1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82

use crate::marker::PhantomData;
use crate::os::fd::{AsFd, AsRawFd};
use crate::slice;

use libc::{c_void, iovec};

#[derive(Copy, Clone)]
#[repr(transparent)]
pub struct IoSlice<'a> {
    vec: iovec,
    _p: PhantomData<&'a [u8]>,
}

impl<'a> IoSlice<'a> {
    #[inline]
    pub fn new(buf: &'a [u8]) -> IoSlice<'a> {
        IoSlice {
            vec: iovec { iov_base: buf.as_ptr() as *mut u8 as *mut c_void, iov_len: buf.len() },
            _p: PhantomData,
        }
    }

    #[inline]
    pub fn advance(&mut self, n: usize) {
        if self.vec.iov_len < n {
            panic!("advancing IoSlice beyond its length");
        }

        unsafe {
            self.vec.iov_len -= n;
            self.vec.iov_base = self.vec.iov_base.add(n);
        }
    }

    #[inline]
    pub fn as_slice(&self) -> &[u8] {
        unsafe { slice::from_raw_parts(self.vec.iov_base as *mut u8, self.vec.iov_len) }
    }
}

#[repr(transparent)]
pub struct IoSliceMut<'a> {
    vec: iovec,
    _p: PhantomData<&'a mut [u8]>,
}

impl<'a> IoSliceMut<'a> {
    #[inline]
    pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> {
        IoSliceMut {
            vec: iovec { iov_base: buf.as_mut_ptr() as *mut c_void, iov_len: buf.len() },
            _p: PhantomData,
        }
    }

    #[inline]
    pub fn advance(&mut self, n: usize) {
        if self.vec.iov_len < n {
            panic!("advancing IoSliceMut beyond its length");
        }

        unsafe {
            self.vec.iov_len -= n;
            self.vec.iov_base = self.vec.iov_base.add(n);
        }
    }

    #[inline]
    pub fn as_slice(&self) -> &[u8] {
        unsafe { slice::from_raw_parts(self.vec.iov_base as *mut u8, self.vec.iov_len) }
    }

    #[inline]
    pub fn as_mut_slice(&mut self) -> &mut [u8] {
        unsafe { slice::from_raw_parts_mut(self.vec.iov_base as *mut u8, self.vec.iov_len) }
    }
}

pub fn is_terminal(fd: &impl AsFd) -> bool {
    let fd = fd.as_fd();
    unsafe { libc::isatty(fd.as_raw_fd()) != 0 }
}