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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:17:27 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:17:27 +0000 |
commit | f215e02bf85f68d3a6106c2a1f4f7f063f819064 (patch) | |
tree | 6bb5b92c046312c4e95ac2620b10ddf482d3fa8b /src/VBox/Runtime/r3/posix/fileio-sg-at-posix.cpp | |
parent | Initial commit. (diff) | |
download | virtualbox-f215e02bf85f68d3a6106c2a1f4f7f063f819064.tar.xz virtualbox-f215e02bf85f68d3a6106c2a1f4f7f063f819064.zip |
Adding upstream version 7.0.14-dfsg.upstream/7.0.14-dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/VBox/Runtime/r3/posix/fileio-sg-at-posix.cpp')
-rw-r--r-- | src/VBox/Runtime/r3/posix/fileio-sg-at-posix.cpp | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/posix/fileio-sg-at-posix.cpp b/src/VBox/Runtime/r3/posix/fileio-sg-at-posix.cpp new file mode 100644 index 00000000..5fdea41a --- /dev/null +++ b/src/VBox/Runtime/r3/posix/fileio-sg-at-posix.cpp @@ -0,0 +1,298 @@ +/* $Id: fileio-sg-at-posix.cpp $ */ +/** @file + * IPRT - File I/O, RTFileSgReadAt & RTFileSgWriteAt, posixy. + */ + +/* + * Copyright (C) 2006-2023 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 * +*********************************************************************************************************************************/ +/* + * Determin whether we've got preadv and pwritev. + */ +#include <iprt/cdefs.h> +#ifdef RT_OS_LINUX +/* Linux has these since glibc 2.10 and Linux 2.6.30: */ +# include <features.h> +# ifdef __GLIBC_PREREQ +# if __GLIBC_PREREQ(2,10) +# define HAVE_PREADV_AND_PWRITEV 1 +#else +# endif +# endif + +#elif defined(RT_OS_FREEBSD) +/* FreeBSD has these since 6.0: */ +# include <osreldate.h> +# ifdef __FreeBSD_version +# if __FreeBSD_version >= 600000 +# define HAVE_PREADV_AND_PWRITEV 1 +# endif +# endif + +#endif + +#ifndef HAVE_PREADV_AND_PWRITEV + +# include "../../generic/fileio-sg-at-generic.cpp" + +#else /* HAVE_PREADV_AND_PWRITEV - rest of the file */ + +# include <errno.h> +# include <sys/types.h> +# include <sys/uio.h> +# include <unistd.h> +# include <limits.h> +# if defined(RT_OS_DARWIN) || defined(RT_OS_FREEBSD) || defined(RT_OS_NETBSD) || defined(RT_OS_OPENBSD) +# include <sys/syslimits.h> +# endif + +# include "internal/iprt.h" +# include <iprt/file.h> + +# include <iprt/assert.h> +# include <iprt/err.h> +# include <iprt/log.h> + +# ifndef UIO_MAXIOV +# ifdef IOV_MAX +# define UIO_MAXIOV IOV_MAX +# else +# error "UIO_MAXIOV and IOV_MAX are undefined" +# endif +# endif + + +/* These assumptions simplifies things a lot here. */ +AssertCompileMembersSameSizeAndOffset(struct iovec, iov_base, RTSGSEG, pvSeg); +AssertCompileMembersSameSizeAndOffset(struct iovec, iov_len, RTSGSEG, cbSeg); + + +RTDECL(int) RTFileSgReadAt(RTFILE hFile, RTFOFF off, PRTSGBUF pSgBuf, size_t cbToRead, size_t *pcbRead) +{ + /* + * Make sure we set pcbRead. + */ + if (pcbRead) + *pcbRead = 0; + + /* + * Special case: Zero read == seek. + */ + if (cbToRead == 0) + return RTFileSeek(hFile, off, RTFILE_SEEK_BEGIN, NULL); + + /* + * We can use the segment array directly if we're at the start of the + * current S/G segment and cbToRead matches the remainder exactly. + */ + size_t cbTotalRead = 0; + + size_t const cbSgBufLeft = RTSgBufCalcLengthLeft(pSgBuf); + AssertMsgReturn(cbSgBufLeft >= cbToRead, ("%#zx vs %#zx\n", cbSgBufLeft, cbToRead), VERR_INVALID_PARAMETER); + + if (cbToRead == cbSgBufLeft) + while (RTSgBufIsAtStartOfSegment(pSgBuf)) + { + size_t const cSegsLeft = pSgBuf->cSegs - pSgBuf->idxSeg; + ssize_t cbThisRead = preadv(RTFileToNative(hFile), (const struct iovec *)&pSgBuf->paSegs[pSgBuf->idxSeg], + RT_MIN(cSegsLeft, UIO_MAXIOV), off); + if (cbThisRead >= 0) + { + AssertStmt((size_t)cbThisRead <= cbToRead, cbThisRead = cbToRead); + + RTSgBufAdvance(pSgBuf, cbThisRead); + cbTotalRead += cbThisRead; + cbToRead -= cbThisRead; + if (cbToRead == 0) + { + if (pcbRead) + *pcbRead = cbTotalRead; + return VINF_SUCCESS; + } + + if ( pcbRead + && ( cSegsLeft <= UIO_MAXIOV + || cbThisRead == 0 /* typically EOF */ )) + { + *pcbRead = cbTotalRead; + return VINF_SUCCESS; + } + if (cbThisRead == 0) + return VERR_EOF; + + off += cbThisRead; + } + else if (cbTotalRead > 0 && pcbRead) + { + *pcbRead = cbTotalRead; + return VINF_SUCCESS; + } + else + return RTErrConvertFromErrno(errno); + } + + /* + * Unaligned start or not reading the whole buffer. For reasons of + * simplicity, we work the input segment by segment like the generic code. + */ + int rc = VINF_SUCCESS; + while (cbToRead > 0) + { + size_t cbSeg; + void *pvSeg = RTSgBufGetCurrentSegment(pSgBuf, cbToRead, &cbSeg); + size_t cbThisRead = cbSeg; + rc = RTFileReadAt(hFile, off, pvSeg, cbSeg, pcbRead ? &cbThisRead : NULL); + if (RT_SUCCESS(rc)) + { + RTSgBufAdvance(pSgBuf, cbThisRead); + cbTotalRead += cbThisRead; + } + else + break; + if ((size_t)cbThisRead < cbSeg) + { + AssertStmt(pcbRead, rc = VERR_INTERNAL_ERROR_2); + break; + } + + Assert(cbSeg == cbThisRead); + cbToRead -= cbSeg; + off += cbSeg; + } + if (pcbRead) + *pcbRead = cbTotalRead; + return rc; +} + + +RTDECL(int) RTFileSgWriteAt(RTFILE hFile, RTFOFF off, PRTSGBUF pSgBuf, size_t cbToWrite, size_t *pcbWritten) +{ + /* + * Make sure we set pcbWritten. + */ + if (pcbWritten) + *pcbWritten = 0; + + /* + * Special case: Zero write == seek. + */ + if (cbToWrite == 0) + return RTFileSeek(hFile, off, RTFILE_SEEK_BEGIN, NULL); + + /* + * We can use the segment array directly if we're at the start of the + * current S/G segment and cbToWrite matches the remainder exactly. + */ + size_t cbTotalWritten = 0; + + size_t const cbSgBufLeft = RTSgBufCalcLengthLeft(pSgBuf); + AssertMsgReturn(cbSgBufLeft >= cbToWrite, ("%#zx vs %#zx\n", cbSgBufLeft, cbToWrite), VERR_INVALID_PARAMETER); + + if (cbToWrite == cbSgBufLeft) + while (RTSgBufIsAtStartOfSegment(pSgBuf)) + { + size_t const cSegsLeft = pSgBuf->cSegs - pSgBuf->idxSeg; + ssize_t cbThisWritten = pwritev(RTFileToNative(hFile), (const struct iovec *)&pSgBuf->paSegs[pSgBuf->idxSeg], + RT_MIN(cSegsLeft, UIO_MAXIOV), off); + if (cbThisWritten >= 0) + { + AssertStmt((size_t)cbThisWritten <= cbToWrite, cbThisWritten = cbToWrite); + + RTSgBufAdvance(pSgBuf, cbThisWritten); + cbTotalWritten += cbThisWritten; + cbToWrite -= cbThisWritten; + if (cbToWrite == 0) + { + if (pcbWritten) + *pcbWritten = cbTotalWritten; + return VINF_SUCCESS; + } + + if ( pcbWritten + && ( cSegsLeft <= UIO_MAXIOV + || cbThisWritten == 0 /* non-file, full buffer/whatever */ )) + { + *pcbWritten = cbTotalWritten; + return VINF_SUCCESS; + } + if (cbThisWritten == 0) + return VERR_TRY_AGAIN; + + off += cbThisWritten; + } + else if (cbTotalWritten > 0 && pcbWritten) + { + *pcbWritten = cbTotalWritten; + return VINF_SUCCESS; + } + else + return RTErrConvertFromErrno(errno); + } + + /* + * Unaligned start or not writing the whole buffer. For reasons of + * simplicity, we work the input segment by segment like the generic code. + */ + int rc = VINF_SUCCESS; + while (cbToWrite > 0) + { + size_t cbSeg; + void *pvSeg = RTSgBufGetCurrentSegment(pSgBuf, cbToWrite, &cbSeg); + size_t cbThisWritten = cbSeg; + rc = RTFileWriteAt(hFile, off, pvSeg, cbSeg, pcbWritten ? &cbThisWritten : NULL); + if (RT_SUCCESS(rc)) + { + RTSgBufAdvance(pSgBuf, cbThisWritten); + cbTotalWritten += cbThisWritten; + } + else + break; + if ((size_t)cbThisWritten < cbSeg) + { + AssertStmt(pcbWritten, rc = VERR_INTERNAL_ERROR_2); + break; + } + + Assert(cbSeg == cbThisWritten); + cbToWrite -= cbSeg; + off += cbSeg; + } + if (pcbWritten) + *pcbWritten = cbTotalWritten; + return rc; +} + +#endif /* HAVE_PREADV_AND_PWRITEV */ + |