2 * SHLWAPI DataBlock List functions
4 * Copyright 2002 Jon Griffiths
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
30 #include "wine/debug.h"
32 WINE_DEFAULT_DEBUG_CHANNEL(shell);
34 /* dwSignature for contained DATABLOCK_HEADER items */
35 #define CLIST_ID_CONTAINER (~0U)
37 /*************************************************************************
40 * Internal helper: move a DataBlock pointer to the next item.
42 static inline LPDATABLOCK_HEADER NextItem(LPDBLIST lpList)
44 char* address = (char*)lpList;
45 address += lpList->cbSize;
46 return (LPDATABLOCK_HEADER)address;
49 /*************************************************************************
52 * Insert a new item into a DataBlock list.
55 * lppList [0] Pointer to the List
56 * lpNewItem [I] The new item to add to the list
59 * Success: S_OK. The item is added to the list.
60 * Failure: An HRESULT error code.
63 * If the size of the element to be inserted is less than the size of a
64 * DATABLOCK_HEADER node, or the Id for the item is CLIST_ID_CONTAINER,
65 * the call returns S_OK but does not actually add the element.
66 * See SHWriteDataBlockList.
68 HRESULT WINAPI SHAddDataBlock(LPDBLIST* lppList, const DATABLOCK_HEADER *lpNewItem)
70 LPDATABLOCK_HEADER lpInsertAt = NULL;
73 TRACE("(%p,%p)\n", lppList, lpNewItem);
75 if(!lppList || !lpNewItem )
78 if (lpNewItem->cbSize < sizeof(DATABLOCK_HEADER) ||
79 lpNewItem->dwSignature == CLIST_ID_CONTAINER)
82 ulSize = lpNewItem->cbSize;
86 /* Tune size to a ULONG boundary, add space for container element */
87 ulSize = ((ulSize + 0x3) & 0xFFFFFFFC) + sizeof(DATABLOCK_HEADER);
88 TRACE("Creating container item, new size = %d\n", ulSize);
93 /* An empty list. Allocate space for terminal ulSize also */
94 *lppList = (LPDATABLOCK_HEADER)LocalAlloc(LMEM_ZEROINIT,
95 ulSize + sizeof(ULONG));
96 lpInsertAt = *lppList;
100 /* Append to the end of the list */
101 ULONG ulTotalSize = 0;
102 LPDATABLOCK_HEADER lpIter = *lppList;
104 /* Iterate to the end of the list, calculating the total size */
105 while (lpIter->cbSize)
107 ulTotalSize += lpIter->cbSize;
108 lpIter = NextItem(lpIter);
111 /* Increase the size of the list */
112 lpIter = (LPDATABLOCK_HEADER)LocalReAlloc((HLOCAL)*lppList,
113 ulTotalSize + ulSize+sizeof(ULONG),
114 LMEM_ZEROINIT | LMEM_MOVEABLE);
118 lpInsertAt = (LPDATABLOCK_HEADER)((char*)lpIter + ulTotalSize); /* At end */
124 /* Copy in the new item */
125 LPDATABLOCK_HEADER lpDest = lpInsertAt;
127 if(ulSize != lpNewItem->cbSize)
129 lpInsertAt->cbSize = ulSize;
130 lpInsertAt->dwSignature = CLIST_ID_CONTAINER;
133 memcpy(lpDest, lpNewItem, lpNewItem->cbSize);
135 /* Terminate the list */
136 lpInsertAt = NextItem(lpInsertAt);
137 lpInsertAt->cbSize = 0;
139 return lpNewItem->cbSize;
144 /*************************************************************************
147 * Write a DataBlock list to an IStream object.
150 * lpStream [I] IStream object to write the list to
151 * lpList [I] List of items to write
154 * Success: S_OK. The object is written to the stream.
155 * Failure: An HRESULT error code
158 * Ordinals 17,18,19,20,21 and 22 are related and together provide a compact
159 * list structure (a "DataBlock List"), which may be stored and retrieved from
162 * The exposed API consists of:
164 * - SHWriteDataBlockList() - Write a DataBlock list to a stream,
165 * - SHReadDataBlockList() - Read and create a list from a stream,
166 * - SHFreeDataBlockList() - Free a list,
167 * - SHAddDataBlock() - Insert a new item into a list,
168 * - SHRemoveDataBlock() - Remove an item from a list,
169 * - SHFindDataBlock() - Find an item in a list.
171 * The DataBlock list is stored packed into a memory array. Each element has a
172 * size and an associated ID. Elements must be less than 64k if the list is
173 * to be subsequently read from a stream.
175 * Elements are aligned on DWORD boundaries. If an elements data size is not
176 * a DWORD size multiple, the element is wrapped by inserting a surrounding
177 * element with an Id of 0xFFFFFFFF, and size sufficient to pad to a DWORD boundary.
179 * These functions are slow for large objects and long lists.
181 HRESULT WINAPI SHWriteDataBlockList(IStream* lpStream, LPDBLIST lpList)
186 TRACE("(%p,%p)\n", lpStream, lpList);
190 while (lpList->cbSize)
192 LPDATABLOCK_HEADER lpItem = lpList;
194 if(lpList->dwSignature == CLIST_ID_CONTAINER)
197 hRet = IStream_Write(lpStream,lpItem,lpItem->cbSize,&ulSize);
201 if(lpItem->cbSize != ulSize)
202 return STG_E_MEDIUMFULL;
204 lpList = NextItem(lpList);
213 /* Write a terminating list entry with zero size */
214 hRet = IStream_Write(lpStream, &ulSize,sizeof(ulSize),&ulDummy);
220 /*************************************************************************
223 * Read and create a DataBlock list from an IStream object.
226 * lpStream [I] Stream to read the list from
227 * lppList [0] Pointer to receive the new List
231 * Failure: An HRESULT error code
234 * When read from a file, list objects are limited in size to 64k.
235 * See SHWriteDataBlockList.
237 HRESULT WINAPI SHReadDataBlockList(IStream* lpStream, LPDBLIST* lppList)
239 DATABLOCK_HEADER bBuff[128]; /* Temporary storage for new list item */
240 ULONG ulBuffSize = sizeof(bBuff);
241 LPDATABLOCK_HEADER pItem = bBuff;
242 ULONG ulRead, ulSize;
245 TRACE("(%p,%p)\n", lpStream, lppList);
249 /* Free any existing list */
250 LocalFree((HLOCAL)*lppList);
256 /* Read the size of the next item */
257 hRet = IStream_Read(lpStream, &ulSize,sizeof(ulSize),&ulRead);
259 if(FAILED(hRet) || ulRead != sizeof(ulSize) || !ulSize)
260 break; /* Read failed or read zero size (the end of the list) */
264 LARGE_INTEGER liZero;
265 ULARGE_INTEGER ulPos;
269 /* Back the stream up; this object is too big for the list */
270 if(SUCCEEDED(IStream_Seek(lpStream, liZero, STREAM_SEEK_CUR, &ulPos)))
272 liZero.QuadPart = ulPos.QuadPart - sizeof(ULONG);
273 IStream_Seek(lpStream, liZero, STREAM_SEEK_SET, NULL);
277 else if (ulSize >= sizeof(DATABLOCK_HEADER))
279 /* Add this new item to the list */
280 if(ulSize > ulBuffSize)
282 /* We need more buffer space, allocate it */
283 LPDATABLOCK_HEADER lpTemp;
286 lpTemp = (LPDATABLOCK_HEADER)LocalAlloc(LMEM_ZEROINIT, ulSize);
288 lpTemp = (LPDATABLOCK_HEADER)LocalReAlloc((HLOCAL)pItem, ulSize,
289 LMEM_ZEROINIT|LMEM_MOVEABLE);
293 hRet = E_OUTOFMEMORY;
300 pItem->cbSize = ulSize;
301 ulSize -= sizeof(pItem->cbSize); /* already read this member */
303 /* Read the item Id and data */
304 hRet = IStream_Read(lpStream, &pItem->dwSignature, ulSize, &ulRead);
306 if(FAILED(hRet) || ulRead != ulSize)
309 SHAddDataBlock(lppList, pItem); /* Insert Item */
313 /* If we allocated space, free it */
315 LocalFree((HLOCAL)pItem);
320 /*************************************************************************
323 * Free a DataBlock list.
326 * lpList [I] List to free
332 * See SHWriteDataBlockList.
334 VOID WINAPI SHFreeDataBlockList(LPDBLIST lpList)
336 TRACE("(%p)\n", lpList);
339 LocalFree((HLOCAL)lpList);
342 /*************************************************************************
345 * Remove an item from a DataBlock list.
348 * lppList [O] List to remove the item from
349 * dwSignature [I] Id of item to remove
353 * Failure: FALSE, If any parameters are invalid, or the item was not found.
356 * See SHWriteDataBlockList.
358 BOOL WINAPI SHRemoveDataBlock(LPDBLIST* lppList, DWORD dwSignature)
360 LPDATABLOCK_HEADER lpList = 0;
361 LPDATABLOCK_HEADER lpItem = NULL;
362 LPDATABLOCK_HEADER lpNext;
365 TRACE("(%p,%d)\n", lppList, dwSignature);
367 if(lppList && (lpList = *lppList))
369 /* Search for item in list */
370 while (lpList->cbSize)
372 if(lpList->dwSignature == dwSignature ||
373 (lpList->dwSignature == CLIST_ID_CONTAINER && lpList[1].dwSignature == dwSignature))
375 lpItem = lpList; /* Found */
378 lpList = NextItem(lpList);
385 lpList = lpNext = NextItem(lpItem);
387 /* Locate the end of the list */
388 while (lpList->cbSize)
389 lpList = NextItem(lpList);
391 /* Resize the list */
392 ulNewSize = LocalSize((HLOCAL)*lppList) - lpItem->cbSize;
394 /* Copy following elements over lpItem */
395 memmove(lpItem, lpNext, (char *)lpList - (char *)lpNext + sizeof(ULONG));
397 if(ulNewSize <= sizeof(ULONG))
399 LocalFree((HLOCAL)*lppList);
400 *lppList = NULL; /* Removed the last element */
404 lpList = (LPDATABLOCK_HEADER)LocalReAlloc((HLOCAL)*lppList, ulNewSize,
405 LMEM_ZEROINIT|LMEM_MOVEABLE);
412 /*************************************************************************
415 * Find an item in a DataBlock list.
418 * lpList [I] List to search
419 * dwSignature [I] Id of item to find
422 * Success: A pointer to the list item found
426 * See SHWriteDataBlockList.
428 DATABLOCK_HEADER* WINAPI SHFindDataBlock(LPDBLIST lpList, DWORD dwSignature)
430 TRACE("(%p,%d)\n", lpList, dwSignature);
434 while(lpList->cbSize)
436 if(lpList->dwSignature == dwSignature)
437 return lpList; /* Matched */
438 else if(lpList->dwSignature == CLIST_ID_CONTAINER && lpList[1].dwSignature == dwSignature)
439 return lpList + 1; /* Contained item matches */
441 lpList = NextItem(lpList);