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 = LocalAlloc(LMEM_ZEROINIT, ulSize + sizeof(ULONG));
95 lpInsertAt = *lppList;
99 /* Append to the end of the list */
100 ULONG ulTotalSize = 0;
101 LPDATABLOCK_HEADER lpIter = *lppList;
103 /* Iterate to the end of the list, calculating the total size */
104 while (lpIter->cbSize)
106 ulTotalSize += lpIter->cbSize;
107 lpIter = NextItem(lpIter);
110 /* Increase the size of the list */
111 lpIter = LocalReAlloc(*lppList, ulTotalSize + ulSize+sizeof(ULONG),
112 LMEM_ZEROINIT | LMEM_MOVEABLE);
116 lpInsertAt = (LPDATABLOCK_HEADER)((char*)lpIter + ulTotalSize); /* At end */
122 /* Copy in the new item */
123 LPDATABLOCK_HEADER lpDest = lpInsertAt;
125 if(ulSize != lpNewItem->cbSize)
127 lpInsertAt->cbSize = ulSize;
128 lpInsertAt->dwSignature = CLIST_ID_CONTAINER;
131 memcpy(lpDest, lpNewItem, lpNewItem->cbSize);
133 /* Terminate the list */
134 lpInsertAt = NextItem(lpInsertAt);
135 lpInsertAt->cbSize = 0;
137 return lpNewItem->cbSize;
142 /*************************************************************************
145 * Write a DataBlock list to an IStream object.
148 * lpStream [I] IStream object to write the list to
149 * lpList [I] List of items to write
152 * Success: S_OK. The object is written to the stream.
153 * Failure: An HRESULT error code
156 * Ordinals 17,18,19,20,21 and 22 are related and together provide a compact
157 * list structure (a "DataBlock List"), which may be stored and retrieved from
160 * The exposed API consists of:
162 * - SHWriteDataBlockList() - Write a DataBlock list to a stream,
163 * - SHReadDataBlockList() - Read and create a list from a stream,
164 * - SHFreeDataBlockList() - Free a list,
165 * - SHAddDataBlock() - Insert a new item into a list,
166 * - SHRemoveDataBlock() - Remove an item from a list,
167 * - SHFindDataBlock() - Find an item in a list.
169 * The DataBlock list is stored packed into a memory array. Each element has a
170 * size and an associated ID. Elements must be less than 64k if the list is
171 * to be subsequently read from a stream.
173 * Elements are aligned on DWORD boundaries. If an elements data size is not
174 * a DWORD size multiple, the element is wrapped by inserting a surrounding
175 * element with an Id of 0xFFFFFFFF, and size sufficient to pad to a DWORD boundary.
177 * These functions are slow for large objects and long lists.
179 HRESULT WINAPI SHWriteDataBlockList(IStream* lpStream, LPDBLIST lpList)
184 TRACE("(%p,%p)\n", lpStream, lpList);
188 while (lpList->cbSize)
190 LPDATABLOCK_HEADER lpItem = lpList;
192 if(lpList->dwSignature == CLIST_ID_CONTAINER)
195 hRet = IStream_Write(lpStream,lpItem,lpItem->cbSize,&ulSize);
199 if(lpItem->cbSize != ulSize)
200 return STG_E_MEDIUMFULL;
202 lpList = NextItem(lpList);
211 /* Write a terminating list entry with zero size */
212 hRet = IStream_Write(lpStream, &ulSize,sizeof(ulSize),&ulDummy);
218 /*************************************************************************
221 * Read and create a DataBlock list from an IStream object.
224 * lpStream [I] Stream to read the list from
225 * lppList [0] Pointer to receive the new List
229 * Failure: An HRESULT error code
232 * When read from a file, list objects are limited in size to 64k.
233 * See SHWriteDataBlockList.
235 HRESULT WINAPI SHReadDataBlockList(IStream* lpStream, LPDBLIST* lppList)
237 DATABLOCK_HEADER bBuff[128]; /* Temporary storage for new list item */
238 ULONG ulBuffSize = sizeof(bBuff);
239 LPDATABLOCK_HEADER pItem = bBuff;
240 ULONG ulRead, ulSize;
243 TRACE("(%p,%p)\n", lpStream, lppList);
247 /* Free any existing list */
254 /* Read the size of the next item */
255 hRet = IStream_Read(lpStream, &ulSize,sizeof(ulSize),&ulRead);
257 if(FAILED(hRet) || ulRead != sizeof(ulSize) || !ulSize)
258 break; /* Read failed or read zero size (the end of the list) */
262 LARGE_INTEGER liZero;
263 ULARGE_INTEGER ulPos;
267 /* Back the stream up; this object is too big for the list */
268 if(SUCCEEDED(IStream_Seek(lpStream, liZero, STREAM_SEEK_CUR, &ulPos)))
270 liZero.QuadPart = ulPos.QuadPart - sizeof(ULONG);
271 IStream_Seek(lpStream, liZero, STREAM_SEEK_SET, NULL);
275 else if (ulSize >= sizeof(DATABLOCK_HEADER))
277 /* Add this new item to the list */
278 if(ulSize > ulBuffSize)
280 /* We need more buffer space, allocate it */
281 LPDATABLOCK_HEADER lpTemp;
284 lpTemp = LocalAlloc(LMEM_ZEROINIT, ulSize);
286 lpTemp = LocalReAlloc(pItem, ulSize, LMEM_ZEROINIT|LMEM_MOVEABLE);
290 hRet = E_OUTOFMEMORY;
297 pItem->cbSize = ulSize;
298 ulSize -= sizeof(pItem->cbSize); /* already read this member */
300 /* Read the item Id and data */
301 hRet = IStream_Read(lpStream, &pItem->dwSignature, ulSize, &ulRead);
303 if(FAILED(hRet) || ulRead != ulSize)
306 SHAddDataBlock(lppList, pItem); /* Insert Item */
310 /* If we allocated space, free it */
317 /*************************************************************************
320 * Free a DataBlock list.
323 * lpList [I] List to free
329 * See SHWriteDataBlockList.
331 VOID WINAPI SHFreeDataBlockList(LPDBLIST lpList)
333 TRACE("(%p)\n", lpList);
339 /*************************************************************************
342 * Remove an item from a DataBlock list.
345 * lppList [O] List to remove the item from
346 * dwSignature [I] Id of item to remove
350 * Failure: FALSE, If any parameters are invalid, or the item was not found.
353 * See SHWriteDataBlockList.
355 BOOL WINAPI SHRemoveDataBlock(LPDBLIST* lppList, DWORD dwSignature)
357 LPDATABLOCK_HEADER lpList = 0;
358 LPDATABLOCK_HEADER lpItem = NULL;
359 LPDATABLOCK_HEADER lpNext;
362 TRACE("(%p,%d)\n", lppList, dwSignature);
364 if(lppList && (lpList = *lppList))
366 /* Search for item in list */
367 while (lpList->cbSize)
369 if(lpList->dwSignature == dwSignature ||
370 (lpList->dwSignature == CLIST_ID_CONTAINER && lpList[1].dwSignature == dwSignature))
372 lpItem = lpList; /* Found */
375 lpList = NextItem(lpList);
382 lpList = lpNext = NextItem(lpItem);
384 /* Locate the end of the list */
385 while (lpList->cbSize)
386 lpList = NextItem(lpList);
388 /* Resize the list */
389 ulNewSize = LocalSize(*lppList) - lpItem->cbSize;
391 /* Copy following elements over lpItem */
392 memmove(lpItem, lpNext, (char *)lpList - (char *)lpNext + sizeof(ULONG));
394 if(ulNewSize <= sizeof(ULONG))
397 *lppList = NULL; /* Removed the last element */
401 lpList = LocalReAlloc(*lppList, ulNewSize, LMEM_ZEROINIT|LMEM_MOVEABLE);
408 /*************************************************************************
411 * Find an item in a DataBlock list.
414 * lpList [I] List to search
415 * dwSignature [I] Id of item to find
418 * Success: A pointer to the list item found
422 * See SHWriteDataBlockList.
424 DATABLOCK_HEADER* WINAPI SHFindDataBlock(LPDBLIST lpList, DWORD dwSignature)
426 TRACE("(%p,%d)\n", lpList, dwSignature);
430 while(lpList->cbSize)
432 if(lpList->dwSignature == dwSignature)
433 return lpList; /* Matched */
434 else if(lpList->dwSignature == CLIST_ID_CONTAINER && lpList[1].dwSignature == dwSignature)
435 return lpList + 1; /* Contained item matches */
437 lpList = NextItem(lpList);