vfslowlevel.h@ 41549

Last change on this file since 41549 was 41549, checked in by vboxsync, 12 years ago
VFS/Filesystem: Convert the filesystem specific code to the VFS framework and make it work
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1	/** @file
2	* IPRT - Virtual Filesystem.
3	*/
4
5	/*
6	* Copyright (C) 2010 Oracle Corporation
7	*
8	* This file is part of VirtualBox Open Source Edition (OSE), as
9	* available from http://www.virtualbox.org. This file is free software;
10	* you can redistribute it and/or modify it under the terms of the GNU
11	* General Public License (GPL) as published by the Free Software
12	* Foundation, in version 2 as it comes in the "COPYING" file of the
13	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
14	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
15	*
16	* The contents of this file may alternatively be used under the terms
17	* of the Common Development and Distribution License Version 1.0
18	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
19	* VirtualBox OSE distribution, in which case the provisions of the
20	* CDDL are applicable instead of those of the GPL.
21	*
22	* You may elect to license modified versions of this file under the
23	* terms and conditions of either the GPL or the CDDL or both.
24	*/
25
26	#ifndef ___iprt_vfslowlevel_h
27	#define ___iprt_vfslowlevel_h
28
29	#include <iprt/vfs.h>
30	#include <iprt/err.h>
31	#include <iprt/list.h>
32	#include <iprt/param.h>
33
34
35	RT_C_DECLS_BEGIN
36
37	/** @defgroup grp_rt_vfs_lowlevel RTVfs - Low-level Interface.
38	* @ingroup grp_rt_vfs
39	* @{
40	*/
41
42
43	/** @name VFS Lock Abstraction
44	* @todo This should be moved somewhere else as it is of general use.
45	* @{ */
46
47	/**
48	* VFS lock types.
49	*/
50	typedef enum RTVFSLOCKTYPE
51	{
52	/** Invalid lock type. */
53	RTVFSLOCKTYPE_INVALID = 0,
54	/** Read write semaphore. */
55	RTVFSLOCKTYPE_RW,
56	/** Fast mutex semaphore (critical section in ring-3). */
57	RTVFSLOCKTYPE_FASTMUTEX,
58	/** Full fledged mutex semaphore. */
59	RTVFSLOCKTYPE_MUTEX,
60	/** The end of valid lock types. */
61	RTVFSLOCKTYPE_END,
62	/** The customary 32-bit type hack. */
63	RTVFSLOCKTYPE_32BIT_HACK = 0x7fffffff
64	} RTVFSLOCKTYPE;
65
66	/** VFS lock handle. */
67	typedef struct RTVFSLOCKINTERNAL *RTVFSLOCK;
68	/** Pointer to a VFS lock handle. */
69	typedef RTVFSLOCK *PRTVFSLOCK;
70	/** Nil VFS lock handle. */
71	#define NIL_RTVFSLOCK ((RTVFSLOCK)~(uintptr_t)0)
72
73	/** Special handle value for creating a new read/write semaphore based lock. */
74	#define RTVFSLOCK_CREATE_RW ((RTVFSLOCK)~(uintptr_t)1)
75	/** Special handle value for creating a new fast mutex semaphore based lock. */
76	#define RTVFSLOCK_CREATE_FASTMUTEX ((RTVFSLOCK)~(uintptr_t)2)
77	/** Special handle value for creating a new mutex semaphore based lock. */
78	#define RTVFSLOCK_CREATE_MUTEX ((RTVFSLOCK)~(uintptr_t)3)
79
80	/**
81	* Retains a reference to the VFS lock handle.
82	*
83	* @returns New reference count on success, UINT32_MAX on failure.
84	* @param hLock The VFS lock handle.
85	*/
86	RTDECL(uint32_t) RTVfsLockRetain(RTVFSLOCK hLock);
87
88	/**
89	* Releases a reference to the VFS lock handle.
90	*
91	* @returns New reference count on success (0 if closed), UINT32_MAX on failure.
92	* @param hLock The VFS lock handle.
93	*/
94	RTDECL(uint32_t) RTVfsLockRelease(RTVFSLOCK hLock);
95
96	/**
97	* Gets the lock type.
98	*
99	* @returns The lock type on success, RTVFSLOCKTYPE_INVALID if the handle is
100	* not valid.
101	* @param hLock The lock handle.
102	*/
103	RTDECL(RTVFSLOCKTYPE) RTVfsLockGetType(RTVFSLOCK hLock);
104
105
106
107	RTDECL(void) RTVfsLockAcquireReadSlow(RTVFSLOCK hLock);
108	RTDECL(void) RTVfsLockReleaseReadSlow(RTVFSLOCK hLock);
109	RTDECL(void) RTVfsLockAcquireWriteSlow(RTVFSLOCK hLock);
110	RTDECL(void) RTVfsLockReleaseWriteSlow(RTVFSLOCK hLock);
111
112	/**
113	* Acquire a read lock.
114	*
115	* @param hLock The lock handle, can be NIL.
116	*/
117	DECLINLINE(void) RTVfsLockAcquireRead(RTVFSLOCK hLock)
118	{
119	if (hLock != NIL_RTVFSLOCK)
120	RTVfsLockAcquireReadSlow(hLock);
121	}
122
123
124	/**
125	* Release a read lock.
126	*
127	* @param hLock The lock handle, can be NIL.
128	*/
129	DECLINLINE(void) RTVfsLockReleaseRead(RTVFSLOCK hLock)
130	{
131	if (hLock != NIL_RTVFSLOCK)
132	RTVfsLockReleaseReadSlow(hLock);
133	}
134
135
136	/**
137	* Acquire a write lock.
138	*
139	* @param hLock The lock handle, can be NIL.
140	*/
141	DECLINLINE(void) RTVfsLockAcquireWrite(RTVFSLOCK hLock)
142	{
143	if (hLock != NIL_RTVFSLOCK)
144	RTVfsLockAcquireWriteSlow(hLock);
145	}
146
147
148	/**
149	* Release a write lock.
150	*
151	* @param hLock The lock handle, can be NIL.
152	*/
153	DECLINLINE(void) RTVfsLockReleaseWrite(RTVFSLOCK hLock)
154	{
155	if (hLock != NIL_RTVFSLOCK)
156	RTVfsLockReleaseWriteSlow(hLock);
157	}
158
159	/** @} */
160
161	/**
162	* The VFS operations.
163	*/
164	typedef struct RTVFSOPS
165	{
166	/** The structure version (RTVFSOPS_VERSION). */
167	uint32_t uVersion;
168	/** The virtual file system feature mask. */
169	uint32_t fFeatures;
170	/** The name of the operations. */
171	const char *pszName;
172
173	/**
174	* Destructor.
175	*
176	* @param pvThis The implementation specific data.
177	*/
178	DECLCALLBACKMEMBER(void, pfnDestroy)(void *pvThis);
179
180	/**
181	* Opens the root directory.
182	*
183	* @returns IPRT status code.
184	* @param pvThis The implementation specific data.
185	* @param phVfsDir Where to return the handle to the root directory.
186	*/
187	DECLCALLBACKMEMBER(int, pfnOpenRoot)(void *pvThis, PRTVFSDIR phVfsDir);
188
189	/**
190	* Checks whether a given range in the underlying medium
191	* is in use by the virtual filesystem.
192	*
193	* @returns IPRT status code.
194	* @param pvThis The implementation specific data.
195	* @param off Start offset to check.
196	* @param cb Number of bytes to check.
197	* @param pfUsed Where to store whether the given range is in use.
198	*/
199	DECLCALLBACKMEMBER(int, pfnIsRangeInUse)(void *pvThis, RTFOFF off, size_t cb,
200	bool *pfUsed);
201
202	/** @todo There will be more methods here to optimize opening and
203	* querying. */
204
205	#if 0
206	/**
207	* Optional entry point for optimizing path traversal within the file system.
208	*
209	* @returns IPRT status code.
210	* @param pvThis The implementation specific data.
211	* @param pszPath The path to resolve.
212	* @param poffPath The current path offset on input, what we've
213	* traversed to on successful return.
214	* @param phVfs??? Return handle to what we've traversed.
215	* @param p??? Return other stuff...
216	*/
217	DECLCALLBACKMEMBER(int, pfnTraverse)(void pvThis, const char pszPath, size_t poffPath, PRTVFS??? phVfs?, ??? p???);
218	#endif
219
220	/** Marks the end of the structure (RTVFSOPS_VERSION). */
221	uintptr_t uEndMarker;
222	} RTVFSOPS;
223	/** Pointer to constant VFS operations. */
224	typedef RTVFSOPS const *PCRTVFSOPS;
225
226	/** The RTVFSOPS structure version. */
227	#define RTVFSOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x0f,1,0)
228
229	/** @name RTVFSOPS::fFeatures
230	* @{ */
231	/** The VFS supports attaching other systems. */
232	#define RTVFSOPS_FEAT_ATTACH RT_BIT_32(0)
233	/** @} */
234
235	/**
236	* Creates a new VFS handle.
237	*
238	* @returns IPRT status code
239	* @param pVfs Ops The VFS operations.
240	* @param cbInstance The size of the instance data.
241	* @param hVfs The VFS handle to associate this VFS with.
242	* NIL_VFS is ok.
243	* @param hLock Handle to a custom lock to be used with the new
244	* object. The reference is consumed. NIL and
245	* special lock handles are fine.
246	* @param phVfs Where to return the new handle.
247	* @param ppvInstance Where to return the pointer to the instance data
248	* (size is @a cbInstance).
249	*/
250	RTDECL(int) RTVfsNew(PCRTVFSOPS pVfsOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
251	PRTVFS phVfs, void **ppvInstance);
252
253	/**
254	* The basis for all virtual file system objects except RTVFS.
255	*/
256	typedef struct RTVFSOBJOPS
257	{
258	/** The structure version (RTVFSOBJOPS_VERSION). */
259	uint32_t uVersion;
260	/** The object type for type introspection. */
261	RTVFSOBJTYPE enmType;
262	/** The name of the operations. */
263	const char *pszName;
264
265	/**
266	* Close the object.
267	*
268	* @returns IPRT status code.
269	* @param pvThis The implementation specific file data.
270	*/
271	DECLCALLBACKMEMBER(int, pfnClose)(void *pvThis);
272
273	/**
274	* Get information about the file.
275	*
276	* @returns IPRT status code. See RTVfsObjQueryInfo.
277	* @param pvThis The implementation specific file data.
278	* @param pObjInfo Where to return the object info on success.
279	* @param enmAddAttr Which set of additional attributes to request.
280	* @sa RTVfsObjQueryInfo, RTFileQueryInfo, RTPathQueryInfo
281	*/
282	DECLCALLBACKMEMBER(int, pfnQueryInfo)(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr);
283
284	/** Marks the end of the structure (RTVFSOBJOPS_VERSION). */
285	uintptr_t uEndMarker;
286	} RTVFSOBJOPS;
287	/** Pointer to constant VFS object operations. */
288	typedef RTVFSOBJOPS const *PCRTVFSOBJOPS;
289
290	/** The RTVFSOBJOPS structure version. */
291	#define RTVFSOBJOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x1f,1,0)
292
293
294	/**
295	* Creates a new VFS base object handle.
296	*
297	* @returns IPRT status code
298	* @param pObjOps The base object operations.
299	* @param cbInstance The size of the instance data.
300	* @param hVfs The VFS handle to associate this base object
301	* with. NIL_VFS is ok.
302	* @param hLock Handle to a custom lock to be used with the new
303	* object. The reference is consumed. NIL and
304	* special lock handles are fine.
305	* @param phVfsFss Where to return the new handle.
306	* @param ppvInstance Where to return the pointer to the instance data
307	* (size is @a cbInstance).
308	*/
309	RTDECL(int) RTVfsNewBaseObj(PCRTVFSOBJOPS pObjOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
310	PRTVFSOBJ phVfsObj, void **ppvInstance);
311
312
313	/**
314	* Additional operations for setting object attributes.
315	*/
316	typedef struct RTVFSOBJSETOPS
317	{
318	/** The structure version (RTVFSOBJSETOPS_VERSION). */
319	uint32_t uVersion;
320	/** The offset to the RTVFSOBJOPS structure. */
321	int32_t offObjOps;
322
323	/**
324	* Set the unix style owner and group.
325	*
326	* @returns IPRT status code.
327	* @param pvThis The implementation specific file data.
328	* @param fMode The new mode bits.
329	* @param fMask The mask indicating which bits we are
330	* changing.
331	* @sa RTFileSetMode
332	*/
333	DECLCALLBACKMEMBER(int, pfnSetMode)(void *pvThis, RTFMODE fMode, RTFMODE fMask);
334
335	/**
336	* Set the timestamps associated with the object.
337	*
338	* @returns IPRT status code.
339	* @param pvThis The implementation specific file data.
340	* @param pAccessTime Pointer to the new access time. NULL if not
341	* to be changed.
342	* @param pModificationTime Pointer to the new modifcation time. NULL if
343	* not to be changed.
344	* @param pChangeTime Pointer to the new change time. NULL if not
345	* to be changed.
346	* @param pBirthTime Pointer to the new time of birth. NULL if
347	* not to be changed.
348	* @remarks See RTFileSetTimes for restrictions and behavior imposed by the
349	* host OS or underlying VFS provider.
350	* @sa RTFileSetTimes
351	*/
352	DECLCALLBACKMEMBER(int, pfnSetTimes)(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime,
353	PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime);
354
355	/**
356	* Set the unix style owner and group.
357	*
358	* @returns IPRT status code.
359	* @param pvThis The implementation specific file data.
360	* @param uid The user ID of the new owner. NIL_RTUID if
361	* unchanged.
362	* @param gid The group ID of the new owner group. NIL_RTGID if
363	* unchanged.
364	* @sa RTFileSetOwner
365	*/
366	DECLCALLBACKMEMBER(int, pfnSetOwner)(void *pvThis, RTUID uid, RTGID gid);
367
368	/** Marks the end of the structure (RTVFSOBJSETOPS_VERSION). */
369	uintptr_t uEndMarker;
370	} RTVFSOBJSETOPS;
371	/** Pointer to const object attribute setter operations. */
372	typedef RTVFSOBJSETOPS const *PCRTVFSOBJSETOPS;
373
374	/** The RTVFSOBJSETOPS structure version. */
375	#define RTVFSOBJSETOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x2f,1,0)
376
377
378	/**
379	* The filesystem stream operations.
380	*
381	* @extends RTVFSOBJOPS
382	*/
383	typedef struct RTVFSFSSTREAMOPS
384	{
385	/** The basic object operation. */
386	RTVFSOBJOPS Obj;
387	/** The structure version (RTVFSFSSTREAMOPS_VERSION). */
388	uint32_t uVersion;
389	/** Reserved field, MBZ. */
390	uint32_t fReserved;
391
392	/**
393	* Gets the next object in the stream.
394	*
395	* @returns IPRT status code.
396	* @retval VINF_SUCCESS if a new object was retrieved.
397	* @retval VERR_EOF when there are no more objects.
398	* @param pvThis The implementation specific directory data.
399	* @param ppszName Where to return the object name. Must be freed by
400	* calling RTStrFree.
401	* @param penmType Where to return the object type.
402	* @param hVfsObj Where to return the object handle (referenced).
403	* This must be cast to the desired type before use.
404	* @sa RTVfsFsStrmNext
405	*/
406	DECLCALLBACKMEMBER(int, pfnNext)(void pvThis, char ppszName, RTVFSOBJTYPE penmType, PRTVFSOBJ phVfsObj);
407
408	/** Marks the end of the structure (RTVFSFSSTREAMOPS_VERSION). */
409	uintptr_t uEndMarker;
410	} RTVFSFSSTREAMOPS;
411	/** Pointer to const object attribute setter operations. */
412	typedef RTVFSFSSTREAMOPS const *PCRTVFSFSSTREAMOPS;
413
414	/** The RTVFSFSSTREAMOPS structure version. */
415	#define RTVFSFSSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x3f,1,0)
416
417
418	/**
419	* Creates a new VFS filesystem stream handle.
420	*
421	* @returns IPRT status code
422	* @param pFsStreamOps The filesystem stream operations.
423	* @param cbInstance The size of the instance data.
424	* @param hVfs The VFS handle to associate this filesystem
425	* stream with. NIL_VFS is ok.
426	* @param hLock Handle to a custom lock to be used with the new
427	* object. The reference is consumed. NIL and
428	* special lock handles are fine.
429	* @param phVfsFss Where to return the new handle.
430	* @param ppvInstance Where to return the pointer to the instance data
431	* (size is @a cbInstance).
432	*/
433	RTDECL(int) RTVfsNewFsStream(PCRTVFSFSSTREAMOPS pFsStreamOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
434	PRTVFSFSSTREAM phVfsFss, void **ppvInstance);
435
436
437	/**
438	* The directory operations.
439	*
440	* @extends RTVFSOBJOPS
441	* @extends RTVFSOBJSETOPS
442	*/
443	typedef struct RTVFSDIROPS
444	{
445	/** The basic object operation. */
446	RTVFSOBJOPS Obj;
447	/** The structure version (RTVFSDIROPS_VERSION). */
448	uint32_t uVersion;
449	/** Reserved field, MBZ. */
450	uint32_t fReserved;
451	/** The object setter operations. */
452	RTVFSOBJSETOPS ObjSet;
453
454	/**
455	* Opens a directory entry for traversal purposes.
456	*
457	* Method which sole purpose is helping the path traversal. Only one of
458	* the three output variables will be set, the others will left untouched
459	* (caller sets them to NIL).
460	*
461	* @returns IPRT status code.
462	* @retval VERR_PATH_NOT_FOUND if @a pszEntry was not found.
463	* @param pvThis The implementation specific directory data.
464	* @param pszEntry The name of the directory entry to remove.
465	* @param phVfsDir If not NULL and it is a directory, open it and
466	* return the handle here.
467	* @param phVfsSymlink If not NULL and it is a symbolic link, open it
468	* and return the handle here.
469	* @param phVfsMounted If not NULL and it is a mounted VFS directory,
470	* reference it and return the handle here.
471	* @todo Should com dir, symlinks and mount points using some common
472	* ancestor "class".
473	*/
474	DECLCALLBACKMEMBER(int, pfnTraversalOpen)(void pvThis, const char pszEntry, PRTVFSDIR phVfsDir,
475	PRTVFSSYMLINK phVfsSymlink, PRTVFS phVfsMounted);
476
477	/**
478	* Open or create a file.
479	*
480	* @returns IPRT status code.
481	* @param pvThis The implementation specific directory data.
482	* @param pszFilename The name of the immediate file to open or create.
483	* @param fOpen The open flags (RTFILE_O_XXX).
484	* @param phVfsFile Where to return the thandle to the opened file.
485	* @sa RTFileOpen.
486	*/
487	DECLCALLBACKMEMBER(int, pfnOpenFile)(void pvThis, const char pszFilename, uint32_t fOpen, PRTVFSFILE phVfsFile);
488
489	/**
490	* Open an existing subdirectory.
491	*
492	* @returns IPRT status code.
493	* @param pvThis The implementation specific directory data.
494	* @param pszSubDir The name of the immediate subdirectory to open.
495	* @param phVfsDir Where to return the handle to the opened directory.
496	* @sa RTDirOpen.
497	*/
498	DECLCALLBACKMEMBER(int, pfnOpenDir)(void pvThis, const char pszSubDir, PRTVFSDIR phVfsDir);
499
500	/**
501	* Creates a new subdirectory.
502	*
503	* @returns IPRT status code.
504	* @param pvThis The implementation specific directory data.
505	* @param pszSubDir The name of the immediate subdirectory to create.
506	* @param fMode The mode mask of the new directory.
507	* @param phVfsDir Where to optionally return the handle to the newly
508	* create directory.
509	* @sa RTDirCreate.
510	*/
511	DECLCALLBACKMEMBER(int, pfnCreateDir)(void pvThis, const char pszSubDir, RTFMODE fMode, PRTVFSDIR phVfsDir);
512
513	/**
514	* Opens an existing symbolic link.
515	*
516	* @returns IPRT status code.
517	* @param pvThis The implementation specific directory data.
518	* @param pszSymlink The name of the immediate symbolic link to open.
519	* @param phVfsSymlink Where to optionally return the handle to the
520	* newly create symbolic link.
521	* @sa RTSymlinkCreate.
522	*/
523	DECLCALLBACKMEMBER(int, pfnOpenSymlink)(void pvThis, const char pszSymlink, PRTVFSSYMLINK phVfsSymlink);
524
525	/**
526	* Creates a new symbolic link.
527	*
528	* @returns IPRT status code.
529	* @param pvThis The implementation specific directory data.
530	* @param pszSymlink The name of the immediate symbolic link to create.
531	* @param pszTarget The symbolic link target.
532	* @param enmType The symbolic link type.
533	* @param phVfsSymlink Where to optionally return the handle to the
534	* newly create symbolic link.
535	* @sa RTSymlinkCreate.
536	*/
537	DECLCALLBACKMEMBER(int, pfnCreateSymlink)(void pvThis, const char pszSymlink, const char *pszTarget,
538	RTSYMLINKTYPE enmType, PRTVFSSYMLINK phVfsSymlink);
539
540	/**
541	* Removes a directory entry.
542	*
543	* @returns IPRT status code.
544	* @param pvThis The implementation specific directory data.
545	* @param pszEntry The name of the directory entry to remove.
546	* @param fType If non-zero, this restricts the type of the entry to
547	* the object type indicated by the mask
548	* (RTFS_TYPE_XXX).
549	* @sa RTFileRemove, RTDirRemove, RTSymlinkRemove.
550	*/
551	DECLCALLBACKMEMBER(int, pfnUnlinkEntry)(void pvThis, const char pszEntry, RTFMODE fType, PRTVFSDIR phVfsDir);
552
553	/**
554	* Rewind the directory stream so that the next read returns the first
555	* entry.
556	*
557	* @returns IPRT status code.
558	* @param pvThis The implementation specific directory data.
559	*/
560	DECLCALLBACKMEMBER(int, pfnRewindDir)(void *pvThis);
561
562	/**
563	* Rewind the directory stream so that the next read returns the first
564	* entry.
565	*
566	* @returns IPRT status code.
567	* @param pvThis The implementation specific directory data.
568	* @param pDirEntry Output buffer.
569	* @param pcbDirEntry Complicated, see RTDirReadEx.
570	* @param enmAddAttr Which set of additional attributes to request.
571	* @sa RTDirReadEx
572	*/
573	DECLCALLBACKMEMBER(int, pfnReadDir)(void pvThis, PRTDIRENTRYEX pDirEntry, size_t pcbDirEntry, RTFSOBJATTRADD enmAddAttr);
574
575	/** Marks the end of the structure (RTVFSDIROPS_VERSION). */
576	uintptr_t uEndMarker;
577	} RTVFSDIROPS;
578	/** Pointer to const directory operations. */
579	typedef RTVFSDIROPS const *PCRTVFSDIROPS;
580	/** The RTVFSDIROPS structure version. */
581	#define RTVFSDIROPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x4f,1,0)
582
583
584	/**
585	* The symbolic link operations.
586	*
587	* @extends RTVFSOBJOPS
588	* @extends RTVFSOBJSETOPS
589	*/
590	typedef struct RTVFSSYMLINKOPS
591	{
592	/** The basic object operation. */
593	RTVFSOBJOPS Obj;
594	/** The structure version (RTVFSSYMLINKOPS_VERSION). */
595	uint32_t uVersion;
596	/** Reserved field, MBZ. */
597	uint32_t fReserved;
598	/** The object setter operations. */
599	RTVFSOBJSETOPS ObjSet;
600
601	/**
602	* Read the symbolic link target.
603	*
604	* @returns IPRT status code.
605	* @param pvThis The implementation specific symbolic link data.
606	* @param pszTarget The target buffer.
607	* @param cbTarget The size of the target buffer.
608	* @sa RTSymlinkRead
609	*/
610	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, char pszTarget, size_t cbTarget);
611
612	/** Marks the end of the structure (RTVFSSYMLINKOPS_VERSION). */
613	uintptr_t uEndMarker;
614	} RTVFSSYMLINKOPS;
615	/** Pointer to const symbolic link operations. */
616	typedef RTVFSSYMLINKOPS const *PCRTVFSSYMLINKOPS;
617	/** The RTVFSSYMLINKOPS structure version. */
618	#define RTVFSSYMLINKOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x5f,1,0)
619
620
621	/**
622	* Creates a new VFS symlink handle.
623	*
624	* @returns IPRT status code
625	* @param pSymlinkOps The symlink operations.
626	* @param cbInstance The size of the instance data.
627	* @param hVfs The VFS handle to associate this symlink object
628	* with. NIL_VFS is ok.
629	* @param hLock Handle to a custom lock to be used with the new
630	* object. The reference is consumed. NIL and
631	* special lock handles are fine.
632	* @param phVfsSym Where to return the new handle.
633	* @param ppvInstance Where to return the pointer to the instance data
634	* (size is @a cbInstance).
635	*/
636	RTDECL(int) RTVfsNewSymlink(PCRTVFSSYMLINKOPS pSymlinkOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
637	PRTVFSSYMLINK phVfsSym, void **ppvInstance);
638
639
640	/**
641	* The basis for all I/O objects (files, pipes, sockets, devices, ++).
642	*
643	* @extends RTVFSOBJOPS
644	*/
645	typedef struct RTVFSIOSTREAMOPS
646	{
647	/** The basic object operation. */
648	RTVFSOBJOPS Obj;
649	/** The structure version (RTVFSIOSTREAMOPS_VERSION). */
650	uint32_t uVersion;
651	/** Feature field. */
652	uint32_t fFeatures;
653
654	/**
655	* Reads from the file/stream.
656	*
657	* @returns IPRT status code. See RTVfsIoStrmRead.
658	* @param pvThis The implementation specific file data.
659	* @param off Where to read at, -1 for the current position.
660	* @param pSgBuf Gather buffer describing the bytes that are to be
661	* written.
662	* @param fBlocking If @c true, the call is blocking, if @c false it
663	* should not block.
664	* @param pcbRead Where return the number of bytes actually read.
665	* This is set it 0 by the caller. If NULL, try read
666	* all and fail if incomplete.
667	* @sa RTVfsIoStrmRead, RTVfsIoStrmSgRead, RTVfsFileRead,
668	* RTVfsFileReadAt, RTFileRead, RTFileReadAt.
669	*/
670	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbRead);
671
672	/**
673	* Writes to the file/stream.
674	*
675	* @returns IPRT status code.
676	* @param pvThis The implementation specific file data.
677	* @param off Where to start wrinting, -1 for the current
678	* position.
679	* @param pSgBuf Gather buffers describing the bytes that are to be
680	* written.
681	* @param fBlocking If @c true, the call is blocking, if @c false it
682	* should not block.
683	* @param pcbWritten Where to return the number of bytes actually
684	* written. This is set it 0 by the caller. If
685	* NULL, try write it all and fail if incomplete.
686	* @sa RTFileWrite, RTFileWriteAt.
687	*/
688	DECLCALLBACKMEMBER(int, pfnWrite)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbWritten);
689
690	/**
691	* Flushes any pending data writes to the stream.
692	*
693	* @returns IPRT status code.
694	* @param pvThis The implementation specific file data.
695	* @sa RTFileFlush.
696	*/
697	DECLCALLBACKMEMBER(int, pfnFlush)(void *pvThis);
698
699	/**
700	* Poll for events.
701	*
702	* @returns IPRT status code.
703	* @param pvThis The implementation specific file data.
704	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
705	* @param cMillies How long to wait for event to eventuate.
706	* @param fIntr Whether the wait is interruptible and can return
707	* VERR_INTERRUPTED (@c true) or if this condition
708	* should be hidden from the caller (@c false).
709	* @param pfRetEvents Where to return the event mask.
710	* @sa RTPollSetAdd, RTPoll, RTPollNoResume.
711	*/
712	DECLCALLBACKMEMBER(int, pfnPollOne)(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr,
713	uint32_t *pfRetEvents);
714
715	/**
716	* Tells the current file/stream position.
717	*
718	* @returns IPRT status code.
719	* @param pvThis The implementation specific file data.
720	* @param poffActual Where to return the actual offset.
721	* @sa RTFileTell
722	*/
723	DECLCALLBACKMEMBER(int, pfnTell)(void *pvThis, PRTFOFF poffActual);
724
725	/**
726	* Skips @a cb ahead in the stream.
727	*
728	* @returns IPRT status code.
729	* @param pvThis The implementation specific file data.
730	* @param cb The number bytes to skip.
731	* @remarks This is optional and can be NULL.
732	*/
733	DECLCALLBACKMEMBER(int, pfnSkip)(void *pvThis, RTFOFF cb);
734
735	/**
736	* Fills the stream with @a cb zeros.
737	*
738	* @returns IPRT status code.
739	* @param pvThis The implementation specific file data.
740	* @param cb The number of zero bytes to insert.
741	* @remarks This is optional and can be NULL.
742	*/
743	DECLCALLBACKMEMBER(int, pfnZeroFill)(void *pvThis, RTFOFF cb);
744
745	/** Marks the end of the structure (RTVFSIOSTREAMOPS_VERSION). */
746	uintptr_t uEndMarker;
747	} RTVFSIOSTREAMOPS;
748	/** Pointer to const I/O stream operations. */
749	typedef RTVFSIOSTREAMOPS const *PCRTVFSIOSTREAMOPS;
750
751	/** The RTVFSIOSTREAMOPS structure version. */
752	#define RTVFSIOSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x6f,1,0)
753
754	/** @name RTVFSIOSTREAMOPS::fFeatures
755	* @{ */
756	/** No scatter gather lists, thank you. */
757	#define RTVFSIOSTREAMOPS_FEAT_NO_SG RT_BIT_32(0)
758	/** Mask of the valid I/O stream feature flags. */
759	#define RTVFSIOSTREAMOPS_FEAT_VALID_MASK UINT32_C(0x00000001)
760	/** @} */
761
762
763	/**
764	* Creates a new VFS I/O stream handle.
765	*
766	* @returns IPRT status code
767	* @param pIoStreamOps The I/O stream operations.
768	* @param cbInstance The size of the instance data.
769	* @param fOpen The open flags. The minimum is the access mask.
770	* @param hVfs The VFS handle to associate this I/O stream
771	* with. NIL_VFS is ok.
772	* @param hLock Handle to a custom lock to be used with the new
773	* object. The reference is consumed. NIL and
774	* special lock handles are fine.
775	* @param phVfsIos Where to return the new handle.
776	* @param ppvInstance Where to return the pointer to the instance data
777	* (size is @a cbInstance).
778	*/
779	RTDECL(int) RTVfsNewIoStream(PCRTVFSIOSTREAMOPS pIoStreamOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
780	PRTVFSIOSTREAM phVfsIos, void **ppvInstance);
781
782
783	/**
784	* Gets the private data of an I/O stream.
785	*
786	* @returns Pointer to the private data. NULL if the handle is invalid in some
787	* way.
788	* @param hVfsIos The I/O stream handle.
789	* @param pIoStreamOps The I/O stream operations. This servers as a
790	* sort of password.
791	*/
792	RTDECL(void *) RTVfsIoStreamToPrivate(RTVFSIOSTREAM hVfsIos, PCRTVFSIOSTREAMOPS pIoStreamOps);
793
794
795	/**
796	* The file operations.
797	*
798	* @extends RTVFSIOSTREAMOPS
799	* @extends RTVFSOBJSETOPS
800	*/
801	typedef struct RTVFSFILEOPS
802	{
803	/** The I/O stream and basis object operations. */
804	RTVFSIOSTREAMOPS Stream;
805	/** The structure version (RTVFSFILEOPS_VERSION). */
806	uint32_t uVersion;
807	/** Reserved field, MBZ. */
808	uint32_t fReserved;
809	/** The object setter operations. */
810	RTVFSOBJSETOPS ObjSet;
811
812	/**
813	* Changes the current file position.
814	*
815	* @returns IPRT status code.
816	* @param pvThis The implementation specific file data.
817	* @param offSeek The offset to seek.
818	* @param uMethod The seek method, i.e. what the seek is relative to.
819	* @param poffActual Where to return the actual offset.
820	* @sa RTFileSeek
821	*/
822	DECLCALLBACKMEMBER(int, pfnSeek)(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual);
823
824	/**
825	* Get the current file/stream size.
826	*
827	* @returns IPRT status code.
828	* @param pvThis The implementation specific file data.
829	* @param pcbFile Where to store the current file size.
830	* @sa RTFileGetSize
831	*/
832	DECLCALLBACKMEMBER(int, pfnQuerySize)(void pvThis, uint64_t pcbFile);
833
834	/** @todo There will be more methods here. */
835
836	/** Marks the end of the structure (RTVFSFILEOPS_VERSION). */
837	uintptr_t uEndMarker;
838	} RTVFSFILEOPS;
839	/** Pointer to const file operations. */
840	typedef RTVFSFILEOPS const *PCRTVFSFILEOPS;
841
842	/** The RTVFSFILEOPS structure version. */
843	#define RTVFSFILEOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x7f,1,0)
844
845	/**
846	* Creates a new VFS file handle.
847	*
848	* @returns IPRT status code
849	* @param pFileOps The file operations.
850	* @param cbInstance The size of the instance data.
851	* @param fOpen The open flags. The minimum is the access mask.
852	* @param hVfs The VFS handle to associate this file with.
853	* NIL_VFS is ok.
854	* @param hLock Handle to a custom lock to be used with the new
855	* object. The reference is consumed. NIL and
856	* special lock handles are fine.
857	* @param phVfsFile Where to return the new handle.
858	* @param ppvInstance Where to return the pointer to the instance data
859	* (size is @a cbInstance).
860	*/
861	RTDECL(int) RTVfsNewFile(PCRTVFSFILEOPS pFileOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
862	PRTVFSFILE phVfsFile, void **ppvInstance);
863
864
865	/** @defgroup grp_rt_vfs_ll_util VFS Utility APIs
866	* @{ */
867
868	/**
869	* Parsed path.
870	*/
871	typedef struct RTVFSPARSEDPATH
872	{
873	/** The length of the path in szCopy. */
874	uint16_t cch;
875	/** The number of path components. */
876	uint16_t cComponents;
877	/** Set if the path ends with slash, indicating that it's a directory
878	* reference and not a file reference. The slash has been removed from
879	* the copy. */
880	bool fDirSlash;
881	/** The offset where each path component starts, i.e. the char after the
882	* slash. The array has cComponents + 1 entries, where the final one is
883	* cch + 1 so that one can always terminate the current component by
884	* szPath[aoffComponent[i] - 1] = '\0'. */
885	uint16_t aoffComponents[RTPATH_MAX / 2 + 1];
886	/** A normalized copy of the path.
887	* Reserve some extra space so we can be more relaxed about overflow
888	* checks and terminator paddings, especially when recursing. */
889	char szPath[RTPATH_MAX];
890	} RTVFSPARSEDPATH;
891	/** Pointer to a parsed path. */
892	typedef RTVFSPARSEDPATH *PRTVFSPARSEDPATH;
893
894	/** The max accepted path length.
895	* This must be a few chars shorter than RTVFSPARSEDPATH::szPath because we
896	* use two terminators and wish be a little bit lazy with checking. */
897	#define RTVFSPARSEDPATH_MAX (RTPATH_MAX - 4)
898
899	/**
900	* Appends @a pszPath (relative) to the already parsed path @a pPath.
901	*
902	* @retval VINF_SUCCESS
903	* @retval VERR_FILENAME_TOO_LONG
904	* @retval VERR_INTERNAL_ERROR_4
905	* @param pPath The parsed path to append @a pszPath onto.
906	* This is both input and output.
907	* @param pszPath The path to append. This must be relative.
908	* @param piRestartComp The component to restart parsing at. This is
909	* input/output. The input does not have to be
910	* within the valid range. Optional.
911	*/
912	RTDECL(int) RTVfsParsePathAppend(PRTVFSPARSEDPATH pPath, const char pszPath, uint16_t piRestartComp);
913
914	/**
915	* Parses a path.
916	*
917	* @retval VINF_SUCCESS
918	* @retval VERR_FILENAME_TOO_LONG
919	* @param pPath Where to store the parsed path.
920	* @param pszPath The path to parse. Absolute or relative to @a
921	* pszCwd.
922	* @param pszCwd The current working directory. Must be
923	* absolute.
924	*/
925	RTDECL(int) RTVfsParsePath(PRTVFSPARSEDPATH pPath, const char pszPath, const char pszCwd);
926
927	/**
928	* Same as RTVfsParsePath except that it allocates a temporary buffer.
929	*
930	* @retval VINF_SUCCESS
931	* @retval VERR_NO_TMP_MEMORY
932	* @retval VERR_FILENAME_TOO_LONG
933	* @param pszPath The path to parse. Absolute or relative to @a
934	* pszCwd.
935	* @param pszCwd The current working directory. Must be
936	* absolute.
937	* @param ppPath Where to store the pointer to the allocated
938	* buffer containing the parsed path. This must
939	* be freed by calling RTVfsParsePathFree. NULL
940	* will be stored on failured.
941	*/
942	RTDECL(int) RTVfsParsePathA(const char pszPath, const char pszCwd, PRTVFSPARSEDPATH *ppPath);
943
944	/**
945	* Frees a buffer returned by RTVfsParsePathA.
946	*
947	* @param pPath The parsed path buffer to free. NULL is fine.
948	*/
949	RTDECL(void) RTVfsParsePathFree(PRTVFSPARSEDPATH pPath);
950
951	/**
952	* Dummy implementation of RTVFSIOSTREAMOPS::pfnPollOne.
953	*
954	* This handles the case where there is no chance any events my be raised and
955	* all that is required is to wait according to the parameters.
956	*
957	* @returns IPRT status code.
958	* @param pvThis The implementation specific file data.
959	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
960	* @param cMillies How long to wait for event to eventuate.
961	* @param fIntr Whether the wait is interruptible and can return
962	* VERR_INTERRUPTED (@c true) or if this condition
963	* should be hidden from the caller (@c false).
964	* @param pfRetEvents Where to return the event mask.
965	* @sa RTVFSIOSTREAMOPS::pfnPollOne, RTPollSetAdd, RTPoll, RTPollNoResume.
966	*/
967	RTDECL(int) RTVfsUtilDummyPollOne(uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, uint32_t *pfRetEvents);
968
969	/** @} */
970
971
972	/** @defgroup grp_rt_vfs_lowlevel_chain VFS Chains
973	* @ref grp_rt_vfs_chain
974	* @{
975	*/
976
977
978	/**
979	* Chain element input actions.
980	*/
981	typedef enum RTVFSCHAINACTION
982	{
983	/** Invalid action. */
984	RTVFSCHAINACTION_INVALID = 0,
985	/** No action (start of the chain). */
986	RTVFSCHAINACTION_NONE,
987	/** Passive filtering (expressed by pipe symbol). */
988	RTVFSCHAINACTION_PASSIVE,
989	/** Push filtering (expressed by redirection-out symbol). */
990	RTVFSCHAINACTION_PUSH,
991	/** The end of the valid actions. */
992	RTVFSCHAINACTION_END,
993	/** Make sure it's a 32-bit type. */
994	RTVFSCHAINACTION_32BIT_HACK = 0x7fffffff
995	} RTVFSCHAINACTION;
996
997
998	/**
999	* VFS chain element specification.
1000	*/
1001	typedef struct RTVFSCHAINELEMSPEC
1002	{
1003	/** The provider name. */
1004	char *pszProvider;
1005	/** The input type. */
1006	RTVFSOBJTYPE enmTypeIn;
1007	/** The output type. */
1008	RTVFSOBJTYPE enmTypeOut;
1009	/** The action to take (or not). */
1010	RTVFSCHAINACTION enmAction;
1011	/** The number of arguments. */
1012	uint32_t cArgs;
1013	/** Arguments. */
1014	char **papszArgs;
1015	} RTVFSCHAINELEMSPEC;
1016	/** Pointer to a chain element specification. */
1017	typedef RTVFSCHAINELEMSPEC *PRTVFSCHAINELEMSPEC;
1018	/** Pointer to a const chain element specification. */
1019	typedef RTVFSCHAINELEMSPEC const *PCRTVFSCHAINELEMSPEC;
1020
1021
1022	/**
1023	* Parsed VFS chain specification.
1024	*/
1025	typedef struct RTVFSCHAINSPEC
1026	{
1027	/** The action element, UINT32_MAX if none.
1028	* Currently we only support one action element (RTVFSCHAINACTION_PASSIVE
1029	* is not considered). */
1030	uint32_t iActionElement;
1031	/** The number of elements. */
1032	uint32_t cElements;
1033	/** The elements. */
1034	PRTVFSCHAINELEMSPEC paElements;
1035	} RTVFSCHAINSPEC;
1036	/** Pointer to a parsed VFS chain specification. */
1037	typedef RTVFSCHAINSPEC *PRTVFSCHAINSPEC;
1038	/** Pointer to a const, parsed VFS chain specification. */
1039	typedef RTVFSCHAINSPEC const *PCRTVFSCHAINSPEC;
1040
1041
1042	/**
1043	* A chain element provider registration record.
1044	*/
1045	typedef struct RTVFSCHAINELEMENTREG
1046	{
1047	/** The version (RTVFSCHAINELEMENTREG_VERSION). */
1048	uint32_t uVersion;
1049	/** Reserved, MBZ. */
1050	uint32_t fReserved;
1051	/** The provider name (unique). */
1052	const char *pszName;
1053	/** For chaining the providers. */
1054	RTLISTNODE ListEntry;
1055
1056	/**
1057	* Create a VFS from the given chain element specficiation.
1058	*
1059	* @returns IPRT status code.
1060	* @param pSpec The chain element specification.
1061	* @param phVfs Where to returned the VFS handle.
1062	*/
1063	DECLCALLBACKMEMBER(int, pfnOpenVfs)( PCRTVFSCHAINELEMSPEC pSpec, PRTVFS phVfs);
1064
1065	/**
1066	* Open a directory from the given chain element specficiation.
1067	*
1068	* @returns IPRT status code.
1069	* @param pSpec The chain element specification.
1070	* @param phVfsDir Where to returned the directory handle.
1071	*/
1072	DECLCALLBACKMEMBER(int, pfnOpenDir)( PCRTVFSCHAINELEMSPEC pSpec, PRTVFSDIR phVfsDir);
1073
1074	/**
1075	* Open a file from the given chain element specficiation.
1076	*
1077	* @returns IPRT status code.
1078	* @param pSpec The chain element specification.
1079	* @param fOpen The open flag. Can be zero and the
1080	* specification may modify it.
1081	* @param phVfsFile Where to returned the file handle.
1082	*/
1083	DECLCALLBACKMEMBER(int, pfnOpenFile)( PCRTVFSCHAINELEMSPEC pSpec, uint32_t fOpen, PRTVFSFILE phVfsFile);
1084
1085	/**
1086	* Open a symlink from the given chain element specficiation.
1087	*
1088	* @returns IPRT status code.
1089	* @param pSpec The chain element specification.
1090	* @param phVfsSym Where to returned the symlink handle.
1091	*/
1092	DECLCALLBACKMEMBER(int, pfnOpenSymlink)( PCRTVFSCHAINELEMSPEC pSpec, PRTVFSSYMLINK phVfsSym);
1093
1094	/**
1095	* Open a I/O stream from the given chain element specficiation.
1096	*
1097	* @returns IPRT status code.
1098	* @param pSpec The chain element specification.
1099	* @param fOpen The open flag. Can be zero and the
1100	* specification may modify it.
1101	* @param phVfsIos Where to returned the I/O stream handle.
1102	*/
1103	DECLCALLBACKMEMBER(int, pfnOpenIoStream)(PCRTVFSCHAINELEMSPEC pSpec, uint32_t fOpen, PRTVFSIOSTREAM phVfsIos);
1104
1105	/**
1106	* Open a filesystem stream from the given chain element specficiation.
1107	*
1108	* @returns IPRT status code.
1109	* @param pSpec The chain element specification.
1110	* @param phVfsFss Where to returned the filesystem stream handle.
1111	*/
1112	DECLCALLBACKMEMBER(int, pfnOpenFsStream)(PCRTVFSCHAINELEMSPEC pSpec, PRTVFSFSSTREAM phVfsFss);
1113
1114	/** End marker (RTVFSCHAINELEMENTREG_VERSION). */
1115	uintptr_t uEndMarker;
1116	} RTVFSCHAINELEMENTREG;
1117	/** Pointer to a VFS chain element registration record. */
1118	typedef RTVFSCHAINELEMENTREG *PRTVFSCHAINELEMENTREG;
1119	/** Pointer to a const VFS chain element registration record. */
1120	typedef RTVFSCHAINELEMENTREG const *PCRTVFSCHAINELEMENTREG;
1121
1122	/** The VFS chain element registration record version number. */
1123	#define RTVFSCHAINELEMENTREG_VERSION RT_MAKE_U32_FROM_U8(0xff, 0x7f, 1, 0)
1124
1125
1126	/**
1127	* Parses the specification.
1128	*
1129	* @returns IPRT status code.
1130	* @param pszSpec The specification string to parse.
1131	* @param fFlags Flags, see RTVFSCHAIN_PF_XXX.
1132	* @param enmLeadingAction The only allowed leading action type.
1133	* @param enmTrailingAction The only allowed trailing action type.
1134	* @param ppSpec Where to return the pointer to the parsed
1135	* specification. This must be freed by calling
1136	* RTVfsChainSpecFree. Will always be set (unless
1137	* invalid parameters.)
1138	* @param ppszError On failure, this will point at the error
1139	* location in @a pszSpec. Optional.
1140	*/
1141	RTDECL(int) RTVfsChainSpecParse(const char *pszSpec, uint32_t fFlags, RTVFSCHAINACTION enmLeadingAction,
1142	RTVFSCHAINACTION enmTrailingAction,
1143	PRTVFSCHAINSPEC ppSpec, const char *ppszError);
1144
1145	/** @name RTVfsChainSpecParse
1146	* @{ */
1147	/** No real action is permitted, i.e. only passive filtering (aka pipe). */
1148	#define RTVFSCHAIN_PF_NO_REAL_ACTION RT_BIT_32(0)
1149	/** The specified leading action is optional. */
1150	#define RTVFSCHAIN_PF_LEADING_ACTION_OPTIONAL RT_BIT_32(1)
1151	/** The specified trailing action is optional. */
1152	#define RTVFSCHAIN_PF_TRAILING_ACTION_OPTIONAL RT_BIT_32(2)
1153	/** Mask of valid flags. */
1154	#define RTVFSCHAIN_PF_VALID_MASK UINT32_C(0x00000007)
1155	/** @}*/
1156
1157	/**
1158	* Frees a parsed chain specification.
1159	*
1160	* @param pSpec What RTVfsChainSpecParse returned. NULL is
1161	* quietly ignored.
1162	*/
1163	RTDECL(void) RTVfsChainSpecFree(PRTVFSCHAINSPEC pSpec);
1164
1165	/**
1166	* Registers a chain element provider.
1167	*
1168	* @returns IPRT status code
1169	* @param pRegRec The registration record.
1170	* @param fFromCtor Indicates where we're called from.
1171	*/
1172	RTDECL(int) RTVfsChainElementRegisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromCtor);
1173
1174	/**
1175	* Deregisters a chain element provider.
1176	*
1177	* @returns IPRT status code
1178	* @param pRegRec The registration record.
1179	* @param fFromDtor Indicates where we're called from.
1180	*/
1181	RTDECL(int) RTVfsChainElementDeregisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromDtor);
1182
1183
1184	/** @def RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER
1185	* Automatically registers a chain element provider using a global constructor
1186	* and destructor hack.
1187	*
1188	* @param pRegRec Pointer to the registration record.
1189	* @param name Some unique variable name prefix.
1190	*/
1191
1192	#ifdef __cplusplus
1193	/**
1194	* Class used for registering a VFS chain element provider.
1195	*/
1196	class RTVfsChainElementAutoRegisterHack
1197	{
1198	private:
1199	/** The registration record, NULL if registration failed. */
1200	PRTVFSCHAINELEMENTREG m_pRegRec;
1201
1202	public:
1203	RTVfsChainElementAutoRegisterHack(PRTVFSCHAINELEMENTREG a_pRegRec)
1204	: m_pRegRec(a_pRegRec)
1205	{
1206	int rc = RTVfsChainElementRegisterProvider(m_pRegRec, true);
1207	if (RT_FAILURE(rc))
1208	m_pRegRec = NULL;
1209	}
1210
1211	~RTVfsChainElementAutoRegisterHack()
1212	{
1213	RTVfsChainElementDeregisterProvider(m_pRegRec, true);
1214	m_pRegRec = NULL;
1215	}
1216	};
1217
1218	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1219	static RTVfsChainElementAutoRegisterHack name ## AutoRegistrationHack(pRegRec)
1220
1221	#else
1222	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1223	extern void *name ## AutoRegistrationHack = \
1224	&Sorry_but_RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER_does_not_work_in_c_source_files
1225	#endif
1226
1227
1228	/** @} */
1229
1230
1231	/** @} */
1232
1233	RT_C_DECLS_END
1234
1235	#endif /* !___iprt_vfslowlevel_h */
1236

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source: vbox/trunk/include/iprt/vfslowlevel.h@ 41549

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