#![unstable(reason = "not public", issue = "0", feature = "fd")]
use crate::cmp;
use crate::io::{self, Read, Initializer, IoSlice, IoSliceMut};
use crate::mem;
use crate::sync::atomic::{AtomicBool, Ordering};
use crate::sys::cvt;
use crate::sys_common::AsInner;
use libc::{c_int, c_void, ssize_t};
#[derive(Debug)]
pub struct FileDesc {
fd: c_int,
}
fn max_len() -> usize {
if cfg!(target_os = "macos") {
<c_int>::max_value() as usize - 1
} else {
<ssize_t>::max_value() as usize
}
}
impl FileDesc {
pub fn new(fd: c_int) -> FileDesc {
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(), max_len()))
})?;
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(), c_int::max_value() as usize) as c_int)
})?;
Ok(ret as usize)
}
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(target_os = "emscripten")]
unsafe fn cvt_pread64(fd: c_int, buf: *mut c_void, count: usize, offset: i64)
-> io::Result<isize>
{
use crate::convert::TryInto;
use libc::pread64;
if let Ok(o) = offset.try_into() {
cvt(pread64(fd, buf, count, o))
} else {
Err(io::Error::new(io::ErrorKind::InvalidInput,
"cannot pread >2GB"))
}
}
#[cfg(not(any(target_os = "android", target_os = "emscripten")))]
unsafe fn cvt_pread64(fd: c_int, buf: *mut c_void, count: usize, offset: i64)
-> io::Result<isize>
{
#[cfg(target_os = "linux")]
use libc::pread64;
#[cfg(not(target_os = "linux"))]
use libc::pread as pread64;
cvt(pread64(fd, buf, count, offset))
}
unsafe {
cvt_pread64(self.fd,
buf.as_mut_ptr() as *mut c_void,
cmp::min(buf.len(), max_len()),
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(), max_len()))
})?;
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(), c_int::max_value() as usize) as c_int)
})?;
Ok(ret as usize)
}
pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
#[cfg(target_os = "android")]
use super::android::cvt_pwrite64;
#[cfg(target_os = "emscripten")]
unsafe fn cvt_pwrite64(fd: c_int, buf: *const c_void, count: usize, offset: i64)
-> io::Result<isize>
{
use crate::convert::TryInto;
use libc::pwrite64;
if let Ok(o) = offset.try_into() {
cvt(pwrite64(fd, buf, count, o))
} else {
Err(io::Error::new(io::ErrorKind::InvalidInput,
"cannot pwrite >2GB"))
}
}
#[cfg(not(any(target_os = "android", target_os = "emscripten")))]
unsafe fn cvt_pwrite64(fd: c_int, buf: *const c_void, count: usize, offset: i64)
-> io::Result<isize>
{
#[cfg(target_os = "linux")]
use libc::pwrite64;
#[cfg(not(target_os = "linux"))]
use libc::pwrite as pwrite64;
cvt(pwrite64(fd, buf, count, offset))
}
unsafe {
cvt_pwrite64(self.fd,
buf.as_ptr() as *const c_void,
cmp::min(buf.len(), max_len()),
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 = "emscripten",
target_os = "fuchsia",
target_os = "l4re",
target_os = "haiku")))]
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 = "emscripten",
target_os = "fuchsia",
target_os = "l4re",
target_os = "haiku"))]
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> {
#[cfg(any(target_os = "android", target_os = "haiku"))]
use libc::F_DUPFD as F_DUPFD_CLOEXEC;
#[cfg(not(any(target_os = "android", target_os="haiku")))]
use libc::F_DUPFD_CLOEXEC;
let make_filedesc = |fd| {
let fd = FileDesc::new(fd);
fd.set_cloexec()?;
Ok(fd)
};
static TRY_CLOEXEC: AtomicBool =
AtomicBool::new(!cfg!(target_os = "android"));
let fd = self.raw();
if TRY_CLOEXEC.load(Ordering::Relaxed) {
match cvt(unsafe { libc::fcntl(fd, F_DUPFD_CLOEXEC, 0) }) {
Ok(fd) => {
return Ok(if cfg!(target_os = "linux") {
make_filedesc(fd)?
} else {
FileDesc::new(fd)
})
}
Err(ref e) if e.raw_os_error() == Some(libc::EINVAL) => {
TRY_CLOEXEC.store(false, Ordering::Relaxed);
}
Err(e) => return Err(e),
}
}
cvt(unsafe { libc::fcntl(fd, libc::F_DUPFD, 0) }).and_then(make_filedesc)
}
}
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) };
}
}