vfsstdfile.cpp@ 104626

Last change on this file since 104626 was 104626, checked in by vboxsync, 7 months ago
IPRT/VFS: Fixed warnings. bugref:3409
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 21.2 KB

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1	/* $Id: vfsstdfile.cpp 104626 2024-05-14 12:06:12Z vboxsync $ */
2	/** @file
3	* IPRT - Virtual File System, Standard File Implementation.
4	*/
5
6	/*
7	* Copyright (C) 2010-2023 Oracle and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* The contents of this file may alternatively be used under the terms
26	* of the Common Development and Distribution License Version 1.0
27	* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
28	* in the VirtualBox distribution, in which case the provisions of the
29	* CDDL are applicable instead of those of the GPL.
30	*
31	* You may elect to license modified versions of this file under the
32	* terms and conditions of either the GPL or the CDDL or both.
33	*
34	* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
35	*/
36
37
38	/*********************************************************************************************************************************
39	* Header Files *
40	*********************************************************************************************************************************/
41	#include <iprt/vfs.h>
42	#include <iprt/vfslowlevel.h>
43
44	#include <iprt/assert.h>
45	#include <iprt/err.h>
46	#include <iprt/file.h>
47	#include <iprt/poll.h>
48	#include <iprt/string.h>
49	#include <iprt/thread.h>
50
51
52	/*********************************************************************************************************************************
53	* Structures and Typedefs *
54	*********************************************************************************************************************************/
55	/**
56	* Private data of a standard file.
57	*/
58	typedef struct RTVFSSTDFILE
59	{
60	/** The file handle. */
61	RTFILE hFile;
62	/** Whether to leave the handle open when the VFS handle is closed. */
63	bool fLeaveOpen;
64	} RTVFSSTDFILE;
65	/** Pointer to the private data of a standard file. */
66	typedef RTVFSSTDFILE *PRTVFSSTDFILE;
67
68
69	/**
70	* @interface_method_impl{RTVFSOBJOPS,pfnClose}
71	*/
72	static DECLCALLBACK(int) rtVfsStdFile_Close(void *pvThis)
73	{
74	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
75
76	int rc;
77	if (!pThis->fLeaveOpen)
78	rc = RTFileClose(pThis->hFile);
79	else
80	rc = VINF_SUCCESS;
81	pThis->hFile = NIL_RTFILE;
82
83	return rc;
84	}
85
86
87	/**
88	* @interface_method_impl{RTVFSOBJOPS,pfnQueryInfo}
89	*/
90	static DECLCALLBACK(int) rtVfsStdFile_QueryInfo(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr)
91	{
92	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
93	return RTFileQueryInfo(pThis->hFile, pObjInfo, enmAddAttr);
94	}
95
96
97	/**
98	* RTFileRead and RTFileReadAt does not return VINF_EOF or VINF_TRY_AGAIN, this
99	* function tries to fix this as best as it can.
100	*
101	* This fixing can be subject to races if some other thread or process is
102	* modifying the file size between the read and our size query here.
103	*
104	* @returns VINF_SUCCESS, VINF_EOF or VINF_TRY_AGAIN.
105	* @param pThis The instance data.
106	* @param off The offset parameter.
107	* @param cbToRead The number of bytes attempted read .
108	* @param cbActuallyRead The number of bytes actually read.
109	*/
110	DECLINLINE(int) rtVfsStdFile_ReadFixRC(PRTVFSSTDFILE pThis, RTFOFF off, size_t cbToRead, size_t cbActuallyRead)
111	{
112	/* If the read returned less bytes than requested, it means the end of the
113	file has been reached. */
114	if (cbToRead > cbActuallyRead)
115	return VINF_EOF;
116
117	/* The other case here is the very special zero byte read at the end of the
118	file, where we're supposed to indicate EOF. */
119	if (cbToRead > 0)
120	return VINF_SUCCESS;
121
122	uint64_t cbFile;
123	int rc = RTFileQuerySize(pThis->hFile, &cbFile);
124	if (RT_FAILURE(rc))
125	return rc;
126
127	uint64_t off2;
128	if (off >= 0)
129	off2 = off;
130	else
131	{
132	rc = RTFileSeek(pThis->hFile, 0, RTFILE_SEEK_CURRENT, &off2);
133	if (RT_FAILURE(rc))
134	return rc;
135	}
136
137	return off2 >= cbFile ? VINF_EOF : VINF_SUCCESS;
138	}
139
140
141	/**
142	* @interface_method_impl{RTVFSIOSTREAMOPS,pfnRead}
143	*/
144	static DECLCALLBACK(int) rtVfsStdFile_Read(void pvThis, RTFOFF off, PRTSGBUF pSgBuf, bool fBlocking, size_t pcbRead)
145	{
146	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
147	int rc;
148
149	NOREF(fBlocking);
150	if (pSgBuf->cSegs == 1)
151	{
152	size_t cbToRead = 0;
153	void * const pvDst = RTSgBufGetCurrentSegment(pSgBuf, ~(size_t)0, &cbToRead);
154
155	if (off < 0)
156	rc = RTFileRead(pThis->hFile, pvDst, cbToRead, pcbRead);
157	else
158	{
159	rc = RTFileReadAt(pThis->hFile, off, pvDst, cbToRead, pcbRead);
160	if (RT_SUCCESS(rc)) /* RTFileReadAt() doesn't increment the file-position indicator on some platforms */
161	rc = RTFileSeek(pThis->hFile, off + (pcbRead ? *pcbRead : cbToRead), RTFILE_SEEK_BEGIN, NULL);
162	}
163	if (rc == VINF_SUCCESS && pcbRead)
164	rc = rtVfsStdFile_ReadFixRC(pThis, off, cbToRead, *pcbRead);
165	if (RT_SUCCESS(rc))
166	RTSgBufAdvance(pSgBuf, pcbRead ? *pcbRead : cbToRead);
167	}
168	else
169	{
170	size_t cbSeg = 0;
171	size_t cbRead = 0;
172	rc = VINF_SUCCESS;
173
174	while (!RTSgBufIsAtEnd(pSgBuf))
175	{
176	void * const pvSeg = RTSgBufGetCurrentSegment(pSgBuf, ~(size_t)0, &cbSeg);
177
178	size_t cbReadSeg = cbSeg;
179	if (off < 0)
180	rc = RTFileRead( pThis->hFile, pvSeg, cbSeg, pcbRead ? &cbReadSeg : NULL);
181	else
182	{
183	rc = RTFileReadAt(pThis->hFile, off, pvSeg, cbSeg, pcbRead ? &cbReadSeg : NULL);
184	if (RT_SUCCESS(rc)) /* RTFileReadAt() doesn't increment the file-position indicator on some platforms */
185	rc = RTFileSeek(pThis->hFile, off + cbReadSeg, RTFILE_SEEK_BEGIN, NULL);
186	}
187	if (RT_FAILURE(rc))
188	break;
189
190	if (off >= 0)
191	off += cbReadSeg;
192	cbRead += cbReadSeg;
193	RTSgBufAdvance(pSgBuf, cbReadSeg);
194
195	if ((pcbRead && cbReadSeg != cbSeg) \|\| rc != VINF_SUCCESS)
196	break;
197	}
198
199	if (pcbRead)
200	{
201	*pcbRead = cbRead;
202	if (rc == VINF_SUCCESS)
203	rc = rtVfsStdFile_ReadFixRC(pThis, off, cbSeg, cbRead);
204	}
205	}
206
207	return rc;
208	}
209
210
211	/**
212	* @interface_method_impl{RTVFSIOSTREAMOPS,pfnWrite}
213	*/
214	static DECLCALLBACK(int) rtVfsStdFile_Write(void pvThis, RTFOFF off, PRTSGBUF pSgBuf, bool fBlocking, size_t pcbWritten)
215	{
216	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
217	int rc;
218
219	NOREF(fBlocking);
220	if (pSgBuf->cSegs == 1)
221	{
222	size_t cbToWrite = 0;
223	void const * const pvSrc = RTSgBufGetCurrentSegment(pSgBuf, ~(size_t)0, &cbToWrite);
224
225	if (off < 0)
226	rc = RTFileWrite(pThis->hFile, pvSrc, cbToWrite, pcbWritten);
227	else
228	{
229	rc = RTFileWriteAt(pThis->hFile, off, pvSrc, cbToWrite, pcbWritten);
230	if (RT_SUCCESS(rc)) /* RTFileWriteAt() doesn't increment the file-position indicator on some platforms */
231	rc = RTFileSeek(pThis->hFile, off + (pcbWritten ? *pcbWritten : cbToWrite), RTFILE_SEEK_BEGIN, NULL);
232	}
233	if (RT_SUCCESS(rc))
234	RTSgBufAdvance(pSgBuf, pcbWritten ? *pcbWritten : cbToWrite);
235	}
236	else
237	{
238	size_t cbWritten = 0;
239	size_t cbWrittenSeg;
240	size_t *pcbWrittenSeg = pcbWritten ? &cbWrittenSeg : NULL;
241	rc = VINF_SUCCESS;
242
243	while (!RTSgBufIsAtEnd(pSgBuf))
244	{
245	size_t cbSeg = 0;
246	void const * const pvSeg = RTSgBufGetCurrentSegment(pSgBuf, ~(size_t)0, &cbSeg);
247
248	cbWrittenSeg = 0;
249	if (off < 0)
250	rc = RTFileWrite(pThis->hFile, pvSeg, cbSeg, pcbWrittenSeg);
251	else
252	{
253	rc = RTFileWriteAt(pThis->hFile, off, pvSeg, cbSeg, pcbWrittenSeg);
254	if (RT_SUCCESS(rc))
255	{
256	off += pcbWrittenSeg ? *pcbWrittenSeg : cbSeg;
257	/* RTFileWriteAt() doesn't increment the file-position indicator on some platforms */
258	rc = RTFileSeek(pThis->hFile, off, RTFILE_SEEK_BEGIN, NULL);
259	}
260	}
261	if (RT_FAILURE(rc))
262	break;
263	if (pcbWritten)
264	{
265	RTSgBufAdvance(pSgBuf, cbWrittenSeg);
266	cbWritten += cbWrittenSeg;
267	if (cbWrittenSeg != cbSeg)
268	break;
269	}
270	else
271	RTSgBufAdvance(pSgBuf, cbSeg);
272	}
273
274	if (pcbWritten)
275	*pcbWritten = cbWritten;
276	}
277
278	return rc;
279	}
280
281
282	/**
283	* @interface_method_impl{RTVFSIOSTREAMOPS,pfnFlush}
284	*/
285	static DECLCALLBACK(int) rtVfsStdFile_Flush(void *pvThis)
286	{
287	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
288	int rc = RTFileFlush(pThis->hFile);
289	#ifdef RT_OS_WINDOWS
290	/* Workaround for console handles. / /* @todo push this further down? */
291	if ( rc == VERR_INVALID_HANDLE
292	&& RTFileIsValid(pThis->hFile))
293	rc = VINF_NOT_SUPPORTED; /* not flushable */
294	#endif
295	return rc;
296	}
297
298
299	/**
300	* @interface_method_impl{RTVFSIOSTREAMOPS,pfnPollOne}
301	*/
302	static DECLCALLBACK(int) rtVfsStdFile_PollOne(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr,
303	uint32_t *pfRetEvents)
304	{
305	NOREF(pvThis);
306	int rc;
307	if (fEvents != RTPOLL_EVT_ERROR)
308	{
309	*pfRetEvents = fEvents & ~RTPOLL_EVT_ERROR;
310	rc = VINF_SUCCESS;
311	}
312	else if (fIntr)
313	rc = RTThreadSleep(cMillies);
314	else
315	{
316	uint64_t uMsStart = RTTimeMilliTS();
317	do
318	rc = RTThreadSleep(cMillies);
319	while ( rc == VERR_INTERRUPTED
320	&& RTTimeMilliTS() - uMsStart < cMillies);
321	if (rc == VERR_INTERRUPTED)
322	rc = VERR_TIMEOUT;
323	}
324	return rc;
325	}
326
327
328	/**
329	* @interface_method_impl{RTVFSIOSTREAMOPS,pfnTell}
330	*/
331	static DECLCALLBACK(int) rtVfsStdFile_Tell(void *pvThis, PRTFOFF poffActual)
332	{
333	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
334	uint64_t offActual;
335	int rc = RTFileSeek(pThis->hFile, 0, RTFILE_SEEK_CURRENT, &offActual);
336	if (RT_SUCCESS(rc))
337	*poffActual = (RTFOFF)offActual;
338	return rc;
339	}
340
341
342	/**
343	* @interface_method_impl{RTVFSIOSTREAMOPS,pfnSkip}
344	*/
345	static DECLCALLBACK(int) rtVfsStdFile_Skip(void *pvThis, RTFOFF cb)
346	{
347	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
348	uint64_t offIgnore;
349	return RTFileSeek(pThis->hFile, cb, RTFILE_SEEK_CURRENT, &offIgnore);
350	}
351
352
353	/**
354	* @interface_method_impl{RTVFSOBJSETOPS,pfnMode}
355	*/
356	static DECLCALLBACK(int) rtVfsStdFile_SetMode(void *pvThis, RTFMODE fMode, RTFMODE fMask)
357	{
358	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
359	if (fMask != ~RTFS_TYPE_MASK)
360	{
361	#if 0
362	RTFMODE fCurMode;
363	int rc = RTFileGetMode(pThis->hFile, &fCurMode);
364	if (RT_FAILURE(rc))
365	return rc;
366	fMode \|= ~fMask & fCurMode;
367	#else
368	RTFSOBJINFO ObjInfo;
369	int rc = RTFileQueryInfo(pThis->hFile, &ObjInfo, RTFSOBJATTRADD_NOTHING);
370	if (RT_FAILURE(rc))
371	return rc;
372	fMode \|= ~fMask & ObjInfo.Attr.fMode;
373	#endif
374	}
375	return RTFileSetMode(pThis->hFile, fMode);
376	}
377
378
379	/**
380	* @interface_method_impl{RTVFSOBJSETOPS,pfnSetTimes}
381	*/
382	static DECLCALLBACK(int) rtVfsStdFile_SetTimes(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime,
383	PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime)
384	{
385	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
386	return RTFileSetTimes(pThis->hFile, pAccessTime, pModificationTime, pChangeTime, pBirthTime);
387	}
388
389
390	/**
391	* @interface_method_impl{RTVFSOBJSETOPS,pfnSetOwner}
392	*/
393	static DECLCALLBACK(int) rtVfsStdFile_SetOwner(void *pvThis, RTUID uid, RTGID gid)
394	{
395	#if 0
396	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
397	return RTFileSetOwner(pThis->hFile, uid, gid);
398	#else
399	NOREF(pvThis); NOREF(uid); NOREF(gid);
400	return VERR_NOT_IMPLEMENTED;
401	#endif
402	}
403
404
405	/**
406	* @interface_method_impl{RTVFSFILEOPS,pfnSeek}
407	*/
408	static DECLCALLBACK(int) rtVfsStdFile_Seek(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual)
409	{
410	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
411	uint64_t offActual = 0;
412	int rc = RTFileSeek(pThis->hFile, offSeek, uMethod, &offActual);
413	if (RT_SUCCESS(rc))
414	*poffActual = offActual;
415	return rc;
416	}
417
418
419	/**
420	* @interface_method_impl{RTVFSFILEOPS,pfnQuerySize}
421	*/
422	static DECLCALLBACK(int) rtVfsStdFile_QuerySize(void pvThis, uint64_t pcbFile)
423	{
424	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
425	return RTFileQuerySize(pThis->hFile, pcbFile);
426	}
427
428
429	/**
430	* @interface_method_impl{RTVFSFILEOPS,pfnSetSize}
431	*/
432	static DECLCALLBACK(int) rtVfsStdFile_SetSize(void *pvThis, uint64_t cbFile, uint32_t fFlags)
433	{
434	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
435	switch (fFlags & RTVFSFILE_SIZE_F_ACTION_MASK)
436	{
437	case RTVFSFILE_SIZE_F_NORMAL:
438	return RTFileSetSize(pThis->hFile, cbFile);
439	case RTVFSFILE_SIZE_F_GROW:
440	return RTFileSetAllocationSize(pThis->hFile, cbFile, RTFILE_ALLOC_SIZE_F_DEFAULT);
441	case RTVFSFILE_SIZE_F_GROW_KEEP_SIZE:
442	return RTFileSetAllocationSize(pThis->hFile, cbFile, RTFILE_ALLOC_SIZE_F_KEEP_SIZE);
443	default:
444	return VERR_NOT_SUPPORTED;
445	}
446	}
447
448
449	/**
450	* @interface_method_impl{RTVFSFILEOPS,pfnQueryMaxSize}
451	*/
452	static DECLCALLBACK(int) rtVfsStdFile_QueryMaxSize(void pvThis, uint64_t pcbMax)
453	{
454	PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis;
455	RTFOFF cbMax = 0;
456	int rc = RTFileQueryMaxSizeEx(pThis->hFile, &cbMax);
457	if (RT_SUCCESS(rc))
458	*pcbMax = cbMax;
459	return rc;
460	}
461
462
463	/**
464	* Standard file operations.
465	*/
466	DECL_HIDDEN_CONST(const RTVFSFILEOPS) g_rtVfsStdFileOps =
467	{
468	{ /* Stream */
469	{ /* Obj */
470	RTVFSOBJOPS_VERSION,
471	RTVFSOBJTYPE_FILE,
472	"StdFile",
473	rtVfsStdFile_Close,
474	rtVfsStdFile_QueryInfo,
475	NULL,
476	RTVFSOBJOPS_VERSION
477	},
478	RTVFSIOSTREAMOPS_VERSION,
479	0,
480	rtVfsStdFile_Read,
481	rtVfsStdFile_Write,
482	rtVfsStdFile_Flush,
483	rtVfsStdFile_PollOne,
484	rtVfsStdFile_Tell,
485	rtVfsStdFile_Skip,
486	NULL /ZeroFill/,
487	RTVFSIOSTREAMOPS_VERSION,
488	},
489	RTVFSFILEOPS_VERSION,
490	0,
491	{ /* ObjSet */
492	RTVFSOBJSETOPS_VERSION,
493	RT_UOFFSETOF(RTVFSFILEOPS, ObjSet) - RT_UOFFSETOF(RTVFSFILEOPS, Stream.Obj),
494	rtVfsStdFile_SetMode,
495	rtVfsStdFile_SetTimes,
496	rtVfsStdFile_SetOwner,
497	RTVFSOBJSETOPS_VERSION
498	},
499	rtVfsStdFile_Seek,
500	rtVfsStdFile_QuerySize,
501	rtVfsStdFile_SetSize,
502	rtVfsStdFile_QueryMaxSize,
503	RTVFSFILEOPS_VERSION
504	};
505
506
507	/**
508	* Internal worker for RTVfsFileFromRTFile and RTVfsFileOpenNormal.
509	*
510	* @returns IRPT status code.
511	* @param hFile The IPRT file handle.
512	* @param fOpen The RTFILE_O_XXX flags.
513	* @param fLeaveOpen Whether to leave it open or close it.
514	* @param phVfsFile Where to return the handle.
515	*/
516	static int rtVfsFileFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSFILE phVfsFile)
517	{
518	PRTVFSSTDFILE pThis;
519	RTVFSFILE hVfsFile;
520	int rc = RTVfsNewFile(&g_rtVfsStdFileOps, sizeof(RTVFSSTDFILE), fOpen, NIL_RTVFS, NIL_RTVFSLOCK,
521	&hVfsFile, (void **)&pThis);
522	if (RT_FAILURE(rc))
523	return rc;
524
525	pThis->hFile = hFile;
526	pThis->fLeaveOpen = fLeaveOpen;
527	*phVfsFile = hVfsFile;
528	return VINF_SUCCESS;
529	}
530
531
532	RTDECL(int) RTVfsFileFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSFILE phVfsFile)
533	{
534	/*
535	* Check the handle validity.
536	*/
537	RTFSOBJINFO ObjInfo;
538	int rc = RTFileQueryInfo(hFile, &ObjInfo, RTFSOBJATTRADD_NOTHING);
539	if (RT_FAILURE(rc))
540	return rc;
541
542	/*
543	* Set up some fake fOpen flags if necessary and create a VFS file handle.
544	*/
545	if (!fOpen)
546	fOpen = RTFILE_O_READWRITE \| RTFILE_O_DENY_NONE \| RTFILE_O_OPEN_CREATE;
547
548	return rtVfsFileFromRTFile(hFile, fOpen, fLeaveOpen, phVfsFile);
549	}
550
551
552	RTDECL(int) RTVfsFileOpenNormal(const char *pszFilename, uint64_t fOpen, PRTVFSFILE phVfsFile)
553	{
554	/*
555	* Open the file the normal way and pass it to RTVfsFileFromRTFile.
556	*/
557	RTFILE hFile;
558	int rc = RTFileOpen(&hFile, pszFilename, fOpen);
559	if (RT_SUCCESS(rc))
560	{
561	/*
562	* Create a VFS file handle.
563	*/
564	rc = rtVfsFileFromRTFile(hFile, fOpen, false /fLeaveOpen/, phVfsFile);
565	if (RT_FAILURE(rc))
566	RTFileClose(hFile);
567	}
568	return rc;
569	}
570
571
572	RTDECL(int) RTVfsIoStrmFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSIOSTREAM phVfsIos)
573	{
574	RTVFSFILE hVfsFile;
575	int rc = RTVfsFileFromRTFile(hFile, fOpen, fLeaveOpen, &hVfsFile);
576	if (RT_SUCCESS(rc))
577	{
578	*phVfsIos = RTVfsFileToIoStream(hVfsFile);
579	RTVfsFileRelease(hVfsFile);
580	}
581	return rc;
582	}
583
584
585	RTDECL(int) RTVfsIoStrmOpenNormal(const char *pszFilename, uint64_t fOpen, PRTVFSIOSTREAM phVfsIos)
586	{
587	RTVFSFILE hVfsFile;
588	int rc = RTVfsFileOpenNormal(pszFilename, fOpen, &hVfsFile);
589	if (RT_SUCCESS(rc))
590	{
591	*phVfsIos = RTVfsFileToIoStream(hVfsFile);
592	RTVfsFileRelease(hVfsFile);
593	}
594	return rc;
595	}
596
597
598
599	/**
600	* @interface_method_impl{RTVFSCHAINELEMENTREG,pfnValidate}
601	*/
602	static DECLCALLBACK(int) rtVfsChainStdFile_Validate(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec,
603	PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo)
604	{
605	RT_NOREF(pProviderReg);
606
607	/*
608	* Basic checks.
609	*/
610	if (pElement->enmTypeIn != RTVFSOBJTYPE_INVALID)
611	return VERR_VFS_CHAIN_MUST_BE_FIRST_ELEMENT;
612	if ( pElement->enmType != RTVFSOBJTYPE_FILE
613	&& pElement->enmType != RTVFSOBJTYPE_IO_STREAM)
614	return VERR_VFS_CHAIN_ONLY_FILE_OR_IOS;
615
616	/*
617	* Join common cause with the 'open' provider.
618	*/
619	return RTVfsChainValidateOpenFileOrIoStream(pSpec, pElement, poffError, pErrInfo);
620	}
621
622
623	/**
624	* @interface_method_impl{RTVFSCHAINELEMENTREG,pfnInstantiate}
625	*/
626	static DECLCALLBACK(int) rtVfsChainStdFile_Instantiate(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec,
627	PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj,
628	PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo)
629	{
630	RT_NOREF(pProviderReg, pSpec, poffError, pErrInfo);
631	AssertReturn(hPrevVfsObj == NIL_RTVFSOBJ, VERR_VFS_CHAIN_IPE);
632
633	RTVFSFILE hVfsFile;
634	int rc = RTVfsFileOpenNormal(pElement->paArgs[0].psz, pElement->uProvider, &hVfsFile);
635	if (RT_SUCCESS(rc))
636	{
637	*phVfsObj = RTVfsObjFromFile(hVfsFile);
638	RTVfsFileRelease(hVfsFile);
639	if (*phVfsObj != NIL_RTVFSOBJ)
640	return VINF_SUCCESS;
641	rc = VERR_VFS_CHAIN_CAST_FAILED;
642	}
643	return rc;
644	}
645
646
647	/**
648	* @interface_method_impl{RTVFSCHAINELEMENTREG,pfnCanReuseElement}
649	*/
650	static DECLCALLBACK(bool) rtVfsChainStdFile_CanReuseElement(PCRTVFSCHAINELEMENTREG pProviderReg,
651	PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement,
652	PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement)
653	{
654	RT_NOREF(pProviderReg, pSpec, pReuseSpec);
655	if (strcmp(pElement->paArgs[0].psz, pReuseElement->paArgs[0].psz) == 0)
656	if (pElement->paArgs[0].uProvider == pReuseElement->paArgs[0].uProvider)
657	return true;
658	return false;
659	}
660
661
662	/** VFS chain element 'file'. */
663	static RTVFSCHAINELEMENTREG g_rtVfsChainStdFileReg =
664	{
665	/* uVersion = */ RTVFSCHAINELEMENTREG_VERSION,
666	/* fReserved = */ 0,
667	/* pszName = */ "stdfile",
668	/* ListEntry = */ { NULL, NULL },
669	/* pszHelp = */ "Open a real file, providing either a file or an I/O stream object. Initial element.\n"
670	"First argument is the filename path.\n"
671	"Second argument is access mode, optional: r, w, rw.\n"
672	"Third argument is open disposition, optional: create, create-replace, open, open-create, open-append, open-truncate.\n"
673	"Forth argument is file sharing, optional: nr, nw, nrw, d.",
674	/* pfnValidate = */ rtVfsChainStdFile_Validate,
675	/* pfnInstantiate = */ rtVfsChainStdFile_Instantiate,
676	/* pfnCanReuseElement = */ rtVfsChainStdFile_CanReuseElement,
677	/* uEndMarker = */ RTVFSCHAINELEMENTREG_VERSION
678	};
679
680	RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(&g_rtVfsChainStdFileReg, rtVfsChainStdFileReg);
681

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source: vbox/trunk/src/VBox/Runtime/common/vfs/vfsstdfile.cpp@ 104626

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