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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:17:27 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:17:27 +0000
commitf215e02bf85f68d3a6106c2a1f4f7f063f819064 (patch)
tree6bb5b92c046312c4e95ac2620b10ddf482d3fa8b /src/VBox/Runtime/r3/posix/fileio-sg-at-posix.cpp
parentInitial commit. (diff)
downloadvirtualbox-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')
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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
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+/* $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 */
+