#[derive(Clone, Copy, Debug)]
#[repr(transparent)]
pub struct IoVec {
raw: libc::iovec,
}
impl IoVec {
#[must_use]
pub const fn empty() -> Self {
Self {
raw: libc::iovec {
iov_base: std::ptr::null_mut(),
iov_len: 0,
},
}
}
#[must_use]
pub fn from_slice(buf: &[u8], off: usize) -> Self {
let start = off.min(buf.len());
let tail = &buf[start..];
Self {
raw: libc::iovec {
iov_base: tail.as_ptr() as *mut libc::c_void,
iov_len: tail.len(),
},
}
}
#[inline(always)]
#[must_use]
pub fn raw(ptr: *const u8, len: usize) -> libc::iovec {
libc::iovec {
iov_base: ptr as *mut libc::c_void,
iov_len: len,
}
}
#[must_use]
pub fn from_mut_slice(buf: &mut [u8]) -> Self {
Self {
raw: libc::iovec {
iov_base: buf.as_mut_ptr() as *mut libc::c_void,
iov_len: buf.len(),
},
}
}
pub fn set_len(&mut self, len: usize) {
self.raw.iov_len = len;
}
pub fn len(&self) -> usize {
self.raw.iov_len
}
pub fn is_empty(&self) -> bool {
self.raw.iov_len == 0
}
pub fn as_ptr(&self) -> *const u8 {
self.raw.iov_base.cast()
}
#[inline(always)]
pub fn as_libc(&self) -> libc::iovec {
self.raw
}
pub fn advance(&mut self, n: usize) {
let step = n.min(self.raw.iov_len);
self.raw.iov_base = unsafe { (self.raw.iov_base as *mut u8).add(step) }.cast();
self.raw.iov_len -= step;
}
}