cosmopolitan/libc/calls/fadvise-nt.c

66 lines
3.7 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/internal.h"
#include "libc/nt/enum/fileflagandattributes.h"
#include "libc/nt/enum/filesharemode.h"
#include "libc/nt/enum/status.h"
#include "libc/nt/files.h"
#include "libc/nt/nt/file.h"
#include "libc/nt/ntdll.h"
#include "libc/nt/runtime.h"
#include "libc/nt/struct/fileaccessinformation.h"
#include "libc/nt/struct/filebasicinformation.h"
#include "libc/nt/struct/iostatusblock.h"
#include "libc/runtime/runtime.h"
#include "libc/sysv/errfuns.h"
textwindows int fadvise$nt(int fd, uint64_t offset, uint64_t len, int advice) {
int64_t h2;
NtStatus status;
uint32_t sharemode;
struct NtIoStatusBlock iostatus;
struct NtFileBasicInformation basicinfo;
struct NtFileAccessInformation accessinfo;
if (!isfdkind(fd, kFdFile)) return ebadf();
sharemode = /* xxx: no clue how to query this */
kNtFileShareRead | kNtFileShareWrite | kNtFileShareDelete;
/* TODO(jart): can we do it in one call w/ NtQueryObject? */
if (!NtError(status = NtQueryInformationFile(g_fds.p[fd].handle, &iostatus,
&basicinfo, sizeof(basicinfo),
kNtFileBasicInformation)) &&
!NtError(status = NtQueryInformationFile(g_fds.p[fd].handle, &iostatus,
&accessinfo, sizeof(accessinfo),
kNtFileAccessInformation))) {
if ((h2 = ReOpenFile(g_fds.p[fd].handle, accessinfo.AccessFlags, sharemode,
advice | basicinfo.FileAttributes)) != -1) {
if (h2 != g_fds.p[fd].handle) {
CloseHandle(g_fds.p[fd].handle);
g_fds.p[fd].handle = h2;
}
return 0;
}
return winerr();
} else if (status == kNtStatusDllNotFound) {
return enosys();
} else {
return ntreturn(status);
}
}