diff options
Diffstat (limited to 'src/VBox/Runtime/common/vfs/vfsstdfile.cpp')
| -rw-r--r-- | src/VBox/Runtime/common/vfs/vfsstdfile.cpp | 669 |
1 files changed, 669 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/vfs/vfsstdfile.cpp b/src/VBox/Runtime/common/vfs/vfsstdfile.cpp new file mode 100644 index 00000000..92ba028c --- /dev/null +++ b/src/VBox/Runtime/common/vfs/vfsstdfile.cpp @@ -0,0 +1,669 @@ +/* $Id: vfsstdfile.cpp $ */ +/** @file + * IPRT - Virtual File System, Standard File Implementation. + */ + +/* + * Copyright (C) 2010-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include <iprt/vfs.h> +#include <iprt/vfslowlevel.h> + +#include <iprt/assert.h> +#include <iprt/err.h> +#include <iprt/file.h> +#include <iprt/poll.h> +#include <iprt/string.h> +#include <iprt/thread.h> + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +/** + * Private data of a standard file. + */ +typedef struct RTVFSSTDFILE +{ + /** The file handle. */ + RTFILE hFile; + /** Whether to leave the handle open when the VFS handle is closed. */ + bool fLeaveOpen; +} RTVFSSTDFILE; +/** Pointer to the private data of a standard file. */ +typedef RTVFSSTDFILE *PRTVFSSTDFILE; + + +/** + * @interface_method_impl{RTVFSOBJOPS,pfnClose} + */ +static DECLCALLBACK(int) rtVfsStdFile_Close(void *pvThis) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + + int rc; + if (!pThis->fLeaveOpen) + rc = RTFileClose(pThis->hFile); + else + rc = VINF_SUCCESS; + pThis->hFile = NIL_RTFILE; + + return rc; +} + + +/** + * @interface_method_impl{RTVFSOBJOPS,pfnQueryInfo} + */ +static DECLCALLBACK(int) rtVfsStdFile_QueryInfo(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + return RTFileQueryInfo(pThis->hFile, pObjInfo, enmAddAttr); +} + + +/** + * RTFileRead and RTFileReadAt does not return VINF_EOF or VINF_TRY_AGAIN, this + * function tries to fix this as best as it can. + * + * This fixing can be subject to races if some other thread or process is + * modifying the file size between the read and our size query here. + * + * @returns VINF_SUCCESS, VINF_EOF or VINF_TRY_AGAIN. + * @param pThis The instance data. + * @param off The offset parameter. + * @param cbToRead The number of bytes attempted read . + * @param cbActuallyRead The number of bytes actually read. + */ +DECLINLINE(int) rtVfsStdFile_ReadFixRC(PRTVFSSTDFILE pThis, RTFOFF off, size_t cbToRead, size_t cbActuallyRead) +{ + /* If the read returned less bytes than requested, it means the end of the + file has been reached. */ + if (cbToRead > cbActuallyRead) + return VINF_EOF; + + /* The other case here is the very special zero byte read at the end of the + file, where we're supposed to indicate EOF. */ + if (cbToRead > 0) + return VINF_SUCCESS; + + uint64_t cbFile; + int rc = RTFileQuerySize(pThis->hFile, &cbFile); + if (RT_FAILURE(rc)) + return rc; + + uint64_t off2; + if (off >= 0) + off2 = off; + else + { + rc = RTFileSeek(pThis->hFile, 0, RTFILE_SEEK_CURRENT, &off2); + if (RT_FAILURE(rc)) + return rc; + } + + return off2 >= cbFile ? VINF_EOF : VINF_SUCCESS; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnRead} + */ +static DECLCALLBACK(int) rtVfsStdFile_Read(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbRead) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + int rc; + + NOREF(fBlocking); + if (pSgBuf->cSegs == 1) + { + if (off < 0) + rc = RTFileRead( pThis->hFile, pSgBuf->paSegs[0].pvSeg, pSgBuf->paSegs[0].cbSeg, pcbRead); + else + { + rc = RTFileReadAt(pThis->hFile, off, pSgBuf->paSegs[0].pvSeg, pSgBuf->paSegs[0].cbSeg, pcbRead); + if (RT_SUCCESS(rc)) /* RTFileReadAt() doesn't increment the file-position indicator on some platforms */ + rc = RTFileSeek(pThis->hFile, off + (pcbRead ? *pcbRead : pSgBuf->paSegs[0].cbSeg), RTFILE_SEEK_BEGIN, NULL); + } + if (rc == VINF_SUCCESS && pcbRead) + rc = rtVfsStdFile_ReadFixRC(pThis, off, pSgBuf->paSegs[0].cbSeg, *pcbRead); + } + else + { + size_t cbSeg = 0; + size_t cbRead = 0; + size_t cbReadSeg = 0; + rc = VINF_SUCCESS; + + for (uint32_t iSeg = 0; iSeg < pSgBuf->cSegs; iSeg++) + { + void *pvSeg = pSgBuf->paSegs[iSeg].pvSeg; + cbSeg = pSgBuf->paSegs[iSeg].cbSeg; + + cbReadSeg = cbSeg; + if (off < 0) + rc = RTFileRead( pThis->hFile, pvSeg, cbSeg, pcbRead ? &cbReadSeg : NULL); + else + { + rc = RTFileReadAt(pThis->hFile, off, pvSeg, cbSeg, pcbRead ? &cbReadSeg : NULL); + if (RT_SUCCESS(rc)) /* RTFileReadAt() doesn't increment the file-position indicator on some platforms */ + rc = RTFileSeek(pThis->hFile, off + cbReadSeg, RTFILE_SEEK_BEGIN, NULL); + } + if (RT_FAILURE(rc)) + break; + if (off >= 0) + off += cbReadSeg; + cbRead += cbReadSeg; + if ((pcbRead && cbReadSeg != cbSeg) || rc != VINF_SUCCESS) + break; + } + + if (pcbRead) + { + *pcbRead = cbRead; + if (rc == VINF_SUCCESS) + rc = rtVfsStdFile_ReadFixRC(pThis, off, cbSeg, cbReadSeg); + } + } + + return rc; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnWrite} + */ +static DECLCALLBACK(int) rtVfsStdFile_Write(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbWritten) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + int rc; + + NOREF(fBlocking); + if (pSgBuf->cSegs == 1) + { + if (off < 0) + rc = RTFileWrite(pThis->hFile, pSgBuf->paSegs[0].pvSeg, pSgBuf->paSegs[0].cbSeg, pcbWritten); + else + { + rc = RTFileWriteAt(pThis->hFile, off, pSgBuf->paSegs[0].pvSeg, pSgBuf->paSegs[0].cbSeg, pcbWritten); + if (RT_SUCCESS(rc)) /* RTFileWriteAt() doesn't increment the file-position indicator on some platforms */ + rc = RTFileSeek(pThis->hFile, off + (pcbWritten ? *pcbWritten : pSgBuf->paSegs[0].cbSeg), RTFILE_SEEK_BEGIN, + NULL); + } + } + else + { + size_t cbWritten = 0; + size_t cbWrittenSeg; + size_t *pcbWrittenSeg = pcbWritten ? &cbWrittenSeg : NULL; + rc = VINF_SUCCESS; + + for (uint32_t iSeg = 0; iSeg < pSgBuf->cSegs; iSeg++) + { + void *pvSeg = pSgBuf->paSegs[iSeg].pvSeg; + size_t cbSeg = pSgBuf->paSegs[iSeg].cbSeg; + + cbWrittenSeg = 0; + if (off < 0) + rc = RTFileWrite(pThis->hFile, pvSeg, cbSeg, pcbWrittenSeg); + else + { + rc = RTFileWriteAt(pThis->hFile, off, pvSeg, cbSeg, pcbWrittenSeg); + if (RT_SUCCESS(rc)) + { + off += pcbWrittenSeg ? *pcbWrittenSeg : cbSeg; + /* RTFileWriteAt() doesn't increment the file-position indicator on some platforms */ + rc = RTFileSeek(pThis->hFile, off, RTFILE_SEEK_BEGIN, NULL); + } + } + if (RT_FAILURE(rc)) + break; + if (pcbWritten) + { + cbWritten += cbWrittenSeg; + if (cbWrittenSeg != cbSeg) + break; + } + } + + if (pcbWritten) + *pcbWritten = cbWritten; + } + + return rc; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnFlush} + */ +static DECLCALLBACK(int) rtVfsStdFile_Flush(void *pvThis) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + int rc = RTFileFlush(pThis->hFile); +#ifdef RT_OS_WINDOWS + /* Workaround for console handles. */ /** @todo push this further down? */ + if ( rc == VERR_INVALID_HANDLE + && RTFileIsValid(pThis->hFile)) + rc = VINF_NOT_SUPPORTED; /* not flushable */ +#endif + return rc; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnPollOne} + */ +static DECLCALLBACK(int) rtVfsStdFile_PollOne(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, + uint32_t *pfRetEvents) +{ + NOREF(pvThis); + int rc; + if (fEvents != RTPOLL_EVT_ERROR) + { + *pfRetEvents = fEvents & ~RTPOLL_EVT_ERROR; + rc = VINF_SUCCESS; + } + else if (fIntr) + rc = RTThreadSleep(cMillies); + else + { + uint64_t uMsStart = RTTimeMilliTS(); + do + rc = RTThreadSleep(cMillies); + while ( rc == VERR_INTERRUPTED + && !fIntr + && RTTimeMilliTS() - uMsStart < cMillies); + if (rc == VERR_INTERRUPTED) + rc = VERR_TIMEOUT; + } + return rc; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnTell} + */ +static DECLCALLBACK(int) rtVfsStdFile_Tell(void *pvThis, PRTFOFF poffActual) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + uint64_t offActual; + int rc = RTFileSeek(pThis->hFile, 0, RTFILE_SEEK_CURRENT, &offActual); + if (RT_SUCCESS(rc)) + *poffActual = (RTFOFF)offActual; + return rc; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnSkip} + */ +static DECLCALLBACK(int) rtVfsStdFile_Skip(void *pvThis, RTFOFF cb) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + uint64_t offIgnore; + return RTFileSeek(pThis->hFile, cb, RTFILE_SEEK_CURRENT, &offIgnore); +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnMode} + */ +static DECLCALLBACK(int) rtVfsStdFile_SetMode(void *pvThis, RTFMODE fMode, RTFMODE fMask) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + if (fMask != ~RTFS_TYPE_MASK) + { +#if 0 + RTFMODE fCurMode; + int rc = RTFileGetMode(pThis->hFile, &fCurMode); + if (RT_FAILURE(rc)) + return rc; + fMode |= ~fMask & fCurMode; +#else + RTFSOBJINFO ObjInfo; + int rc = RTFileQueryInfo(pThis->hFile, &ObjInfo, RTFSOBJATTRADD_NOTHING); + if (RT_FAILURE(rc)) + return rc; + fMode |= ~fMask & ObjInfo.Attr.fMode; +#endif + } + return RTFileSetMode(pThis->hFile, fMode); +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnSetTimes} + */ +static DECLCALLBACK(int) rtVfsStdFile_SetTimes(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime, + PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + return RTFileSetTimes(pThis->hFile, pAccessTime, pModificationTime, pChangeTime, pBirthTime); +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnSetOwner} + */ +static DECLCALLBACK(int) rtVfsStdFile_SetOwner(void *pvThis, RTUID uid, RTGID gid) +{ +#if 0 + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + return RTFileSetOwner(pThis->hFile, uid, gid); +#else + NOREF(pvThis); NOREF(uid); NOREF(gid); + return VERR_NOT_IMPLEMENTED; +#endif +} + + +/** + * @interface_method_impl{RTVFSFILEOPS,pfnSeek} + */ +static DECLCALLBACK(int) rtVfsStdFile_Seek(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + uint64_t offActual = 0; + int rc = RTFileSeek(pThis->hFile, offSeek, uMethod, &offActual); + if (RT_SUCCESS(rc)) + *poffActual = offActual; + return rc; +} + + +/** + * @interface_method_impl{RTVFSFILEOPS,pfnQuerySize} + */ +static DECLCALLBACK(int) rtVfsStdFile_QuerySize(void *pvThis, uint64_t *pcbFile) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + return RTFileQuerySize(pThis->hFile, pcbFile); +} + + +/** + * @interface_method_impl{RTVFSFILEOPS,pfnSetSize} + */ +static DECLCALLBACK(int) rtVfsStdFile_SetSize(void *pvThis, uint64_t cbFile, uint32_t fFlags) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + switch (fFlags & RTVFSFILE_SIZE_F_ACTION_MASK) + { + case RTVFSFILE_SIZE_F_NORMAL: + return RTFileSetSize(pThis->hFile, cbFile); + case RTVFSFILE_SIZE_F_GROW: + return RTFileSetAllocationSize(pThis->hFile, cbFile, RTFILE_ALLOC_SIZE_F_DEFAULT); + case RTVFSFILE_SIZE_F_GROW_KEEP_SIZE: + return RTFileSetAllocationSize(pThis->hFile, cbFile, RTFILE_ALLOC_SIZE_F_KEEP_SIZE); + default: + return VERR_NOT_SUPPORTED; + } +} + + +/** + * @interface_method_impl{RTVFSFILEOPS,pfnQueryMaxSize} + */ +static DECLCALLBACK(int) rtVfsStdFile_QueryMaxSize(void *pvThis, uint64_t *pcbMax) +{ + PRTVFSSTDFILE pThis = (PRTVFSSTDFILE)pvThis; + RTFOFF cbMax = 0; + int rc = RTFileQueryMaxSizeEx(pThis->hFile, &cbMax); + if (RT_SUCCESS(rc)) + *pcbMax = cbMax; + return rc; +} + + +/** + * Standard file operations. + */ +DECL_HIDDEN_CONST(const RTVFSFILEOPS) g_rtVfsStdFileOps = +{ + { /* Stream */ + { /* Obj */ + RTVFSOBJOPS_VERSION, + RTVFSOBJTYPE_FILE, + "StdFile", + rtVfsStdFile_Close, + rtVfsStdFile_QueryInfo, + NULL, + RTVFSOBJOPS_VERSION + }, + RTVFSIOSTREAMOPS_VERSION, + 0, + rtVfsStdFile_Read, + rtVfsStdFile_Write, + rtVfsStdFile_Flush, + rtVfsStdFile_PollOne, + rtVfsStdFile_Tell, + rtVfsStdFile_Skip, + NULL /*ZeroFill*/, + RTVFSIOSTREAMOPS_VERSION, + }, + RTVFSFILEOPS_VERSION, + 0, + { /* ObjSet */ + RTVFSOBJSETOPS_VERSION, + RT_UOFFSETOF(RTVFSFILEOPS, ObjSet) - RT_UOFFSETOF(RTVFSFILEOPS, Stream.Obj), + rtVfsStdFile_SetMode, + rtVfsStdFile_SetTimes, + rtVfsStdFile_SetOwner, + RTVFSOBJSETOPS_VERSION + }, + rtVfsStdFile_Seek, + rtVfsStdFile_QuerySize, + rtVfsStdFile_SetSize, + rtVfsStdFile_QueryMaxSize, + RTVFSFILEOPS_VERSION +}; + + +/** + * Internal worker for RTVfsFileFromRTFile and RTVfsFileOpenNormal. + * + * @returns IRPT status code. + * @param hFile The IPRT file handle. + * @param fOpen The RTFILE_O_XXX flags. + * @param fLeaveOpen Whether to leave it open or close it. + * @param phVfsFile Where to return the handle. + */ +static int rtVfsFileFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSFILE phVfsFile) +{ + PRTVFSSTDFILE pThis; + RTVFSFILE hVfsFile; + int rc = RTVfsNewFile(&g_rtVfsStdFileOps, sizeof(RTVFSSTDFILE), fOpen, NIL_RTVFS, NIL_RTVFSLOCK, + &hVfsFile, (void **)&pThis); + if (RT_FAILURE(rc)) + return rc; + + pThis->hFile = hFile; + pThis->fLeaveOpen = fLeaveOpen; + *phVfsFile = hVfsFile; + return VINF_SUCCESS; +} + + +RTDECL(int) RTVfsFileFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSFILE phVfsFile) +{ + /* + * Check the handle validity. + */ + RTFSOBJINFO ObjInfo; + int rc = RTFileQueryInfo(hFile, &ObjInfo, RTFSOBJATTRADD_NOTHING); + if (RT_FAILURE(rc)) + return rc; + + /* + * Set up some fake fOpen flags if necessary and create a VFS file handle. + */ + if (!fOpen) + fOpen = RTFILE_O_READWRITE | RTFILE_O_DENY_NONE | RTFILE_O_OPEN_CREATE; + + return rtVfsFileFromRTFile(hFile, fOpen, fLeaveOpen, phVfsFile); +} + + +RTDECL(int) RTVfsFileOpenNormal(const char *pszFilename, uint64_t fOpen, PRTVFSFILE phVfsFile) +{ + /* + * Open the file the normal way and pass it to RTVfsFileFromRTFile. + */ + RTFILE hFile; + int rc = RTFileOpen(&hFile, pszFilename, fOpen); + if (RT_SUCCESS(rc)) + { + /* + * Create a VFS file handle. + */ + rc = rtVfsFileFromRTFile(hFile, fOpen, false /*fLeaveOpen*/, phVfsFile); + if (RT_FAILURE(rc)) + RTFileClose(hFile); + } + return rc; +} + + +RTDECL(int) RTVfsIoStrmFromRTFile(RTFILE hFile, uint64_t fOpen, bool fLeaveOpen, PRTVFSIOSTREAM phVfsIos) +{ + RTVFSFILE hVfsFile; + int rc = RTVfsFileFromRTFile(hFile, fOpen, fLeaveOpen, &hVfsFile); + if (RT_SUCCESS(rc)) + { + *phVfsIos = RTVfsFileToIoStream(hVfsFile); + RTVfsFileRelease(hVfsFile); + } + return rc; +} + + +RTDECL(int) RTVfsIoStrmOpenNormal(const char *pszFilename, uint64_t fOpen, PRTVFSIOSTREAM phVfsIos) +{ + RTVFSFILE hVfsFile; + int rc = RTVfsFileOpenNormal(pszFilename, fOpen, &hVfsFile); + if (RT_SUCCESS(rc)) + { + *phVfsIos = RTVfsFileToIoStream(hVfsFile); + RTVfsFileRelease(hVfsFile); + } + return rc; +} + + + +/** + * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnValidate} + */ +static DECLCALLBACK(int) rtVfsChainStdFile_Validate(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec, + PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo) +{ + RT_NOREF(pProviderReg); + + /* + * Basic checks. + */ + if (pElement->enmTypeIn != RTVFSOBJTYPE_INVALID) + return VERR_VFS_CHAIN_MUST_BE_FIRST_ELEMENT; + if ( pElement->enmType != RTVFSOBJTYPE_FILE + && pElement->enmType != RTVFSOBJTYPE_IO_STREAM) + return VERR_VFS_CHAIN_ONLY_FILE_OR_IOS; + + /* + * Join common cause with the 'open' provider. + */ + return RTVfsChainValidateOpenFileOrIoStream(pSpec, pElement, poffError, pErrInfo); +} + + +/** + * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnInstantiate} + */ +static DECLCALLBACK(int) rtVfsChainStdFile_Instantiate(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec, + PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj, + PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo) +{ + RT_NOREF(pProviderReg, pSpec, poffError, pErrInfo); + AssertReturn(hPrevVfsObj == NIL_RTVFSOBJ, VERR_VFS_CHAIN_IPE); + + RTVFSFILE hVfsFile; + int rc = RTVfsFileOpenNormal(pElement->paArgs[0].psz, pElement->uProvider, &hVfsFile); + if (RT_SUCCESS(rc)) + { + *phVfsObj = RTVfsObjFromFile(hVfsFile); + RTVfsFileRelease(hVfsFile); + if (*phVfsObj != NIL_RTVFSOBJ) + return VINF_SUCCESS; + rc = VERR_VFS_CHAIN_CAST_FAILED; + } + return rc; +} + + +/** + * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnCanReuseElement} + */ +static DECLCALLBACK(bool) rtVfsChainStdFile_CanReuseElement(PCRTVFSCHAINELEMENTREG pProviderReg, + PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement, + PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement) +{ + RT_NOREF(pProviderReg, pSpec, pReuseSpec); + if (strcmp(pElement->paArgs[0].psz, pReuseElement->paArgs[0].psz) == 0) + if (pElement->paArgs[0].uProvider == pReuseElement->paArgs[0].uProvider) + return true; + return false; +} + + +/** VFS chain element 'file'. */ +static RTVFSCHAINELEMENTREG g_rtVfsChainStdFileReg = +{ + /* uVersion = */ RTVFSCHAINELEMENTREG_VERSION, + /* fReserved = */ 0, + /* pszName = */ "stdfile", + /* ListEntry = */ { NULL, NULL }, + /* pszHelp = */ "Open a real file, providing either a file or an I/O stream object. Initial element.\n" + "First argument is the filename path.\n" + "Second argument is access mode, optional: r, w, rw.\n" + "Third argument is open disposition, optional: create, create-replace, open, open-create, open-append, open-truncate.\n" + "Forth argument is file sharing, optional: nr, nw, nrw, d.", + /* pfnValidate = */ rtVfsChainStdFile_Validate, + /* pfnInstantiate = */ rtVfsChainStdFile_Instantiate, + /* pfnCanReuseElement = */ rtVfsChainStdFile_CanReuseElement, + /* uEndMarker = */ RTVFSCHAINELEMENTREG_VERSION +}; + +RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(&g_rtVfsChainStdFileReg, rtVfsChainStdFileReg); + |