dlls/ole32/memlockbytes.c

   1 /******************************************************************************
   2  *
   3  * Global memory implementation of ILockBytes.
   4  *
   5  * Copyright 1999 Thuy Nguyen
   6  *
   7  */
   8
   9 #include "config.h"
  10
  11 #include <string.h>
  12
  13 #include "windef.h"
  14 #include "objbase.h"
  15 #include "ole2.h"
  16 #include "winbase.h"
  17 #include "winerror.h"
  18
  19 #include "debugtools.h"
  20
  21 DEFAULT_DEBUG_CHANNEL(ole);
  22
  23 /******************************************************************************
  24  * HGLOBALLockBytesImpl definition.
  25  *
  26  * This class imlements the ILockBytes inteface and represents a byte array
  27  * object supported by an HGLOBAL pointer.
  28  */
  29 struct HGLOBALLockBytesImpl
  30 {
  31   /*
  32    * Needs to be the first item in the stuct
  33    * since we want to cast this in an ILockBytes pointer
  34    */
  35   ICOM_VFIELD(ILockBytes);
  36
  37   /*
  38    * Reference count
  39    */
  40   ULONG        ref;
  41
  42   /*
  43    * Support for the LockBytes object
  44    */
  45   HGLOBAL supportHandle;
  46
  47   /*
  48    * This flag is TRUE if the HGLOBAL is destroyed when the object
  49    * is finally released.
  50    */
  51   BOOL    deleteOnRelease;
  52
  53   /*
  54    * Helper variable that contains the size of the byte array
  55    */
  56   ULARGE_INTEGER     byteArraySize;
  57 };
  58
  59 typedef struct HGLOBALLockBytesImpl HGLOBALLockBytesImpl;
  60
  61 /*
  62  * Method definition for the HGLOBALLockBytesImpl class.
  63  */
  64 HGLOBALLockBytesImpl* HGLOBALLockBytesImpl_Construct(
  65     HGLOBAL  hGlobal,
  66     BOOL     fDeleteOnRelease);
  67
  68 void HGLOBALLockBytesImpl_Destroy(HGLOBALLockBytesImpl* This);
  69
  70 HRESULT WINAPI HGLOBALLockBytesImpl_QueryInterface(
  71     ILockBytes*   iface,
  72     REFIID        riid,        /* [in] */
  73     void**        ppvObject);  /* [iid_is][out] */
  74
  75 ULONG WINAPI HGLOBALLockBytesImpl_AddRef(
  76     ILockBytes*   iface);
  77
  78 ULONG WINAPI HGLOBALLockBytesImpl_Release(
  79     ILockBytes*   iface);
  80
  81 HRESULT WINAPI HGLOBALLockBytesImpl_ReadAt(
  82     ILockBytes*    iface,
  83     ULARGE_INTEGER ulOffset,  /* [in] */
  84     void*          pv,        /* [length_is][size_is][out] */
  85     ULONG          cb,        /* [in] */
  86     ULONG*         pcbRead);  /* [out] */
  87
  88 HRESULT WINAPI HGLOBALLockBytesImpl_WriteAt(
  89     ILockBytes*    iface,
  90     ULARGE_INTEGER ulOffset,    /* [in] */
  91     const void*    pv,          /* [size_is][in] */
  92     ULONG          cb,          /* [in] */
  93     ULONG*         pcbWritten); /* [out] */
  94
  95 HRESULT WINAPI HGLOBALLockBytesImpl_Flush(
  96     ILockBytes*     iface);
  97
  98 HRESULT WINAPI HGLOBALLockBytesImpl_SetSize(
  99     ILockBytes*     iface,
 100     ULARGE_INTEGER  libNewSize);  /* [in] */
 101
 102 HRESULT WINAPI HGLOBALLockBytesImpl_LockRegion(
 103     ILockBytes*    iface,
 104     ULARGE_INTEGER libOffset,   /* [in] */
 105     ULARGE_INTEGER cb,          /* [in] */
 106     DWORD          dwLockType); /* [in] */
 107
 108 HRESULT WINAPI HGLOBALLockBytesImpl_UnlockRegion(
 109     ILockBytes*    iface,
 110     ULARGE_INTEGER libOffset,   /* [in] */
 111     ULARGE_INTEGER cb,          /* [in] */
 112     DWORD          dwLockType); /* [in] */
 113
 114 HRESULT WINAPI HGLOBALLockBytesImpl_Stat(
 115     ILockBytes*    iface,
 116     STATSTG*       pstatstg,     /* [out] */
 117     DWORD          grfStatFlag); /* [in]  */
 118
 119 /*
 120  * Virtual function table for the HGLOBALLockBytesImpl class.
 121  */
 122 static ICOM_VTABLE(ILockBytes) HGLOBALLockBytesImpl_Vtbl =
 123 {
 124     ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE
 125     HGLOBALLockBytesImpl_QueryInterface,
 126     HGLOBALLockBytesImpl_AddRef,
 127     HGLOBALLockBytesImpl_Release,
 128     HGLOBALLockBytesImpl_ReadAt,
 129     HGLOBALLockBytesImpl_WriteAt,
 130     HGLOBALLockBytesImpl_Flush,
 131     HGLOBALLockBytesImpl_SetSize,
 132     HGLOBALLockBytesImpl_LockRegion,
 133     HGLOBALLockBytesImpl_UnlockRegion,
 134     HGLOBALLockBytesImpl_Stat,
 135 };
 136
 137 /******************************************************************************
 138  *           CreateILockBytesOnHGlobal     [OLE32.57]
 139  */
 140 HRESULT WINAPI CreateILockBytesOnHGlobal(HGLOBAL      hGlobal,
 141                                          BOOL         fDeleteOnRelease,
 142                                          LPLOCKBYTES* ppLkbyt)
 143 {
 144   HGLOBALLockBytesImpl* newLockBytes;
 145
 146   newLockBytes = HGLOBALLockBytesImpl_Construct(hGlobal, fDeleteOnRelease);
 147
 148   if (newLockBytes != NULL)
 149   {
 150     return IUnknown_QueryInterface((IUnknown*)newLockBytes,
 151                                    &IID_ILockBytes,
 152                                    (void**)ppLkbyt);
 153   }
 154
 155   return E_OUTOFMEMORY;
 156 }
 157
 158 /******************************************************************************
 159  *           GetHGlobalFromILockBytes     [OLE32.70]
 160  */
 161 HRESULT WINAPI GetHGlobalFromILockBytes(ILockBytes* plkbyt, HGLOBAL* phglobal)
 162 {
 163   HGLOBALLockBytesImpl* const pMemLockBytes = (HGLOBALLockBytesImpl*)plkbyt;
 164
 165   if (ICOM_VTBL(pMemLockBytes) == &HGLOBALLockBytesImpl_Vtbl)
 166     *phglobal = pMemLockBytes->supportHandle;
 167   else
 168     *phglobal = 0;
 169
 170   if (*phglobal == 0)
 171     return E_INVALIDARG;
 172
 173   return S_OK;
 174 }
 175
 176 /******************************************************************************
 177  *
 178  * HGLOBALLockBytesImpl implementation
 179  *
 180  */
 181
 182 /******************************************************************************
 183  * This is the constructor for the HGLOBALLockBytesImpl class.
 184  *
 185  * Params:
 186  *    hGlobal          - Handle that will support the stream. can be NULL.
 187  *    fDeleteOnRelease - Flag set to TRUE if the HGLOBAL will be released
 188  *                       when the IStream object is destroyed.
 189  */
 190 HGLOBALLockBytesImpl* HGLOBALLockBytesImpl_Construct(HGLOBAL hGlobal,
 191                                                      BOOL    fDeleteOnRelease)
 192 {
 193   HGLOBALLockBytesImpl* newLockBytes;
 194   newLockBytes = HeapAlloc(GetProcessHeap(), 0, sizeof(HGLOBALLockBytesImpl));
 195
 196   if (newLockBytes!=0)
 197   {
 198     /*
 199      * Set up the virtual function table and reference count.
 200      */
 201     ICOM_VTBL(newLockBytes) = &HGLOBALLockBytesImpl_Vtbl;
 202     newLockBytes->ref    = 0;
 203
 204     /*
 205      * Initialize the support.
 206      */
 207     newLockBytes->supportHandle = hGlobal;
 208     newLockBytes->deleteOnRelease = fDeleteOnRelease;
 209
 210     /*
 211      * This method will allocate a handle if one is not supplied.
 212      */
 213     if (newLockBytes->supportHandle == 0)
 214     {
 215       newLockBytes->supportHandle = GlobalAlloc(GMEM_MOVEABLE |
 216                                                 GMEM_NODISCARD,
 217                                                 0);
 218     }
 219
 220     /*
 221      * Initialize the size of the array to the size of the handle.
 222      */
 223     newLockBytes->byteArraySize.s.HighPart = 0;
 224     newLockBytes->byteArraySize.s.LowPart  = GlobalSize(
 225                                               newLockBytes->supportHandle);
 226   }
 227
 228   return newLockBytes;
 229 }
 230
 231 /******************************************************************************
 232  * This is the destructor of the HGLOBALStreamImpl class.
 233  *
 234  * This method will clean-up all the resources used-up by the given
 235  * HGLOBALLockBytesImpl class. The pointer passed-in to this function will be
 236  * freed and will not be valid anymore.
 237  */
 238 void HGLOBALLockBytesImpl_Destroy(HGLOBALLockBytesImpl* This)
 239 {
 240   /*
 241    * Release the HGlobal if the constructor asked for that.
 242    */
 243   if (This->deleteOnRelease)
 244   {
 245     GlobalFree(This->supportHandle);
 246     This->supportHandle = 0;
 247   }
 248
 249   /*
 250    * Finally, free the memory used-up by the class.
 251    */
 252   HeapFree(GetProcessHeap(), 0, This);
 253 }
 254
 255 /******************************************************************************
 256  * This implements the IUnknown method QueryInterface for this
 257  * class
 258  */
 259 HRESULT WINAPI HGLOBALLockBytesImpl_QueryInterface(
 260       ILockBytes*  iface,
 261       REFIID       riid,        /* [in] */
 262       void**       ppvObject)   /* [iid_is][out] */
 263 {
 264   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 265
 266   /*
 267    * Perform a sanity check on the parameters.
 268    */
 269   if (ppvObject==0)
 270     return E_INVALIDARG;
 271
 272   /*
 273    * Initialize the return parameter.
 274    */
 275   *ppvObject = 0;
 276
 277   /*
 278    * Compare the riid with the interface IDs implemented by this object.
 279    */
 280   if (memcmp(&IID_IUnknown, riid, sizeof(IID_IUnknown)) == 0)
 281   {
 282     *ppvObject = (ILockBytes*)This;
 283   }
 284   else if (memcmp(&IID_ILockBytes, riid, sizeof(IID_ILockBytes)) == 0)
 285   {
 286     *ppvObject = (ILockBytes*)This;
 287   }
 288
 289   /*
 290    * Check that we obtained an interface.
 291    */
 292   if ((*ppvObject)==0)
 293     return E_NOINTERFACE;
 294
 295   /*
 296    * Query Interface always increases the reference count by one when it is
 297    * successful
 298    */
 299   HGLOBALLockBytesImpl_AddRef(iface);
 300
 301   return S_OK;;
 302 }
 303
 304 /******************************************************************************
 305  * This implements the IUnknown method AddRef for this
 306  * class
 307  */
 308 ULONG WINAPI HGLOBALLockBytesImpl_AddRef(ILockBytes* iface)
 309 {
 310   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 311
 312   This->ref++;
 313
 314   return This->ref;
 315 }
 316
 317 /******************************************************************************
 318  * This implements the IUnknown method Release for this
 319  * class
 320  */
 321 ULONG WINAPI HGLOBALLockBytesImpl_Release(ILockBytes* iface)
 322 {
 323   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 324
 325   ULONG newRef;
 326
 327   This->ref--;
 328
 329   newRef = This->ref;
 330
 331   /*
 332    * If the reference count goes down to 0, perform suicide.
 333    */
 334   if (newRef==0)
 335   {
 336     HGLOBALLockBytesImpl_Destroy(This);
 337   }
 338
 339   return newRef;
 340 }
 341
 342 /******************************************************************************
 343  * This method is part of the ILockBytes interface.
 344  *
 345  * It reads a block of information from the byte array at the specified
 346  * offset.
 347  *
 348  * See the documentation of ILockBytes for more info.
 349  */
 350 HRESULT WINAPI HGLOBALLockBytesImpl_ReadAt(
 351       ILockBytes*    iface,
 352       ULARGE_INTEGER ulOffset,  /* [in] */
 353       void*          pv,        /* [length_is][size_is][out] */
 354       ULONG          cb,        /* [in] */
 355       ULONG*         pcbRead)   /* [out] */
 356 {
 357   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 358
 359   void* supportBuffer;
 360   ULONG bytesReadBuffer = 0;
 361   ULONG bytesToReadFromBuffer;
 362
 363   /*
 364    * If the caller is not interested in the number of bytes read,
 365    * we use another buffer to avoid "if" statements in the code.
 366    */
 367   if (pcbRead == 0)
 368     pcbRead = &bytesReadBuffer;
 369
 370   /*
 371    * Make sure the offset is valid.
 372    */
 373   if (ulOffset.s.LowPart > This->byteArraySize.s.LowPart)
 374     return E_FAIL;
 375
 376   /*
 377    * Using the known size of the array, calculate the number of bytes
 378    * to read.
 379    */
 380   bytesToReadFromBuffer = min(This->byteArraySize.s.LowPart -
 381                               ulOffset.s.LowPart, cb);
 382
 383   /*
 384    * Lock the buffer in position and copy the data.
 385    */
 386   supportBuffer = GlobalLock(This->supportHandle);
 387
 388   memcpy(pv,
 389          (char *) supportBuffer + ulOffset.s.LowPart,
 390          bytesToReadFromBuffer);
 391
 392   /*
 393    * Return the number of bytes read.
 394    */
 395   *pcbRead = bytesToReadFromBuffer;
 396
 397   /*
 398    * Cleanup
 399    */
 400   GlobalUnlock(This->supportHandle);
 401
 402   /*
 403    * The function returns S_OK if the specified number of bytes were read
 404    * or the end of the array was reached.
 405    * It returns STG_E_READFAULT if the number of bytes to read does not equal
 406    * the number of bytes actually read.
 407    */
 408   if(*pcbRead == cb)
 409     return S_OK;
 410
 411   return STG_E_READFAULT;
 412 }
 413
 414 /******************************************************************************
 415  * This method is part of the ILockBytes interface.
 416  *
 417  * It writes the specified bytes at the specified offset.
 418  * position. If the array is too small, it will be resized.
 419  *
 420  * See the documentation of ILockBytes for more info.
 421  */
 422 HRESULT WINAPI HGLOBALLockBytesImpl_WriteAt(
 423       ILockBytes*    iface,
 424       ULARGE_INTEGER ulOffset,    /* [in] */
 425       const void*    pv,          /* [size_is][in] */
 426       ULONG          cb,          /* [in] */
 427       ULONG*         pcbWritten)  /* [out] */
 428 {
 429   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 430
 431   void*          supportBuffer;
 432   ULARGE_INTEGER newSize;
 433   ULONG          bytesWritten = 0;
 434
 435   /*
 436    * If the caller is not interested in the number of bytes written,
 437    * we use another buffer to avoid "if" statements in the code.
 438    */
 439   if (pcbWritten == 0)
 440     pcbWritten = &bytesWritten;
 441
 442   if (cb == 0)
 443   {
 444     return S_OK;
 445   }
 446   else
 447   {
 448     newSize.s.HighPart = 0;
 449     newSize.s.LowPart = ulOffset.s.LowPart + cb;
 450   }
 451
 452   /*
 453    * Verify if we need to grow the stream
 454    */
 455   if (newSize.s.LowPart > This->byteArraySize.s.LowPart)
 456   {
 457     /* grow stream */
 458     if (HGLOBALLockBytesImpl_SetSize(iface, newSize) == STG_E_MEDIUMFULL)
 459       return STG_E_MEDIUMFULL;
 460   }
 461
 462   /*
 463    * Lock the buffer in position and copy the data.
 464    */
 465   supportBuffer = GlobalLock(This->supportHandle);
 466
 467   memcpy((char *) supportBuffer + ulOffset.s.LowPart, pv, cb);
 468
 469   /*
 470    * Return the number of bytes written.
 471    */
 472   *pcbWritten = cb;
 473
 474   /*
 475    * Cleanup
 476    */
 477   GlobalUnlock(This->supportHandle);
 478
 479   return S_OK;
 480 }
 481
 482 /******************************************************************************
 483  * This method is part of the ILockBytes interface.
 484  *
 485  * See the documentation of ILockBytes for more info.
 486  */
 487 HRESULT WINAPI HGLOBALLockBytesImpl_Flush(ILockBytes* iface)
 488 {
 489   return S_OK;
 490 }
 491
 492 /******************************************************************************
 493  * This method is part of the ILockBytes interface.
 494  *
 495  * It will change the size of the byte array.
 496  *
 497  * See the documentation of ILockBytes for more info.
 498  */
 499 HRESULT WINAPI HGLOBALLockBytesImpl_SetSize(
 500       ILockBytes*     iface,
 501       ULARGE_INTEGER  libNewSize)   /* [in] */
 502 {
 503   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 504
 505   /*
 506    * As documented.
 507    */
 508   if (libNewSize.s.HighPart != 0)
 509     return STG_E_INVALIDFUNCTION;
 510
 511   if (This->byteArraySize.s.LowPart == libNewSize.s.LowPart)
 512     return S_OK;
 513
 514   /*
 515    * Re allocate the HGlobal to fit the new size of the stream.
 516    */
 517   This->supportHandle = GlobalReAlloc(This->supportHandle,
 518                                       libNewSize.s.LowPart,
 519                                       0);
 520
 521   if (This->supportHandle == 0)
 522     return STG_E_MEDIUMFULL;
 523
 524   This->byteArraySize.s.LowPart = libNewSize.s.LowPart;
 525
 526   return S_OK;
 527 }
 528
 529 /******************************************************************************
 530  * This method is part of the ILockBytes interface.
 531  *
 532  * The global memory implementation of ILockBytes does not support locking.
 533  *
 534  * See the documentation of ILockBytes for more info.
 535  */
 536 HRESULT WINAPI HGLOBALLockBytesImpl_LockRegion(
 537       ILockBytes*    iface,
 538       ULARGE_INTEGER libOffset,   /* [in] */
 539       ULARGE_INTEGER cb,          /* [in] */
 540       DWORD          dwLockType)  /* [in] */
 541 {
 542   return STG_E_INVALIDFUNCTION;
 543 }
 544
 545 /******************************************************************************
 546  * This method is part of the ILockBytes interface.
 547  *
 548  * The global memory implementation of ILockBytes does not support locking.
 549  *
 550  * See the documentation of ILockBytes for more info.
 551  */
 552 HRESULT WINAPI HGLOBALLockBytesImpl_UnlockRegion(
 553       ILockBytes*    iface,
 554       ULARGE_INTEGER libOffset,   /* [in] */
 555       ULARGE_INTEGER cb,          /* [in] */
 556       DWORD          dwLockType)  /* [in] */
 557 {
 558   return STG_E_INVALIDFUNCTION;
 559 }
 560
 561 /******************************************************************************
 562  * This method is part of the ILockBytes interface.
 563  *
 564  * This method returns information about the current
 565  * byte array object.
 566  *
 567  * See the documentation of ILockBytes for more info.
 568  */
 569 HRESULT WINAPI HGLOBALLockBytesImpl_Stat(
 570       ILockBytes*  iface,
 571       STATSTG*     pstatstg,     /* [out] */
 572       DWORD        grfStatFlag)  /* [in] */
 573 {
 574   HGLOBALLockBytesImpl* const This=(HGLOBALLockBytesImpl*)iface;
 575
 576   memset(pstatstg, 0, sizeof(STATSTG));
 577
 578   pstatstg->pwcsName = NULL;
 579   pstatstg->type     = STGTY_LOCKBYTES;
 580   pstatstg->cbSize   = This->byteArraySize;
 581
 582   return S_OK;
 583 }
 584