| use crate::marker::PhantomData; |
| use crate::slice; |
| |
| use ::wasi::wasi_unstable as wasi; |
| use core::ffi::c_void; |
| |
| #[repr(transparent)] |
| pub struct IoSlice<'a> { |
| vec: wasi::CIoVec, |
| _p: PhantomData<&'a [u8]>, |
| } |
| |
| impl<'a> IoSlice<'a> { |
| #[inline] |
| pub fn new(buf: &'a [u8]) -> IoSlice<'a> { |
| IoSlice { |
| vec: wasi::CIoVec { |
| buf: buf.as_ptr() as *const c_void, |
| buf_len: buf.len(), |
| }, |
| _p: PhantomData, |
| } |
| } |
| |
| #[inline] |
| pub fn advance(&mut self, n: usize) { |
| if self.vec.buf_len < n { |
| panic!("advancing IoSlice beyond its length"); |
| } |
| |
| unsafe { |
| self.vec.buf_len -= n; |
| self.vec.buf = self.vec.buf.add(n); |
| } |
| } |
| |
| #[inline] |
| pub fn as_slice(&self) -> &[u8] { |
| unsafe { |
| slice::from_raw_parts(self.vec.buf as *const u8, self.vec.buf_len) |
| } |
| } |
| } |
| |
| #[repr(transparent)] |
| pub struct IoSliceMut<'a> { |
| vec: wasi::IoVec, |
| _p: PhantomData<&'a mut [u8]>, |
| } |
| |
| impl<'a> IoSliceMut<'a> { |
| #[inline] |
| pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> { |
| IoSliceMut { |
| vec: wasi::IoVec { |
| buf: buf.as_mut_ptr() as *mut c_void, |
| buf_len: buf.len() |
| }, |
| _p: PhantomData, |
| } |
| } |
| |
| #[inline] |
| pub fn advance(&mut self, n: usize) { |
| if self.vec.buf_len < n { |
| panic!("advancing IoSlice beyond its length"); |
| } |
| |
| unsafe { |
| self.vec.buf_len -= n; |
| self.vec.buf = self.vec.buf.add(n); |
| } |
| } |
| |
| #[inline] |
| pub fn as_slice(&self) -> &[u8] { |
| unsafe { |
| slice::from_raw_parts(self.vec.buf as *const u8, self.vec.buf_len) |
| } |
| } |
| |
| #[inline] |
| pub fn as_mut_slice(&mut self) -> &mut [u8] { |
| unsafe { |
| slice::from_raw_parts_mut(self.vec.buf as *mut u8, self.vec.buf_len) |
| } |
| } |
| } |