mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 20:51:11 +00:00
688903eb3e
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
60 lines
2.1 KiB
C
60 lines
2.1 KiB
C
/* sendfile -- copy data directly from one file descriptor to another
|
|
Copyright (C) 2002-2018 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <sys/sendfile.h>
|
|
#include <hurd.h>
|
|
#include <hurd/fd.h>
|
|
#include <sys/mman.h>
|
|
|
|
/* Send COUNT bytes from file associated with IN_FD starting at OFFSET to
|
|
descriptor OUT_FD. */
|
|
ssize_t
|
|
sendfile64 (int out_fd, int in_fd, off64_t *offset, size_t count)
|
|
{
|
|
/* We just do a vanilla io_read followed by a vanilla io_write here.
|
|
In theory the IN_FD filesystem can return us out-of-line data that
|
|
we then send out-of-line to the OUT_FD filesystem and no copying
|
|
takes place until those pages need to be flushed or packaged by
|
|
that filesystem (e.g. packetized by a network socket). However,
|
|
we momentarily consume COUNT bytes of our local address space,
|
|
which might blow if it's huge or address space is real tight. */
|
|
|
|
char *data = 0;
|
|
size_t datalen = 0;
|
|
error_t err = HURD_DPORT_USE (in_fd,
|
|
__io_read (port, &data, &datalen,
|
|
offset ? *offset : (off_t) -1,
|
|
count));
|
|
if (err == 0)
|
|
{
|
|
size_t nwrote;
|
|
if (datalen == 0)
|
|
return 0;
|
|
err = HURD_DPORT_USE (out_fd, __io_write (port, data, datalen,
|
|
(off_t) -1, &nwrote));
|
|
munmap (data, datalen);
|
|
if (err == 0)
|
|
{
|
|
if (offset)
|
|
*offset += datalen;
|
|
return nwrote;
|
|
}
|
|
}
|
|
return __hurd_fail (err);
|
|
}
|