cosmopolitan/libc/calls/fadvise-nt.c
2022-06-08 20:33:13 -07:00

82 lines
3.5 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 │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/internal.h"
#include "libc/calls/state.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/intrin/spinlock.h"
#include "libc/nt/createfile.h"
#include "libc/nt/enum/fileflagandattributes.h"
#include "libc/nt/files.h"
#include "libc/nt/runtime.h"
#include "libc/sysv/consts/madv.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/errfuns.h"
textwindows int sys_fadvise_nt(int fd, uint64_t offset, uint64_t len,
int advice) {
int64_t h1, h2;
int rc, flags, mode;
uint32_t perm, share, attr;
if (!__isfdkind(fd, kFdFile)) return ebadf();
h1 = g_fds.p[fd].handle;
mode = g_fds.p[fd].mode;
flags = g_fds.p[fd].flags;
flags &= ~(O_SEQUENTIAL | O_RANDOM);
switch (advice) {
case MADV_NORMAL:
break;
case MADV_RANDOM:
flags |= O_RANDOM;
break;
case MADV_WILLNEED:
case MADV_SEQUENTIAL:
flags |= O_SEQUENTIAL;
break;
default:
return einval();
}
if (GetNtOpenFlags(flags, mode, &perm, &share, 0, &attr) == -1) {
return -1;
}
// MSDN says only these are allowed, otherwise it returns EINVAL.
attr &= kNtFileFlagBackupSemantics | kNtFileFlagDeleteOnClose |
kNtFileFlagNoBuffering | kNtFileFlagOpenNoRecall |
kNtFileFlagOpenReparsePoint | kNtFileFlagOverlapped |
kNtFileFlagPosixSemantics | kNtFileFlagRandomAccess |
kNtFileFlagSequentialScan | kNtFileFlagWriteThrough;
__fds_lock();
if ((h2 = ReOpenFile(h1, perm, share, attr)) != -1) {
if (h2 != h1) {
CloseHandle(h1);
g_fds.p[fd].handle = h2;
}
g_fds.p[fd].flags = flags;
rc = 0;
} else {
rc = __winerr();
}
__fds_unlock();
return rc;
}