vfslowlevel.h@ 78377

Last change on this file since 78377 was 77047, checked in by vboxsync, 6 years ago
iprt/isomaker: Optimized native handle (file descriptor) usage when adding real directories.
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1	/** @file
2	* IPRT - Virtual Filesystem.
3	*/
4
5	/*
6	* Copyright (C) 2010-2019 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_INCLUDED_vfslowlevel_h
27	#define IPRT_INCLUDED_vfslowlevel_h
28	#ifndef RT_WITHOUT_PRAGMA_ONCE
29	# pragma once
30	#endif
31
32	#include <iprt/vfs.h>
33	#include <iprt/errcore.h>
34	#include <iprt/list.h>
35	#include <iprt/param.h>
36
37
38	RT_C_DECLS_BEGIN
39
40	/** @defgroup grp_rt_vfs_lowlevel RTVfs - Low-level Interface.
41	* @ingroup grp_rt_vfs
42	* @{
43	*/
44
45
46	/** @name VFS Lock Abstraction
47	* @todo This should be moved somewhere else as it is of general use.
48	* @{ */
49
50	/**
51	* VFS lock types.
52	*/
53	typedef enum RTVFSLOCKTYPE
54	{
55	/** Invalid lock type. */
56	RTVFSLOCKTYPE_INVALID = 0,
57	/** Read write semaphore. */
58	RTVFSLOCKTYPE_RW,
59	/** Fast mutex semaphore (critical section in ring-3). */
60	RTVFSLOCKTYPE_FASTMUTEX,
61	/** Full fledged mutex semaphore. */
62	RTVFSLOCKTYPE_MUTEX,
63	/** The end of valid lock types. */
64	RTVFSLOCKTYPE_END,
65	/** The customary 32-bit type hack. */
66	RTVFSLOCKTYPE_32BIT_HACK = 0x7fffffff
67	} RTVFSLOCKTYPE;
68
69	/** VFS lock handle. */
70	typedef struct RTVFSLOCKINTERNAL *RTVFSLOCK;
71	/** Pointer to a VFS lock handle. */
72	typedef RTVFSLOCK *PRTVFSLOCK;
73	/** Nil VFS lock handle. */
74	#define NIL_RTVFSLOCK ((RTVFSLOCK)~(uintptr_t)0)
75
76	/** Special handle value for creating a new read/write semaphore based lock. */
77	#define RTVFSLOCK_CREATE_RW ((RTVFSLOCK)~(uintptr_t)1)
78	/** Special handle value for creating a new fast mutex semaphore based lock. */
79	#define RTVFSLOCK_CREATE_FASTMUTEX ((RTVFSLOCK)~(uintptr_t)2)
80	/** Special handle value for creating a new mutex semaphore based lock. */
81	#define RTVFSLOCK_CREATE_MUTEX ((RTVFSLOCK)~(uintptr_t)3)
82
83	/**
84	* Retains a reference to the VFS lock handle.
85	*
86	* @returns New reference count on success, UINT32_MAX on failure.
87	* @param hLock The VFS lock handle.
88	*/
89	RTDECL(uint32_t) RTVfsLockRetain(RTVFSLOCK hLock);
90
91	/**
92	* Releases a reference to the VFS lock handle.
93	*
94	* @returns New reference count on success (0 if closed), UINT32_MAX on failure.
95	* @param hLock The VFS lock handle.
96	*/
97	RTDECL(uint32_t) RTVfsLockRelease(RTVFSLOCK hLock);
98
99	/**
100	* Gets the lock type.
101	*
102	* @returns The lock type on success, RTVFSLOCKTYPE_INVALID if the handle is
103	* not valid.
104	* @param hLock The lock handle.
105	*/
106	RTDECL(RTVFSLOCKTYPE) RTVfsLockGetType(RTVFSLOCK hLock);
107
108
109
110	RTDECL(void) RTVfsLockAcquireReadSlow(RTVFSLOCK hLock);
111	RTDECL(void) RTVfsLockReleaseReadSlow(RTVFSLOCK hLock);
112	RTDECL(void) RTVfsLockAcquireWriteSlow(RTVFSLOCK hLock);
113	RTDECL(void) RTVfsLockReleaseWriteSlow(RTVFSLOCK hLock);
114
115	/**
116	* Acquire a read lock.
117	*
118	* @param hLock The lock handle, can be NIL.
119	*/
120	DECLINLINE(void) RTVfsLockAcquireRead(RTVFSLOCK hLock)
121	{
122	if (hLock != NIL_RTVFSLOCK)
123	RTVfsLockAcquireReadSlow(hLock);
124	}
125
126
127	/**
128	* Release a read lock.
129	*
130	* @param hLock The lock handle, can be NIL.
131	*/
132	DECLINLINE(void) RTVfsLockReleaseRead(RTVFSLOCK hLock)
133	{
134	if (hLock != NIL_RTVFSLOCK)
135	RTVfsLockReleaseReadSlow(hLock);
136	}
137
138
139	/**
140	* Acquire a write lock.
141	*
142	* @param hLock The lock handle, can be NIL.
143	*/
144	DECLINLINE(void) RTVfsLockAcquireWrite(RTVFSLOCK hLock)
145	{
146	if (hLock != NIL_RTVFSLOCK)
147	RTVfsLockAcquireWriteSlow(hLock);
148	}
149
150
151	/**
152	* Release a write lock.
153	*
154	* @param hLock The lock handle, can be NIL.
155	*/
156	DECLINLINE(void) RTVfsLockReleaseWrite(RTVFSLOCK hLock)
157	{
158	if (hLock != NIL_RTVFSLOCK)
159	RTVfsLockReleaseWriteSlow(hLock);
160	}
161
162	/** @} */
163
164	/**
165	* The basis for all virtual file system objects.
166	*/
167	typedef struct RTVFSOBJOPS
168	{
169	/** The structure version (RTVFSOBJOPS_VERSION). */
170	uint32_t uVersion;
171	/** The object type for type introspection. */
172	RTVFSOBJTYPE enmType;
173	/** The name of the operations. */
174	const char *pszName;
175
176	/**
177	* Close the object.
178	*
179	* @returns IPRT status code.
180	* @param pvThis The implementation specific file data.
181	*/
182	DECLCALLBACKMEMBER(int, pfnClose)(void *pvThis);
183
184	/**
185	* Get information about the file.
186	*
187	* @returns IPRT status code. See RTVfsObjQueryInfo.
188	* @retval VERR_WRONG_TYPE if file system or file system stream.
189	* @param pvThis The implementation specific file data.
190	* @param pObjInfo Where to return the object info on success.
191	* @param enmAddAttr Which set of additional attributes to request.
192	* @sa RTVfsObjQueryInfo, RTFileQueryInfo, RTPathQueryInfo
193	*/
194	DECLCALLBACKMEMBER(int, pfnQueryInfo)(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr);
195
196	/** Marks the end of the structure (RTVFSOBJOPS_VERSION). */
197	uintptr_t uEndMarker;
198	} RTVFSOBJOPS;
199	/** Pointer to constant VFS object operations. */
200	typedef RTVFSOBJOPS const *PCRTVFSOBJOPS;
201
202	/** The RTVFSOBJOPS structure version. */
203	#define RTVFSOBJOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x1f,1,0)
204
205
206	/**
207	* The VFS operations.
208	*/
209	typedef struct RTVFSOPS
210	{
211	/** The basic object operation. */
212	RTVFSOBJOPS Obj;
213	/** The structure version (RTVFSOPS_VERSION). */
214	uint32_t uVersion;
215	/** The virtual file system feature mask. */
216	uint32_t fFeatures;
217
218	/**
219	* Opens the root directory.
220	*
221	* @returns IPRT status code.
222	* @param pvThis The implementation specific data.
223	* @param phVfsDir Where to return the handle to the root directory.
224	*/
225	DECLCALLBACKMEMBER(int, pfnOpenRoot)(void *pvThis, PRTVFSDIR phVfsDir);
226
227	/**
228	* Query the status of the given storage range (optional).
229	*
230	* This can be used by the image compaction utilites to evict non-zero blocks
231	* that aren't currently being used by the file system.
232	*
233	* @returns IPRT status code.
234	* @param pvThis The implementation specific data.
235	* @param off Start offset to check.
236	* @param cb Number of bytes to check.
237	* @param pfUsed Where to store whether the given range is in use.
238	*/
239	DECLCALLBACKMEMBER(int, pfnQueryRangeState)(void pvThis, uint64_t off, size_t cb, bool pfUsed);
240
241	/** @todo There will be more methods here to optimize opening and
242	* querying. */
243
244	#if 0
245	/**
246	* Optional entry point for optimizing path traversal within the file system.
247	*
248	* @returns IPRT status code.
249	* @param pvThis The implementation specific data.
250	* @param pszPath The path to resolve.
251	* @param poffPath The current path offset on input, what we've
252	* traversed to on successful return.
253	* @param phVfs??? Return handle to what we've traversed.
254	* @param p??? Return other stuff...
255	*/
256	DECLCALLBACKMEMBER(int, pfnTraverse)(void pvThis, const char pszPath, size_t poffPath, PRTVFS??? phVfs?, ??? p???);
257	#endif
258
259	/** @todo need rename API */
260
261	/** Marks the end of the structure (RTVFSOPS_VERSION). */
262	uintptr_t uEndMarker;
263	} RTVFSOPS;
264	/** Pointer to constant VFS operations. */
265	typedef RTVFSOPS const *PCRTVFSOPS;
266
267	/** The RTVFSOPS structure version. */
268	#define RTVFSOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x0f,1,0)
269
270	/** @name RTVFSOPS::fFeatures
271	* @{ */
272	/** The VFS supports attaching other systems. */
273	#define RTVFSOPS_FEAT_ATTACH RT_BIT_32(0)
274	/** @} */
275
276	/**
277	* Creates a new VFS handle.
278	*
279	* @returns IPRT status code
280	* @param pVfsOps The VFS operations.
281	* @param cbInstance The size of the instance data.
282	* @param hVfs The VFS handle to associate this VFS with.
283	* NIL_VFS is ok.
284	* @param hLock Handle to a custom lock to be used with the new
285	* object. The reference is consumed. NIL and
286	* special lock handles are fine.
287	* @param phVfs Where to return the new handle.
288	* @param ppvInstance Where to return the pointer to the instance data
289	* (size is @a cbInstance).
290	*/
291	RTDECL(int) RTVfsNew(PCRTVFSOPS pVfsOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
292	PRTVFS phVfs, void **ppvInstance);
293
294
295	/**
296	* Creates a new VFS base object handle.
297	*
298	* @returns IPRT status code
299	* @param pObjOps The base object operations.
300	* @param cbInstance The size of the instance data.
301	* @param hVfs The VFS handle to associate this base object
302	* with. NIL_VFS is ok.
303	* @param hLock Handle to a custom lock to be used with the new
304	* object. The reference is consumed. NIL and
305	* special lock handles are fine.
306	* @param phVfsObj Where to return the new handle.
307	* @param ppvInstance Where to return the pointer to the instance data
308	* (size is @a cbInstance).
309	*/
310	RTDECL(int) RTVfsNewBaseObj(PCRTVFSOBJOPS pObjOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
311	PRTVFSOBJ phVfsObj, void **ppvInstance);
312
313
314	/**
315	* Additional operations for setting object attributes.
316	*/
317	typedef struct RTVFSOBJSETOPS
318	{
319	/** The structure version (RTVFSOBJSETOPS_VERSION). */
320	uint32_t uVersion;
321	/** The offset back to the RTVFSOBJOPS structure. */
322	uint32_t offObjOps;
323
324	/**
325	* Set the unix style owner and group.
326	*
327	* @returns IPRT status code.
328	* @param pvThis The implementation specific file data.
329	* @param fMode The new mode bits.
330	* @param fMask The mask indicating which bits we are
331	* changing.
332	* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
333	* @sa RTFileSetMode
334	*/
335	DECLCALLBACKMEMBER(int, pfnSetMode)(void *pvThis, RTFMODE fMode, RTFMODE fMask);
336
337	/**
338	* Set the timestamps associated with the object.
339	*
340	* @returns IPRT status code.
341	* @param pvThis The implementation specific file data.
342	* @param pAccessTime Pointer to the new access time. NULL if not
343	* to be changed.
344	* @param pModificationTime Pointer to the new modifcation time. NULL if
345	* not to be changed.
346	* @param pChangeTime Pointer to the new change time. NULL if not
347	* to be changed.
348	* @param pBirthTime Pointer to the new time of birth. NULL if
349	* not to be changed.
350	* @remarks See RTFileSetTimes for restrictions and behavior imposed by the
351	* host OS or underlying VFS provider.
352	* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
353	* @sa RTFileSetTimes
354	*/
355	DECLCALLBACKMEMBER(int, pfnSetTimes)(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime,
356	PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime);
357
358	/**
359	* Set the unix style owner and group.
360	*
361	* @returns IPRT status code.
362	* @param pvThis The implementation specific file data.
363	* @param uid The user ID of the new owner. NIL_RTUID if
364	* unchanged.
365	* @param gid The group ID of the new owner group. NIL_RTGID if
366	* unchanged.
367	* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
368	* @sa RTFileSetOwner
369	*/
370	DECLCALLBACKMEMBER(int, pfnSetOwner)(void *pvThis, RTUID uid, RTGID gid);
371
372	/** Marks the end of the structure (RTVFSOBJSETOPS_VERSION). */
373	uintptr_t uEndMarker;
374	} RTVFSOBJSETOPS;
375	/** Pointer to const object attribute setter operations. */
376	typedef RTVFSOBJSETOPS const *PCRTVFSOBJSETOPS;
377
378	/** The RTVFSOBJSETOPS structure version. */
379	#define RTVFSOBJSETOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x2f,1,0)
380
381
382	/**
383	* The filesystem stream operations.
384	*
385	* @extends RTVFSOBJOPS
386	*/
387	typedef struct RTVFSFSSTREAMOPS
388	{
389	/** The basic object operation. */
390	RTVFSOBJOPS Obj;
391	/** The structure version (RTVFSFSSTREAMOPS_VERSION). */
392	uint32_t uVersion;
393	/** Reserved field, MBZ. */
394	uint32_t fReserved;
395
396	/**
397	* Gets the next object in the stream.
398	*
399	* Readable streams only.
400	*
401	* @returns IPRT status code.
402	* @retval VINF_SUCCESS if a new object was retrieved.
403	* @retval VERR_EOF when there are no more objects.
404	* @param pvThis The implementation specific directory data.
405	* @param ppszName Where to return the object name. Must be freed by
406	* calling RTStrFree.
407	* @param penmType Where to return the object type.
408	* @param phVfsObj Where to return the object handle (referenced). This
409	* must be cast to the desired type before use.
410	* @sa RTVfsFsStrmNext
411	*
412	* @note Setting this member to NULL is okay for write-only streams.
413	*/
414	DECLCALLBACKMEMBER(int, pfnNext)(void pvThis, char ppszName, RTVFSOBJTYPE penmType, PRTVFSOBJ phVfsObj);
415
416	/**
417	* Adds another object into the stream.
418	*
419	* Writable streams only.
420	*
421	* @returns IPRT status code.
422	* @param pvThis The implementation specific directory data.
423	* @param pszPath The path to the object.
424	* @param hVfsObj The object to add.
425	* @param fFlags Reserved for the future, MBZ.
426	* @sa RTVfsFsStrmAdd
427	*
428	* @note Setting this member to NULL is okay for read-only streams.
429	*/
430	DECLCALLBACKMEMBER(int, pfnAdd)(void pvThis, const char pszPath, RTVFSOBJ hVfsObj, uint32_t fFlags);
431
432	/**
433	* Pushes an byte stream onto the stream (optional).
434	*
435	* Writable streams only.
436	*
437	* This differs from RTVFSFSSTREAMOPS::pfnAdd() in that it will create a regular
438	* file in the output file system stream and provide the actual content bytes
439	* via the returned I/O stream object.
440	*
441	* @returns IPRT status code.
442	* @param pvThis The implementation specific directory data.
443	* @param pszPath The path to the file.
444	* @param cbFile The file size. This can also be set to UINT64_MAX if
445	* the file system stream is backed by a file.
446	* @param paObjInfo Array of zero or more RTFSOBJINFO structures containing
447	* different pieces of information about the file. If any
448	* provided, the first one should be a RTFSOBJATTRADD_UNIX
449	* one, additional can be supplied if wanted. What exactly
450	* is needed depends on the underlying FS stream
451	* implementation.
452	* @param cObjInfo Number of items in the array @a paObjInfo points at.
453	* @param fFlags RTVFSFSSTRM_PUSH_F_XXX.
454	* @param phVfsIos Where to return the I/O stream to feed the file content
455	* to. If the FS stream is backed by a file, the returned
456	* handle can be cast to a file if necessary.
457	*/
458	DECLCALLBACKMEMBER(int, pfnPushFile)(void pvThis, const char pszPath, uint64_t cbFile,
459	PCRTFSOBJINFO paObjInfo, uint32_t cObjInfo, uint32_t fFlags, PRTVFSIOSTREAM phVfsIos);
460
461	/**
462	* Marks the end of the stream.
463	*
464	* Writable streams only.
465	*
466	* @returns IPRT status code.
467	* @param pvThis The implementation specific directory data.
468	* @sa RTVfsFsStrmEnd
469	*
470	* @note Setting this member to NULL is okay for read-only streams.
471	*/
472	DECLCALLBACKMEMBER(int, pfnEnd)(void *pvThis);
473
474	/** Marks the end of the structure (RTVFSFSSTREAMOPS_VERSION). */
475	uintptr_t uEndMarker;
476	} RTVFSFSSTREAMOPS;
477	/** Pointer to const object attribute setter operations. */
478	typedef RTVFSFSSTREAMOPS const *PCRTVFSFSSTREAMOPS;
479
480	/** The RTVFSFSSTREAMOPS structure version. */
481	#define RTVFSFSSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x3f,2,0)
482
483
484	/**
485	* Creates a new VFS filesystem stream handle.
486	*
487	* @returns IPRT status code
488	* @param pFsStreamOps The filesystem stream operations.
489	* @param cbInstance The size of the instance data.
490	* @param hVfs The VFS handle to associate this filesystem
491	* stream with. NIL_VFS is ok.
492	* @param hLock Handle to a custom lock to be used with the new
493	* object. The reference is consumed. NIL and
494	* special lock handles are fine.
495	* @param fReadOnly Set if read-only, clear if write-only.
496	* @param phVfsFss Where to return the new handle.
497	* @param ppvInstance Where to return the pointer to the instance data
498	* (size is @a cbInstance).
499	*/
500	RTDECL(int) RTVfsNewFsStream(PCRTVFSFSSTREAMOPS pFsStreamOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock, bool fReadOnly,
501	PRTVFSFSSTREAM phVfsFss, void **ppvInstance);
502
503	/**
504	* Gets the private data of an filesystem stream.
505	*
506	* @returns Pointer to the private data. NULL if the handle is invalid in some
507	* way.
508	* @param hVfsFss The FS stream handle.
509	* @param pFsStreamOps The FS stream operations. This servers as a
510	* sort of password.
511	*/
512	RTDECL(void *) RTVfsFsStreamToPrivate(RTVFSFSSTREAM hVfsFss, PCRTVFSFSSTREAMOPS pFsStreamOps);
513
514
515	/**
516	* The directory operations.
517	*
518	* @extends RTVFSOBJOPS
519	* @extends RTVFSOBJSETOPS
520	*/
521	typedef struct RTVFSDIROPS
522	{
523	/** The basic object operation. */
524	RTVFSOBJOPS Obj;
525	/** The structure version (RTVFSDIROPS_VERSION). */
526	uint32_t uVersion;
527	/** Reserved field, MBZ. */
528	uint32_t fReserved;
529	/** The object setter operations. */
530	RTVFSOBJSETOPS ObjSet;
531
532	/**
533	* Generic method for opening any kind of file system object.
534	*
535	* Can also create files and directories. Symbolic links, devices and such
536	* needs to be created using special methods or this would end up being way more
537	* complicated than it already is.
538	*
539	* There are optional specializations available.
540	*
541	* @returns IPRT status code.
542	* @retval VERR_PATH_NOT_FOUND or VERR_FILE_NOT_FOUND if @a pszEntry was not
543	* found.
544	* @retval VERR_IS_A_FILE if @a pszEntry is a file or similar but @a fFlags
545	* indicates that the type of object should not be opened.
546	* @retval VERR_IS_A_DIRECTORY if @a pszEntry is a directory but @a fFlags
547	* indicates that directories should not be opened.
548	* @retval VERR_IS_A_SYMLINK if @a pszEntry is a symbolic link but @a fFlags
549	* indicates that symbolic links should not be opened (or followed).
550	* @retval VERR_IS_A_FIFO if @a pszEntry is a FIFO but @a fFlags indicates that
551	* FIFOs should not be opened.
552	* @retval VERR_IS_A_SOCKET if @a pszEntry is a socket but @a fFlags indicates
553	* that sockets should not be opened.
554	* @retval VERR_IS_A_BLOCK_DEVICE if @a pszEntry is a block device but
555	* @a fFlags indicates that block devices should not be opened.
556	* @retval VERR_IS_A_BLOCK_DEVICE if @a pszEntry is a character device but
557	* @a fFlags indicates that character devices should not be opened.
558	*
559	* @param pvThis The implementation specific directory data.
560	* @param pszEntry The name of the immediate file to open or create.
561	* @param fOpenFile RTFILE_O_XXX combination.
562	* @param fObjFlags More flags: RTVFSOBJ_F_XXX, RTPATH_F_XXX.
563	* The meaning of RTPATH_F_FOLLOW_LINK differs here, if
564	* @a pszEntry is a symlink it should be opened for
565	* traversal rather than according to @a fOpenFile.
566	* @param phVfsObj Where to return the handle to the opened object.
567	* @sa RTFileOpen, RTDirOpen
568	*/
569	DECLCALLBACKMEMBER(int, pfnOpen)(void pvThis, const char pszEntry, uint64_t fOpenFile,
570	uint32_t fObjFlags, PRTVFSOBJ phVfsObj);
571
572	/**
573	* Optional method for symbolic link handling in the vfsstddir.cpp.
574	*
575	* This is really just a hack to make symbolic link handling work when working
576	* with directory objects that doesn't have an associated VFS. It also helps
577	* deal with drive letters in symbolic links on Windows and OS/2.
578	*
579	* @returns IPRT status code.
580	* @retval VERR_PATH_IS_RELATIVE if @a pszPath isn't absolute and should be
581	* handled using pfnOpen().
582	*
583	* @param pvThis The implementation specific directory data.
584	* @param pszRoot Path to the alleged root.
585	* @param phVfsDir Where to return the handle to the specified root
586	* directory (or may current dir on a drive letter).
587	*/
588	DECLCALLBACKMEMBER(int, pfnFollowAbsoluteSymlink)(void pvThis, const char pszRoot, PRTVFSDIR phVfsDir);
589
590	/**
591	* Open or create a file.
592	*
593	* @returns IPRT status code.
594	* @param pvThis The implementation specific directory data.
595	* @param pszFilename The name of the immediate file to open or create.
596	* @param fOpen The open flags (RTFILE_O_XXX).
597	* @param phVfsFile Where to return the handle to the opened file.
598	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
599	* @sa RTFileOpen.
600	*/
601	DECLCALLBACKMEMBER(int, pfnOpenFile)(void pvThis, const char pszFilename, uint64_t fOpen, PRTVFSFILE phVfsFile);
602
603	/**
604	* Open an existing subdirectory.
605	*
606	* @returns IPRT status code.
607	* @retval VERR_IS_A_SYMLINK if @a pszSubDir is a symbolic link.
608	* @retval VERR_NOT_A_DIRECTORY is okay for symbolic links too.
609	*
610	* @param pvThis The implementation specific directory data.
611	* @param pszSubDir The name of the immediate subdirectory to open.
612	* @param fFlags RTDIR_F_XXX.
613	* @param phVfsDir Where to return the handle to the opened directory.
614	* Optional.
615	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
616	* @sa RTDirOpen.
617	*/
618	DECLCALLBACKMEMBER(int, pfnOpenDir)(void pvThis, const char pszSubDir, uint32_t fFlags, PRTVFSDIR phVfsDir);
619
620	/**
621	* Creates a new subdirectory.
622	*
623	* @returns IPRT status code.
624	* @param pvThis The implementation specific directory data.
625	* @param pszSubDir The name of the immediate subdirectory to create.
626	* @param fMode The mode mask of the new directory.
627	* @param phVfsDir Where to optionally return the handle to the newly
628	* create directory.
629	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
630	* @sa RTDirCreate.
631	*/
632	DECLCALLBACKMEMBER(int, pfnCreateDir)(void pvThis, const char pszSubDir, RTFMODE fMode, PRTVFSDIR phVfsDir);
633
634	/**
635	* Opens an existing symbolic link.
636	*
637	* @returns IPRT status code.
638	* @param pvThis The implementation specific directory data.
639	* @param pszSymlink The name of the immediate symbolic link to open.
640	* @param phVfsSymlink Where to optionally return the handle to the
641	* newly create symbolic link.
642	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
643	* @sa RTSymlinkCreate.
644	*/
645	DECLCALLBACKMEMBER(int, pfnOpenSymlink)(void pvThis, const char pszSymlink, PRTVFSSYMLINK phVfsSymlink);
646
647	/**
648	* Creates a new symbolic link.
649	*
650	* @returns IPRT status code.
651	* @param pvThis The implementation specific directory data.
652	* @param pszSymlink The name of the immediate symbolic link to create.
653	* @param pszTarget The symbolic link target.
654	* @param enmType The symbolic link type.
655	* @param phVfsSymlink Where to optionally return the handle to the
656	* newly create symbolic link.
657	* @sa RTSymlinkCreate.
658	*/
659	DECLCALLBACKMEMBER(int, pfnCreateSymlink)(void pvThis, const char pszSymlink, const char *pszTarget,
660	RTSYMLINKTYPE enmType, PRTVFSSYMLINK phVfsSymlink);
661
662	/**
663	* Query information about an entry.
664	*
665	* @returns IPRT status code.
666	* @param pvThis The implementation specific directory data.
667	* @param pszEntry The name of the directory entry to remove.
668	* @param pObjInfo Where to return the info on success.
669	* @param enmAddAttr Which set of additional attributes to request.
670	* @note Optional. RTVFSDIROPS::pfnOpenObj and RTVFSOBJOPS::pfnQueryInfo
671	* will be used if NULL.
672	* @sa RTPathQueryInfo, RTVFSOBJOPS::pfnQueryInfo
673	*/
674	DECLCALLBACKMEMBER(int, pfnQueryEntryInfo)(void pvThis, const char pszEntry,
675	PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr);
676
677	/**
678	* Removes a directory entry.
679	*
680	* @returns IPRT status code.
681	* @param pvThis The implementation specific directory data.
682	* @param pszEntry The name of the directory entry to remove.
683	* @param fType If non-zero, this restricts the type of the entry to
684	* the object type indicated by the mask
685	* (RTFS_TYPE_XXX).
686	* @sa RTFileRemove, RTDirRemove, RTSymlinkRemove.
687	*/
688	DECLCALLBACKMEMBER(int, pfnUnlinkEntry)(void pvThis, const char pszEntry, RTFMODE fType);
689
690	/**
691	* Renames a directory entry.
692	*
693	* @returns IPRT status code.
694	* @param pvThis The implementation specific directory data.
695	* @param pszEntry The name of the directory entry to rename.
696	* @param fType If non-zero, this restricts the type of the entry to
697	* the object type indicated by the mask
698	* (RTFS_TYPE_XXX).
699	* @param pszNewName The new entry name.
700	* @sa RTPathRename
701	*
702	* @todo This API is not flexible enough, must be able to rename between
703	* directories within a file system.
704	*/
705	DECLCALLBACKMEMBER(int, pfnRenameEntry)(void pvThis, const char pszEntry, RTFMODE fType, const char *pszNewName);
706
707	/**
708	* Rewind the directory stream so that the next read returns the first
709	* entry.
710	*
711	* @returns IPRT status code.
712	* @param pvThis The implementation specific directory data.
713	*/
714	DECLCALLBACKMEMBER(int, pfnRewindDir)(void *pvThis);
715
716	/**
717	* Rewind the directory stream so that the next read returns the first
718	* entry.
719	*
720	* @returns IPRT status code.
721	* @param pvThis The implementation specific directory data.
722	* @param pDirEntry Output buffer.
723	* @param pcbDirEntry Complicated, see RTDirReadEx.
724	* @param enmAddAttr Which set of additional attributes to request.
725	* @sa RTDirReadEx
726	*/
727	DECLCALLBACKMEMBER(int, pfnReadDir)(void pvThis, PRTDIRENTRYEX pDirEntry, size_t pcbDirEntry, RTFSOBJATTRADD enmAddAttr);
728
729	/** Marks the end of the structure (RTVFSDIROPS_VERSION). */
730	uintptr_t uEndMarker;
731	} RTVFSDIROPS;
732	/** Pointer to const directory operations. */
733	typedef RTVFSDIROPS const *PCRTVFSDIROPS;
734	/** The RTVFSDIROPS structure version. */
735	#define RTVFSDIROPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x4f,1,0)
736
737
738	/**
739	* Creates a new VFS directory handle.
740	*
741	* @returns IPRT status code
742	* @param pDirOps The directory operations.
743	* @param cbInstance The size of the instance data.
744	* @param fFlags RTVFSDIR_F_XXX
745	* @param hVfs The VFS handle to associate this directory with.
746	* NIL_VFS is ok.
747	* @param hLock Handle to a custom lock to be used with the new
748	* object. The reference is consumed. NIL and
749	* special lock handles are fine.
750	* @param phVfsDir Where to return the new handle.
751	* @param ppvInstance Where to return the pointer to the instance data
752	* (size is @a cbInstance).
753	*/
754	RTDECL(int) RTVfsNewDir(PCRTVFSDIROPS pDirOps, size_t cbInstance, uint32_t fFlags, RTVFS hVfs, RTVFSLOCK hLock,
755	PRTVFSDIR phVfsDir, void **ppvInstance);
756
757	/** @name RTVFSDIR_F_XXX
758	* @{ */
759	/** Don't reference the @a hVfs parameter passed to RTVfsNewDir.
760	* This is a permanent root directory hack. */
761	#define RTVFSDIR_F_NO_VFS_REF RT_BIT_32(0)
762	/** @} */
763
764	/**
765	* Gets the private data of a directory.
766	*
767	* @returns Pointer to the private data. NULL if the handle is invalid in some
768	* way.
769	* @param hVfsDir The directory handle.
770	* @param pDirOps The directory operations. This servers as a
771	* sort of password.
772	*/
773	RTDECL(void *) RTVfsDirToPrivate(RTVFSDIR hVfsDir, PCRTVFSDIROPS pDirOps);
774
775
776	/**
777	* The symbolic link operations.
778	*
779	* @extends RTVFSOBJOPS
780	* @extends RTVFSOBJSETOPS
781	*/
782	typedef struct RTVFSSYMLINKOPS
783	{
784	/** The basic object operation. */
785	RTVFSOBJOPS Obj;
786	/** The structure version (RTVFSSYMLINKOPS_VERSION). */
787	uint32_t uVersion;
788	/** Reserved field, MBZ. */
789	uint32_t fReserved;
790	/** The object setter operations. */
791	RTVFSOBJSETOPS ObjSet;
792
793	/**
794	* Read the symbolic link target.
795	*
796	* @returns IPRT status code.
797	* @param pvThis The implementation specific symbolic link data.
798	* @param pszTarget The target buffer.
799	* @param cbTarget The size of the target buffer.
800	* @sa RTSymlinkRead
801	*/
802	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, char pszTarget, size_t cbTarget);
803
804	/** Marks the end of the structure (RTVFSSYMLINKOPS_VERSION). */
805	uintptr_t uEndMarker;
806	} RTVFSSYMLINKOPS;
807	/** Pointer to const symbolic link operations. */
808	typedef RTVFSSYMLINKOPS const *PCRTVFSSYMLINKOPS;
809	/** The RTVFSSYMLINKOPS structure version. */
810	#define RTVFSSYMLINKOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x5f,1,0)
811
812
813	/**
814	* Creates a new VFS symlink handle.
815	*
816	* @returns IPRT status code
817	* @param pSymlinkOps The symlink operations.
818	* @param cbInstance The size of the instance data.
819	* @param hVfs The VFS handle to associate this symlink object
820	* with. NIL_VFS is ok.
821	* @param hLock Handle to a custom lock to be used with the new
822	* object. The reference is consumed. NIL and
823	* special lock handles are fine.
824	* @param phVfsSym Where to return the new handle.
825	* @param ppvInstance Where to return the pointer to the instance data
826	* (size is @a cbInstance).
827	*/
828	RTDECL(int) RTVfsNewSymlink(PCRTVFSSYMLINKOPS pSymlinkOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
829	PRTVFSSYMLINK phVfsSym, void **ppvInstance);
830
831
832	/**
833	* The basis for all I/O objects (files, pipes, sockets, devices, ++).
834	*
835	* @extends RTVFSOBJOPS
836	*/
837	typedef struct RTVFSIOSTREAMOPS
838	{
839	/** The basic object operation. */
840	RTVFSOBJOPS Obj;
841	/** The structure version (RTVFSIOSTREAMOPS_VERSION). */
842	uint32_t uVersion;
843	/** Feature field. */
844	uint32_t fFeatures;
845
846	/**
847	* Reads from the file/stream.
848	*
849	* @returns IPRT status code. See RTVfsIoStrmRead.
850	* @param pvThis The implementation specific file data.
851	* @param off Where to read at, -1 for the current position.
852	* @param pSgBuf Gather buffer describing the bytes that are to be
853	* written.
854	* @param fBlocking If @c true, the call is blocking, if @c false it
855	* should not block.
856	* @param pcbRead Where return the number of bytes actually read.
857	* This is set it 0 by the caller. If NULL, try read
858	* all and fail if incomplete.
859	* @sa RTVfsIoStrmRead, RTVfsIoStrmSgRead, RTVfsFileRead,
860	* RTVfsFileReadAt, RTFileRead, RTFileReadAt.
861	*/
862	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbRead);
863
864	/**
865	* Writes to the file/stream.
866	*
867	* @returns IPRT status code.
868	* @param pvThis The implementation specific file data.
869	* @param off Where to start wrinting, -1 for the current
870	* position.
871	* @param pSgBuf Gather buffers describing the bytes that are to be
872	* written.
873	* @param fBlocking If @c true, the call is blocking, if @c false it
874	* should not block.
875	* @param pcbWritten Where to return the number of bytes actually
876	* written. This is set it 0 by the caller. If
877	* NULL, try write it all and fail if incomplete.
878	* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
879	* @sa RTFileWrite, RTFileWriteAt.
880	*/
881	DECLCALLBACKMEMBER(int, pfnWrite)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbWritten);
882
883	/**
884	* Flushes any pending data writes to the stream.
885	*
886	* @returns IPRT status code.
887	* @param pvThis The implementation specific file data.
888	* @sa RTFileFlush.
889	*/
890	DECLCALLBACKMEMBER(int, pfnFlush)(void *pvThis);
891
892	/**
893	* Poll for events.
894	*
895	* @returns IPRT status code.
896	* @param pvThis The implementation specific file data.
897	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
898	* @param cMillies How long to wait for event to eventuate.
899	* @param fIntr Whether the wait is interruptible and can return
900	* VERR_INTERRUPTED (@c true) or if this condition
901	* should be hidden from the caller (@c false).
902	* @param pfRetEvents Where to return the event mask.
903	* @note Optional. If NULL, immediately return all requested non-error
904	* events, waiting for errors works like sleep.
905	* @sa RTPollSetAdd, RTPoll, RTPollNoResume.
906	*/
907	DECLCALLBACKMEMBER(int, pfnPollOne)(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr,
908	uint32_t *pfRetEvents);
909
910	/**
911	* Tells the current file/stream position.
912	*
913	* @returns IPRT status code.
914	* @param pvThis The implementation specific file data.
915	* @param poffActual Where to return the actual offset.
916	* @sa RTFileTell
917	*/
918	DECLCALLBACKMEMBER(int, pfnTell)(void *pvThis, PRTFOFF poffActual);
919
920	/**
921	* Skips @a cb ahead in the stream.
922	*
923	* @returns IPRT status code.
924	* @param pvThis The implementation specific file data.
925	* @param cb The number bytes to skip.
926	* @remarks This is optional and can be NULL.
927	*/
928	DECLCALLBACKMEMBER(int, pfnSkip)(void *pvThis, RTFOFF cb);
929
930	/**
931	* Fills the stream with @a cb zeros.
932	*
933	* @returns IPRT status code.
934	* @param pvThis The implementation specific file data.
935	* @param cb The number of zero bytes to insert.
936	* @remarks This is optional and can be NULL.
937	*/
938	DECLCALLBACKMEMBER(int, pfnZeroFill)(void *pvThis, RTFOFF cb);
939
940	/** Marks the end of the structure (RTVFSIOSTREAMOPS_VERSION). */
941	uintptr_t uEndMarker;
942	} RTVFSIOSTREAMOPS;
943	/** Pointer to const I/O stream operations. */
944	typedef RTVFSIOSTREAMOPS const *PCRTVFSIOSTREAMOPS;
945
946	/** The RTVFSIOSTREAMOPS structure version. */
947	#define RTVFSIOSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x6f,1,0)
948
949	/** @name RTVFSIOSTREAMOPS::fFeatures
950	* @{ */
951	/** No scatter gather lists, thank you. */
952	#define RTVFSIOSTREAMOPS_FEAT_NO_SG RT_BIT_32(0)
953	/** Mask of the valid I/O stream feature flags. */
954	#define RTVFSIOSTREAMOPS_FEAT_VALID_MASK UINT32_C(0x00000001)
955	/** @} */
956
957
958	/**
959	* Creates a new VFS I/O stream handle.
960	*
961	* @returns IPRT status code
962	* @param pIoStreamOps The I/O stream operations.
963	* @param cbInstance The size of the instance data.
964	* @param fOpen The open flags. The minimum is the access mask.
965	* @param hVfs The VFS handle to associate this I/O stream
966	* with. NIL_VFS is ok.
967	* @param hLock Handle to a custom lock to be used with the new
968	* object. The reference is consumed. NIL and
969	* special lock handles are fine.
970	* @param phVfsIos Where to return the new handle.
971	* @param ppvInstance Where to return the pointer to the instance data
972	* (size is @a cbInstance).
973	*/
974	RTDECL(int) RTVfsNewIoStream(PCRTVFSIOSTREAMOPS pIoStreamOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
975	PRTVFSIOSTREAM phVfsIos, void **ppvInstance);
976
977
978	/**
979	* Gets the private data of an I/O stream.
980	*
981	* @returns Pointer to the private data. NULL if the handle is invalid in some
982	* way.
983	* @param hVfsIos The I/O stream handle.
984	* @param pIoStreamOps The I/O stream operations. This servers as a
985	* sort of password.
986	*/
987	RTDECL(void *) RTVfsIoStreamToPrivate(RTVFSIOSTREAM hVfsIos, PCRTVFSIOSTREAMOPS pIoStreamOps);
988
989
990	/**
991	* The file operations.
992	*
993	* @extends RTVFSIOSTREAMOPS
994	* @extends RTVFSOBJSETOPS
995	*/
996	typedef struct RTVFSFILEOPS
997	{
998	/** The I/O stream and basis object operations. */
999	RTVFSIOSTREAMOPS Stream;
1000	/** The structure version (RTVFSFILEOPS_VERSION). */
1001	uint32_t uVersion;
1002	/** Reserved field, MBZ. */
1003	uint32_t fReserved;
1004	/** The object setter operations. */
1005	RTVFSOBJSETOPS ObjSet;
1006
1007	/**
1008	* Changes the current file position.
1009	*
1010	* @returns IPRT status code.
1011	* @param pvThis The implementation specific file data.
1012	* @param offSeek The offset to seek.
1013	* @param uMethod The seek method, i.e. what the seek is relative to.
1014	* @param poffActual Where to return the actual offset.
1015	* @sa RTFileSeek
1016	*/
1017	DECLCALLBACKMEMBER(int, pfnSeek)(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual);
1018
1019	/**
1020	* Get the current file size.
1021	*
1022	* @returns IPRT status code.
1023	* @param pvThis The implementation specific file data.
1024	* @param pcbFile Where to store the current file size.
1025	* @sa RTFileGetSize
1026	*/
1027	DECLCALLBACKMEMBER(int, pfnQuerySize)(void pvThis, uint64_t pcbFile);
1028
1029	/**
1030	* Change the file size.
1031	*
1032	* @returns IPRT status code.
1033	* @retval VERR_ACCESS_DENIED if handle isn't writable.
1034	* @retval VERR_WRITE_PROTECT if read-only file system.
1035	* @retval VERR_FILE_TOO_BIG if cbSize is larger than what the file system can
1036	* theoretically deal with.
1037	* @retval VERR_DISK_FULL if the file system if full.
1038	* @retval VERR_NOT_SUPPORTED if fFlags indicates some operation that's not
1039	* supported by the file system / host operating system.
1040	*
1041	* @param pvThis The implementation specific file data.
1042	* @param pcbFile Where to store the current file size.
1043	* @param fFlags RTVFSFILE_SET_SIZE_F_XXX.
1044	* @note Optional. If NULL, VERR_WRITE_PROTECT will be returned.
1045	* @sa RTFileSetSize, RTFileSetAllocationSize
1046	*/
1047	DECLCALLBACKMEMBER(int, pfnSetSize)(void *pvThis, uint64_t cbFile, uint32_t fFlags);
1048
1049	/**
1050	* Determine the maximum file size.
1051	*
1052	* This won't take amount of freespace into account, just the limitations of the
1053	* underlying file system / host operating system.
1054	*
1055	* @returns IPRT status code.
1056	* @param pvThis The implementation specific file data.
1057	* @param pcbMax Where to return the max file size.
1058	* @note Optional. If NULL, VERR_NOT_IMPLEMENTED will be returned.
1059	* @sa RTFileGetMaxSizeEx
1060	*/
1061	DECLCALLBACKMEMBER(int, pfnQueryMaxSize)(void pvThis, uint64_t pcbMax);
1062
1063	/** @todo There will be more methods here. */
1064
1065	/** Marks the end of the structure (RTVFSFILEOPS_VERSION). */
1066	uintptr_t uEndMarker;
1067	} RTVFSFILEOPS;
1068	/** Pointer to const file operations. */
1069	typedef RTVFSFILEOPS const *PCRTVFSFILEOPS;
1070
1071	/** The RTVFSFILEOPS structure version. */
1072	#define RTVFSFILEOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x7f,2,0)
1073
1074	/**
1075	* Creates a new VFS file handle.
1076	*
1077	* @returns IPRT status code
1078	* @param pFileOps The file operations.
1079	* @param cbInstance The size of the instance data.
1080	* @param fOpen The open flags. The minimum is the access mask.
1081	* @param hVfs The VFS handle to associate this file with.
1082	* NIL_VFS is ok.
1083	* @param hLock Handle to a custom lock to be used with the new
1084	* object. The reference is consumed. NIL and
1085	* special lock handles are fine.
1086	* @param phVfsFile Where to return the new handle.
1087	* @param ppvInstance Where to return the pointer to the instance data
1088	* (size is @a cbInstance).
1089	*/
1090	RTDECL(int) RTVfsNewFile(PCRTVFSFILEOPS pFileOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
1091	PRTVFSFILE phVfsFile, void **ppvInstance);
1092
1093
1094	/** @defgroup grp_rt_vfs_ll_util VFS Utility APIs
1095	* @{ */
1096
1097	/**
1098	* Parsed path.
1099	*/
1100	typedef struct RTVFSPARSEDPATH
1101	{
1102	/** The length of the path in szCopy. */
1103	uint16_t cch;
1104	/** The number of path components. */
1105	uint16_t cComponents;
1106	/** Set if the path ends with slash, indicating that it's a directory
1107	* reference and not a file reference. The slash has been removed from
1108	* the copy. */
1109	bool fDirSlash;
1110	/** Set if absolute. */
1111	bool fAbsolute;
1112	/** The offset where each path component starts, i.e. the char after the
1113	* slash. The array has cComponents + 1 entries, where the final one is
1114	* cch + 1 so that one can always terminate the current component by
1115	* szPath[aoffComponent[i] - 1] = '\0'. */
1116	uint16_t aoffComponents[RTPATH_MAX / 2 + 1];
1117	/** A normalized copy of the path.
1118	* Reserve some extra space so we can be more relaxed about overflow
1119	* checks and terminator paddings, especially when recursing. */
1120	char szPath[RTPATH_MAX];
1121	} RTVFSPARSEDPATH;
1122	/** Pointer to a parsed path. */
1123	typedef RTVFSPARSEDPATH *PRTVFSPARSEDPATH;
1124
1125	/** The max accepted path length.
1126	* This must be a few chars shorter than RTVFSPARSEDPATH::szPath because we
1127	* use two terminators and wish be a little bit lazy with checking. */
1128	#define RTVFSPARSEDPATH_MAX (RTPATH_MAX - 4)
1129
1130	/**
1131	* Appends @a pszPath (relative) to the already parsed path @a pPath.
1132	*
1133	* @retval VINF_SUCCESS
1134	* @retval VERR_FILENAME_TOO_LONG
1135	* @retval VERR_INTERNAL_ERROR_4
1136	* @param pPath The parsed path to append @a pszPath onto.
1137	* This is both input and output.
1138	* @param pszPath The path to append. This must be relative.
1139	* @param piRestartComp The component to restart parsing at. This is
1140	* input/output. The input does not have to be
1141	* within the valid range. Optional.
1142	*/
1143	RTDECL(int) RTVfsParsePathAppend(PRTVFSPARSEDPATH pPath, const char pszPath, uint16_t piRestartComp);
1144
1145	/**
1146	* Parses a path.
1147	*
1148	* @retval VINF_SUCCESS
1149	* @retval VERR_FILENAME_TOO_LONG
1150	* @param pPath Where to store the parsed path.
1151	* @param pszPath The path to parse. Absolute or relative to @a
1152	* pszCwd.
1153	* @param pszCwd The current working directory. Must be
1154	* absolute.
1155	*/
1156	RTDECL(int) RTVfsParsePath(PRTVFSPARSEDPATH pPath, const char pszPath, const char pszCwd);
1157
1158	/**
1159	* Same as RTVfsParsePath except that it allocates a temporary buffer.
1160	*
1161	* @retval VINF_SUCCESS
1162	* @retval VERR_NO_TMP_MEMORY
1163	* @retval VERR_FILENAME_TOO_LONG
1164	* @param pszPath The path to parse. Absolute or relative to @a
1165	* pszCwd.
1166	* @param pszCwd The current working directory. Must be
1167	* absolute.
1168	* @param ppPath Where to store the pointer to the allocated
1169	* buffer containing the parsed path. This must
1170	* be freed by calling RTVfsParsePathFree. NULL
1171	* will be stored on failured.
1172	*/
1173	RTDECL(int) RTVfsParsePathA(const char pszPath, const char pszCwd, PRTVFSPARSEDPATH *ppPath);
1174
1175	/**
1176	* Frees a buffer returned by RTVfsParsePathA.
1177	*
1178	* @param pPath The parsed path buffer to free. NULL is fine.
1179	*/
1180	RTDECL(void) RTVfsParsePathFree(PRTVFSPARSEDPATH pPath);
1181
1182	/**
1183	* Dummy implementation of RTVFSIOSTREAMOPS::pfnPollOne.
1184	*
1185	* This handles the case where there is no chance any events my be raised and
1186	* all that is required is to wait according to the parameters.
1187	*
1188	* @returns IPRT status code.
1189	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
1190	* @param cMillies How long to wait for event to eventuate.
1191	* @param fIntr Whether the wait is interruptible and can return
1192	* VERR_INTERRUPTED (@c true) or if this condition
1193	* should be hidden from the caller (@c false).
1194	* @param pfRetEvents Where to return the event mask.
1195	* @sa RTVFSIOSTREAMOPS::pfnPollOne, RTPollSetAdd, RTPoll, RTPollNoResume.
1196	*/
1197	RTDECL(int) RTVfsUtilDummyPollOne(uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, uint32_t *pfRetEvents);
1198
1199	/** @} */
1200
1201
1202	/** @defgroup grp_rt_vfs_lowlevel_chain VFS Chains (Low Level)
1203	* @ref grp_rt_vfs_chain
1204	* @{
1205	*/
1206
1207	/** Pointer to a VFS chain element registration record. */
1208	typedef struct RTVFSCHAINELEMENTREG *PRTVFSCHAINELEMENTREG;
1209	/** Pointer to a const VFS chain element registration record. */
1210	typedef struct RTVFSCHAINELEMENTREG const *PCRTVFSCHAINELEMENTREG;
1211
1212	/**
1213	* VFS chain element argument.
1214	*/
1215	typedef struct RTVFSCHAINELEMENTARG
1216	{
1217	/** The string argument value. */
1218	char *psz;
1219	/** The specification offset of this argument. */
1220	uint16_t offSpec;
1221	/** Provider specific value. */
1222	uint64_t uProvider;
1223	} RTVFSCHAINELEMENTARG;
1224	/** Pointer to a VFS chain element argument. */
1225	typedef RTVFSCHAINELEMENTARG *PRTVFSCHAINELEMENTARG;
1226
1227
1228	/**
1229	* VFS chain element specification.
1230	*/
1231	typedef struct RTVFSCHAINELEMSPEC
1232	{
1233	/** The provider name.
1234	* This can be NULL if this is the final component and it's just a path. */
1235	char *pszProvider;
1236	/** The input type, RTVFSOBJTYPE_INVALID if first. */
1237	RTVFSOBJTYPE enmTypeIn;
1238	/** The element type.
1239	* RTVFSOBJTYPE_END if this is the final component and it's just a path. */
1240	RTVFSOBJTYPE enmType;
1241	/** The input spec offset of this element. */
1242	uint16_t offSpec;
1243	/** The length of the input spec. */
1244	uint16_t cchSpec;
1245	/** The number of arguments. */
1246	uint32_t cArgs;
1247	/** Arguments. */
1248	PRTVFSCHAINELEMENTARG paArgs;
1249
1250	/** The provider. */
1251	PCRTVFSCHAINELEMENTREG pProvider;
1252	/** Provider specific value. */
1253	uint64_t uProvider;
1254	/** The object (with reference). */
1255	RTVFSOBJ hVfsObj;
1256	} RTVFSCHAINELEMSPEC;
1257	/** Pointer to a chain element specification. */
1258	typedef RTVFSCHAINELEMSPEC *PRTVFSCHAINELEMSPEC;
1259	/** Pointer to a const chain element specification. */
1260	typedef RTVFSCHAINELEMSPEC const *PCRTVFSCHAINELEMSPEC;
1261
1262
1263	/**
1264	* Parsed VFS chain specification.
1265	*/
1266	typedef struct RTVFSCHAINSPEC
1267	{
1268	/** Open directory flags (RTFILE_O_XXX). */
1269	uint64_t fOpenFile;
1270	/** To be defined. */
1271	uint32_t fOpenDir;
1272	/** The type desired by the caller. */
1273	RTVFSOBJTYPE enmDesiredType;
1274	/** The number of elements. */
1275	uint32_t cElements;
1276	/** The elements. */
1277	PRTVFSCHAINELEMSPEC paElements;
1278	} RTVFSCHAINSPEC;
1279	/** Pointer to a parsed VFS chain specification. */
1280	typedef RTVFSCHAINSPEC *PRTVFSCHAINSPEC;
1281	/** Pointer to a const, parsed VFS chain specification. */
1282	typedef RTVFSCHAINSPEC const *PCRTVFSCHAINSPEC;
1283
1284
1285	/**
1286	* A chain element provider registration record.
1287	*/
1288	typedef struct RTVFSCHAINELEMENTREG
1289	{
1290	/** The version (RTVFSCHAINELEMENTREG_VERSION). */
1291	uint32_t uVersion;
1292	/** Reserved, MBZ. */
1293	uint32_t fReserved;
1294	/** The provider name (unique). */
1295	const char *pszName;
1296	/** For chaining the providers. */
1297	RTLISTNODE ListEntry;
1298	/** Help text. */
1299	const char *pszHelp;
1300
1301	/**
1302	* Checks the element specification.
1303	*
1304	* This is allowed to parse arguments and use pSpec->uProvider and
1305	* pElement->paArgs[].uProvider to store information that pfnInstantiate and
1306	* pfnCanReuseElement may use later on, thus avoiding duplicating work/code.
1307	*
1308	* @returns IPRT status code.
1309	* @param pProviderReg Pointer to the element provider registration.
1310	* @param pSpec The chain specification.
1311	* @param pElement The chain element specification to validate.
1312	* @param poffError Where to return error offset on failure. This is
1313	* set to the pElement->offSpec on input, so it only
1314	* needs to be adjusted if an argument is at fault.
1315	* @param pErrInfo Where to return additional error information, if
1316	* available. Optional.
1317	*/
1318	DECLCALLBACKMEMBER(int, pfnValidate)(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec,
1319	PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo);
1320
1321	/**
1322	* Create a VFS object according to the element specification.
1323	*
1324	* @returns IPRT status code.
1325	* @param pProviderReg Pointer to the element provider registration.
1326	* @param pSpec The chain specification.
1327	* @param pElement The chain element specification to instantiate.
1328	* @param hPrevVfsObj Handle to the previous VFS object, NIL_RTVFSOBJ if
1329	* first.
1330	* @param phVfsObj Where to return the VFS object handle.
1331	* @param poffError Where to return error offset on failure. This is
1332	* set to the pElement->offSpec on input, so it only
1333	* needs to be adjusted if an argument is at fault.
1334	* @param pErrInfo Where to return additional error information, if
1335	* available. Optional.
1336	*/
1337	DECLCALLBACKMEMBER(int, pfnInstantiate)(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec,
1338	PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj,
1339	PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo);
1340
1341	/**
1342	* Determins whether the element can be reused.
1343	*
1344	* This is for handling situations accessing the same file system twice, like
1345	* for both the source and destiation of a copy operation. This allows not only
1346	* sharing resources and avoid doing things twice, but also helps avoid file
1347	* sharing violations and inconsistencies araising from the image being updated
1348	* and read independently.
1349	*
1350	* @returns true if the element from @a pReuseSpec an be reused, false if not.
1351	* @param pProviderReg Pointer to the element provider registration.
1352	* @param pSpec The chain specification.
1353	* @param pElement The chain element specification.
1354	* @param pReuseSpec The chain specification of the existing chain.
1355	* @param pReuseElement The chain element specification of the existing
1356	* element that is being considered for reuse.
1357	*/
1358	DECLCALLBACKMEMBER(bool, pfnCanReuseElement)(PCRTVFSCHAINELEMENTREG pProviderReg,
1359	PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement,
1360	PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement);
1361
1362	/** End marker (RTVFSCHAINELEMENTREG_VERSION). */
1363	uintptr_t uEndMarker;
1364	} RTVFSCHAINELEMENTREG;
1365
1366	/** The VFS chain element registration record version number. */
1367	#define RTVFSCHAINELEMENTREG_VERSION RT_MAKE_U32_FROM_U8(0xff, 0x7f, 1, 0)
1368
1369
1370	/**
1371	* Parses the specification.
1372	*
1373	* @returns IPRT status code.
1374	* @param pszSpec The specification string to parse.
1375	* @param fFlags Flags, see RTVFSCHAIN_PF_XXX.
1376	* @param enmDesiredType The object type the caller wants to interface with.
1377	* @param ppSpec Where to return the pointer to the parsed
1378	* specification. This must be freed by calling
1379	* RTVfsChainSpecFree. Will always be set (unless
1380	* invalid parameters.)
1381	* @param poffError Where to return the offset into the input
1382	* specification of what's causing trouble. Always
1383	* set, unless this argument causes an invalid pointer
1384	* error.
1385	*/
1386	RTDECL(int) RTVfsChainSpecParse(const char *pszSpec, uint32_t fFlags, RTVFSOBJTYPE enmDesiredType,
1387	PRTVFSCHAINSPEC ppSpec, uint32_t poffError);
1388
1389	/** @name RTVfsChainSpecParse
1390	* @{ */
1391	/** Mask of valid flags. */
1392	#define RTVFSCHAIN_PF_VALID_MASK UINT32_C(0x00000000)
1393	/** @} */
1394
1395	/**
1396	* Checks and setups the chain.
1397	*
1398	* @returns IPRT status code.
1399	* @param pSpec The parsed specification.
1400	* @param pReuseSpec Spec to reuse if applicable. Optional.
1401	* @param phVfsObj Where to return the VFS object.
1402	* @param ppszFinalPath Where to return the pointer to the final path if
1403	* applicable. The caller needs to check whether this
1404	* is NULL or a path, in the former case nothing more
1405	* needs doing, whereas in the latter the caller must
1406	* perform the desired operation(s) on *phVfsObj using
1407	* the final path.
1408	* @param poffError Where to return the offset into the input
1409	* specification of what's causing trouble. Always
1410	* set, unless this argument causes an invalid pointer
1411	* error.
1412	* @param pErrInfo Where to return additional error information, if
1413	* available. Optional.
1414	*/
1415	RTDECL(int) RTVfsChainSpecCheckAndSetup(PRTVFSCHAINSPEC pSpec, PCRTVFSCHAINSPEC pReuseSpec,
1416	PRTVFSOBJ phVfsObj, const char *ppszFinalPath, uint32_t poffError, PRTERRINFO pErrInfo);
1417
1418	/**
1419	* Frees a parsed chain specification.
1420	*
1421	* @param pSpec What RTVfsChainSpecParse returned. NULL is
1422	* quietly ignored.
1423	*/
1424	RTDECL(void) RTVfsChainSpecFree(PRTVFSCHAINSPEC pSpec);
1425
1426	/**
1427	* Registers a chain element provider.
1428	*
1429	* @returns IPRT status code
1430	* @param pRegRec The registration record.
1431	* @param fFromCtor Indicates where we're called from.
1432	*/
1433	RTDECL(int) RTVfsChainElementRegisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromCtor);
1434
1435	/**
1436	* Deregisters a chain element provider.
1437	*
1438	* @returns IPRT status code
1439	* @param pRegRec The registration record.
1440	* @param fFromDtor Indicates where we're called from.
1441	*/
1442	RTDECL(int) RTVfsChainElementDeregisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromDtor);
1443
1444
1445	/** @def RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER
1446	* Automatically registers a chain element provider using a global constructor
1447	* and destructor hack.
1448	*
1449	* @param pRegRec Pointer to the registration record.
1450	* @param name Some unique variable name prefix.
1451	*/
1452
1453	#ifdef __cplusplus
1454	/**
1455	* Class used for registering a VFS chain element provider.
1456	*/
1457	class RTVfsChainElementAutoRegisterHack
1458	{
1459	private:
1460	/** The registration record, NULL if registration failed. */
1461	PRTVFSCHAINELEMENTREG m_pRegRec;
1462
1463	public:
1464	RTVfsChainElementAutoRegisterHack(PRTVFSCHAINELEMENTREG a_pRegRec)
1465	: m_pRegRec(a_pRegRec)
1466	{
1467	int rc = RTVfsChainElementRegisterProvider(m_pRegRec, true);
1468	if (RT_FAILURE(rc))
1469	m_pRegRec = NULL;
1470	}
1471
1472	~RTVfsChainElementAutoRegisterHack()
1473	{
1474	RTVfsChainElementDeregisterProvider(m_pRegRec, true);
1475	m_pRegRec = NULL;
1476	}
1477	};
1478
1479	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1480	static RTVfsChainElementAutoRegisterHack name ## AutoRegistrationHack(pRegRec)
1481
1482	#else
1483	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1484	extern void *name ## AutoRegistrationHack = \
1485	&Sorry_but_RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER_does_not_work_in_c_source_files
1486	#endif
1487
1488
1489	/**
1490	* Common worker for the 'stdfile' and 'open' providers for implementing
1491	* RTVFSCHAINELEMENTREG::pfnValidate.
1492	*
1493	* Stores the RTFILE_O_XXX flags in pSpec->uProvider.
1494	*
1495	* @returns IPRT status code.
1496	* @param pSpec The chain specification.
1497	* @param pElement The chain element specification to validate.
1498	* @param poffError Where to return error offset on failure. This is set to
1499	* the pElement->offSpec on input, so it only needs to be
1500	* adjusted if an argument is at fault.
1501	* @param pErrInfo Where to return additional error information, if
1502	* available. Optional.
1503	*/
1504	RTDECL(int) RTVfsChainValidateOpenFileOrIoStream(PRTVFSCHAINSPEC pSpec, PRTVFSCHAINELEMSPEC pElement,
1505	uint32_t *poffError, PRTERRINFO pErrInfo);
1506
1507
1508	/** @} */
1509
1510
1511	/** @} */
1512
1513	RT_C_DECLS_END
1514
1515	#endif /* !IPRT_INCLUDED_vfslowlevel_h */
1516

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source: vbox/trunk/include/iprt/vfslowlevel.h@ 78377

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