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#[cfg(feature = "serialize")]
use serde::{Deserialize, Serialize};
use std::collections::VecDeque;
#[cfg_attr(feature = "serialize", derive(Deserialize, PartialEq, Serialize))]
#[derive(Clone, Debug)]
pub struct EvictedQueue<T> {
queue: VecDeque<T>,
capacity: u32,
dropped_count: u32,
}
impl<T> EvictedQueue<T> {
pub(crate) fn new(capacity: u32) -> Self {
EvictedQueue {
queue: Default::default(),
capacity,
dropped_count: 0,
}
}
pub(crate) fn push_front(&mut self, value: T) {
if self.queue.len() as u32 == self.capacity {
self.queue.pop_back();
self.dropped_count += 1;
}
self.queue.push_front(value);
}
pub fn append_vec(&mut self, other: &mut Vec<T>) {
self.extend(other.drain(..));
}
pub fn is_empty(&self) -> bool {
self.queue.is_empty()
}
pub fn iter(&self) -> std::collections::vec_deque::Iter<T> {
self.queue.iter()
}
}
impl<T> IntoIterator for EvictedQueue<T> {
type Item = T;
type IntoIter = std::collections::vec_deque::IntoIter<T>;
fn into_iter(self) -> Self::IntoIter {
self.queue.into_iter()
}
}
impl<'a, T> IntoIterator for &'a EvictedQueue<T> {
type Item = &'a T;
type IntoIter = std::collections::vec_deque::Iter<'a, T>;
fn into_iter(self) -> Self::IntoIter {
self.queue.iter()
}
}
impl<'a, T> IntoIterator for &'a mut EvictedQueue<T> {
type Item = &'a mut T;
type IntoIter = std::collections::vec_deque::IterMut<'a, T>;
fn into_iter(self) -> Self::IntoIter {
self.queue.iter_mut()
}
}
impl<T> Extend<T> for EvictedQueue<T> {
fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
iter.into_iter().for_each(move |elt| self.push_front(elt));
}
}