vfslowlevel.h@ 69826

Last change on this file since 69826 was 69826, checked in by vboxsync, 7 years ago
IPRT/VFS: More path parsing work. Symlinks should work better now.
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1	/** @file
2	* IPRT - Virtual Filesystem.
3	*/
4
5	/*
6	* Copyright (C) 2010-2017 Oracle Corporation
7	*
8	* This file is part of VirtualBox Open Source Edition (OSE), as
9	* available from http://www.virtualbox.org. This file is free software;
10	* you can redistribute it and/or modify it under the terms of the GNU
11	* General Public License (GPL) as published by the Free Software
12	* Foundation, in version 2 as it comes in the "COPYING" file of the
13	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
14	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
15	*
16	* The contents of this file may alternatively be used under the terms
17	* of the Common Development and Distribution License Version 1.0
18	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
19	* VirtualBox OSE distribution, in which case the provisions of the
20	* CDDL are applicable instead of those of the GPL.
21	*
22	* You may elect to license modified versions of this file under the
23	* terms and conditions of either the GPL or the CDDL or both.
24	*/
25
26	#ifndef ___iprt_vfslowlevel_h
27	#define ___iprt_vfslowlevel_h
28
29	#include <iprt/vfs.h>
30	#include <iprt/err.h>
31	#include <iprt/list.h>
32	#include <iprt/param.h>
33
34
35	RT_C_DECLS_BEGIN
36
37	/** @defgroup grp_rt_vfs_lowlevel RTVfs - Low-level Interface.
38	* @ingroup grp_rt_vfs
39	* @{
40	*/
41
42
43	/** @name VFS Lock Abstraction
44	* @todo This should be moved somewhere else as it is of general use.
45	* @{ */
46
47	/**
48	* VFS lock types.
49	*/
50	typedef enum RTVFSLOCKTYPE
51	{
52	/** Invalid lock type. */
53	RTVFSLOCKTYPE_INVALID = 0,
54	/** Read write semaphore. */
55	RTVFSLOCKTYPE_RW,
56	/** Fast mutex semaphore (critical section in ring-3). */
57	RTVFSLOCKTYPE_FASTMUTEX,
58	/** Full fledged mutex semaphore. */
59	RTVFSLOCKTYPE_MUTEX,
60	/** The end of valid lock types. */
61	RTVFSLOCKTYPE_END,
62	/** The customary 32-bit type hack. */
63	RTVFSLOCKTYPE_32BIT_HACK = 0x7fffffff
64	} RTVFSLOCKTYPE;
65
66	/** VFS lock handle. */
67	typedef struct RTVFSLOCKINTERNAL *RTVFSLOCK;
68	/** Pointer to a VFS lock handle. */
69	typedef RTVFSLOCK *PRTVFSLOCK;
70	/** Nil VFS lock handle. */
71	#define NIL_RTVFSLOCK ((RTVFSLOCK)~(uintptr_t)0)
72
73	/** Special handle value for creating a new read/write semaphore based lock. */
74	#define RTVFSLOCK_CREATE_RW ((RTVFSLOCK)~(uintptr_t)1)
75	/** Special handle value for creating a new fast mutex semaphore based lock. */
76	#define RTVFSLOCK_CREATE_FASTMUTEX ((RTVFSLOCK)~(uintptr_t)2)
77	/** Special handle value for creating a new mutex semaphore based lock. */
78	#define RTVFSLOCK_CREATE_MUTEX ((RTVFSLOCK)~(uintptr_t)3)
79
80	/**
81	* Retains a reference to the VFS lock handle.
82	*
83	* @returns New reference count on success, UINT32_MAX on failure.
84	* @param hLock The VFS lock handle.
85	*/
86	RTDECL(uint32_t) RTVfsLockRetain(RTVFSLOCK hLock);
87
88	/**
89	* Releases a reference to the VFS lock handle.
90	*
91	* @returns New reference count on success (0 if closed), UINT32_MAX on failure.
92	* @param hLock The VFS lock handle.
93	*/
94	RTDECL(uint32_t) RTVfsLockRelease(RTVFSLOCK hLock);
95
96	/**
97	* Gets the lock type.
98	*
99	* @returns The lock type on success, RTVFSLOCKTYPE_INVALID if the handle is
100	* not valid.
101	* @param hLock The lock handle.
102	*/
103	RTDECL(RTVFSLOCKTYPE) RTVfsLockGetType(RTVFSLOCK hLock);
104
105
106
107	RTDECL(void) RTVfsLockAcquireReadSlow(RTVFSLOCK hLock);
108	RTDECL(void) RTVfsLockReleaseReadSlow(RTVFSLOCK hLock);
109	RTDECL(void) RTVfsLockAcquireWriteSlow(RTVFSLOCK hLock);
110	RTDECL(void) RTVfsLockReleaseWriteSlow(RTVFSLOCK hLock);
111
112	/**
113	* Acquire a read lock.
114	*
115	* @param hLock The lock handle, can be NIL.
116	*/
117	DECLINLINE(void) RTVfsLockAcquireRead(RTVFSLOCK hLock)
118	{
119	if (hLock != NIL_RTVFSLOCK)
120	RTVfsLockAcquireReadSlow(hLock);
121	}
122
123
124	/**
125	* Release a read lock.
126	*
127	* @param hLock The lock handle, can be NIL.
128	*/
129	DECLINLINE(void) RTVfsLockReleaseRead(RTVFSLOCK hLock)
130	{
131	if (hLock != NIL_RTVFSLOCK)
132	RTVfsLockReleaseReadSlow(hLock);
133	}
134
135
136	/**
137	* Acquire a write lock.
138	*
139	* @param hLock The lock handle, can be NIL.
140	*/
141	DECLINLINE(void) RTVfsLockAcquireWrite(RTVFSLOCK hLock)
142	{
143	if (hLock != NIL_RTVFSLOCK)
144	RTVfsLockAcquireWriteSlow(hLock);
145	}
146
147
148	/**
149	* Release a write lock.
150	*
151	* @param hLock The lock handle, can be NIL.
152	*/
153	DECLINLINE(void) RTVfsLockReleaseWrite(RTVFSLOCK hLock)
154	{
155	if (hLock != NIL_RTVFSLOCK)
156	RTVfsLockReleaseWriteSlow(hLock);
157	}
158
159	/** @} */
160
161	/**
162	* The basis for all virtual file system objects.
163	*/
164	typedef struct RTVFSOBJOPS
165	{
166	/** The structure version (RTVFSOBJOPS_VERSION). */
167	uint32_t uVersion;
168	/** The object type for type introspection. */
169	RTVFSOBJTYPE enmType;
170	/** The name of the operations. */
171	const char *pszName;
172
173	/**
174	* Close the object.
175	*
176	* @returns IPRT status code.
177	* @param pvThis The implementation specific file data.
178	*/
179	DECLCALLBACKMEMBER(int, pfnClose)(void *pvThis);
180
181	/**
182	* Get information about the file.
183	*
184	* @returns IPRT status code. See RTVfsObjQueryInfo.
185	* @retval VERR_WRONG_TYPE if file system or file system stream.
186	* @param pvThis The implementation specific file data.
187	* @param pObjInfo Where to return the object info on success.
188	* @param enmAddAttr Which set of additional attributes to request.
189	* @sa RTVfsObjQueryInfo, RTFileQueryInfo, RTPathQueryInfo
190	*/
191	DECLCALLBACKMEMBER(int, pfnQueryInfo)(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr);
192
193	/** Marks the end of the structure (RTVFSOBJOPS_VERSION). */
194	uintptr_t uEndMarker;
195	} RTVFSOBJOPS;
196	/** Pointer to constant VFS object operations. */
197	typedef RTVFSOBJOPS const *PCRTVFSOBJOPS;
198
199	/** The RTVFSOBJOPS structure version. */
200	#define RTVFSOBJOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x1f,1,0)
201
202
203	/**
204	* The VFS operations.
205	*/
206	typedef struct RTVFSOPS
207	{
208	/** The basic object operation. */
209	RTVFSOBJOPS Obj;
210	/** The structure version (RTVFSOPS_VERSION). */
211	uint32_t uVersion;
212	/** The virtual file system feature mask. */
213	uint32_t fFeatures;
214
215	/**
216	* Opens the root directory.
217	*
218	* @returns IPRT status code.
219	* @param pvThis The implementation specific data.
220	* @param phVfsDir Where to return the handle to the root directory.
221	*/
222	DECLCALLBACKMEMBER(int, pfnOpenRoot)(void *pvThis, PRTVFSDIR phVfsDir);
223
224	/**
225	* Optional entry point to check whether a given range in the underlying medium
226	* is in use by the virtual filesystem.
227	*
228	* @returns IPRT status code.
229	* @param pvThis The implementation specific data.
230	* @param off Start offset to check.
231	* @param cb Number of bytes to check.
232	* @param pfUsed Where to store whether the given range is in use.
233	*/
234	DECLCALLBACKMEMBER(int, pfnIsRangeInUse)(void pvThis, RTFOFF off, size_t cb, bool pfUsed);
235
236	/** @todo There will be more methods here to optimize opening and
237	* querying. */
238
239	#if 0
240	/**
241	* Optional entry point for optimizing path traversal within the file system.
242	*
243	* @returns IPRT status code.
244	* @param pvThis The implementation specific data.
245	* @param pszPath The path to resolve.
246	* @param poffPath The current path offset on input, what we've
247	* traversed to on successful return.
248	* @param phVfs??? Return handle to what we've traversed.
249	* @param p??? Return other stuff...
250	*/
251	DECLCALLBACKMEMBER(int, pfnTraverse)(void pvThis, const char pszPath, size_t poffPath, PRTVFS??? phVfs?, ??? p???);
252	#endif
253
254	/** @todo need rename API */
255
256	/** Marks the end of the structure (RTVFSOPS_VERSION). */
257	uintptr_t uEndMarker;
258	} RTVFSOPS;
259	/** Pointer to constant VFS operations. */
260	typedef RTVFSOPS const *PCRTVFSOPS;
261
262	/** The RTVFSOPS structure version. */
263	#define RTVFSOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x0f,1,0)
264
265	/** @name RTVFSOPS::fFeatures
266	* @{ */
267	/** The VFS supports attaching other systems. */
268	#define RTVFSOPS_FEAT_ATTACH RT_BIT_32(0)
269	/** @} */
270
271	/**
272	* Creates a new VFS handle.
273	*
274	* @returns IPRT status code
275	* @param pVfsOps The VFS operations.
276	* @param cbInstance The size of the instance data.
277	* @param hVfs The VFS handle to associate this VFS with.
278	* NIL_VFS is ok.
279	* @param hLock Handle to a custom lock to be used with the new
280	* object. The reference is consumed. NIL and
281	* special lock handles are fine.
282	* @param phVfs Where to return the new handle.
283	* @param ppvInstance Where to return the pointer to the instance data
284	* (size is @a cbInstance).
285	*/
286	RTDECL(int) RTVfsNew(PCRTVFSOPS pVfsOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
287	PRTVFS phVfs, void **ppvInstance);
288
289
290	/**
291	* Creates a new VFS base object handle.
292	*
293	* @returns IPRT status code
294	* @param pObjOps The base object operations.
295	* @param cbInstance The size of the instance data.
296	* @param hVfs The VFS handle to associate this base object
297	* with. NIL_VFS is ok.
298	* @param hLock Handle to a custom lock to be used with the new
299	* object. The reference is consumed. NIL and
300	* special lock handles are fine.
301	* @param phVfsObj Where to return the new handle.
302	* @param ppvInstance Where to return the pointer to the instance data
303	* (size is @a cbInstance).
304	*/
305	RTDECL(int) RTVfsNewBaseObj(PCRTVFSOBJOPS pObjOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
306	PRTVFSOBJ phVfsObj, void **ppvInstance);
307
308
309	/**
310	* Additional operations for setting object attributes.
311	*/
312	typedef struct RTVFSOBJSETOPS
313	{
314	/** The structure version (RTVFSOBJSETOPS_VERSION). */
315	uint32_t uVersion;
316	/** The offset to the RTVFSOBJOPS structure. */
317	int32_t offObjOps;
318
319	/**
320	* Set the unix style owner and group.
321	*
322	* @returns IPRT status code.
323	* @param pvThis The implementation specific file data.
324	* @param fMode The new mode bits.
325	* @param fMask The mask indicating which bits we are
326	* changing.
327	* @sa RTFileSetMode
328	*/
329	DECLCALLBACKMEMBER(int, pfnSetMode)(void *pvThis, RTFMODE fMode, RTFMODE fMask);
330
331	/**
332	* Set the timestamps associated with the object.
333	*
334	* @returns IPRT status code.
335	* @param pvThis The implementation specific file data.
336	* @param pAccessTime Pointer to the new access time. NULL if not
337	* to be changed.
338	* @param pModificationTime Pointer to the new modifcation time. NULL if
339	* not to be changed.
340	* @param pChangeTime Pointer to the new change time. NULL if not
341	* to be changed.
342	* @param pBirthTime Pointer to the new time of birth. NULL if
343	* not to be changed.
344	* @remarks See RTFileSetTimes for restrictions and behavior imposed by the
345	* host OS or underlying VFS provider.
346	* @sa RTFileSetTimes
347	*/
348	DECLCALLBACKMEMBER(int, pfnSetTimes)(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime,
349	PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime);
350
351	/**
352	* Set the unix style owner and group.
353	*
354	* @returns IPRT status code.
355	* @param pvThis The implementation specific file data.
356	* @param uid The user ID of the new owner. NIL_RTUID if
357	* unchanged.
358	* @param gid The group ID of the new owner group. NIL_RTGID if
359	* unchanged.
360	* @sa RTFileSetOwner
361	*/
362	DECLCALLBACKMEMBER(int, pfnSetOwner)(void *pvThis, RTUID uid, RTGID gid);
363
364	/** Marks the end of the structure (RTVFSOBJSETOPS_VERSION). */
365	uintptr_t uEndMarker;
366	} RTVFSOBJSETOPS;
367	/** Pointer to const object attribute setter operations. */
368	typedef RTVFSOBJSETOPS const *PCRTVFSOBJSETOPS;
369
370	/** The RTVFSOBJSETOPS structure version. */
371	#define RTVFSOBJSETOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x2f,1,0)
372
373
374	/**
375	* The filesystem stream operations.
376	*
377	* @extends RTVFSOBJOPS
378	*/
379	typedef struct RTVFSFSSTREAMOPS
380	{
381	/** The basic object operation. */
382	RTVFSOBJOPS Obj;
383	/** The structure version (RTVFSFSSTREAMOPS_VERSION). */
384	uint32_t uVersion;
385	/** Reserved field, MBZ. */
386	uint32_t fReserved;
387
388	/**
389	* Gets the next object in the stream.
390	*
391	* Readable streams only.
392	*
393	* @returns IPRT status code.
394	* @retval VINF_SUCCESS if a new object was retrieved.
395	* @retval VERR_EOF when there are no more objects.
396	* @param pvThis The implementation specific directory data.
397	* @param ppszName Where to return the object name. Must be freed by
398	* calling RTStrFree.
399	* @param penmType Where to return the object type.
400	* @param phVfsObj Where to return the object handle (referenced). This
401	* must be cast to the desired type before use.
402	* @sa RTVfsFsStrmNext
403	*
404	* @note Setting this member to NULL is okay for write-only streams.
405	*/
406	DECLCALLBACKMEMBER(int, pfnNext)(void pvThis, char ppszName, RTVFSOBJTYPE penmType, PRTVFSOBJ phVfsObj);
407
408	/**
409	* Adds another object into the stream.
410	*
411	* Writable streams only.
412	*
413	* @returns IPRT status code.
414	* @param pvThis The implementation specific directory data.
415	* @param pszPath The path to the object.
416	* @param hVfsObj The object to add.
417	* @param fFlags Reserved for the future, MBZ.
418	* @sa RTVfsFsStrmAdd
419	*
420	* @note Setting this member to NULL is okay for read-only streams.
421	*/
422	DECLCALLBACKMEMBER(int, pfnAdd)(void pvThis, const char pszPath, RTVFSOBJ hVfsObj, uint32_t fFlags);
423
424	/**
425	* Pushes an byte stream onto the stream (optional).
426	*
427	* Writable streams only.
428	*
429	* This differs from RTVFSFSSTREAMOPS::pfnAdd() in that it will create a regular
430	* file in the output file system stream and provide the actual content bytes
431	* via the returned I/O stream object.
432	*
433	* @returns IPRT status code.
434	* @param pvThis The implementation specific directory data.
435	* @param pszPath The path to the file.
436	* @param cbFile The file size. This can also be set to UINT64_MAX if
437	* the file system stream is backed by a file.
438	* @param paObjInfo Array of zero or more RTFSOBJINFO structures containing
439	* different pieces of information about the file. If any
440	* provided, the first one should be a RTFSOBJATTRADD_UNIX
441	* one, additional can be supplied if wanted. What exactly
442	* is needed depends on the underlying FS stream
443	* implementation.
444	* @param cObjInfo Number of items in the array @a paObjInfo points at.
445	* @param fFlags RTVFSFSSTRM_PUSH_F_XXX.
446	* @param phVfsIos Where to return the I/O stream to feed the file content
447	* to. If the FS stream is backed by a file, the returned
448	* handle can be cast to a file if necessary.
449	*/
450	DECLCALLBACKMEMBER(int, pfnPushFile)(void pvThis, const char pszPath, uint64_t cbFile,
451	PCRTFSOBJINFO paObjInfo, uint32_t cObjInfo, uint32_t fFlags, PRTVFSIOSTREAM phVfsIos);
452
453	/**
454	* Marks the end of the stream.
455	*
456	* Writable streams only.
457	*
458	* @returns IPRT status code.
459	* @param pvThis The implementation specific directory data.
460	* @sa RTVfsFsStrmEnd
461	*
462	* @note Setting this member to NULL is okay for read-only streams.
463	*/
464	DECLCALLBACKMEMBER(int, pfnEnd)(void *pvThis);
465
466	/** Marks the end of the structure (RTVFSFSSTREAMOPS_VERSION). */
467	uintptr_t uEndMarker;
468	} RTVFSFSSTREAMOPS;
469	/** Pointer to const object attribute setter operations. */
470	typedef RTVFSFSSTREAMOPS const *PCRTVFSFSSTREAMOPS;
471
472	/** The RTVFSFSSTREAMOPS structure version. */
473	#define RTVFSFSSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x3f,2,0)
474
475
476	/**
477	* Creates a new VFS filesystem stream handle.
478	*
479	* @returns IPRT status code
480	* @param pFsStreamOps The filesystem stream operations.
481	* @param cbInstance The size of the instance data.
482	* @param hVfs The VFS handle to associate this filesystem
483	* stream with. NIL_VFS is ok.
484	* @param hLock Handle to a custom lock to be used with the new
485	* object. The reference is consumed. NIL and
486	* special lock handles are fine.
487	* @param fReadOnly Set if read-only, clear if write-only.
488	* @param phVfsFss Where to return the new handle.
489	* @param ppvInstance Where to return the pointer to the instance data
490	* (size is @a cbInstance).
491	*/
492	RTDECL(int) RTVfsNewFsStream(PCRTVFSFSSTREAMOPS pFsStreamOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock, bool fReadOnly,
493	PRTVFSFSSTREAM phVfsFss, void **ppvInstance);
494
495	/**
496	* Gets the private data of an filesystem stream.
497	*
498	* @returns Pointer to the private data. NULL if the handle is invalid in some
499	* way.
500	* @param hVfsFss The FS stream handle.
501	* @param pFsStreamOps The FS stream operations. This servers as a
502	* sort of password.
503	*/
504	RTDECL(void *) RTVfsFsStreamToPrivate(RTVFSFSSTREAM hVfsFss, PCRTVFSFSSTREAMOPS pFsStreamOps);
505
506
507	/**
508	* The directory operations.
509	*
510	* @extends RTVFSOBJOPS
511	* @extends RTVFSOBJSETOPS
512	*/
513	typedef struct RTVFSDIROPS
514	{
515	/** The basic object operation. */
516	RTVFSOBJOPS Obj;
517	/** The structure version (RTVFSDIROPS_VERSION). */
518	uint32_t uVersion;
519	/** Reserved field, MBZ. */
520	uint32_t fReserved;
521	/** The object setter operations. */
522	RTVFSOBJSETOPS ObjSet;
523
524	/**
525	* Generic method for opening any kind of file system object.
526	*
527	* Can also create files and directories. Symbolic links, devices and such
528	* needs to be created using special methods or this would end up being way more
529	* complicated than it already is.
530	*
531	* There are optional specializations available.
532	*
533	* @returns IPRT status code.
534	* @retval VERR_PATH_NOT_FOUND or VERR_FILE_NOT_FOUND if @a pszEntry was not
535	* found.
536	* @retval VERR_IS_A_FILE if @a pszEntry is a file or similar but @a fFlags
537	* indicates that the type of object should not be opened.
538	* @retval VERR_IS_A_DIRECTORY if @a pszEntry is a directory but @a fFlags
539	* indicates that directories should not be opened.
540	* @retval VERR_IS_A_SYMLINK if @a pszEntry is a symbolic link but @a fFlags
541	* indicates that symbolic links should not be opened (or followed).
542	* @retval VERR_IS_A_FIFO if @a pszEntry is a FIFO but @a fFlags indicates that
543	* FIFOs should not be opened.
544	* @retval VERR_IS_A_SOCKET if @a pszEntry is a socket but @a fFlags indicates
545	* that sockets should not be opened.
546	* @retval VERR_IS_A_BLOCK_DEVICE if @a pszEntry is a block device but
547	* @a fFlags indicates that block devices should not be opened.
548	* @retval VERR_IS_A_BLOCK_DEVICE if @a pszEntry is a character device but
549	* @a fFlags indicates that character devices should not be opened.
550	*
551	* @param pvThis The implementation specific directory data.
552	* @param pszEntry The name of the immediate file to open or create.
553	* @param fOpenFile RTFILE_O_XXX combination.
554	* @param fObjFlags More flags: RTVFSOBJ_F_XXX, RTPATH_F_XXX.
555	* The meaning of RTPATH_F_FOLLOW_LINK differs here, if
556	* @a pszEntry is a symlink it should be opened for
557	* traversal rather than according to @a fOpenFile.
558	* @param phVfsObj Where to return the handle to the opened object.
559	* @sa RTFileOpen, RTDirOpen
560	*/
561	DECLCALLBACKMEMBER(int, pfnOpen)(void pvThis, const char pszEntry, uint64_t fOpenFile,
562	uint32_t fObjFlags, PRTVFSOBJ phVfsObj);
563
564	/**
565	* Optional method for symbolic link handling in the vfsstddir.cpp.
566	*
567	* This is really just a hack to make symbolic link handling work when working
568	* with directory objects that doesn't have an associated VFS. It also helps
569	* deal with drive letters in symbolic links on Windows and OS/2.
570	*
571	* @returns IPRT status code.
572	* @retval VERR_PATH_IS_RELATIVE if @a pszPath isn't absolute and should be
573	* handled using pfnOpen().
574	*
575	* @param pvThis The implementation specific directory data.
576	* @param pszRoot Path to the alleged root.
577	* @param phVfsDir Where to return the handle to the specified root
578	* directory (or may current dir on a drive letter).
579	*/
580	DECLCALLBACKMEMBER(int, pfnFollowAbsoluteSymlink)(void pvThis, const char pszRoot, PRTVFSDIR phVfsDir);
581
582	/**
583	* Open or create a file.
584	*
585	* @returns IPRT status code.
586	* @param pvThis The implementation specific directory data.
587	* @param pszFilename The name of the immediate file to open or create.
588	* @param fOpen The open flags (RTFILE_O_XXX).
589	* @param phVfsFile Where to return the handle to the opened file.
590	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
591	* @sa RTFileOpen.
592	*/
593	DECLCALLBACKMEMBER(int, pfnOpenFile)(void pvThis, const char pszFilename, uint64_t fOpen, PRTVFSFILE phVfsFile);
594
595	/**
596	* Open an existing subdirectory.
597	*
598	* @returns IPRT status code.
599	* @param pvThis The implementation specific directory data.
600	* @param pszSubDir The name of the immediate subdirectory to open.
601	* @param fFlags RTDIR_F_XXX.
602	* @param phVfsDir Where to return the handle to the opened directory.
603	* Optional.
604	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
605	* @sa RTDirOpen.
606	*/
607	DECLCALLBACKMEMBER(int, pfnOpenDir)(void pvThis, const char pszSubDir, uint32_t fFlags, PRTVFSDIR phVfsDir);
608
609	/**
610	* Creates a new subdirectory.
611	*
612	* @returns IPRT status code.
613	* @param pvThis The implementation specific directory data.
614	* @param pszSubDir The name of the immediate subdirectory to create.
615	* @param fMode The mode mask of the new directory.
616	* @param phVfsDir Where to optionally return the handle to the newly
617	* create directory.
618	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
619	* @sa RTDirCreate.
620	*/
621	DECLCALLBACKMEMBER(int, pfnCreateDir)(void pvThis, const char pszSubDir, RTFMODE fMode, PRTVFSDIR phVfsDir);
622
623	/**
624	* Opens an existing symbolic link.
625	*
626	* @returns IPRT status code.
627	* @param pvThis The implementation specific directory data.
628	* @param pszSymlink The name of the immediate symbolic link to open.
629	* @param phVfsSymlink Where to optionally return the handle to the
630	* newly create symbolic link.
631	* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
632	* @sa RTSymlinkCreate.
633	*/
634	DECLCALLBACKMEMBER(int, pfnOpenSymlink)(void pvThis, const char pszSymlink, PRTVFSSYMLINK phVfsSymlink);
635
636	/**
637	* Creates a new symbolic link.
638	*
639	* @returns IPRT status code.
640	* @param pvThis The implementation specific directory data.
641	* @param pszSymlink The name of the immediate symbolic link to create.
642	* @param pszTarget The symbolic link target.
643	* @param enmType The symbolic link type.
644	* @param phVfsSymlink Where to optionally return the handle to the
645	* newly create symbolic link.
646	* @sa RTSymlinkCreate.
647	*/
648	DECLCALLBACKMEMBER(int, pfnCreateSymlink)(void pvThis, const char pszSymlink, const char *pszTarget,
649	RTSYMLINKTYPE enmType, PRTVFSSYMLINK phVfsSymlink);
650
651	/**
652	* Query information about an entry.
653	*
654	* @returns IPRT status code.
655	* @param pvThis The implementation specific directory data.
656	* @param pszEntry The name of the directory entry to remove.
657	* @param pObjInfo Where to return the info on success.
658	* @param enmAddAttr Which set of additional attributes to request.
659	* @note Optional. RTVFSDIROPS::pfnOpenObj and RTVFSOBJOPS::pfnQueryInfo
660	* will be used if NULL.
661	* @sa RTPathQueryInfo, RTVFSOBJOPS::pfnQueryInfo
662	*/
663	DECLCALLBACKMEMBER(int, pfnQueryEntryInfo)(void pvThis, const char pszEntry,
664	PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr);
665
666	/**
667	* Removes a directory entry.
668	*
669	* @returns IPRT status code.
670	* @param pvThis The implementation specific directory data.
671	* @param pszEntry The name of the directory entry to remove.
672	* @param fType If non-zero, this restricts the type of the entry to
673	* the object type indicated by the mask
674	* (RTFS_TYPE_XXX).
675	* @sa RTFileRemove, RTDirRemove, RTSymlinkRemove.
676	*/
677	DECLCALLBACKMEMBER(int, pfnUnlinkEntry)(void pvThis, const char pszEntry, RTFMODE fType);
678
679	/**
680	* Renames a directory entry.
681	*
682	* @returns IPRT status code.
683	* @param pvThis The implementation specific directory data.
684	* @param pszEntry The name of the directory entry to rename.
685	* @param fType If non-zero, this restricts the type of the entry to
686	* the object type indicated by the mask
687	* (RTFS_TYPE_XXX).
688	* @param pszNewName The new entry name.
689	* @sa RTPathRename
690	*
691	* @todo This API is not flexible enough, must be able to rename between
692	* directories within a file system.
693	*/
694	DECLCALLBACKMEMBER(int, pfnRenameEntry)(void pvThis, const char pszEntry, RTFMODE fType, const char *pszNewName);
695
696	/**
697	* Rewind the directory stream so that the next read returns the first
698	* entry.
699	*
700	* @returns IPRT status code.
701	* @param pvThis The implementation specific directory data.
702	*/
703	DECLCALLBACKMEMBER(int, pfnRewindDir)(void *pvThis);
704
705	/**
706	* Rewind the directory stream so that the next read returns the first
707	* entry.
708	*
709	* @returns IPRT status code.
710	* @param pvThis The implementation specific directory data.
711	* @param pDirEntry Output buffer.
712	* @param pcbDirEntry Complicated, see RTDirReadEx.
713	* @param enmAddAttr Which set of additional attributes to request.
714	* @sa RTDirReadEx
715	*/
716	DECLCALLBACKMEMBER(int, pfnReadDir)(void pvThis, PRTDIRENTRYEX pDirEntry, size_t pcbDirEntry, RTFSOBJATTRADD enmAddAttr);
717
718	/** Marks the end of the structure (RTVFSDIROPS_VERSION). */
719	uintptr_t uEndMarker;
720	} RTVFSDIROPS;
721	/** Pointer to const directory operations. */
722	typedef RTVFSDIROPS const *PCRTVFSDIROPS;
723	/** The RTVFSDIROPS structure version. */
724	#define RTVFSDIROPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x4f,1,0)
725
726
727	/**
728	* Creates a new VFS directory handle.
729	*
730	* @returns IPRT status code
731	* @param pDirOps The directory operations.
732	* @param cbInstance The size of the instance data.
733	* @param fFlags RTVFSDIR_F_XXX
734	* @param hVfs The VFS handle to associate this directory with.
735	* NIL_VFS is ok.
736	* @param hLock Handle to a custom lock to be used with the new
737	* object. The reference is consumed. NIL and
738	* special lock handles are fine.
739	* @param phVfsDir Where to return the new handle.
740	* @param ppvInstance Where to return the pointer to the instance data
741	* (size is @a cbInstance).
742	*/
743	RTDECL(int) RTVfsNewDir(PCRTVFSDIROPS pDirOps, size_t cbInstance, uint32_t fFlags, RTVFS hVfs, RTVFSLOCK hLock,
744	PRTVFSDIR phVfsDir, void **ppvInstance);
745
746	/** @name RTVFSDIR_F_XXX
747	* @{ */
748	/** Don't reference the @a hVfs parameter passed to RTVfsNewDir.
749	* This is a permanent root directory hack. */
750	#define RTVFSDIR_F_NO_VFS_REF RT_BIT_32(0)
751	/** @} */
752
753
754	/**
755	* The symbolic link operations.
756	*
757	* @extends RTVFSOBJOPS
758	* @extends RTVFSOBJSETOPS
759	*/
760	typedef struct RTVFSSYMLINKOPS
761	{
762	/** The basic object operation. */
763	RTVFSOBJOPS Obj;
764	/** The structure version (RTVFSSYMLINKOPS_VERSION). */
765	uint32_t uVersion;
766	/** Reserved field, MBZ. */
767	uint32_t fReserved;
768	/** The object setter operations. */
769	RTVFSOBJSETOPS ObjSet;
770
771	/**
772	* Read the symbolic link target.
773	*
774	* @returns IPRT status code.
775	* @param pvThis The implementation specific symbolic link data.
776	* @param pszTarget The target buffer.
777	* @param cbTarget The size of the target buffer.
778	* @sa RTSymlinkRead
779	*/
780	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, char pszTarget, size_t cbTarget);
781
782	/** Marks the end of the structure (RTVFSSYMLINKOPS_VERSION). */
783	uintptr_t uEndMarker;
784	} RTVFSSYMLINKOPS;
785	/** Pointer to const symbolic link operations. */
786	typedef RTVFSSYMLINKOPS const *PCRTVFSSYMLINKOPS;
787	/** The RTVFSSYMLINKOPS structure version. */
788	#define RTVFSSYMLINKOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x5f,1,0)
789
790
791	/**
792	* Creates a new VFS symlink handle.
793	*
794	* @returns IPRT status code
795	* @param pSymlinkOps The symlink operations.
796	* @param cbInstance The size of the instance data.
797	* @param hVfs The VFS handle to associate this symlink object
798	* with. NIL_VFS is ok.
799	* @param hLock Handle to a custom lock to be used with the new
800	* object. The reference is consumed. NIL and
801	* special lock handles are fine.
802	* @param phVfsSym Where to return the new handle.
803	* @param ppvInstance Where to return the pointer to the instance data
804	* (size is @a cbInstance).
805	*/
806	RTDECL(int) RTVfsNewSymlink(PCRTVFSSYMLINKOPS pSymlinkOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
807	PRTVFSSYMLINK phVfsSym, void **ppvInstance);
808
809
810	/**
811	* The basis for all I/O objects (files, pipes, sockets, devices, ++).
812	*
813	* @extends RTVFSOBJOPS
814	*/
815	typedef struct RTVFSIOSTREAMOPS
816	{
817	/** The basic object operation. */
818	RTVFSOBJOPS Obj;
819	/** The structure version (RTVFSIOSTREAMOPS_VERSION). */
820	uint32_t uVersion;
821	/** Feature field. */
822	uint32_t fFeatures;
823
824	/**
825	* Reads from the file/stream.
826	*
827	* @returns IPRT status code. See RTVfsIoStrmRead.
828	* @param pvThis The implementation specific file data.
829	* @param off Where to read at, -1 for the current position.
830	* @param pSgBuf Gather buffer describing the bytes that are to be
831	* written.
832	* @param fBlocking If @c true, the call is blocking, if @c false it
833	* should not block.
834	* @param pcbRead Where return the number of bytes actually read.
835	* This is set it 0 by the caller. If NULL, try read
836	* all and fail if incomplete.
837	* @sa RTVfsIoStrmRead, RTVfsIoStrmSgRead, RTVfsFileRead,
838	* RTVfsFileReadAt, RTFileRead, RTFileReadAt.
839	*/
840	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbRead);
841
842	/**
843	* Writes to the file/stream.
844	*
845	* @returns IPRT status code.
846	* @param pvThis The implementation specific file data.
847	* @param off Where to start wrinting, -1 for the current
848	* position.
849	* @param pSgBuf Gather buffers describing the bytes that are to be
850	* written.
851	* @param fBlocking If @c true, the call is blocking, if @c false it
852	* should not block.
853	* @param pcbWritten Where to return the number of bytes actually
854	* written. This is set it 0 by the caller. If
855	* NULL, try write it all and fail if incomplete.
856	* @sa RTFileWrite, RTFileWriteAt.
857	*/
858	DECLCALLBACKMEMBER(int, pfnWrite)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbWritten);
859
860	/**
861	* Flushes any pending data writes to the stream.
862	*
863	* @returns IPRT status code.
864	* @param pvThis The implementation specific file data.
865	* @sa RTFileFlush.
866	*/
867	DECLCALLBACKMEMBER(int, pfnFlush)(void *pvThis);
868
869	/**
870	* Poll for events.
871	*
872	* @returns IPRT status code.
873	* @param pvThis The implementation specific file data.
874	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
875	* @param cMillies How long to wait for event to eventuate.
876	* @param fIntr Whether the wait is interruptible and can return
877	* VERR_INTERRUPTED (@c true) or if this condition
878	* should be hidden from the caller (@c false).
879	* @param pfRetEvents Where to return the event mask.
880	* @sa RTPollSetAdd, RTPoll, RTPollNoResume.
881	*/
882	DECLCALLBACKMEMBER(int, pfnPollOne)(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr,
883	uint32_t *pfRetEvents);
884
885	/**
886	* Tells the current file/stream position.
887	*
888	* @returns IPRT status code.
889	* @param pvThis The implementation specific file data.
890	* @param poffActual Where to return the actual offset.
891	* @sa RTFileTell
892	*/
893	DECLCALLBACKMEMBER(int, pfnTell)(void *pvThis, PRTFOFF poffActual);
894
895	/**
896	* Skips @a cb ahead in the stream.
897	*
898	* @returns IPRT status code.
899	* @param pvThis The implementation specific file data.
900	* @param cb The number bytes to skip.
901	* @remarks This is optional and can be NULL.
902	*/
903	DECLCALLBACKMEMBER(int, pfnSkip)(void *pvThis, RTFOFF cb);
904
905	/**
906	* Fills the stream with @a cb zeros.
907	*
908	* @returns IPRT status code.
909	* @param pvThis The implementation specific file data.
910	* @param cb The number of zero bytes to insert.
911	* @remarks This is optional and can be NULL.
912	*/
913	DECLCALLBACKMEMBER(int, pfnZeroFill)(void *pvThis, RTFOFF cb);
914
915	/** Marks the end of the structure (RTVFSIOSTREAMOPS_VERSION). */
916	uintptr_t uEndMarker;
917	} RTVFSIOSTREAMOPS;
918	/** Pointer to const I/O stream operations. */
919	typedef RTVFSIOSTREAMOPS const *PCRTVFSIOSTREAMOPS;
920
921	/** The RTVFSIOSTREAMOPS structure version. */
922	#define RTVFSIOSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x6f,1,0)
923
924	/** @name RTVFSIOSTREAMOPS::fFeatures
925	* @{ */
926	/** No scatter gather lists, thank you. */
927	#define RTVFSIOSTREAMOPS_FEAT_NO_SG RT_BIT_32(0)
928	/** Mask of the valid I/O stream feature flags. */
929	#define RTVFSIOSTREAMOPS_FEAT_VALID_MASK UINT32_C(0x00000001)
930	/** @} */
931
932
933	/**
934	* Creates a new VFS I/O stream handle.
935	*
936	* @returns IPRT status code
937	* @param pIoStreamOps The I/O stream operations.
938	* @param cbInstance The size of the instance data.
939	* @param fOpen The open flags. The minimum is the access mask.
940	* @param hVfs The VFS handle to associate this I/O stream
941	* with. NIL_VFS is ok.
942	* @param hLock Handle to a custom lock to be used with the new
943	* object. The reference is consumed. NIL and
944	* special lock handles are fine.
945	* @param phVfsIos Where to return the new handle.
946	* @param ppvInstance Where to return the pointer to the instance data
947	* (size is @a cbInstance).
948	*/
949	RTDECL(int) RTVfsNewIoStream(PCRTVFSIOSTREAMOPS pIoStreamOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
950	PRTVFSIOSTREAM phVfsIos, void **ppvInstance);
951
952
953	/**
954	* Gets the private data of an I/O stream.
955	*
956	* @returns Pointer to the private data. NULL if the handle is invalid in some
957	* way.
958	* @param hVfsIos The I/O stream handle.
959	* @param pIoStreamOps The I/O stream operations. This servers as a
960	* sort of password.
961	*/
962	RTDECL(void *) RTVfsIoStreamToPrivate(RTVFSIOSTREAM hVfsIos, PCRTVFSIOSTREAMOPS pIoStreamOps);
963
964
965	/**
966	* The file operations.
967	*
968	* @extends RTVFSIOSTREAMOPS
969	* @extends RTVFSOBJSETOPS
970	*/
971	typedef struct RTVFSFILEOPS
972	{
973	/** The I/O stream and basis object operations. */
974	RTVFSIOSTREAMOPS Stream;
975	/** The structure version (RTVFSFILEOPS_VERSION). */
976	uint32_t uVersion;
977	/** Reserved field, MBZ. */
978	uint32_t fReserved;
979	/** The object setter operations. */
980	RTVFSOBJSETOPS ObjSet;
981
982	/**
983	* Changes the current file position.
984	*
985	* @returns IPRT status code.
986	* @param pvThis The implementation specific file data.
987	* @param offSeek The offset to seek.
988	* @param uMethod The seek method, i.e. what the seek is relative to.
989	* @param poffActual Where to return the actual offset.
990	* @sa RTFileSeek
991	*/
992	DECLCALLBACKMEMBER(int, pfnSeek)(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual);
993
994	/**
995	* Get the current file/stream size.
996	*
997	* @returns IPRT status code.
998	* @param pvThis The implementation specific file data.
999	* @param pcbFile Where to store the current file size.
1000	* @sa RTFileGetSize
1001	*/
1002	DECLCALLBACKMEMBER(int, pfnQuerySize)(void pvThis, uint64_t pcbFile);
1003
1004	/** @todo There will be more methods here. */
1005
1006	/** Marks the end of the structure (RTVFSFILEOPS_VERSION). */
1007	uintptr_t uEndMarker;
1008	} RTVFSFILEOPS;
1009	/** Pointer to const file operations. */
1010	typedef RTVFSFILEOPS const *PCRTVFSFILEOPS;
1011
1012	/** The RTVFSFILEOPS structure version. */
1013	#define RTVFSFILEOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x7f,1,0)
1014
1015	/**
1016	* Creates a new VFS file handle.
1017	*
1018	* @returns IPRT status code
1019	* @param pFileOps The file operations.
1020	* @param cbInstance The size of the instance data.
1021	* @param fOpen The open flags. The minimum is the access mask.
1022	* @param hVfs The VFS handle to associate this file with.
1023	* NIL_VFS is ok.
1024	* @param hLock Handle to a custom lock to be used with the new
1025	* object. The reference is consumed. NIL and
1026	* special lock handles are fine.
1027	* @param phVfsFile Where to return the new handle.
1028	* @param ppvInstance Where to return the pointer to the instance data
1029	* (size is @a cbInstance).
1030	*/
1031	RTDECL(int) RTVfsNewFile(PCRTVFSFILEOPS pFileOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
1032	PRTVFSFILE phVfsFile, void **ppvInstance);
1033
1034
1035	/** @defgroup grp_rt_vfs_ll_util VFS Utility APIs
1036	* @{ */
1037
1038	/**
1039	* Parsed path.
1040	*/
1041	typedef struct RTVFSPARSEDPATH
1042	{
1043	/** The length of the path in szCopy. */
1044	uint16_t cch;
1045	/** The number of path components. */
1046	uint16_t cComponents;
1047	/** Set if the path ends with slash, indicating that it's a directory
1048	* reference and not a file reference. The slash has been removed from
1049	* the copy. */
1050	bool fDirSlash;
1051	/** Set if absolute. */
1052	bool fAbsolute;
1053	/** The offset where each path component starts, i.e. the char after the
1054	* slash. The array has cComponents + 1 entries, where the final one is
1055	* cch + 1 so that one can always terminate the current component by
1056	* szPath[aoffComponent[i] - 1] = '\0'. */
1057	uint16_t aoffComponents[RTPATH_MAX / 2 + 1];
1058	/** A normalized copy of the path.
1059	* Reserve some extra space so we can be more relaxed about overflow
1060	* checks and terminator paddings, especially when recursing. */
1061	char szPath[RTPATH_MAX];
1062	} RTVFSPARSEDPATH;
1063	/** Pointer to a parsed path. */
1064	typedef RTVFSPARSEDPATH *PRTVFSPARSEDPATH;
1065
1066	/** The max accepted path length.
1067	* This must be a few chars shorter than RTVFSPARSEDPATH::szPath because we
1068	* use two terminators and wish be a little bit lazy with checking. */
1069	#define RTVFSPARSEDPATH_MAX (RTPATH_MAX - 4)
1070
1071	/**
1072	* Appends @a pszPath (relative) to the already parsed path @a pPath.
1073	*
1074	* @retval VINF_SUCCESS
1075	* @retval VERR_FILENAME_TOO_LONG
1076	* @retval VERR_INTERNAL_ERROR_4
1077	* @param pPath The parsed path to append @a pszPath onto.
1078	* This is both input and output.
1079	* @param pszPath The path to append. This must be relative.
1080	* @param piRestartComp The component to restart parsing at. This is
1081	* input/output. The input does not have to be
1082	* within the valid range. Optional.
1083	*/
1084	RTDECL(int) RTVfsParsePathAppend(PRTVFSPARSEDPATH pPath, const char pszPath, uint16_t piRestartComp);
1085
1086	/**
1087	* Parses a path.
1088	*
1089	* @retval VINF_SUCCESS
1090	* @retval VERR_FILENAME_TOO_LONG
1091	* @param pPath Where to store the parsed path.
1092	* @param pszPath The path to parse. Absolute or relative to @a
1093	* pszCwd.
1094	* @param pszCwd The current working directory. Must be
1095	* absolute.
1096	*/
1097	RTDECL(int) RTVfsParsePath(PRTVFSPARSEDPATH pPath, const char pszPath, const char pszCwd);
1098
1099	/**
1100	* Same as RTVfsParsePath except that it allocates a temporary buffer.
1101	*
1102	* @retval VINF_SUCCESS
1103	* @retval VERR_NO_TMP_MEMORY
1104	* @retval VERR_FILENAME_TOO_LONG
1105	* @param pszPath The path to parse. Absolute or relative to @a
1106	* pszCwd.
1107	* @param pszCwd The current working directory. Must be
1108	* absolute.
1109	* @param ppPath Where to store the pointer to the allocated
1110	* buffer containing the parsed path. This must
1111	* be freed by calling RTVfsParsePathFree. NULL
1112	* will be stored on failured.
1113	*/
1114	RTDECL(int) RTVfsParsePathA(const char pszPath, const char pszCwd, PRTVFSPARSEDPATH *ppPath);
1115
1116	/**
1117	* Frees a buffer returned by RTVfsParsePathA.
1118	*
1119	* @param pPath The parsed path buffer to free. NULL is fine.
1120	*/
1121	RTDECL(void) RTVfsParsePathFree(PRTVFSPARSEDPATH pPath);
1122
1123	/**
1124	* Dummy implementation of RTVFSIOSTREAMOPS::pfnPollOne.
1125	*
1126	* This handles the case where there is no chance any events my be raised and
1127	* all that is required is to wait according to the parameters.
1128	*
1129	* @returns IPRT status code.
1130	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
1131	* @param cMillies How long to wait for event to eventuate.
1132	* @param fIntr Whether the wait is interruptible and can return
1133	* VERR_INTERRUPTED (@c true) or if this condition
1134	* should be hidden from the caller (@c false).
1135	* @param pfRetEvents Where to return the event mask.
1136	* @sa RTVFSIOSTREAMOPS::pfnPollOne, RTPollSetAdd, RTPoll, RTPollNoResume.
1137	*/
1138	RTDECL(int) RTVfsUtilDummyPollOne(uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, uint32_t *pfRetEvents);
1139
1140	/** @} */
1141
1142
1143	/** @defgroup grp_rt_vfs_lowlevel_chain VFS Chains (Low Level)
1144	* @ref grp_rt_vfs_chain
1145	* @{
1146	*/
1147
1148	/** Pointer to a VFS chain element registration record. */
1149	typedef struct RTVFSCHAINELEMENTREG *PRTVFSCHAINELEMENTREG;
1150	/** Pointer to a const VFS chain element registration record. */
1151	typedef struct RTVFSCHAINELEMENTREG const *PCRTVFSCHAINELEMENTREG;
1152
1153	/**
1154	* VFS chain element argument.
1155	*/
1156	typedef struct RTVFSCHAINELEMENTARG
1157	{
1158	/** The string argument value. */
1159	char *psz;
1160	/** The specification offset of this argument. */
1161	uint16_t offSpec;
1162	/** Provider specific value. */
1163	uint64_t uProvider;
1164	} RTVFSCHAINELEMENTARG;
1165	/** Pointer to a VFS chain element argument. */
1166	typedef RTVFSCHAINELEMENTARG *PRTVFSCHAINELEMENTARG;
1167
1168
1169	/**
1170	* VFS chain element specification.
1171	*/
1172	typedef struct RTVFSCHAINELEMSPEC
1173	{
1174	/** The provider name.
1175	* This can be NULL if this is the final component and it's just a path. */
1176	char *pszProvider;
1177	/** The input type, RTVFSOBJTYPE_INVALID if first. */
1178	RTVFSOBJTYPE enmTypeIn;
1179	/** The element type.
1180	* RTVFSOBJTYPE_END if this is the final component and it's just a path. */
1181	RTVFSOBJTYPE enmType;
1182	/** The input spec offset of this element. */
1183	uint16_t offSpec;
1184	/** The length of the input spec. */
1185	uint16_t cchSpec;
1186	/** The number of arguments. */
1187	uint32_t cArgs;
1188	/** Arguments. */
1189	PRTVFSCHAINELEMENTARG paArgs;
1190
1191	/** The provider. */
1192	PCRTVFSCHAINELEMENTREG pProvider;
1193	/** Provider specific value. */
1194	uint64_t uProvider;
1195	/** The object (with reference). */
1196	RTVFSOBJ hVfsObj;
1197	} RTVFSCHAINELEMSPEC;
1198	/** Pointer to a chain element specification. */
1199	typedef RTVFSCHAINELEMSPEC *PRTVFSCHAINELEMSPEC;
1200	/** Pointer to a const chain element specification. */
1201	typedef RTVFSCHAINELEMSPEC const *PCRTVFSCHAINELEMSPEC;
1202
1203
1204	/**
1205	* Parsed VFS chain specification.
1206	*/
1207	typedef struct RTVFSCHAINSPEC
1208	{
1209	/** Open directory flags (RTFILE_O_XXX). */
1210	uint64_t fOpenFile;
1211	/** To be defined. */
1212	uint32_t fOpenDir;
1213	/** The type desired by the caller. */
1214	RTVFSOBJTYPE enmDesiredType;
1215	/** The number of elements. */
1216	uint32_t cElements;
1217	/** The elements. */
1218	PRTVFSCHAINELEMSPEC paElements;
1219	} RTVFSCHAINSPEC;
1220	/** Pointer to a parsed VFS chain specification. */
1221	typedef RTVFSCHAINSPEC *PRTVFSCHAINSPEC;
1222	/** Pointer to a const, parsed VFS chain specification. */
1223	typedef RTVFSCHAINSPEC const *PCRTVFSCHAINSPEC;
1224
1225
1226	/**
1227	* A chain element provider registration record.
1228	*/
1229	typedef struct RTVFSCHAINELEMENTREG
1230	{
1231	/** The version (RTVFSCHAINELEMENTREG_VERSION). */
1232	uint32_t uVersion;
1233	/** Reserved, MBZ. */
1234	uint32_t fReserved;
1235	/** The provider name (unique). */
1236	const char *pszName;
1237	/** For chaining the providers. */
1238	RTLISTNODE ListEntry;
1239	/** Help text. */
1240	const char *pszHelp;
1241
1242	/**
1243	* Checks the element specification.
1244	*
1245	* This is allowed to parse arguments and use pSpec->uProvider and
1246	* pElement->paArgs[].uProvider to store information that pfnInstantiate and
1247	* pfnCanReuseElement may use later on, thus avoiding duplicating work/code.
1248	*
1249	* @returns IPRT status code.
1250	* @param pProviderReg Pointer to the element provider registration.
1251	* @param pSpec The chain specification.
1252	* @param pElement The chain element specification to validate.
1253	* @param poffError Where to return error offset on failure. This is
1254	* set to the pElement->offSpec on input, so it only
1255	* needs to be adjusted if an argument is at fault.
1256	* @param pErrInfo Where to return additional error information, if
1257	* available. Optional.
1258	*/
1259	DECLCALLBACKMEMBER(int, pfnValidate)(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec,
1260	PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo);
1261
1262	/**
1263	* Create a VFS object according to the element specification.
1264	*
1265	* @returns IPRT status code.
1266	* @param pProviderReg Pointer to the element provider registration.
1267	* @param pSpec The chain specification.
1268	* @param pElement The chain element specification to instantiate.
1269	* @param hPrevVfsObj Handle to the previous VFS object, NIL_RTVFSOBJ if
1270	* first.
1271	* @param phVfsObj Where to return the VFS object handle.
1272	* @param poffError Where to return error offset on failure. This is
1273	* set to the pElement->offSpec on input, so it only
1274	* needs to be adjusted if an argument is at fault.
1275	* @param pErrInfo Where to return additional error information, if
1276	* available. Optional.
1277	*/
1278	DECLCALLBACKMEMBER(int, pfnInstantiate)(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec,
1279	PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj,
1280	PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo);
1281
1282	/**
1283	* Determins whether the element can be reused.
1284	*
1285	* This is for handling situations accessing the same file system twice, like
1286	* for both the source and destiation of a copy operation. This allows not only
1287	* sharing resources and avoid doing things twice, but also helps avoid file
1288	* sharing violations and inconsistencies araising from the image being updated
1289	* and read independently.
1290	*
1291	* @returns true if the element from @a pReuseSpec an be reused, false if not.
1292	* @param pProviderReg Pointer to the element provider registration.
1293	* @param pSpec The chain specification.
1294	* @param pElement The chain element specification.
1295	* @param pReuseSpec The chain specification of the existing chain.
1296	* @param pReuseElement The chain element specification of the existing
1297	* element that is being considered for reuse.
1298	*/
1299	DECLCALLBACKMEMBER(bool, pfnCanReuseElement)(PCRTVFSCHAINELEMENTREG pProviderReg,
1300	PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement,
1301	PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement);
1302
1303	/** End marker (RTVFSCHAINELEMENTREG_VERSION). */
1304	uintptr_t uEndMarker;
1305	} RTVFSCHAINELEMENTREG;
1306
1307	/** The VFS chain element registration record version number. */
1308	#define RTVFSCHAINELEMENTREG_VERSION RT_MAKE_U32_FROM_U8(0xff, 0x7f, 1, 0)
1309
1310
1311	/**
1312	* Parses the specification.
1313	*
1314	* @returns IPRT status code.
1315	* @param pszSpec The specification string to parse.
1316	* @param fFlags Flags, see RTVFSCHAIN_PF_XXX.
1317	* @param enmDesiredType The object type the caller wants to interface with.
1318	* @param ppSpec Where to return the pointer to the parsed
1319	* specification. This must be freed by calling
1320	* RTVfsChainSpecFree. Will always be set (unless
1321	* invalid parameters.)
1322	* @param poffError Where to return the offset into the input
1323	* specification of what's causing trouble. Always
1324	* set, unless this argument causes an invalid pointer
1325	* error.
1326	*/
1327	RTDECL(int) RTVfsChainSpecParse(const char *pszSpec, uint32_t fFlags, RTVFSOBJTYPE enmDesiredType,
1328	PRTVFSCHAINSPEC ppSpec, uint32_t poffError);
1329
1330	/** @name RTVfsChainSpecParse
1331	* @{ */
1332	/** Mask of valid flags. */
1333	#define RTVFSCHAIN_PF_VALID_MASK UINT32_C(0x00000000)
1334	/** @} */
1335
1336	/**
1337	* Checks and setups the chain.
1338	*
1339	* @returns IPRT status code.
1340	* @param pSpec The parsed specification.
1341	* @param pReuseSpec Spec to reuse if applicable. Optional.
1342	* @param phVfsObj Where to return the VFS object.
1343	* @param ppszFinalPath Where to return the pointer to the final path if
1344	* applicable. The caller needs to check whether this
1345	* is NULL or a path, in the former case nothing more
1346	* needs doing, whereas in the latter the caller must
1347	* perform the desired operation(s) on *phVfsObj using
1348	* the final path.
1349	* @param poffError Where to return the offset into the input
1350	* specification of what's causing trouble. Always
1351	* set, unless this argument causes an invalid pointer
1352	* error.
1353	* @param pErrInfo Where to return additional error information, if
1354	* available. Optional.
1355	*/
1356	RTDECL(int) RTVfsChainSpecCheckAndSetup(PRTVFSCHAINSPEC pSpec, PCRTVFSCHAINSPEC pReuseSpec,
1357	PRTVFSOBJ phVfsObj, const char *ppszFinalPath, uint32_t poffError, PRTERRINFO pErrInfo);
1358
1359	/**
1360	* Frees a parsed chain specification.
1361	*
1362	* @param pSpec What RTVfsChainSpecParse returned. NULL is
1363	* quietly ignored.
1364	*/
1365	RTDECL(void) RTVfsChainSpecFree(PRTVFSCHAINSPEC pSpec);
1366
1367	/**
1368	* Registers a chain element provider.
1369	*
1370	* @returns IPRT status code
1371	* @param pRegRec The registration record.
1372	* @param fFromCtor Indicates where we're called from.
1373	*/
1374	RTDECL(int) RTVfsChainElementRegisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromCtor);
1375
1376	/**
1377	* Deregisters a chain element provider.
1378	*
1379	* @returns IPRT status code
1380	* @param pRegRec The registration record.
1381	* @param fFromDtor Indicates where we're called from.
1382	*/
1383	RTDECL(int) RTVfsChainElementDeregisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromDtor);
1384
1385
1386	/** @def RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER
1387	* Automatically registers a chain element provider using a global constructor
1388	* and destructor hack.
1389	*
1390	* @param pRegRec Pointer to the registration record.
1391	* @param name Some unique variable name prefix.
1392	*/
1393
1394	#ifdef __cplusplus
1395	/**
1396	* Class used for registering a VFS chain element provider.
1397	*/
1398	class RTVfsChainElementAutoRegisterHack
1399	{
1400	private:
1401	/** The registration record, NULL if registration failed. */
1402	PRTVFSCHAINELEMENTREG m_pRegRec;
1403
1404	public:
1405	RTVfsChainElementAutoRegisterHack(PRTVFSCHAINELEMENTREG a_pRegRec)
1406	: m_pRegRec(a_pRegRec)
1407	{
1408	int rc = RTVfsChainElementRegisterProvider(m_pRegRec, true);
1409	if (RT_FAILURE(rc))
1410	m_pRegRec = NULL;
1411	}
1412
1413	~RTVfsChainElementAutoRegisterHack()
1414	{
1415	RTVfsChainElementDeregisterProvider(m_pRegRec, true);
1416	m_pRegRec = NULL;
1417	}
1418	};
1419
1420	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1421	static RTVfsChainElementAutoRegisterHack name ## AutoRegistrationHack(pRegRec)
1422
1423	#else
1424	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1425	extern void *name ## AutoRegistrationHack = \
1426	&Sorry_but_RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER_does_not_work_in_c_source_files
1427	#endif
1428
1429
1430	/**
1431	* Common worker for the 'stdfile' and 'open' providers for implementing
1432	* RTVFSCHAINELEMENTREG::pfnValidate.
1433	*
1434	* Stores the RTFILE_O_XXX flags in pSpec->uProvider.
1435	*
1436	* @returns IPRT status code.
1437	* @param pSpec The chain specification.
1438	* @param pElement The chain element specification to validate.
1439	* @param poffError Where to return error offset on failure. This is set to
1440	* the pElement->offSpec on input, so it only needs to be
1441	* adjusted if an argument is at fault.
1442	* @param pErrInfo Where to return additional error information, if
1443	* available. Optional.
1444	*/
1445	RTDECL(int) RTVfsChainValidateOpenFileOrIoStream(PRTVFSCHAINSPEC pSpec, PRTVFSCHAINELEMSPEC pElement,
1446	uint32_t *poffError, PRTERRINFO pErrInfo);
1447
1448
1449	/** @} */
1450
1451
1452	/** @} */
1453
1454	RT_C_DECLS_END
1455
1456	#endif /* !___iprt_vfslowlevel_h */
1457

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source: vbox/trunk/include/iprt/vfslowlevel.h@ 69826

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