cosmopolitan/libc/calls/fadvise-nt.c

65 lines
3.6 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/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);
}
}