vfslowlevel.h@ 66615

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1	/** @file
2	* IPRT - Virtual Filesystem.
3	*/
4
5	/*
6	* Copyright (C) 2010-2016 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	/** Marks the end of the structure (RTVFSOPS_VERSION). */
255	uintptr_t uEndMarker;
256	} RTVFSOPS;
257	/** Pointer to constant VFS operations. */
258	typedef RTVFSOPS const *PCRTVFSOPS;
259
260	/** The RTVFSOPS structure version. */
261	#define RTVFSOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x0f,1,0)
262
263	/** @name RTVFSOPS::fFeatures
264	* @{ */
265	/** The VFS supports attaching other systems. */
266	#define RTVFSOPS_FEAT_ATTACH RT_BIT_32(0)
267	/** @} */
268
269	/**
270	* Creates a new VFS handle.
271	*
272	* @returns IPRT status code
273	* @param pVfsOps The VFS operations.
274	* @param cbInstance The size of the instance data.
275	* @param hVfs The VFS handle to associate this VFS with.
276	* NIL_VFS is ok.
277	* @param hLock Handle to a custom lock to be used with the new
278	* object. The reference is consumed. NIL and
279	* special lock handles are fine.
280	* @param phVfs Where to return the new handle.
281	* @param ppvInstance Where to return the pointer to the instance data
282	* (size is @a cbInstance).
283	*/
284	RTDECL(int) RTVfsNew(PCRTVFSOPS pVfsOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
285	PRTVFS phVfs, void **ppvInstance);
286
287
288	/**
289	* Creates a new VFS base object handle.
290	*
291	* @returns IPRT status code
292	* @param pObjOps The base object operations.
293	* @param cbInstance The size of the instance data.
294	* @param hVfs The VFS handle to associate this base object
295	* with. NIL_VFS is ok.
296	* @param hLock Handle to a custom lock to be used with the new
297	* object. The reference is consumed. NIL and
298	* special lock handles are fine.
299	* @param phVfsObj Where to return the new handle.
300	* @param ppvInstance Where to return the pointer to the instance data
301	* (size is @a cbInstance).
302	*/
303	RTDECL(int) RTVfsNewBaseObj(PCRTVFSOBJOPS pObjOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
304	PRTVFSOBJ phVfsObj, void **ppvInstance);
305
306
307	/**
308	* Additional operations for setting object attributes.
309	*/
310	typedef struct RTVFSOBJSETOPS
311	{
312	/** The structure version (RTVFSOBJSETOPS_VERSION). */
313	uint32_t uVersion;
314	/** The offset to the RTVFSOBJOPS structure. */
315	int32_t offObjOps;
316
317	/**
318	* Set the unix style owner and group.
319	*
320	* @returns IPRT status code.
321	* @param pvThis The implementation specific file data.
322	* @param fMode The new mode bits.
323	* @param fMask The mask indicating which bits we are
324	* changing.
325	* @sa RTFileSetMode
326	*/
327	DECLCALLBACKMEMBER(int, pfnSetMode)(void *pvThis, RTFMODE fMode, RTFMODE fMask);
328
329	/**
330	* Set the timestamps associated with the object.
331	*
332	* @returns IPRT status code.
333	* @param pvThis The implementation specific file data.
334	* @param pAccessTime Pointer to the new access time. NULL if not
335	* to be changed.
336	* @param pModificationTime Pointer to the new modifcation time. NULL if
337	* not to be changed.
338	* @param pChangeTime Pointer to the new change time. NULL if not
339	* to be changed.
340	* @param pBirthTime Pointer to the new time of birth. NULL if
341	* not to be changed.
342	* @remarks See RTFileSetTimes for restrictions and behavior imposed by the
343	* host OS or underlying VFS provider.
344	* @sa RTFileSetTimes
345	*/
346	DECLCALLBACKMEMBER(int, pfnSetTimes)(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime,
347	PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime);
348
349	/**
350	* Set the unix style owner and group.
351	*
352	* @returns IPRT status code.
353	* @param pvThis The implementation specific file data.
354	* @param uid The user ID of the new owner. NIL_RTUID if
355	* unchanged.
356	* @param gid The group ID of the new owner group. NIL_RTGID if
357	* unchanged.
358	* @sa RTFileSetOwner
359	*/
360	DECLCALLBACKMEMBER(int, pfnSetOwner)(void *pvThis, RTUID uid, RTGID gid);
361
362	/** Marks the end of the structure (RTVFSOBJSETOPS_VERSION). */
363	uintptr_t uEndMarker;
364	} RTVFSOBJSETOPS;
365	/** Pointer to const object attribute setter operations. */
366	typedef RTVFSOBJSETOPS const *PCRTVFSOBJSETOPS;
367
368	/** The RTVFSOBJSETOPS structure version. */
369	#define RTVFSOBJSETOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x2f,1,0)
370
371
372	/**
373	* The filesystem stream operations.
374	*
375	* @extends RTVFSOBJOPS
376	*/
377	typedef struct RTVFSFSSTREAMOPS
378	{
379	/** The basic object operation. */
380	RTVFSOBJOPS Obj;
381	/** The structure version (RTVFSFSSTREAMOPS_VERSION). */
382	uint32_t uVersion;
383	/** Reserved field, MBZ. */
384	uint32_t fReserved;
385
386	/**
387	* Gets the next object in the stream.
388	*
389	* @returns IPRT status code.
390	* @retval VINF_SUCCESS if a new object was retrieved.
391	* @retval VERR_EOF when there are no more objects.
392	* @param pvThis The implementation specific directory data.
393	* @param ppszName Where to return the object name. Must be freed by
394	* calling RTStrFree.
395	* @param penmType Where to return the object type.
396	* @param hVfsObj Where to return the object handle (referenced).
397	* This must be cast to the desired type before use.
398	* @sa RTVfsFsStrmNext
399	*/
400	DECLCALLBACKMEMBER(int, pfnNext)(void pvThis, char ppszName, RTVFSOBJTYPE penmType, PRTVFSOBJ phVfsObj);
401
402	/** Marks the end of the structure (RTVFSFSSTREAMOPS_VERSION). */
403	uintptr_t uEndMarker;
404	} RTVFSFSSTREAMOPS;
405	/** Pointer to const object attribute setter operations. */
406	typedef RTVFSFSSTREAMOPS const *PCRTVFSFSSTREAMOPS;
407
408	/** The RTVFSFSSTREAMOPS structure version. */
409	#define RTVFSFSSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x3f,1,0)
410
411
412	/**
413	* Creates a new VFS filesystem stream handle.
414	*
415	* @returns IPRT status code
416	* @param pFsStreamOps The filesystem stream operations.
417	* @param cbInstance The size of the instance data.
418	* @param hVfs The VFS handle to associate this filesystem
419	* stream with. NIL_VFS is ok.
420	* @param hLock Handle to a custom lock to be used with the new
421	* object. The reference is consumed. NIL and
422	* special lock handles are fine.
423	* @param phVfsFss Where to return the new handle.
424	* @param ppvInstance Where to return the pointer to the instance data
425	* (size is @a cbInstance).
426	*/
427	RTDECL(int) RTVfsNewFsStream(PCRTVFSFSSTREAMOPS pFsStreamOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
428	PRTVFSFSSTREAM phVfsFss, void **ppvInstance);
429
430
431	/**
432	* The directory operations.
433	*
434	* @extends RTVFSOBJOPS
435	* @extends RTVFSOBJSETOPS
436	*/
437	typedef struct RTVFSDIROPS
438	{
439	/** The basic object operation. */
440	RTVFSOBJOPS Obj;
441	/** The structure version (RTVFSDIROPS_VERSION). */
442	uint32_t uVersion;
443	/** Reserved field, MBZ. */
444	uint32_t fReserved;
445	/** The object setter operations. */
446	RTVFSOBJSETOPS ObjSet;
447
448	/**
449	* Opens a directory entry for traversal purposes.
450	*
451	* Method which sole purpose is helping the path traversal. Only one of
452	* the three output variables will be set, the others will left untouched
453	* (caller sets them to NIL).
454	*
455	* @returns IPRT status code.
456	* @retval VERR_PATH_NOT_FOUND if @a pszEntry was not found.
457	* @param pvThis The implementation specific directory data.
458	* @param pszEntry The name of the directory entry to remove.
459	* @param phVfsDir If not NULL and it is a directory, open it and
460	* return the handle here.
461	* @param phVfsSymlink If not NULL and it is a symbolic link, open it
462	* and return the handle here.
463	* @param phVfsMounted If not NULL and it is a mounted VFS directory,
464	* reference it and return the handle here.
465	* @todo Should com dir, symlinks and mount points using some common
466	* ancestor "class".
467	*/
468	DECLCALLBACKMEMBER(int, pfnTraversalOpen)(void pvThis, const char pszEntry, PRTVFSDIR phVfsDir,
469	PRTVFSSYMLINK phVfsSymlink, PRTVFS phVfsMounted);
470
471	/**
472	* Open or create a file.
473	*
474	* @returns IPRT status code.
475	* @param pvThis The implementation specific directory data.
476	* @param pszFilename The name of the immediate file to open or create.
477	* @param fOpen The open flags (RTFILE_O_XXX).
478	* @param phVfsFile Where to return the thandle to the opened file.
479	* @sa RTFileOpen.
480	*/
481	DECLCALLBACKMEMBER(int, pfnOpenFile)(void pvThis, const char pszFilename, uint32_t fOpen, PRTVFSFILE phVfsFile);
482
483	/**
484	* Open an existing subdirectory.
485	*
486	* @returns IPRT status code.
487	* @param pvThis The implementation specific directory data.
488	* @param pszSubDir The name of the immediate subdirectory to open.
489	* @param phVfsDir Where to return the handle to the opened directory.
490	* @sa RTDirOpen.
491	*/
492	DECLCALLBACKMEMBER(int, pfnOpenDir)(void pvThis, const char pszSubDir, uint32_t fFlags, PRTVFSDIR phVfsDir);
493
494	/**
495	* Creates a new subdirectory.
496	*
497	* @returns IPRT status code.
498	* @param pvThis The implementation specific directory data.
499	* @param pszSubDir The name of the immediate subdirectory to create.
500	* @param fMode The mode mask of the new directory.
501	* @param phVfsDir Where to optionally return the handle to the newly
502	* create directory.
503	* @sa RTDirCreate.
504	*/
505	DECLCALLBACKMEMBER(int, pfnCreateDir)(void pvThis, const char pszSubDir, RTFMODE fMode, PRTVFSDIR phVfsDir);
506
507	/**
508	* Opens an existing symbolic link.
509	*
510	* @returns IPRT status code.
511	* @param pvThis The implementation specific directory data.
512	* @param pszSymlink The name of the immediate symbolic link to open.
513	* @param phVfsSymlink Where to optionally return the handle to the
514	* newly create symbolic link.
515	* @sa RTSymlinkCreate.
516	*/
517	DECLCALLBACKMEMBER(int, pfnOpenSymlink)(void pvThis, const char pszSymlink, PRTVFSSYMLINK phVfsSymlink);
518
519	/**
520	* Creates a new symbolic link.
521	*
522	* @returns IPRT status code.
523	* @param pvThis The implementation specific directory data.
524	* @param pszSymlink The name of the immediate symbolic link to create.
525	* @param pszTarget The symbolic link target.
526	* @param enmType The symbolic link type.
527	* @param phVfsSymlink Where to optionally return the handle to the
528	* newly create symbolic link.
529	* @sa RTSymlinkCreate.
530	*/
531	DECLCALLBACKMEMBER(int, pfnCreateSymlink)(void pvThis, const char pszSymlink, const char *pszTarget,
532	RTSYMLINKTYPE enmType, PRTVFSSYMLINK phVfsSymlink);
533
534	/**
535	* Removes a directory entry.
536	*
537	* @returns IPRT status code.
538	* @param pvThis The implementation specific directory data.
539	* @param pszEntry The name of the directory entry to remove.
540	* @param fType If non-zero, this restricts the type of the entry to
541	* the object type indicated by the mask
542	* (RTFS_TYPE_XXX).
543	* @sa RTFileRemove, RTDirRemove, RTSymlinkRemove.
544	*/
545	DECLCALLBACKMEMBER(int, pfnUnlinkEntry)(void pvThis, const char pszEntry, RTFMODE fType);
546
547	/**
548	* Rewind the directory stream so that the next read returns the first
549	* entry.
550	*
551	* @returns IPRT status code.
552	* @param pvThis The implementation specific directory data.
553	*/
554	DECLCALLBACKMEMBER(int, pfnRewindDir)(void *pvThis);
555
556	/**
557	* Rewind the directory stream so that the next read returns the first
558	* entry.
559	*
560	* @returns IPRT status code.
561	* @param pvThis The implementation specific directory data.
562	* @param pDirEntry Output buffer.
563	* @param pcbDirEntry Complicated, see RTDirReadEx.
564	* @param enmAddAttr Which set of additional attributes to request.
565	* @sa RTDirReadEx
566	*/
567	DECLCALLBACKMEMBER(int, pfnReadDir)(void pvThis, PRTDIRENTRYEX pDirEntry, size_t pcbDirEntry, RTFSOBJATTRADD enmAddAttr);
568
569	/** Marks the end of the structure (RTVFSDIROPS_VERSION). */
570	uintptr_t uEndMarker;
571	} RTVFSDIROPS;
572	/** Pointer to const directory operations. */
573	typedef RTVFSDIROPS const *PCRTVFSDIROPS;
574	/** The RTVFSDIROPS structure version. */
575	#define RTVFSDIROPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x4f,1,0)
576
577
578	/**
579	* Creates a new VFS directory handle.
580	*
581	* @returns IPRT status code
582	* @param pDirOps The directory operations.
583	* @param cbInstance The size of the instance data.
584	* @param fFlags Reserved, MBZ.
585	* @param hVfs The VFS handle to associate this directory with.
586	* NIL_VFS is ok.
587	* @param hLock Handle to a custom lock to be used with the new
588	* object. The reference is consumed. NIL and
589	* special lock handles are fine.
590	* @param phVfsDir Where to return the new handle.
591	* @param ppvInstance Where to return the pointer to the instance data
592	* (size is @a cbInstance).
593	*/
594	RTDECL(int) RTVfsNewDir(PCRTVFSDIROPS pDirOps, size_t cbInstance, uint32_t fFlags, RTVFS hVfs, RTVFSLOCK hLock,
595	PRTVFSDIR phVfsDir, void **ppvInstance);
596
597
598	/**
599	* The symbolic link operations.
600	*
601	* @extends RTVFSOBJOPS
602	* @extends RTVFSOBJSETOPS
603	*/
604	typedef struct RTVFSSYMLINKOPS
605	{
606	/** The basic object operation. */
607	RTVFSOBJOPS Obj;
608	/** The structure version (RTVFSSYMLINKOPS_VERSION). */
609	uint32_t uVersion;
610	/** Reserved field, MBZ. */
611	uint32_t fReserved;
612	/** The object setter operations. */
613	RTVFSOBJSETOPS ObjSet;
614
615	/**
616	* Read the symbolic link target.
617	*
618	* @returns IPRT status code.
619	* @param pvThis The implementation specific symbolic link data.
620	* @param pszTarget The target buffer.
621	* @param cbTarget The size of the target buffer.
622	* @sa RTSymlinkRead
623	*/
624	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, char pszTarget, size_t cbTarget);
625
626	/** Marks the end of the structure (RTVFSSYMLINKOPS_VERSION). */
627	uintptr_t uEndMarker;
628	} RTVFSSYMLINKOPS;
629	/** Pointer to const symbolic link operations. */
630	typedef RTVFSSYMLINKOPS const *PCRTVFSSYMLINKOPS;
631	/** The RTVFSSYMLINKOPS structure version. */
632	#define RTVFSSYMLINKOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x5f,1,0)
633
634
635	/**
636	* Creates a new VFS symlink handle.
637	*
638	* @returns IPRT status code
639	* @param pSymlinkOps The symlink operations.
640	* @param cbInstance The size of the instance data.
641	* @param hVfs The VFS handle to associate this symlink object
642	* with. NIL_VFS is ok.
643	* @param hLock Handle to a custom lock to be used with the new
644	* object. The reference is consumed. NIL and
645	* special lock handles are fine.
646	* @param phVfsSym Where to return the new handle.
647	* @param ppvInstance Where to return the pointer to the instance data
648	* (size is @a cbInstance).
649	*/
650	RTDECL(int) RTVfsNewSymlink(PCRTVFSSYMLINKOPS pSymlinkOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
651	PRTVFSSYMLINK phVfsSym, void **ppvInstance);
652
653
654	/**
655	* The basis for all I/O objects (files, pipes, sockets, devices, ++).
656	*
657	* @extends RTVFSOBJOPS
658	*/
659	typedef struct RTVFSIOSTREAMOPS
660	{
661	/** The basic object operation. */
662	RTVFSOBJOPS Obj;
663	/** The structure version (RTVFSIOSTREAMOPS_VERSION). */
664	uint32_t uVersion;
665	/** Feature field. */
666	uint32_t fFeatures;
667
668	/**
669	* Reads from the file/stream.
670	*
671	* @returns IPRT status code. See RTVfsIoStrmRead.
672	* @param pvThis The implementation specific file data.
673	* @param off Where to read at, -1 for the current position.
674	* @param pSgBuf Gather buffer describing the bytes that are to be
675	* written.
676	* @param fBlocking If @c true, the call is blocking, if @c false it
677	* should not block.
678	* @param pcbRead Where return the number of bytes actually read.
679	* This is set it 0 by the caller. If NULL, try read
680	* all and fail if incomplete.
681	* @sa RTVfsIoStrmRead, RTVfsIoStrmSgRead, RTVfsFileRead,
682	* RTVfsFileReadAt, RTFileRead, RTFileReadAt.
683	*/
684	DECLCALLBACKMEMBER(int, pfnRead)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbRead);
685
686	/**
687	* Writes to the file/stream.
688	*
689	* @returns IPRT status code.
690	* @param pvThis The implementation specific file data.
691	* @param off Where to start wrinting, -1 for the current
692	* position.
693	* @param pSgBuf Gather buffers describing the bytes that are to be
694	* written.
695	* @param fBlocking If @c true, the call is blocking, if @c false it
696	* should not block.
697	* @param pcbWritten Where to return the number of bytes actually
698	* written. This is set it 0 by the caller. If
699	* NULL, try write it all and fail if incomplete.
700	* @sa RTFileWrite, RTFileWriteAt.
701	*/
702	DECLCALLBACKMEMBER(int, pfnWrite)(void pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t pcbWritten);
703
704	/**
705	* Flushes any pending data writes to the stream.
706	*
707	* @returns IPRT status code.
708	* @param pvThis The implementation specific file data.
709	* @sa RTFileFlush.
710	*/
711	DECLCALLBACKMEMBER(int, pfnFlush)(void *pvThis);
712
713	/**
714	* Poll for events.
715	*
716	* @returns IPRT status code.
717	* @param pvThis The implementation specific file data.
718	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
719	* @param cMillies How long to wait for event to eventuate.
720	* @param fIntr Whether the wait is interruptible and can return
721	* VERR_INTERRUPTED (@c true) or if this condition
722	* should be hidden from the caller (@c false).
723	* @param pfRetEvents Where to return the event mask.
724	* @sa RTPollSetAdd, RTPoll, RTPollNoResume.
725	*/
726	DECLCALLBACKMEMBER(int, pfnPollOne)(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr,
727	uint32_t *pfRetEvents);
728
729	/**
730	* Tells the current file/stream position.
731	*
732	* @returns IPRT status code.
733	* @param pvThis The implementation specific file data.
734	* @param poffActual Where to return the actual offset.
735	* @sa RTFileTell
736	*/
737	DECLCALLBACKMEMBER(int, pfnTell)(void *pvThis, PRTFOFF poffActual);
738
739	/**
740	* Skips @a cb ahead in the stream.
741	*
742	* @returns IPRT status code.
743	* @param pvThis The implementation specific file data.
744	* @param cb The number bytes to skip.
745	* @remarks This is optional and can be NULL.
746	*/
747	DECLCALLBACKMEMBER(int, pfnSkip)(void *pvThis, RTFOFF cb);
748
749	/**
750	* Fills the stream with @a cb zeros.
751	*
752	* @returns IPRT status code.
753	* @param pvThis The implementation specific file data.
754	* @param cb The number of zero bytes to insert.
755	* @remarks This is optional and can be NULL.
756	*/
757	DECLCALLBACKMEMBER(int, pfnZeroFill)(void *pvThis, RTFOFF cb);
758
759	/** Marks the end of the structure (RTVFSIOSTREAMOPS_VERSION). */
760	uintptr_t uEndMarker;
761	} RTVFSIOSTREAMOPS;
762	/** Pointer to const I/O stream operations. */
763	typedef RTVFSIOSTREAMOPS const *PCRTVFSIOSTREAMOPS;
764
765	/** The RTVFSIOSTREAMOPS structure version. */
766	#define RTVFSIOSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x6f,1,0)
767
768	/** @name RTVFSIOSTREAMOPS::fFeatures
769	* @{ */
770	/** No scatter gather lists, thank you. */
771	#define RTVFSIOSTREAMOPS_FEAT_NO_SG RT_BIT_32(0)
772	/** Mask of the valid I/O stream feature flags. */
773	#define RTVFSIOSTREAMOPS_FEAT_VALID_MASK UINT32_C(0x00000001)
774	/** @} */
775
776
777	/**
778	* Creates a new VFS I/O stream handle.
779	*
780	* @returns IPRT status code
781	* @param pIoStreamOps The I/O stream operations.
782	* @param cbInstance The size of the instance data.
783	* @param fOpen The open flags. The minimum is the access mask.
784	* @param hVfs The VFS handle to associate this I/O stream
785	* with. NIL_VFS is ok.
786	* @param hLock Handle to a custom lock to be used with the new
787	* object. The reference is consumed. NIL and
788	* special lock handles are fine.
789	* @param phVfsIos Where to return the new handle.
790	* @param ppvInstance Where to return the pointer to the instance data
791	* (size is @a cbInstance).
792	*/
793	RTDECL(int) RTVfsNewIoStream(PCRTVFSIOSTREAMOPS pIoStreamOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
794	PRTVFSIOSTREAM phVfsIos, void **ppvInstance);
795
796
797	/**
798	* Gets the private data of an I/O stream.
799	*
800	* @returns Pointer to the private data. NULL if the handle is invalid in some
801	* way.
802	* @param hVfsIos The I/O stream handle.
803	* @param pIoStreamOps The I/O stream operations. This servers as a
804	* sort of password.
805	*/
806	RTDECL(void *) RTVfsIoStreamToPrivate(RTVFSIOSTREAM hVfsIos, PCRTVFSIOSTREAMOPS pIoStreamOps);
807
808
809	/**
810	* The file operations.
811	*
812	* @extends RTVFSIOSTREAMOPS
813	* @extends RTVFSOBJSETOPS
814	*/
815	typedef struct RTVFSFILEOPS
816	{
817	/** The I/O stream and basis object operations. */
818	RTVFSIOSTREAMOPS Stream;
819	/** The structure version (RTVFSFILEOPS_VERSION). */
820	uint32_t uVersion;
821	/** Reserved field, MBZ. */
822	uint32_t fReserved;
823	/** The object setter operations. */
824	RTVFSOBJSETOPS ObjSet;
825
826	/**
827	* Changes the current file position.
828	*
829	* @returns IPRT status code.
830	* @param pvThis The implementation specific file data.
831	* @param offSeek The offset to seek.
832	* @param uMethod The seek method, i.e. what the seek is relative to.
833	* @param poffActual Where to return the actual offset.
834	* @sa RTFileSeek
835	*/
836	DECLCALLBACKMEMBER(int, pfnSeek)(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual);
837
838	/**
839	* Get the current file/stream size.
840	*
841	* @returns IPRT status code.
842	* @param pvThis The implementation specific file data.
843	* @param pcbFile Where to store the current file size.
844	* @sa RTFileGetSize
845	*/
846	DECLCALLBACKMEMBER(int, pfnQuerySize)(void pvThis, uint64_t pcbFile);
847
848	/** @todo There will be more methods here. */
849
850	/** Marks the end of the structure (RTVFSFILEOPS_VERSION). */
851	uintptr_t uEndMarker;
852	} RTVFSFILEOPS;
853	/** Pointer to const file operations. */
854	typedef RTVFSFILEOPS const *PCRTVFSFILEOPS;
855
856	/** The RTVFSFILEOPS structure version. */
857	#define RTVFSFILEOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x7f,1,0)
858
859	/**
860	* Creates a new VFS file handle.
861	*
862	* @returns IPRT status code
863	* @param pFileOps The file operations.
864	* @param cbInstance The size of the instance data.
865	* @param fOpen The open flags. The minimum is the access mask.
866	* @param hVfs The VFS handle to associate this file with.
867	* NIL_VFS is ok.
868	* @param hLock Handle to a custom lock to be used with the new
869	* object. The reference is consumed. NIL and
870	* special lock handles are fine.
871	* @param phVfsFile Where to return the new handle.
872	* @param ppvInstance Where to return the pointer to the instance data
873	* (size is @a cbInstance).
874	*/
875	RTDECL(int) RTVfsNewFile(PCRTVFSFILEOPS pFileOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
876	PRTVFSFILE phVfsFile, void **ppvInstance);
877
878
879	/** @defgroup grp_rt_vfs_ll_util VFS Utility APIs
880	* @{ */
881
882	/**
883	* Parsed path.
884	*/
885	typedef struct RTVFSPARSEDPATH
886	{
887	/** The length of the path in szCopy. */
888	uint16_t cch;
889	/** The number of path components. */
890	uint16_t cComponents;
891	/** Set if the path ends with slash, indicating that it's a directory
892	* reference and not a file reference. The slash has been removed from
893	* the copy. */
894	bool fDirSlash;
895	/** The offset where each path component starts, i.e. the char after the
896	* slash. The array has cComponents + 1 entries, where the final one is
897	* cch + 1 so that one can always terminate the current component by
898	* szPath[aoffComponent[i] - 1] = '\0'. */
899	uint16_t aoffComponents[RTPATH_MAX / 2 + 1];
900	/** A normalized copy of the path.
901	* Reserve some extra space so we can be more relaxed about overflow
902	* checks and terminator paddings, especially when recursing. */
903	char szPath[RTPATH_MAX];
904	} RTVFSPARSEDPATH;
905	/** Pointer to a parsed path. */
906	typedef RTVFSPARSEDPATH *PRTVFSPARSEDPATH;
907
908	/** The max accepted path length.
909	* This must be a few chars shorter than RTVFSPARSEDPATH::szPath because we
910	* use two terminators and wish be a little bit lazy with checking. */
911	#define RTVFSPARSEDPATH_MAX (RTPATH_MAX - 4)
912
913	/**
914	* Appends @a pszPath (relative) to the already parsed path @a pPath.
915	*
916	* @retval VINF_SUCCESS
917	* @retval VERR_FILENAME_TOO_LONG
918	* @retval VERR_INTERNAL_ERROR_4
919	* @param pPath The parsed path to append @a pszPath onto.
920	* This is both input and output.
921	* @param pszPath The path to append. This must be relative.
922	* @param piRestartComp The component to restart parsing at. This is
923	* input/output. The input does not have to be
924	* within the valid range. Optional.
925	*/
926	RTDECL(int) RTVfsParsePathAppend(PRTVFSPARSEDPATH pPath, const char pszPath, uint16_t piRestartComp);
927
928	/**
929	* Parses a path.
930	*
931	* @retval VINF_SUCCESS
932	* @retval VERR_FILENAME_TOO_LONG
933	* @param pPath Where to store the parsed path.
934	* @param pszPath The path to parse. Absolute or relative to @a
935	* pszCwd.
936	* @param pszCwd The current working directory. Must be
937	* absolute.
938	*/
939	RTDECL(int) RTVfsParsePath(PRTVFSPARSEDPATH pPath, const char pszPath, const char pszCwd);
940
941	/**
942	* Same as RTVfsParsePath except that it allocates a temporary buffer.
943	*
944	* @retval VINF_SUCCESS
945	* @retval VERR_NO_TMP_MEMORY
946	* @retval VERR_FILENAME_TOO_LONG
947	* @param pszPath The path to parse. Absolute or relative to @a
948	* pszCwd.
949	* @param pszCwd The current working directory. Must be
950	* absolute.
951	* @param ppPath Where to store the pointer to the allocated
952	* buffer containing the parsed path. This must
953	* be freed by calling RTVfsParsePathFree. NULL
954	* will be stored on failured.
955	*/
956	RTDECL(int) RTVfsParsePathA(const char pszPath, const char pszCwd, PRTVFSPARSEDPATH *ppPath);
957
958	/**
959	* Frees a buffer returned by RTVfsParsePathA.
960	*
961	* @param pPath The parsed path buffer to free. NULL is fine.
962	*/
963	RTDECL(void) RTVfsParsePathFree(PRTVFSPARSEDPATH pPath);
964
965	/**
966	* Dummy implementation of RTVFSIOSTREAMOPS::pfnPollOne.
967	*
968	* This handles the case where there is no chance any events my be raised and
969	* all that is required is to wait according to the parameters.
970	*
971	* @returns IPRT status code.
972	* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
973	* @param cMillies How long to wait for event to eventuate.
974	* @param fIntr Whether the wait is interruptible and can return
975	* VERR_INTERRUPTED (@c true) or if this condition
976	* should be hidden from the caller (@c false).
977	* @param pfRetEvents Where to return the event mask.
978	* @sa RTVFSIOSTREAMOPS::pfnPollOne, RTPollSetAdd, RTPoll, RTPollNoResume.
979	*/
980	RTDECL(int) RTVfsUtilDummyPollOne(uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, uint32_t *pfRetEvents);
981
982	/** @} */
983
984
985	/** @defgroup grp_rt_vfs_lowlevel_chain VFS Chains (Low Level)
986	* @ref grp_rt_vfs_chain
987	* @{
988	*/
989
990	/** Pointer to a VFS chain element registration record. */
991	typedef struct RTVFSCHAINELEMENTREG *PRTVFSCHAINELEMENTREG;
992	/** Pointer to a const VFS chain element registration record. */
993	typedef struct RTVFSCHAINELEMENTREG const *PCRTVFSCHAINELEMENTREG;
994
995	/**
996	* VFS chain element argument.
997	*/
998	typedef struct RTVFSCHAINELEMENTARG
999	{
1000	/** The string argument value. */
1001	char *psz;
1002	/** The specification offset of this argument. */
1003	uint16_t offSpec;
1004	/** Provider specific value. */
1005	uint64_t uProvider;
1006	} RTVFSCHAINELEMENTARG;
1007	/** Pointer to a VFS chain element argument. */
1008	typedef RTVFSCHAINELEMENTARG *PRTVFSCHAINELEMENTARG;
1009
1010
1011	/**
1012	* VFS chain element specification.
1013	*/
1014	typedef struct RTVFSCHAINELEMSPEC
1015	{
1016	/** The provider name. */
1017	char *pszProvider;
1018	/** The input type, RTVFSOBJTYPE_INVALID if first. */
1019	RTVFSOBJTYPE enmTypeIn;
1020	/** The element type. */
1021	RTVFSOBJTYPE enmType;
1022	/** The input spec offset of this element. */
1023	uint16_t offSpec;
1024	/** The length of the input spec. */
1025	uint16_t cchSpec;
1026	/** The number of arguments. */
1027	uint32_t cArgs;
1028	/** Arguments. */
1029	PRTVFSCHAINELEMENTARG paArgs;
1030
1031	/** The provider. */
1032	PCRTVFSCHAINELEMENTREG pProvider;
1033	/** Provider specific value. */
1034	uint64_t uProvider;
1035	/** The object (with reference). */
1036	RTVFSOBJ hVfsObj;
1037	} RTVFSCHAINELEMSPEC;
1038	/** Pointer to a chain element specification. */
1039	typedef RTVFSCHAINELEMSPEC *PRTVFSCHAINELEMSPEC;
1040	/** Pointer to a const chain element specification. */
1041	typedef RTVFSCHAINELEMSPEC const *PCRTVFSCHAINELEMSPEC;
1042
1043
1044	/**
1045	* Parsed VFS chain specification.
1046	*/
1047	typedef struct RTVFSCHAINSPEC
1048	{
1049	/** Open directory flags (RTFILE_O_XXX). */
1050	uint32_t fOpenFile;
1051	/** To be defined. */
1052	uint32_t fOpenDir;
1053	/** The type desired by the caller. */
1054	RTVFSOBJTYPE enmDesiredType;
1055	/** The number of elements. */
1056	uint32_t cElements;
1057	/** The elements. */
1058	PRTVFSCHAINELEMSPEC paElements;
1059	} RTVFSCHAINSPEC;
1060	/** Pointer to a parsed VFS chain specification. */
1061	typedef RTVFSCHAINSPEC *PRTVFSCHAINSPEC;
1062	/** Pointer to a const, parsed VFS chain specification. */
1063	typedef RTVFSCHAINSPEC const *PCRTVFSCHAINSPEC;
1064
1065
1066	/**
1067	* A chain element provider registration record.
1068	*/
1069	typedef struct RTVFSCHAINELEMENTREG
1070	{
1071	/** The version (RTVFSCHAINELEMENTREG_VERSION). */
1072	uint32_t uVersion;
1073	/** Reserved, MBZ. */
1074	uint32_t fReserved;
1075	/** The provider name (unique). */
1076	const char *pszName;
1077	/** For chaining the providers. */
1078	RTLISTNODE ListEntry;
1079	/** Help text. */
1080	const char *pszHelp;
1081
1082	/**
1083	* Checks the element specification.
1084	*
1085	* This is allowed to parse arguments and use pSpec->uProvider and
1086	* pElement->paArgs[].uProvider to store information that pfnInstantiate and
1087	* pfnCanReuseElement may use later on, thus avoiding duplicating work/code.
1088	*
1089	* @returns IPRT status code.
1090	* @param pProviderReg Pointer to the element provider registration.
1091	* @param pSpec The chain specification.
1092	* @param pElement The chain element specification to validate.
1093	* @param poffError Where to return error offset on failure. This is
1094	* set to the pElement->offSpec on input, so it only
1095	* needs to be adjusted if an argument is at fault.
1096	* @param pErrInfo Where to return additional error information, if
1097	* available. Optional.
1098	*/
1099	DECLCALLBACKMEMBER(int, pfnValidate)(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec,
1100	PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo);
1101
1102	/**
1103	* Create a VFS object according to the element specification.
1104	*
1105	* @returns IPRT status code.
1106	* @param pProviderReg Pointer to the element provider registration.
1107	* @param pSpec The chain specification.
1108	* @param pElement The chain element specification to instantiate.
1109	* @param hPrevVfsObj Handle to the previous VFS object, NIL_RTVFSOBJ if
1110	* first.
1111	* @param phVfsObj Where to return the VFS object handle.
1112	* @param poffError Where to return error offset on failure. This is
1113	* set to the pElement->offSpec on input, so it only
1114	* needs to be adjusted if an argument is at fault.
1115	* @param pErrInfo Where to return additional error information, if
1116	* available. Optional.
1117	*/
1118	DECLCALLBACKMEMBER(int, pfnInstantiate)(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec,
1119	PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj,
1120	PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo);
1121
1122	/**
1123	* Determins whether the element can be reused.
1124	*
1125	* This is for handling situations accessing the same file system twice, like
1126	* for both the source and destiation of a copy operation. This allows not only
1127	* sharing resources and avoid doing things twice, but also helps avoid file
1128	* sharing violations and inconsistencies araising from the image being updated
1129	* and read independently.
1130	*
1131	* @returns true if the element from @a pReuseSpec an be reused, false if not.
1132	* @param pProviderReg Pointer to the element provider registration.
1133	* @param pSpec The chain specification.
1134	* @param pElement The chain element specification.
1135	* @param pReuseSpec The chain specification of the existing chain.
1136	* @param pReuseElement The chain element specification of the existing
1137	* element that is being considered for reuse.
1138	*/
1139	DECLCALLBACKMEMBER(bool, pfnCanReuseElement)(PCRTVFSCHAINELEMENTREG pProviderReg,
1140	PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement,
1141	PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement);
1142
1143	/** End marker (RTVFSCHAINELEMENTREG_VERSION). */
1144	uintptr_t uEndMarker;
1145	} RTVFSCHAINELEMENTREG;
1146
1147	/** The VFS chain element registration record version number. */
1148	#define RTVFSCHAINELEMENTREG_VERSION RT_MAKE_U32_FROM_U8(0xff, 0x7f, 1, 0)
1149
1150
1151	/**
1152	* Parses the specification.
1153	*
1154	* @returns IPRT status code.
1155	* @param pszSpec The specification string to parse.
1156	* @param fFlags Flags, see RTVFSCHAIN_PF_XXX.
1157	* @param enmDesiredType The object type the caller wants to interface with.
1158	* @param ppSpec Where to return the pointer to the parsed
1159	* specification. This must be freed by calling
1160	* RTVfsChainSpecFree. Will always be set (unless
1161	* invalid parameters.)
1162	* @param poffError Where to return the offset into the input
1163	* specification of what's causing trouble. Always
1164	* set, unless this argument causes an invalid pointer
1165	* error.
1166	*/
1167	RTDECL(int) RTVfsChainSpecParse(const char *pszSpec, uint32_t fFlags, RTVFSOBJTYPE enmDesiredType,
1168	PRTVFSCHAINSPEC ppSpec, uint32_t poffError);
1169
1170	/** @name RTVfsChainSpecParse
1171	* @{ */
1172	/** Mask of valid flags. */
1173	#define RTVFSCHAIN_PF_VALID_MASK UINT32_C(0x00000000)
1174	/** @} */
1175
1176	/**
1177	* Checks and setups the chain.
1178	*
1179	* @returns IPRT status code.
1180	* @param pSpec The parsed specification.
1181	* @param pReuseSpec Spec to reuse if applicable. Optional.
1182	* @param phVfsObj Where to return the VFS object.
1183	* @param poffError Where to return the offset into the input specification
1184	* of what's causing trouble. Always set, unless this
1185	* argument causes an invalid pointer error.
1186	* @param pErrInfo Where to return additional error information, if
1187	* available. Optional.
1188	*/
1189	RTDECL(int) RTVfsChainSpecCheckAndSetup(PRTVFSCHAINSPEC pSpec, PCRTVFSCHAINSPEC pReuseSpec,
1190	PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo);
1191
1192	/**
1193	* Frees a parsed chain specification.
1194	*
1195	* @param pSpec What RTVfsChainSpecParse returned. NULL is
1196	* quietly ignored.
1197	*/
1198	RTDECL(void) RTVfsChainSpecFree(PRTVFSCHAINSPEC pSpec);
1199
1200	/**
1201	* Registers a chain element provider.
1202	*
1203	* @returns IPRT status code
1204	* @param pRegRec The registration record.
1205	* @param fFromCtor Indicates where we're called from.
1206	*/
1207	RTDECL(int) RTVfsChainElementRegisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromCtor);
1208
1209	/**
1210	* Deregisters a chain element provider.
1211	*
1212	* @returns IPRT status code
1213	* @param pRegRec The registration record.
1214	* @param fFromDtor Indicates where we're called from.
1215	*/
1216	RTDECL(int) RTVfsChainElementDeregisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromDtor);
1217
1218
1219	/** @def RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER
1220	* Automatically registers a chain element provider using a global constructor
1221	* and destructor hack.
1222	*
1223	* @param pRegRec Pointer to the registration record.
1224	* @param name Some unique variable name prefix.
1225	*/
1226
1227	#ifdef __cplusplus
1228	/**
1229	* Class used for registering a VFS chain element provider.
1230	*/
1231	class RTVfsChainElementAutoRegisterHack
1232	{
1233	private:
1234	/** The registration record, NULL if registration failed. */
1235	PRTVFSCHAINELEMENTREG m_pRegRec;
1236
1237	public:
1238	RTVfsChainElementAutoRegisterHack(PRTVFSCHAINELEMENTREG a_pRegRec)
1239	: m_pRegRec(a_pRegRec)
1240	{
1241	int rc = RTVfsChainElementRegisterProvider(m_pRegRec, true);
1242	if (RT_FAILURE(rc))
1243	m_pRegRec = NULL;
1244	}
1245
1246	~RTVfsChainElementAutoRegisterHack()
1247	{
1248	RTVfsChainElementDeregisterProvider(m_pRegRec, true);
1249	m_pRegRec = NULL;
1250	}
1251	};
1252
1253	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1254	static RTVfsChainElementAutoRegisterHack name ## AutoRegistrationHack(pRegRec)
1255
1256	#else
1257	# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
1258	extern void *name ## AutoRegistrationHack = \
1259	&Sorry_but_RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER_does_not_work_in_c_source_files
1260	#endif
1261
1262
1263	/**
1264	* Common worker for the 'stdfile' and 'open' providers for implementing
1265	* RTVFSCHAINELEMENTREG::pfnValidate.
1266	*
1267	* Stores the RTFILE_O_XXX flags in pSpec->uProvider.
1268	*
1269	* @returns IPRT status code.
1270	* @param pSpec The chain specification.
1271	* @param pElement The chain element specification to validate.
1272	* @param poffError Where to return error offset on failure. This is set to
1273	* the pElement->offSpec on input, so it only needs to be
1274	* adjusted if an argument is at fault.
1275	* @param pErrInfo Where to return additional error information, if
1276	* available. Optional.
1277	*/
1278	RTDECL(int) RTVfsChainValidateOpenFileOrIoStream(PRTVFSCHAINSPEC pSpec, PRTVFSCHAINELEMSPEC pElement,
1279	uint32_t *poffError, PRTERRINFO pErrInfo);
1280
1281
1282	/** @} */
1283
1284
1285	/** @} */
1286
1287	RT_C_DECLS_END
1288
1289	#endif /* !___iprt_vfslowlevel_h */
1290

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source: vbox/trunk/include/iprt/vfslowlevel.h@ 66615

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