use std::io::{self, Read};
pub struct Chunks<R> {
read: R,
size: usize,
hint: (usize, Option<usize>),
}
impl<R> Chunks<R> {
pub fn new(read: R, size: usize) -> Self {
Self {
read,
size,
hint: (0, None),
}
}
}
impl<R> Iterator for Chunks<R>
where
R: Read,
{
type Item = io::Result<Vec<u8>>;
fn next(&mut self) -> Option<Self::Item> {
let mut chunk = Vec::with_capacity(self.size);
match self
.read
.by_ref()
.take(chunk.capacity() as u64)
.read_to_end(&mut chunk)
{
Ok(n) => {
if n != 0 {
Some(Ok(chunk))
} else {
None
}
}
Err(e) => Some(Err(e)),
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.hint
}
}
pub(crate) trait ReadPlus: Read {
fn chunks(self, size: usize) -> Chunks<Self>
where
Self: Sized,
{
Chunks::new(self, size)
}
}
impl<T: ?Sized> ReadPlus for T where T: Read {}