rlibdht/utils/
linked_hashmap.rs

1use std::collections::{HashMap, VecDeque};
2use std::hash::Hash;
3
4#[derive(Debug, Clone, PartialEq)]
5pub struct LinkedHashMap<K: Eq + Hash, V> {
6    map: HashMap<K, V>,
7    order: VecDeque<K>,
8    capacity: usize
9}
10
11impl<K, V> LinkedHashMap<K, V> where K: Eq + Hash + Clone, V: Clone {
12
13    pub fn new() -> Self {
14        Self {
15            map: HashMap::new(),
16            order: VecDeque::new(),
17            capacity: 0
18        }
19    }
20
21    pub fn with_capacity(capacity: usize) -> Self {
22        Self {
23            map: HashMap::with_capacity(capacity),
24            order: VecDeque::with_capacity(capacity),
25            capacity
26        }
27    }
28
29    pub fn insert(&mut self, key: K, value: V) {
30        if self.map.len() >= self.capacity {
31            if let Some(eldest) = self.order.pop_front() {
32                self.map.remove(&eldest);
33            }
34        }
35        self.order.push_back(key.clone());
36        self.map.insert(key, value);
37    }
38
39    pub fn get(&self, key: &K) -> Option<&V> {
40        self.map.get(key)
41    }
42
43    pub fn values(&self) -> Vec<V> {
44        self.order
45            .iter()
46            .filter_map(|key| self.map.get(key).cloned())
47            .collect()
48    }
49
50    pub fn len(&self) -> usize {
51        self.map.len()
52    }
53
54    pub fn is_empty(&self) -> bool {
55        self.map.is_empty()
56    }
57}
rlibdht/utils/linked_hashmap.rs

rlibdht/utils/
linked_hashmap.rs
