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// Silence invalid warnings due to rust-lang/rust#16719
#![allow(improper_ctypes)]
use {Result, Error};
use errno::Errno;
use fcntl::Fd;
use libc::{c_int, c_void, size_t};
use std::marker::PhantomData;
mod ffi {
use super::IoVec;
use libc::{ssize_t, c_int};
use fcntl::Fd;
extern {
// vectorized version of write
// doc: http://man7.org/linux/man-pages/man2/writev.2.html
pub fn writev(fd: Fd, iov: *const IoVec<&[u8]>, iovcnt: c_int) -> ssize_t;
// vectorized version of read
// doc: http://man7.org/linux/man-pages/man2/readv.2.html
pub fn readv(fd: Fd, iov: *const IoVec<&mut [u8]>, iovcnt: c_int) -> ssize_t;
}
}
pub fn writev(fd: Fd, iov: &[IoVec<&[u8]>]) -> Result<usize> {
let res = unsafe { ffi::writev(fd, iov.as_ptr(), iov.len() as c_int) };
if res < 0 {
return Err(Error::Sys(Errno::last()));
}
return Ok(res as usize)
}
pub fn readv(fd: Fd, iov: &mut [IoVec<&mut [u8]>]) -> Result<usize> {
let res = unsafe { ffi::readv(fd, iov.as_ptr(), iov.len() as c_int) };
if res < 0 {
return Err(Error::Sys(Errno::last()));
}
return Ok(res as usize)
}
#[repr(C)]
pub struct IoVec<T> {
iov_base: *mut c_void,
iov_len: size_t,
phantom: PhantomData<T>
}
impl<T> IoVec<T> {
#[inline]
pub fn as_slice<'a>(&'a self) -> &'a [u8] {
use std::slice;
unsafe {
slice::from_raw_parts(
self.iov_base as *const u8,
self.iov_len as usize)
}
}
}
impl<'a> IoVec<&'a [u8]> {
pub fn from_slice(buf: &'a [u8]) -> IoVec<&'a [u8]> {
IoVec {
iov_base: buf.as_ptr() as *mut c_void,
iov_len: buf.len() as size_t,
phantom: PhantomData
}
}
}
impl<'a> IoVec<&'a mut [u8]> {
pub fn from_mut_slice(buf: &'a mut [u8]) -> IoVec<&'a mut [u8]> {
IoVec {
iov_base: buf.as_ptr() as *mut c_void,
iov_len: buf.len() as size_t,
phantom: PhantomData
}
}
}
#[test]
pub fn test_size_of_io_vec() {
use nixtest;
nixtest::assert_size_of::<IoVec<&[u8]>>("iovec");
}
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