asterinas/kernel/libs/xarray/src/range.rs

48 lines
1.2 KiB
Rust

// SPDX-License-Identifier: MPL-2.0
use ostd::sync::non_null::NonNullPtr;
use crate::{cursor::Cursor, mark::NoneMark};
/// An iterator over a range of entries in an [`XArray`].
///
/// The typical way to obtain a `Range` instance is to call [`XArray::range`].
///
/// [`XArray`]: super::XArray
/// [`XArray::range`]: super::XArray::range
pub struct Range<'a, P, M = NoneMark>
where
P: NonNullPtr + Send + Sync,
{
cursor: Cursor<'a, P, M>,
end: u64,
}
impl<'a, P: NonNullPtr + Send + Sync, M> Range<'a, P, M> {
pub(super) fn new(cursor: Cursor<'a, P, M>, end: u64) -> Self {
Range { cursor, end }
}
}
impl<'a, P: NonNullPtr + Send + Sync, M> core::iter::Iterator for Range<'a, P, M> {
type Item = (u64, P::Ref<'a>);
fn next(&mut self) -> Option<Self::Item> {
loop {
if self.cursor.index() >= self.end {
return None;
}
let item = self.cursor.load();
if item.is_none() {
self.cursor.next();
continue;
}
let res = item.map(|item| (self.cursor.index(), item));
self.cursor.next();
return res;
}
}
}