 136  */
 137 HRESULT WINAPI CreateILockBytesOnHGlobal(HGLOBAL      hGlobal,
 138                                          BOOL         fDeleteOnRelease,
 139                                          LPLOCKBYTES* ppLkbyt)
 140 {
 141   HGLOBALLockBytesImpl* newLockBytes;
 142
 143   newLockBytes = HGLOBALLockBytesImpl_Construct(hGlobal, fDeleteOnRelease);
 144
 145   if (newLockBytes != NULL)
 146   {
 147     return IUnknown_QueryInterface((IUnknown*)newLockBytes,
 148                                    &IID_ILockBytes,
 149                                    (void**)ppLkbyt);
 150   }
 151
 152   return E_OUTOFMEMORY;
 153 }
 154
 155 /******************************************************************************
 156  *           GetHGlobalFromILockBytes     [OLE32.70]
 157  */
 158 HRESULT WINAPI GetHGlobalFromILockBytes(ILockBytes* plkbyt, HGLOBAL* phglobal)
 159 {
 160   HGLOBALLockBytesImpl* const pMemLockBytes = (HGLOBALLockBytesImpl*)plkbyt;
 161
 162   if (ICOM_VTBL(pMemLockBytes) == &HGLOBALLockBytesImpl_Vtbl)
 163     *phglobal = pMemLockBytes->supportHandle;
 164   else
 165     *phglobal = 0;
 166
 167   if (*phglobal == 0)
 168     return E_INVALIDARG;
 169
 170   return S_OK;
 171 }
 172
 173 /******************************************************************************
 174  *
 175  * HGLOBALLockBytesImpl implementation
 176  *
 177  */
 178
 179 /******************************************************************************
 180  * This is the constructor for the HGLOBALLockBytesImpl class.
 181  *
 182  * Params:
 183  *    hGlobal          - Handle that will support the stream. can be NULL.
 184  *    fDeleteOnRelease - Flag set to TRUE if the HGLOBAL will be released
 185  *                       when the IStream object is destroyed.
 186  */
 187 HGLOBALLockBytesImpl* HGLOBALLockBytesImpl_Construct(HGLOBAL hGlobal,
 188                                                      BOOL    fDeleteOnRelease)
 189 {
 190   HGLOBALLockBytesImpl* newLockBytes;
 191   newLockBytes = HeapAlloc(GetProcessHeap(), 0, sizeof(HGLOBALLockBytesImpl));
 192
 193   if (newLockBytes!=0)
 194   {
 195     /*
 196      * Set up the virtual function table and reference count.
 197      */
 198     ICOM_VTBL(newLockBytes) = &HGLOBALLockBytesImpl_Vtbl;
 199     newLockBytes->ref    = 0;
 200
 201     /*
 202      * Initialize the support.
 203      */
 204     newLockBytes->supportHandle = hGlobal;
 205     newLockBytes->deleteOnRelease = fDeleteOnRelease;
 206
 207     /*
 208      * This method will allocate a handle if one is not supplied.
 209      */
 210     if (newLockBytes->supportHandle == 0)
 211     {
 212       newLockBytes->supportHandle = GlobalAlloc(GMEM_MOVEABLE |
 213                                                 GMEM_NODISCARD,
 214                                                 0);
 215     }
 216
 217     /*
 218      * Initialize the size of the array to the size of the handle.
 219      */
 220     newLockBytes->byteArraySize.u.HighPart = 0;
 221     newLockBytes->byteArraySize.u.LowPart  = GlobalSize(
 222                                               newLockBytes->supportHandle);
 223   }
 224
 225   return newLockBytes;
 226 }
 227
 228 /******************************************************************************
 229  * This is the destructor of the HGLOBALStreamImpl class.
 230  *
 231  * This method will clean-up all the resources used-up by the given
 232  * HGLOBALLockBytesImpl class. The pointer passed-in to this function will be
 233  * freed and will not be valid anymore.
 234  */
 235 void HGLOBALLockBytesImpl_Destroy(HGLOBALLockBytesImpl* This)
 236 {
 237   /*
 238    * Release the HGlobal if the constructor asked for that.
 239    */
 240   if (This->deleteOnRelease)
 241   {
 242     GlobalFree(This->supportHandle);
 243     This->supportHandle = 0;
 244   }
 245
 246   /*
 247    * Finally, free the memory used-up by the class.
 248    */
 249   HeapFree(GetProcessHeap(), 0, This);
 250 }
 251
 252 /******************************************************************************
 253  * This implements the IUnknown method QueryInterface for this
 254  * class
 255  */
 256 HRESULT WINAPI HGLOBALLockBytesImpl_QueryInterface(
 257       ILockBytes*  iface,
 258       REFIID       riid,        /* [in] */
 259       void**       ppvObject)   /* [iid_is][out] */
 260 {
 261   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 262
 263   /*
 264    * Perform a sanity check on the parameters.
 265    */
 266   if (ppvObject==0)
 267     return E_INVALIDARG;
 268
 269   /*
 270    * Initialize the return parameter.
 271    */
 272   *ppvObject = 0;
 273
 274   /*
 275    * Compare the riid with the interface IDs implemented by this object.
 276    */
 277   if (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
 278   {
 279     *ppvObject = (ILockBytes*)This;
 280   }
 281   else if (memcmp(&IID_ILockBytes, riid, sizeof(IID_ILockBytes)) == 0)
 282   {
 283     *ppvObject = (ILockBytes*)This;
 284   }
 285
 286   /*
 287    * Check that we obtained an interface.
 288    */
 289   if ((*ppvObject)==0)
 290     return E_NOINTERFACE;
 291
 292   /*
 293    * Query Interface always increases the reference count by one when it is
 294    * successful
 295    */
 296   HGLOBALLockBytesImpl_AddRef(iface);
 297
 298   return S_OK;;
 299 }
 300
 301 /******************************************************************************
 302  * This implements the IUnknown method AddRef for this
 303  * class
 304  */
 305 ULONG WINAPI HGLOBALLockBytesImpl_AddRef(ILockBytes* iface)
 306 {
 307   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 308
 309   This->ref++;
 310
 311   return This->ref;
 312 }
 313
 314 /******************************************************************************
 315  * This implements the IUnknown method Release for this
 316  * class
 317  */
 318 ULONG WINAPI HGLOBALLockBytesImpl_Release(ILockBytes* iface)
 319 {
 320   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 321
 322   ULONG newRef;
 323
 324   This->ref--;
 325
 326   newRef = This->ref;
 327
 328   /*
 329    * If the reference count goes down to 0, perform suicide.
 330    */
 331   if (newRef==0)
 332   {
 333     HGLOBALLockBytesImpl_Destroy(This);
 334   }
 335
 336   return newRef;
 337 }
 338
 339 /******************************************************************************
 340  * This method is part of the ILockBytes interface.
 341  *
 342  * It reads a block of information from the byte array at the specified
 343  * offset.
 344  *
 345  * See the documentation of ILockBytes for more info.
 346  */
 347 HRESULT WINAPI HGLOBALLockBytesImpl_ReadAt(
 348       ILockBytes*    iface,
 349       ULARGE_INTEGER ulOffset,  /* [in] */
 350       void*          pv,        /* [length_is][size_is][out] */
 351       ULONG          cb,        /* [in] */
 352       ULONG*         pcbRead)   /* [out] */
 353 {
 354   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 355
 356   void* supportBuffer;
 357   ULONG bytesReadBuffer = 0;
 358   ULONG bytesToReadFromBuffer;
 359
 360   /*
 361    * If the caller is not interested in the number of bytes read,
 362    * we use another buffer to avoid "if" statements in the code.
 363    */
 364   if (pcbRead == 0)
 365     pcbRead = &bytesReadBuffer;
 366
 367   /*
 368    * Make sure the offset is valid.
 369    */
 370   if (ulOffset.u.LowPart > This->byteArraySize.u.LowPart)
 371     return E_FAIL;
 372
 373   /*
 374    * Using the known size of the array, calculate the number of bytes
 375    * to read.
 376    */
 377   bytesToReadFromBuffer = min(This->byteArraySize.u.LowPart -
 378                               ulOffset.u.LowPart, cb);
 379
 380   /*
 381    * Lock the buffer in position and copy the data.
 382    */
 383   supportBuffer = GlobalLock(This->supportHandle);
 384
 385   memcpy(pv,
 386          (char *) supportBuffer + ulOffset.u.LowPart,
 387          bytesToReadFromBuffer);
 388
 389   /*
 390    * Return the number of bytes read.
 391    */
 392   *pcbRead = bytesToReadFromBuffer;
 393
 394   /*
 395    * Cleanup
 396    */
 397   GlobalUnlock(This->supportHandle);
 398
 399   /*
 400    * The function returns S_OK if the specified number of bytes were read
 401    * or the end of the array was reached.
 402    * It returns STG_E_READFAULT if the number of bytes to read does not equal
 403    * the number of bytes actually read.
 404    */
 405   if(*pcbRead == cb)
 406     return S_OK;
 407
 408   return STG_E_READFAULT;
 409 }
 410
 411 /******************************************************************************
 412  * This method is part of the ILockBytes interface.
 413  *
 414  * It writes the specified bytes at the specified offset.
 415  * position. If the array is too small, it will be resized.
 416  *
 417  * See the documentation of ILockBytes for more info.
 418  */
 419 HRESULT WINAPI HGLOBALLockBytesImpl_WriteAt(
 420       ILockBytes*    iface,
 421       ULARGE_INTEGER ulOffset,    /* [in] */
 422       const void*    pv,          /* [size_is][in] */
 423       ULONG          cb,          /* [in] */
 424       ULONG*         pcbWritten)  /* [out] */
 425 {
 426   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 427
 428   void*          supportBuffer;
 429   ULARGE_INTEGER newSize;
 430   ULONG          bytesWritten = 0;
 431
 432   /*
 433    * If the caller is not interested in the number of bytes written,
 434    * we use another buffer to avoid "if" statements in the code.
 435    */
 436   if (pcbWritten == 0)
 437     pcbWritten = &bytesWritten;
 438
 439   if (cb == 0)
 440   {
 441     return S_OK;
 442   }
 443   else
 444   {
 445     newSize.u.HighPart = 0;
 446     newSize.u.LowPart = ulOffset.u.LowPart + cb;
 447   }
 448
 449   /*
 450    * Verify if we need to grow the stream
 451    */
 452   if (newSize.u.LowPart > This->byteArraySize.u.LowPart)
 453   {
 454     /* grow stream */
 455     if (HGLOBALLockBytesImpl_SetSize(iface, newSize) == STG_E_MEDIUMFULL)
 456       return STG_E_MEDIUMFULL;
 457   }
 458
 459   /*
 460    * Lock the buffer in position and copy the data.
 461    */
 462   supportBuffer = GlobalLock(This->supportHandle);
 463
 464   memcpy((char *) supportBuffer + ulOffset.u.LowPart, pv, cb);
 465
 466   /*
 467    * Return the number of bytes written.
 468    */
 469   *pcbWritten = cb;
 470
 471   /*
 472    * Cleanup
 473    */
 474   GlobalUnlock(This->supportHandle);
 475
 476   return S_OK;
 477 }
 478
 479 /******************************************************************************
 480  * This method is part of the ILockBytes interface.
 481  *
 482  * See the documentation of ILockBytes for more info.
 483  */
 484 HRESULT WINAPI HGLOBALLockBytesImpl_Flush(ILockBytes* iface)
 485 {
 486   return S_OK;
 487 }
 488
 489 /******************************************************************************
 490  * This method is part of the ILockBytes interface.
 491  *
 492  * It will change the size of the byte array.
 493  *
 494  * See the documentation of ILockBytes for more info.
 495  */
 496 HRESULT WINAPI HGLOBALLockBytesImpl_SetSize(
 497       ILockBytes*     iface,
 498       ULARGE_INTEGER  libNewSize)   /* [in] */
 499 {
 500   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 501
 502   /*
 503    * As documented.
 504    */
 505   if (libNewSize.u.HighPart != 0)
 506     return STG_E_INVALIDFUNCTION;
 507
 508   if (This->byteArraySize.u.LowPart == libNewSize.u.LowPart)
 509     return S_OK;
 510
 511   /*
 512    * Re allocate the HGlobal to fit the new size of the stream.
 513    */
 514   This->supportHandle = GlobalReAlloc(This->supportHandle,
 515                                       libNewSize.u.LowPart,
 516                                       0);
 517
 518   if (This->supportHandle == 0)
 519     return STG_E_MEDIUMFULL;
 520
 521   This->byteArraySize.u.LowPart = libNewSize.u.LowPart;
 522
 523   return S_OK;
 524 }
 525
 526 /******************************************************************************
 527  * This method is part of the ILockBytes interface.
 528  *
 529  * The global memory implementation of ILockBytes does not support locking.
 530  *
 531  * See the documentation of ILockBytes for more info.
 532  */
 533 HRESULT WINAPI HGLOBALLockBytesImpl_LockRegion(
 534       ILockBytes*    iface,
 535       ULARGE_INTEGER libOffset,   /* [in] */
 536       ULARGE_INTEGER cb,          /* [in] */
 537       DWORD          dwLockType)  /* [in] */
 538 {
 539   return STG_E_INVALIDFUNCTION;
 540 }
 541
 542 /******************************************************************************
 543  * This method is part of the ILockBytes interface.
 544  *
 545  * The global memory implementation of ILockBytes does not support locking.
 546  *
 547  * See the documentation of ILockBytes for more info.
 548  */
 549 HRESULT WINAPI HGLOBALLockBytesImpl_UnlockRegion(
 550       ILockBytes*    iface,
 551       ULARGE_INTEGER libOffset,   /* [in] */
 552       ULARGE_INTEGER cb,          /* [in] */
 553       DWORD          dwLockType)  /* [in] */
 554 {
 555   return STG_E_INVALIDFUNCTION;
 556 }
 557
 558 /******************************************************************************
 559  * This method is part of the ILockBytes interface.
 560  *
 561  * This method returns information about the current
 562  * byte array object.
 563  *
 564  * See the documentation of ILockBytes for more info.
 565  */
 566 HRESULT WINAPI HGLOBALLockBytesImpl_Stat(
 567       ILockBytes*  iface,
 568       STATSTG*     pstatstg,     /* [out] */
 569       DWORD        grfStatFlag)  /* [in] */
 570 {
 571   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 572
 573   memset(pstatstg, 0, sizeof(STATSTG));
 574
 575   pstatstg->pwcsName = NULL;
 576   pstatstg->type     = STGTY_LOCKBYTES;
 577   pstatstg->cbSize   = This->byteArraySize;
 578
 579   return S_OK;
 580 }
 581