std\sys\io\io_slice/
windows.rs

1use crate::marker::PhantomData;
2use crate::slice;
3use crate::sys::c;
4
5#[derive(Copy, Clone)]
6#[repr(transparent)]
7pub struct IoSlice<'a> {
8    vec: c::WSABUF,
9    _p: PhantomData<&'a [u8]>,
10}
11
12impl<'a> IoSlice<'a> {
13    #[inline]
14    pub fn new(buf: &'a [u8]) -> IoSlice<'a> {
15        assert!(buf.len() <= u32::MAX as usize);
16        IoSlice {
17            vec: c::WSABUF { len: buf.len() as u32, buf: buf.as_ptr() as *mut u8 },
18            _p: PhantomData,
19        }
20    }
21
22    #[inline]
23    pub fn advance(&mut self, n: usize) {
24        if (self.vec.len as usize) < n {
25            panic!("advancing IoSlice beyond its length");
26        }
27
28        unsafe {
29            self.vec.len -= n as u32;
30            self.vec.buf = self.vec.buf.add(n);
31        }
32    }
33
34    #[inline]
35    pub const fn as_slice(&self) -> &'a [u8] {
36        unsafe { slice::from_raw_parts(self.vec.buf, self.vec.len as usize) }
37    }
38}
39
40#[repr(transparent)]
41pub struct IoSliceMut<'a> {
42    vec: c::WSABUF,
43    _p: PhantomData<&'a mut [u8]>,
44}
45
46impl<'a> IoSliceMut<'a> {
47    #[inline]
48    pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> {
49        assert!(buf.len() <= u32::MAX as usize);
50        IoSliceMut {
51            vec: c::WSABUF { len: buf.len() as u32, buf: buf.as_mut_ptr() },
52            _p: PhantomData,
53        }
54    }
55
56    #[inline]
57    pub fn advance(&mut self, n: usize) {
58        if (self.vec.len as usize) < n {
59            panic!("advancing IoSliceMut beyond its length");
60        }
61
62        unsafe {
63            self.vec.len -= n as u32;
64            self.vec.buf = self.vec.buf.add(n);
65        }
66    }
67
68    #[inline]
69    pub fn as_slice(&self) -> &[u8] {
70        unsafe { slice::from_raw_parts(self.vec.buf, self.vec.len as usize) }
71    }
72
73    #[inline]
74    pub const fn into_slice(self) -> &'a mut [u8] {
75        unsafe { slice::from_raw_parts_mut(self.vec.buf, self.vec.len as usize) }
76    }
77
78    #[inline]
79    pub fn as_mut_slice(&mut self) -> &mut [u8] {
80        unsafe { slice::from_raw_parts_mut(self.vec.buf, self.vec.len as usize) }
81    }
82}