41 lines
2.5 KiB
C
41 lines
2.5 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
||
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
||
╞══════════════════════════════════════════════════════════════════════════════╡
|
||
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
||
│ │
|
||
│ 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; version 2 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, write to the Free Software │
|
||
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
|
||
│ 02110-1301 USA │
|
||
╚─────────────────────────────────────────────────────────────────────────────*/
|
||
#include "libc/calls/calls.h"
|
||
#include "libc/calls/internal.h"
|
||
#include "libc/dce.h"
|
||
|
||
/**
|
||
* Drops hints to O/S about intended I/O behavior.
|
||
*
|
||
* It makes a huge difference. For example, when copying a large file,
|
||
* it can stop the system from persisting GBs of useless memory content.
|
||
*
|
||
* @param len 0 means ‘til end of file
|
||
* @param advice can be MADV_SEQUENTIAL, MADV_RANDOM, etc.
|
||
* @return -1 on error
|
||
*/
|
||
int fadvise(int fd, uint64_t offset, uint64_t len, int advice) {
|
||
if (!IsWindows()) {
|
||
return fadvise$sysv(fd, offset, len, advice); /* linux & freebsd */
|
||
} else {
|
||
return fadvise$nt(fd, offset, len, advice);
|
||
}
|
||
}
|