vfslowlevel.h@ 83941

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1	/** @file
2	* IPRT - Virtual Filesystem.
3	*/
4
5	/*
6	* Copyright (C) 2010-2020 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, or vice
556	* versa.
557	*
558	* @param pvThis The implementation specific directory data.
559	* @param pszEntry The name of the immediate file to open or create.
560	* @param fOpenFile RTFILE_O_XXX combination.
561	* @param fObjFlags More flags: RTVFSOBJ_F_XXX, RTPATH_F_XXX.
562	* The meaning of RTPATH_F_FOLLOW_LINK differs here, if
563	* @a pszEntry is a symlink it should be opened for
564	* traversal rather than according to @a fOpenFile.
565	* @param phVfsObj Where to return the handle to the opened object.
566	* @sa RTFileOpen, RTDirOpen
567	*/
568	DECLCALLBACKMEMBER(int, pfnOpen)(void pvThis, const char pszEntry, uint64_t fOpenFile,
569	uint32_t fObjFlags, PRTVFSOBJ phVfsObj);
570
571	/**
572	* Optional method for symbolic link handling in the vfsstddir.cpp.
573	*
574	* This is really just a hack to make symbolic link handling work when working
575	* with directory objects that doesn't have an associated VFS. It also helps
576	* deal with drive letters in symbolic links on Windows and OS/2.
577	*
578	* @returns IPRT status code.
579	* @retval VERR_PATH_IS_RELATIVE if @a pszPath isn't absolute and should be
580	* handled using pfnOpen().
581	*
582	* @param pvThis The implementation specific directory data.
583	* @param pszRoot Path to the alleged root.
584	* @param phVfsDir Where to return the handle to the specified root
585	* directory (or may current dir on a drive letter).
586	*/
587	DECLCALLBACKMEMBER(int, pfnFollowAbsoluteSymlink)(void pvThis, const char pszRoot, PRTVFSDIR phVfsDir);
588
589	/**
590	* Open or create a file.
591	*
592	* @returns IPRT status code.
593	* @param pvThis The implementation specific directory data.
594	* @param pszFilename The name of the immediate file to open or create.
595	* @param fOpen The open flags (RTFILE_O_XXX).
596	* @param phVfsFile Where to return the handle to the opened file.
597	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
598	* @sa RTFileOpen.
599	*/
600	DECLCALLBACKMEMBER(int, pfnOpenFile)(void pvThis, const char pszFilename, uint64_t fOpen, PRTVFSFILE phVfsFile);
601
602	/**
603	* Open an existing subdirectory.
604	*
605	* @returns IPRT status code.
606	* @retval VERR_IS_A_SYMLINK if @a pszSubDir is a symbolic link.
607	* @retval VERR_NOT_A_DIRECTORY is okay for symbolic links too.
608	*
609	* @param pvThis The implementation specific directory data.
610	* @param pszSubDir The name of the immediate subdirectory to open.
611	* @param fFlags RTDIR_F_XXX.
612	* @param phVfsDir Where to return the handle to the opened directory.
613	* Optional.
614	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
615	* @sa RTDirOpen.
616	*/
617	DECLCALLBACKMEMBER(int, pfnOpenDir)(void pvThis, const char pszSubDir, uint32_t fFlags, PRTVFSDIR phVfsDir);
618
619	/**
620	* Creates a new subdirectory.
621	*
622	* @returns IPRT status code.
623	* @param pvThis The implementation specific directory data.
624	* @param pszSubDir The name of the immediate subdirectory to create.
625	* @param fMode The mode mask of the new directory.
626	* @param phVfsDir Where to optionally return the handle to the newly
627	* create directory.
628	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
629	* @sa RTDirCreate.
630	*/
631	DECLCALLBACKMEMBER(int, pfnCreateDir)(void pvThis, const char pszSubDir, RTFMODE fMode, PRTVFSDIR phVfsDir);
632
633	/**
634	* Opens an existing symbolic link.
635	*
636	* @returns IPRT status code.
637	* @param pvThis The implementation specific directory data.
638	* @param pszSymlink The name of the immediate symbolic link to open.
639	* @param phVfsSymlink Where to optionally return the handle to the
640	* newly create symbolic link.
641	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
642	* @sa RTSymlinkCreate.
643	*/
644	DECLCALLBACKMEMBER(int, pfnOpenSymlink)(void pvThis, const char pszSymlink, PRTVFSSYMLINK phVfsSymlink);
645
646	/**
647	* Creates a new symbolic link.
648	*
649	* @returns IPRT status code.
650	* @param pvThis The implementation specific directory data.
651	* @param pszSymlink The name of the immediate symbolic link to create.
652	* @param pszTarget The symbolic link target.
653	* @param enmType The symbolic link type.
654	* @param phVfsSymlink Where to optionally return the handle to the
655	* newly create symbolic link.
656	* @sa RTSymlinkCreate.
657	*/
658	DECLCALLBACKMEMBER(int, pfnCreateSymlink)(void pvThis, const char pszSymlink, const char *pszTarget,
659	RTSYMLINKTYPE enmType, PRTVFSSYMLINK phVfsSymlink);
660
661	/**
662	* Query information about an entry.
663	*
664	* @returns IPRT status code.
665	* @param pvThis The implementation specific directory data.
666	* @param pszEntry The name of the directory entry to remove.
667	* @param pObjInfo Where to return the info on success.
668	* @param enmAddAttr Which set of additional attributes to request.
669	* @note Optional. RTVFSDIROPS::pfnOpenObj and RTVFSOBJOPS::pfnQueryInfo
670	* will be used if NULL.
671	* @sa RTPathQueryInfo, RTVFSOBJOPS::pfnQueryInfo
672	*/
673	DECLCALLBACKMEMBER(int, pfnQueryEntryInfo)(void pvThis, const char pszEntry,
674	PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr);
675
676	/**
677	* Removes a directory entry.
678	*
679	* @returns IPRT status code.
680	* @param pvThis The implementation specific directory data.
681	* @param pszEntry The name of the directory entry to remove.
682	* @param fType If non-zero, this restricts the type of the entry to
683	* the object type indicated by the mask
684	* (RTFS_TYPE_XXX).
685	* @sa RTFileRemove, RTDirRemove, RTSymlinkRemove.
686	*/
687	DECLCALLBACKMEMBER(int, pfnUnlinkEntry)(void pvThis, const char pszEntry, RTFMODE fType);
688
689	/**
690	* Renames a directory entry.
691	*
692	* @returns IPRT status code.
693	* @param pvThis The implementation specific directory data.
694	* @param pszEntry The name of the directory entry to rename.
695	* @param fType If non-zero, this restricts the type of the entry to
696	* the object type indicated by the mask
697	* (RTFS_TYPE_XXX).
698	* @param pszNewName The new entry name.
699	* @sa RTPathRename
700	*
701	* @todo This API is not flexible enough, must be able to rename between
702	* directories within a file system.
703	*/
704	DECLCALLBACKMEMBER(int, pfnRenameEntry)(void pvThis, const char pszEntry, RTFMODE fType, const char *pszNewName);
705
706	/**
707	* Rewind the directory stream so that the next read returns the first
708	* entry.
709	*
710	* @returns IPRT status code.
711	* @param pvThis The implementation specific directory data.
712	*/
713	DECLCALLBACKMEMBER(int, pfnRewindDir)(void *pvThis);
714
715	/**
716	* Rewind the directory stream so that the next read returns the first
717	* entry.
718	*
719	* @returns IPRT status code.
720	* @param pvThis The implementation specific directory data.
721	* @param pDirEntry Output buffer.
722	* @param pcbDirEntry Complicated, see RTDirReadEx.
723	* @param enmAddAttr Which set of additional attributes to request.
724	* @sa RTDirReadEx
725	*/
726	DECLCALLBACKMEMBER(int, pfnReadDir)(void pvThis, PRTDIRENTRYEX pDirEntry, size_t pcbDirEntry, RTFSOBJATTRADD enmAddAttr);
727
728	/** Marks the end of the structure (RTVFSDIROPS_VERSION). */
729	uintptr_t uEndMarker;
730	} RTVFSDIROPS;
731	/** Pointer to const directory operations. */
732	typedef RTVFSDIROPS const *PCRTVFSDIROPS;
733	/** The RTVFSDIROPS structure version. */
734	#define RTVFSDIROPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x4f,1,0)
735
736
737	/**
738	* Creates a new VFS directory handle.
739	*
740	* @returns IPRT status code
741	* @param pDirOps The directory operations.
742	* @param cbInstance The size of the instance data.
743	* @param fFlags RTVFSDIR_F_XXX
744	* @param hVfs The VFS handle to associate this directory with.
745	* NIL_VFS is ok.
746	* @param hLock Handle to a custom lock to be used with the new
747	* object. The reference is consumed. NIL and
748	* special lock handles are fine.
749	* @param phVfsDir Where to return the new handle.
750	* @param ppvInstance Where to return the pointer to the instance data
751	* (size is @a cbInstance).
752	*/
753	RTDECL(int) RTVfsNewDir(PCRTVFSDIROPS pDirOps, size_t cbInstance, uint32_t fFlags, RTVFS hVfs, RTVFSLOCK hLock,
754	PRTVFSDIR phVfsDir, void **ppvInstance);
755
756	/** @name RTVFSDIR_F_XXX
757	* @{ */
758	/** Don't reference the @a hVfs parameter passed to RTVfsNewDir.
759	* This is a permanent root directory hack. */
760	#define RTVFSDIR_F_NO_VFS_REF RT_BIT_32(0)
761	/** @} */
762
763	/**
764	* Gets the private data of a directory.
765	*
766	* @returns Pointer to the private data. NULL if the handle is invalid in some
767	* way.
768	* @param hVfsDir The directory handle.
769	* @param pDirOps The directory operations. This servers as a
770	* sort of password.
771	*/
772	RTDECL(void *) RTVfsDirToPrivate(RTVFSDIR hVfsDir, PCRTVFSDIROPS pDirOps);
773
774
775	/**
776	* The symbolic link operations.
777	*
778	* @extends RTVFSOBJOPS
779	* @extends RTVFSOBJSETOPS
780	*/
781	typedef struct RTVFSSYMLINKOPS
782	{
783	/** The basic object operation. */
784	RTVFSOBJOPS Obj;
785	/** The structure version (RTVFSSYMLINKOPS_VERSION). */
786	uint32_t uVersion;
787	/** Reserved field, MBZ. */
788	uint32_t fReserved;
789	/** The object setter operations. */
790	RTVFSOBJSETOPS ObjSet;
791
792	/**
793	* Read the symbolic link target.
794	*
795	* @returns IPRT status code.
796	* @param pvThis The implementation specific symbolic link data.
797	* @param pszTarget The target buffer.
798	* @param cbTarget The size of the target buffer.
799	* @sa RTSymlinkRead
800	*/
801	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, char pszTarget, size_t cbTarget);
802
803	/** Marks the end of the structure (RTVFSSYMLINKOPS_VERSION). */
804	uintptr_t uEndMarker;
805	} RTVFSSYMLINKOPS;
806	/** Pointer to const symbolic link operations. */
807	typedef RTVFSSYMLINKOPS const *PCRTVFSSYMLINKOPS;
808	/** The RTVFSSYMLINKOPS structure version. */
809	#define RTVFSSYMLINKOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x5f,1,0)
810
811
812	/**
813	* Creates a new VFS symlink handle.
814	*
815	* @returns IPRT status code
816	* @param pSymlinkOps The symlink operations.
817	* @param cbInstance The size of the instance data.
818	* @param hVfs The VFS handle to associate this symlink object
819	* with. NIL_VFS is ok.
820	* @param hLock Handle to a custom lock to be used with the new
821	* object. The reference is consumed. NIL and
822	* special lock handles are fine.
823	* @param phVfsSym Where to return the new handle.
824	* @param ppvInstance Where to return the pointer to the instance data
825	* (size is @a cbInstance).
826	*/
827	RTDECL(int) RTVfsNewSymlink(PCRTVFSSYMLINKOPS pSymlinkOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
828	PRTVFSSYMLINK phVfsSym, void **ppvInstance);
829
830
831	/**
832	* The basis for all I/O objects (files, pipes, sockets, devices, ++).
833	*
834	* @extends RTVFSOBJOPS
835	*/
836	typedef struct RTVFSIOSTREAMOPS
837	{
838	/** The basic object operation. */
839	RTVFSOBJOPS Obj;
840	/** The structure version (RTVFSIOSTREAMOPS_VERSION). */
841	uint32_t uVersion;
842	/** Feature field. */
843	uint32_t fFeatures;
844
845	/**
846	* Reads from the file/stream.
847	*
848	* @returns IPRT status code. See RTVfsIoStrmRead.
849	* @param pvThis The implementation specific file data.
850	* @param off Where to read at, -1 for the current position.
851	* @param pSgBuf Gather buffer describing the bytes that are to be
852	* written.
853	* @param fBlocking If @c true, the call is blocking, if @c false it
854	* should not block.
855	* @param pcbRead Where return the number of bytes actually read.
856	* This is set it 0 by the caller. If NULL, try read
857	* all and fail if incomplete.
858	* @sa RTVfsIoStrmRead, RTVfsIoStrmSgRead, RTVfsFileRead,
859	* RTVfsFileReadAt, RTFileRead, RTFileReadAt.
860	*/
861	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbRead);
862
863	/**
864	* Writes to the file/stream.
865	*
866	* @returns IPRT status code.
867	* @param pvThis The implementation specific file data.
868	* @param off Where to start wrinting, -1 for the current
869	* position.
870	* @param pSgBuf Gather buffers describing the bytes that are to be
871	* written.
872	* @param fBlocking If @c true, the call is blocking, if @c false it
873	* should not block.
874	* @param pcbWritten Where to return the number of bytes actually
875	* written. This is set it 0 by the caller. If
876	* NULL, try write it all and fail if incomplete.
877	* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
878	* @sa RTFileWrite, RTFileWriteAt.
879	*/
880	DECLCALLBACKMEMBER(int, pfnWrite)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbWritten);
881
882	/**
883	* Flushes any pending data writes to the stream.
884	*
885	* @returns IPRT status code.
886	* @param pvThis The implementation specific file data.
887	* @sa RTFileFlush.
888	*/
889	DECLCALLBACKMEMBER(int, pfnFlush)(void *pvThis);
890
891	/**
892	* Poll for events.
893	*
894	* @returns IPRT status code.
895	* @param pvThis The implementation specific file data.
896	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
897	* @param cMillies How long to wait for event to eventuate.
898	* @param fIntr Whether the wait is interruptible and can return
899	* VERR_INTERRUPTED (@c true) or if this condition
900	* should be hidden from the caller (@c false).
901	* @param pfRetEvents Where to return the event mask.
902	* @note Optional. If NULL, immediately return all requested non-error
903	* events, waiting for errors works like sleep.
904	* @sa RTPollSetAdd, RTPoll, RTPollNoResume.
905	*/
906	DECLCALLBACKMEMBER(int, pfnPollOne)(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr,
907	uint32_t *pfRetEvents);
908
909	/**
910	* Tells the current file/stream position.
911	*
912	* @returns IPRT status code.
913	* @param pvThis The implementation specific file data.
914	* @param poffActual Where to return the actual offset.
915	* @sa RTFileTell
916	*/
917	DECLCALLBACKMEMBER(int, pfnTell)(void *pvThis, PRTFOFF poffActual);
918
919	/**
920	* Skips @a cb ahead in the stream.
921	*
922	* @returns IPRT status code.
923	* @param pvThis The implementation specific file data.
924	* @param cb The number bytes to skip.
925	* @remarks This is optional and can be NULL.
926	*/
927	DECLCALLBACKMEMBER(int, pfnSkip)(void *pvThis, RTFOFF cb);
928
929	/**
930	* Fills the stream with @a cb zeros.
931	*
932	* @returns IPRT status code.
933	* @param pvThis The implementation specific file data.
934	* @param cb The number of zero bytes to insert.
935	* @remarks This is optional and can be NULL.
936	*/
937	DECLCALLBACKMEMBER(int, pfnZeroFill)(void *pvThis, RTFOFF cb);
938
939	/** Marks the end of the structure (RTVFSIOSTREAMOPS_VERSION). */
940	uintptr_t uEndMarker;
941	} RTVFSIOSTREAMOPS;
942	/** Pointer to const I/O stream operations. */
943	typedef RTVFSIOSTREAMOPS const *PCRTVFSIOSTREAMOPS;
944
945	/** The RTVFSIOSTREAMOPS structure version. */
946	#define RTVFSIOSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x6f,1,0)
947
948	/** @name RTVFSIOSTREAMOPS::fFeatures
949	* @{ */
950	/** No scatter gather lists, thank you. */
951	#define RTVFSIOSTREAMOPS_FEAT_NO_SG RT_BIT_32(0)
952	/** Mask of the valid I/O stream feature flags. */
953	#define RTVFSIOSTREAMOPS_FEAT_VALID_MASK UINT32_C(0x00000001)
954	/** @} */
955
956
957	/**
958	* Creates a new VFS I/O stream handle.
959	*
960	* @returns IPRT status code
961	* @param pIoStreamOps The I/O stream operations.
962	* @param cbInstance The size of the instance data.
963	* @param fOpen The open flags. The minimum is the access mask.
964	* @param hVfs The VFS handle to associate this I/O stream
965	* with. NIL_VFS is ok.
966	* @param hLock Handle to a custom lock to be used with the new
967	* object. The reference is consumed. NIL and
968	* special lock handles are fine.
969	* @param phVfsIos Where to return the new handle.
970	* @param ppvInstance Where to return the pointer to the instance data
971	* (size is @a cbInstance).
972	*/
973	RTDECL(int) RTVfsNewIoStream(PCRTVFSIOSTREAMOPS pIoStreamOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
974	PRTVFSIOSTREAM phVfsIos, void **ppvInstance);
975
976
977	/**
978	* Gets the private data of an I/O stream.
979	*
980	* @returns Pointer to the private data. NULL if the handle is invalid in some
981	* way.
982	* @param hVfsIos The I/O stream handle.
983	* @param pIoStreamOps The I/O stream operations. This servers as a
984	* sort of password.
985	*/
986	RTDECL(void *) RTVfsIoStreamToPrivate(RTVFSIOSTREAM hVfsIos, PCRTVFSIOSTREAMOPS pIoStreamOps);
987
988
989	/**
990	* The file operations.
991	*
992	* @extends RTVFSIOSTREAMOPS
993	* @extends RTVFSOBJSETOPS
994	*/
995	typedef struct RTVFSFILEOPS
996	{
997	/** The I/O stream and basis object operations. */
998	RTVFSIOSTREAMOPS Stream;
999	/** The structure version (RTVFSFILEOPS_VERSION). */
1000	uint32_t uVersion;
1001	/** Reserved field, MBZ. */
1002	uint32_t fReserved;
1003	/** The object setter operations. */
1004	RTVFSOBJSETOPS ObjSet;
1005
1006	/**
1007	* Changes the current file position.
1008	*
1009	* @returns IPRT status code.
1010	* @param pvThis The implementation specific file data.
1011	* @param offSeek The offset to seek.
1012	* @param uMethod The seek method, i.e. what the seek is relative to.
1013	* @param poffActual Where to return the actual offset.
1014	* @sa RTFileSeek
1015	*/
1016	DECLCALLBACKMEMBER(int, pfnSeek)(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual);
1017
1018	/**
1019	* Get the current file size.
1020	*
1021	* @returns IPRT status code.
1022	* @param pvThis The implementation specific file data.
1023	* @param pcbFile Where to store the current file size.
1024	* @sa RTFileQuerySize
1025	*/
1026	DECLCALLBACKMEMBER(int, pfnQuerySize)(void pvThis, uint64_t pcbFile);
1027
1028	/**
1029	* Change the file size.
1030	*
1031	* @returns IPRT status code.
1032	* @retval VERR_ACCESS_DENIED if handle isn't writable.
1033	* @retval VERR_WRITE_PROTECT if read-only file system.
1034	* @retval VERR_FILE_TOO_BIG if cbSize is larger than what the file system can
1035	* theoretically deal with.
1036	* @retval VERR_DISK_FULL if the file system if full.
1037	* @retval VERR_NOT_SUPPORTED if fFlags indicates some operation that's not
1038	* supported by the file system / host operating system.
1039	*
1040	* @param pvThis The implementation specific file data.
1041	* @param pcbFile Where to store the current file size.
1042	* @param fFlags RTVFSFILE_SET_SIZE_F_XXX.
1043	* @note Optional. If NULL, VERR_WRITE_PROTECT will be returned.
1044	* @sa RTFileSetSize, RTFileSetAllocationSize
1045	*/
1046	DECLCALLBACKMEMBER(int, pfnSetSize)(void *pvThis, uint64_t cbFile, uint32_t fFlags);
1047
1048	/**
1049	* Determine the maximum file size.
1050	*
1051	* This won't take amount of freespace into account, just the limitations of the
1052	* underlying file system / host operating system.
1053	*
1054	* @returns IPRT status code.
1055	* @param pvThis The implementation specific file data.
1056	* @param pcbMax Where to return the max file size.
1057	* @note Optional. If NULL, VERR_NOT_IMPLEMENTED will be returned.
1058	* @sa RTFileQueryMaxSizeEx
1059	*/
1060	DECLCALLBACKMEMBER(int, pfnQueryMaxSize)(void pvThis, uint64_t pcbMax);
1061
1062	/** @todo There will be more methods here. */
1063
1064	/** Marks the end of the structure (RTVFSFILEOPS_VERSION). */
1065	uintptr_t uEndMarker;
1066	} RTVFSFILEOPS;
1067	/** Pointer to const file operations. */
1068	typedef RTVFSFILEOPS const *PCRTVFSFILEOPS;
1069
1070	/** The RTVFSFILEOPS structure version. */
1071	#define RTVFSFILEOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x7f,2,0)
1072
1073	/**
1074	* Creates a new VFS file handle.
1075	*
1076	* @returns IPRT status code
1077	* @param pFileOps The file operations.
1078	* @param cbInstance The size of the instance data.
1079	* @param fOpen The open flags. The minimum is the access mask.
1080	* @param hVfs The VFS handle to associate this file with.
1081	* NIL_VFS is ok.
1082	* @param hLock Handle to a custom lock to be used with the new
1083	* object. The reference is consumed. NIL and
1084	* special lock handles are fine.
1085	* @param phVfsFile Where to return the new handle.
1086	* @param ppvInstance Where to return the pointer to the instance data
1087	* (size is @a cbInstance).
1088	*/
1089	RTDECL(int) RTVfsNewFile(PCRTVFSFILEOPS pFileOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
1090	PRTVFSFILE phVfsFile, void **ppvInstance);
1091
1092
1093	/** @defgroup grp_rt_vfs_ll_util VFS Utility APIs
1094	* @{ */
1095
1096	/**
1097	* Parsed path.
1098	*/
1099	typedef struct RTVFSPARSEDPATH
1100	{
1101	/** The length of the path in szCopy. */
1102	uint16_t cch;
1103	/** The number of path components. */
1104	uint16_t cComponents;
1105	/** Set if the path ends with slash, indicating that it's a directory
1106	* reference and not a file reference. The slash has been removed from
1107	* the copy. */
1108	bool fDirSlash;
1109	/** Set if absolute. */
1110	bool fAbsolute;
1111	/** The offset where each path component starts, i.e. the char after the
1112	* slash. The array has cComponents + 1 entries, where the final one is
1113	* cch + 1 so that one can always terminate the current component by
1114	* szPath[aoffComponent[i] - 1] = '\0'. */
1115	uint16_t aoffComponents[RTPATH_MAX / 2 + 1];
1116	/** A normalized copy of the path.
1117	* Reserve some extra space so we can be more relaxed about overflow
1118	* checks and terminator paddings, especially when recursing. */
1119	char szPath[RTPATH_MAX];
1120	} RTVFSPARSEDPATH;
1121	/** Pointer to a parsed path. */
1122	typedef RTVFSPARSEDPATH *PRTVFSPARSEDPATH;
1123
1124	/** The max accepted path length.
1125	* This must be a few chars shorter than RTVFSPARSEDPATH::szPath because we
1126	* use two terminators and wish be a little bit lazy with checking. */
1127	#define RTVFSPARSEDPATH_MAX (RTPATH_MAX - 4)
1128
1129	/**
1130	* Appends @a pszPath (relative) to the already parsed path @a pPath.
1131	*
1132	* @retval VINF_SUCCESS
1133	* @retval VERR_FILENAME_TOO_LONG
1134	* @retval VERR_INTERNAL_ERROR_4
1135	* @param pPath The parsed path to append @a pszPath onto.
1136	* This is both input and output.
1137	* @param pszPath The path to append. This must be relative.
1138	* @param piRestartComp The component to restart parsing at. This is
1139	* input/output. The input does not have to be
1140	* within the valid range. Optional.
1141	*/
1142	RTDECL(int) RTVfsParsePathAppend(PRTVFSPARSEDPATH pPath, const char pszPath, uint16_t piRestartComp);
1143
1144	/**
1145	* Parses a path.
1146	*
1147	* @retval VINF_SUCCESS
1148	* @retval VERR_FILENAME_TOO_LONG
1149	* @param pPath Where to store the parsed path.
1150	* @param pszPath The path to parse. Absolute or relative to @a
1151	* pszCwd.
1152	* @param pszCwd The current working directory. Must be
1153	* absolute.
1154	*/
1155	RTDECL(int) RTVfsParsePath(PRTVFSPARSEDPATH pPath, const char pszPath, const char pszCwd);
1156
1157	/**
1158	* Same as RTVfsParsePath except that it allocates a temporary buffer.
1159	*
1160	* @retval VINF_SUCCESS
1161	* @retval VERR_NO_TMP_MEMORY
1162	* @retval VERR_FILENAME_TOO_LONG
1163	* @param pszPath The path to parse. Absolute or relative to @a
1164	* pszCwd.
1165	* @param pszCwd The current working directory. Must be
1166	* absolute.
1167	* @param ppPath Where to store the pointer to the allocated
1168	* buffer containing the parsed path. This must
1169	* be freed by calling RTVfsParsePathFree. NULL
1170	* will be stored on failured.
1171	*/
1172	RTDECL(int) RTVfsParsePathA(const char pszPath, const char pszCwd, PRTVFSPARSEDPATH *ppPath);
1173
1174	/**
1175	* Frees a buffer returned by RTVfsParsePathA.
1176	*
1177	* @param pPath The parsed path buffer to free. NULL is fine.
1178	*/
1179	RTDECL(void) RTVfsParsePathFree(PRTVFSPARSEDPATH pPath);
1180
1181	/**
1182	* Dummy implementation of RTVFSIOSTREAMOPS::pfnPollOne.
1183	*
1184	* This handles the case where there is no chance any events my be raised and
1185	* all that is required is to wait according to the parameters.
1186	*
1187	* @returns IPRT status code.
1188	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
1189	* @param cMillies How long to wait for event to eventuate.
1190	* @param fIntr Whether the wait is interruptible and can return
1191	* VERR_INTERRUPTED (@c true) or if this condition
1192	* should be hidden from the caller (@c false).
1193	* @param pfRetEvents Where to return the event mask.
1194	* @sa RTVFSIOSTREAMOPS::pfnPollOne, RTPollSetAdd, RTPoll, RTPollNoResume.
1195	*/
1196	RTDECL(int) RTVfsUtilDummyPollOne(uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, uint32_t *pfRetEvents);
1197
1198	/** @} */
1199
1200
1201	/** @defgroup grp_rt_vfs_lowlevel_chain VFS Chains (Low Level)
1202	* @ref grp_rt_vfs_chain
1203	* @{
1204	*/
1205
1206	/** Pointer to a VFS chain element registration record. */
1207	typedef struct RTVFSCHAINELEMENTREG *PRTVFSCHAINELEMENTREG;
1208	/** Pointer to a const VFS chain element registration record. */
1209	typedef struct RTVFSCHAINELEMENTREG const *PCRTVFSCHAINELEMENTREG;
1210
1211	/**
1212	* VFS chain element argument.
1213	*/
1214	typedef struct RTVFSCHAINELEMENTARG
1215	{
1216	/** The string argument value. */
1217	char *psz;
1218	/** The specification offset of this argument. */
1219	uint16_t offSpec;
1220	/** Provider specific value. */
1221	uint64_t uProvider;
1222	} RTVFSCHAINELEMENTARG;
1223	/** Pointer to a VFS chain element argument. */
1224	typedef RTVFSCHAINELEMENTARG *PRTVFSCHAINELEMENTARG;
1225
1226
1227	/**
1228	* VFS chain element specification.
1229	*/
1230	typedef struct RTVFSCHAINELEMSPEC
1231	{
1232	/** The provider name.
1233	* This can be NULL if this is the final component and it's just a path. */
1234	char *pszProvider;
1235	/** The input type, RTVFSOBJTYPE_INVALID if first. */
1236	RTVFSOBJTYPE enmTypeIn;
1237	/** The element type.
1238	* RTVFSOBJTYPE_END if this is the final component and it's just a path. */
1239	RTVFSOBJTYPE enmType;
1240	/** The input spec offset of this element. */
1241	uint16_t offSpec;
1242	/** The length of the input spec. */
1243	uint16_t cchSpec;
1244	/** The number of arguments. */
1245	uint32_t cArgs;
1246	/** Arguments. */
1247	PRTVFSCHAINELEMENTARG paArgs;
1248
1249	/** The provider. */
1250	PCRTVFSCHAINELEMENTREG pProvider;
1251	/** Provider specific value. */
1252	uint64_t uProvider;
1253	/** The object (with reference). */
1254	RTVFSOBJ hVfsObj;
1255	} RTVFSCHAINELEMSPEC;
1256	/** Pointer to a chain element specification. */
1257	typedef RTVFSCHAINELEMSPEC *PRTVFSCHAINELEMSPEC;
1258	/** Pointer to a const chain element specification. */
1259	typedef RTVFSCHAINELEMSPEC const *PCRTVFSCHAINELEMSPEC;
1260
1261
1262	/**
1263	* Parsed VFS chain specification.
1264	*/
1265	typedef struct RTVFSCHAINSPEC
1266	{
1267	/** Open directory flags (RTFILE_O_XXX). */
1268	uint64_t fOpenFile;
1269	/** To be defined. */
1270	uint32_t fOpenDir;
1271	/** The type desired by the caller. */
1272	RTVFSOBJTYPE enmDesiredType;
1273	/** The number of elements. */
1274	uint32_t cElements;
1275	/** The elements. */
1276	PRTVFSCHAINELEMSPEC paElements;
1277	} RTVFSCHAINSPEC;
1278	/** Pointer to a parsed VFS chain specification. */
1279	typedef RTVFSCHAINSPEC *PRTVFSCHAINSPEC;
1280	/** Pointer to a const, parsed VFS chain specification. */
1281	typedef RTVFSCHAINSPEC const *PCRTVFSCHAINSPEC;
1282
1283
1284	/**
1285	* A chain element provider registration record.
1286	*/
1287	typedef struct RTVFSCHAINELEMENTREG
1288	{
1289	/** The version (RTVFSCHAINELEMENTREG_VERSION). */
1290	uint32_t uVersion;
1291	/** Reserved, MBZ. */
1292	uint32_t fReserved;
1293	/** The provider name (unique). */
1294	const char *pszName;
1295	/** For chaining the providers. */
1296	RTLISTNODE ListEntry;
1297	/** Help text. */
1298	const char *pszHelp;
1299
1300	/**
1301	* Checks the element specification.
1302	*
1303	* This is allowed to parse arguments and use pSpec->uProvider and
1304	* pElement->paArgs[].uProvider to store information that pfnInstantiate and
1305	* pfnCanReuseElement may use later on, thus avoiding duplicating work/code.
1306	*
1307	* @returns IPRT status code.
1308	* @param pProviderReg Pointer to the element provider registration.
1309	* @param pSpec The chain specification.
1310	* @param pElement The chain element specification to validate.
1311	* @param poffError Where to return error offset on failure. This is
1312	* set to the pElement->offSpec on input, so it only
1313	* needs to be adjusted if an argument is at fault.
1314	* @param pErrInfo Where to return additional error information, if
1315	* available. Optional.
1316	*/
1317	DECLCALLBACKMEMBER(int, pfnValidate)(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec,
1318	PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo);
1319
1320	/**
1321	* Create a VFS object according to the element specification.
1322	*
1323	* @returns IPRT status code.
1324	* @param pProviderReg Pointer to the element provider registration.
1325	* @param pSpec The chain specification.
1326	* @param pElement The chain element specification to instantiate.
1327	* @param hPrevVfsObj Handle to the previous VFS object, NIL_RTVFSOBJ if
1328	* first.
1329	* @param phVfsObj Where to return the VFS object handle.
1330	* @param poffError Where to return error offset on failure. This is
1331	* set to the pElement->offSpec on input, so it only
1332	* needs to be adjusted if an argument is at fault.
1333	* @param pErrInfo Where to return additional error information, if
1334	* available. Optional.
1335	*/
1336	DECLCALLBACKMEMBER(int, pfnInstantiate)(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec,
1337	PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj,
1338	PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo);
1339
1340	/**
1341	* Determins whether the element can be reused.
1342	*
1343	* This is for handling situations accessing the same file system twice, like
1344	* for both the source and destiation of a copy operation. This allows not only
1345	* sharing resources and avoid doing things twice, but also helps avoid file
1346	* sharing violations and inconsistencies araising from the image being updated
1347	* and read independently.
1348	*
1349	* @returns true if the element from @a pReuseSpec an be reused, false if not.
1350	* @param pProviderReg Pointer to the element provider registration.
1351	* @param pSpec The chain specification.
1352	* @param pElement The chain element specification.
1353	* @param pReuseSpec The chain specification of the existing chain.
1354	* @param pReuseElement The chain element specification of the existing
1355	* element that is being considered for reuse.
1356	*/
1357	DECLCALLBACKMEMBER(bool, pfnCanReuseElement)(PCRTVFSCHAINELEMENTREG pProviderReg,
1358	PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement,
1359	PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement);
1360
1361	/** End marker (RTVFSCHAINELEMENTREG_VERSION). */
1362	uintptr_t uEndMarker;
1363	} RTVFSCHAINELEMENTREG;
1364
1365	/** The VFS chain element registration record version number. */
1366	#define RTVFSCHAINELEMENTREG_VERSION RT_MAKE_U32_FROM_U8(0xff, 0x7f, 1, 0)
1367
1368
1369	/**
1370	* Parses the specification.
1371	*
1372	* @returns IPRT status code.
1373	* @param pszSpec The specification string to parse.
1374	* @param fFlags Flags, see RTVFSCHAIN_PF_XXX.
1375	* @param enmDesiredType The object type the caller wants to interface with.
1376	* @param ppSpec Where to return the pointer to the parsed
1377	* specification. This must be freed by calling
1378	* RTVfsChainSpecFree. Will always be set (unless
1379	* invalid parameters.)
1380	* @param poffError Where to return the offset into the input
1381	* specification of what's causing trouble. Always
1382	* set, unless this argument causes an invalid pointer
1383	* error.
1384	*/
1385	RTDECL(int) RTVfsChainSpecParse(const char *pszSpec, uint32_t fFlags, RTVFSOBJTYPE enmDesiredType,
1386	PRTVFSCHAINSPEC ppSpec, uint32_t poffError);
1387
1388	/** @name RTVfsChainSpecParse
1389	* @{ */
1390	/** Mask of valid flags. */
1391	#define RTVFSCHAIN_PF_VALID_MASK UINT32_C(0x00000000)
1392	/** @} */
1393
1394	/**
1395	* Checks and setups the chain.
1396	*
1397	* @returns IPRT status code.
1398	* @param pSpec The parsed specification.
1399	* @param pReuseSpec Spec to reuse if applicable. Optional.
1400	* @param phVfsObj Where to return the VFS object.
1401	* @param ppszFinalPath Where to return the pointer to the final path if
1402	* applicable. The caller needs to check whether this
1403	* is NULL or a path, in the former case nothing more
1404	* needs doing, whereas in the latter the caller must
1405	* perform the desired operation(s) on *phVfsObj using
1406	* the final path.
1407	* @param poffError Where to return the offset into the input
1408	* specification of what's causing trouble. Always
1409	* set, unless this argument causes an invalid pointer
1410	* error.
1411	* @param pErrInfo Where to return additional error information, if
1412	* available. Optional.
1413	*/
1414	RTDECL(int) RTVfsChainSpecCheckAndSetup(PRTVFSCHAINSPEC pSpec, PCRTVFSCHAINSPEC pReuseSpec,
1415	PRTVFSOBJ phVfsObj, const char *ppszFinalPath, uint32_t poffError, PRTERRINFO pErrInfo);
1416
1417	/**
1418	* Frees a parsed chain specification.
1419	*
1420	* @param pSpec What RTVfsChainSpecParse returned. NULL is
1421	* quietly ignored.
1422	*/
1423	RTDECL(void) RTVfsChainSpecFree(PRTVFSCHAINSPEC pSpec);
1424
1425	/**
1426	* Registers a chain element provider.
1427	*
1428	* @returns IPRT status code
1429	* @param pRegRec The registration record.
1430	* @param fFromCtor Indicates where we're called from.
1431	*/
1432	RTDECL(int) RTVfsChainElementRegisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromCtor);
1433
1434	/**
1435	* Deregisters a chain element provider.
1436	*
1437	* @returns IPRT status code
1438	* @param pRegRec The registration record.
1439	* @param fFromDtor Indicates where we're called from.
1440	*/
1441	RTDECL(int) RTVfsChainElementDeregisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromDtor);
1442
1443
1444	/** @def RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER
1445	* Automatically registers a chain element provider using a global constructor
1446	* and destructor hack.
1447	*
1448	* @param pRegRec Pointer to the registration record.
1449	* @param name Some unique variable name prefix.
1450	*/
1451
1452	#ifdef __cplusplus
1453	/**
1454	* Class used for registering a VFS chain element provider.
1455	*/
1456	class RTVfsChainElementAutoRegisterHack
1457	{
1458	private:
1459	/** The registration record, NULL if registration failed. */
1460	PRTVFSCHAINELEMENTREG m_pRegRec;
1461
1462	public:
1463	RTVfsChainElementAutoRegisterHack(PRTVFSCHAINELEMENTREG a_pRegRec)
1464	: m_pRegRec(a_pRegRec)
1465	{
1466	int rc = RTVfsChainElementRegisterProvider(m_pRegRec, true);
1467	if (RT_FAILURE(rc))
1468	m_pRegRec = NULL;
1469	}
1470
1471	~RTVfsChainElementAutoRegisterHack()
1472	{
1473	RTVfsChainElementDeregisterProvider(m_pRegRec, true);
1474	m_pRegRec = NULL;
1475	}
1476	};
1477
1478	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1479	static RTVfsChainElementAutoRegisterHack name ## AutoRegistrationHack(pRegRec)
1480
1481	#else
1482	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1483	extern void *name ## AutoRegistrationHack = \
1484	&Sorry_but_RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER_does_not_work_in_c_source_files
1485	#endif
1486
1487
1488	/**
1489	* Common worker for the 'stdfile' and 'open' providers for implementing
1490	* RTVFSCHAINELEMENTREG::pfnValidate.
1491	*
1492	* Stores the RTFILE_O_XXX flags in pSpec->uProvider.
1493	*
1494	* @returns IPRT status code.
1495	* @param pSpec The chain specification.
1496	* @param pElement The chain element specification to validate.
1497	* @param poffError Where to return error offset on failure. This is set to
1498	* the pElement->offSpec on input, so it only needs to be
1499	* adjusted if an argument is at fault.
1500	* @param pErrInfo Where to return additional error information, if
1501	* available. Optional.
1502	*/
1503	RTDECL(int) RTVfsChainValidateOpenFileOrIoStream(PRTVFSCHAINSPEC pSpec, PRTVFSCHAINELEMSPEC pElement,
1504	uint32_t *poffError, PRTERRINFO pErrInfo);
1505
1506
1507	/** @} */
1508
1509
1510	/** @} */
1511
1512	RT_C_DECLS_END
1513
1514	#endif /* !IPRT_INCLUDED_vfslowlevel_h */
1515

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source: vbox/trunk/include/iprt/vfslowlevel.h@ 83941

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