41 lines
2.5 KiB
C
41 lines
2.5 KiB
C
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/calls.h"
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#include "libc/calls/internal.h"
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#include "libc/dce.h"
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/**
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* Drops hints to O/S about intended I/O behavior.
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*
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* It makes a huge difference. For example, when copying a large file,
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* it can stop the system from persisting GBs of useless memory content.
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*
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* @param len 0 means ‘til end of file
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* @param advice can be MADV_SEQUENTIAL, MADV_RANDOM, etc.
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* @return -1 on error
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*/
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int fadvise(int fd, uint64_t offset, uint64_t len, int advice) {
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if (!IsWindows()) {
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return fadvise$sysv(fd, offset, len, advice); /* linux & freebsd */
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} else {
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return fadvise$nt(fd, offset, len, advice);
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}
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}
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