#![unstable(reason = "not public", issue = "none", feature = "fd")]
#[cfg(test)]
mod tests;
use crate::cmp;
use crate::io::{self, Initializer, IoSlice, IoSliceMut, Read};
use crate::mem;
use crate::sys::cvt;
use crate::sys_common::AsInner;
use libc::{c_int, c_void};
#[derive(Debug)]
#[rustc_layout_scalar_valid_range_start(0)]
#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
pub struct FileDesc {
fd: c_int,
}
#[cfg(target_os = "macos")]
const READ_LIMIT: usize = c_int::MAX as usize - 1;
#[cfg(not(target_os = "macos"))]
const READ_LIMIT: usize = libc::ssize_t::MAX as usize;
#[cfg(any(
target_os = "dragonfly",
target_os = "freebsd",
target_os = "ios",
target_os = "macos",
target_os = "netbsd",
target_os = "openbsd",
))]
const fn max_iov() -> usize {
libc::IOV_MAX as usize
}
#[cfg(any(target_os = "android", target_os = "emscripten", target_os = "linux"))]
const fn max_iov() -> usize {
libc::UIO_MAXIOV as usize
}
#[cfg(not(any(
target_os = "android",
target_os = "dragonfly",
target_os = "emscripten",
target_os = "freebsd",
target_os = "ios",
target_os = "linux",
target_os = "macos",
target_os = "netbsd",
target_os = "openbsd",
)))]
const fn max_iov() -> usize {
16
}
impl FileDesc {
pub fn new(fd: c_int) -> FileDesc {
assert_ne!(fd, -1i32);
unsafe { FileDesc { fd } }
}
pub fn raw(&self) -> c_int {
self.fd
}
pub fn into_raw(self) -> c_int {
let fd = self.fd;
mem::forget(self);
fd
}
pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::read(self.fd, buf.as_mut_ptr() as *mut c_void, cmp::min(buf.len(), READ_LIMIT))
})?;
Ok(ret as usize)
}
pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::readv(
self.fd,
bufs.as_ptr() as *const libc::iovec,
cmp::min(bufs.len(), max_iov()) as c_int,
)
})?;
Ok(ret as usize)
}
#[inline]
pub fn is_read_vectored(&self) -> bool {
true
}
pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
let mut me = self;
(&mut me).read_to_end(buf)
}
pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
#[cfg(target_os = "android")]
use super::android::cvt_pread64;
#[cfg(not(target_os = "android"))]
unsafe fn cvt_pread64(
fd: c_int,
buf: *mut c_void,
count: usize,
offset: i64,
) -> io::Result<isize> {
#[cfg(not(target_os = "linux"))]
use libc::pread as pread64;
#[cfg(target_os = "linux")]
use libc::pread64;
cvt(pread64(fd, buf, count, offset))
}
unsafe {
cvt_pread64(
self.fd,
buf.as_mut_ptr() as *mut c_void,
cmp::min(buf.len(), READ_LIMIT),
offset as i64,
)
.map(|n| n as usize)
}
}
pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::write(self.fd, buf.as_ptr() as *const c_void, cmp::min(buf.len(), READ_LIMIT))
})?;
Ok(ret as usize)
}
pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
let ret = cvt(unsafe {
libc::writev(
self.fd,
bufs.as_ptr() as *const libc::iovec,
cmp::min(bufs.len(), max_iov()) as c_int,
)
})?;
Ok(ret as usize)
}
#[inline]
pub fn is_write_vectored(&self) -> bool {
true
}
pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
#[cfg(target_os = "android")]
use super::android::cvt_pwrite64;
#[cfg(not(target_os = "android"))]
unsafe fn cvt_pwrite64(
fd: c_int,
buf: *const c_void,
count: usize,
offset: i64,
) -> io::Result<isize> {
#[cfg(not(target_os = "linux"))]
use libc::pwrite as pwrite64;
#[cfg(target_os = "linux")]
use libc::pwrite64;
cvt(pwrite64(fd, buf, count, offset))
}
unsafe {
cvt_pwrite64(
self.fd,
buf.as_ptr() as *const c_void,
cmp::min(buf.len(), READ_LIMIT),
offset as i64,
)
.map(|n| n as usize)
}
}
#[cfg(target_os = "linux")]
pub fn get_cloexec(&self) -> io::Result<bool> {
unsafe { Ok((cvt(libc::fcntl(self.fd, libc::F_GETFD))? & libc::FD_CLOEXEC) != 0) }
}
#[cfg(not(any(
target_env = "newlib",
target_os = "solaris",
target_os = "illumos",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "l4re",
target_os = "linux",
target_os = "haiku",
target_os = "redox",
target_os = "vxworks"
)))]
pub fn set_cloexec(&self) -> io::Result<()> {
unsafe {
cvt(libc::ioctl(self.fd, libc::FIOCLEX))?;
Ok(())
}
}
#[cfg(any(
target_env = "newlib",
target_os = "solaris",
target_os = "illumos",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "l4re",
target_os = "linux",
target_os = "haiku",
target_os = "redox",
target_os = "vxworks"
))]
pub fn set_cloexec(&self) -> io::Result<()> {
unsafe {
let previous = cvt(libc::fcntl(self.fd, libc::F_GETFD))?;
let new = previous | libc::FD_CLOEXEC;
if new != previous {
cvt(libc::fcntl(self.fd, libc::F_SETFD, new))?;
}
Ok(())
}
}
#[cfg(target_os = "linux")]
pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
unsafe {
let v = nonblocking as c_int;
cvt(libc::ioctl(self.fd, libc::FIONBIO, &v))?;
Ok(())
}
}
#[cfg(not(target_os = "linux"))]
pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
unsafe {
let previous = cvt(libc::fcntl(self.fd, libc::F_GETFL))?;
let new = if nonblocking {
previous | libc::O_NONBLOCK
} else {
previous & !libc::O_NONBLOCK
};
if new != previous {
cvt(libc::fcntl(self.fd, libc::F_SETFL, new))?;
}
Ok(())
}
}
pub fn duplicate(&self) -> io::Result<FileDesc> {
let fd = cvt(unsafe { libc::fcntl(self.raw(), libc::F_DUPFD_CLOEXEC, 0) })?;
Ok(FileDesc::new(fd))
}
}
impl<'a> Read for &'a FileDesc {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
(**self).read(buf)
}
#[inline]
unsafe fn initializer(&self) -> Initializer {
Initializer::nop()
}
}
impl AsInner<c_int> for FileDesc {
fn as_inner(&self) -> &c_int {
&self.fd
}
}
impl Drop for FileDesc {
fn drop(&mut self) {
let _ = unsafe { libc::close(self.fd) };
}
}