style: Simplify style sharing code.

This commit is contained in:
Emilio Cobos Álvarez 2017-03-09 15:23:42 +01:00
parent 1eb24f1adc
commit 727be58b4a
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GPG key ID: 056B727BB9C1027C
4 changed files with 17 additions and 80 deletions

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@ -11,14 +11,14 @@ use std::slice::{Iter, IterMut};
/// A LRU cache used to store a set of at most `n` elements at the same time.
///
/// Currently used for the style sharing candidate cache.
pub struct LRUCache<K, V> {
entries: Vec<(K, V)>,
pub struct LRUCache<K> {
entries: Vec<K>,
cache_size: usize,
}
impl<K: PartialEq, V: Clone> LRUCache<K, V> {
impl<K: PartialEq> LRUCache<K> {
/// Create a new LRU cache with `size` elements at most.
pub fn new(size: usize) -> LRUCache<K, V> {
pub fn new(size: usize) -> Self {
LRUCache {
entries: vec![],
cache_size: size,
@ -27,54 +27,30 @@ impl<K: PartialEq, V: Clone> LRUCache<K, V> {
#[inline]
/// Touch a given position, and put it in the last item on the list.
pub fn touch(&mut self, pos: usize) -> &V {
pub fn touch(&mut self, pos: usize) {
let last_index = self.entries.len() - 1;
if pos != last_index {
let entry = self.entries.remove(pos);
self.entries.push(entry);
}
&self.entries[last_index].1
}
/// Iterate over the contents of this cache.
pub fn iter(&self) -> Iter<(K, V)> {
pub fn iter(&self) -> Iter<K> {
self.entries.iter()
}
/// Iterate mutably over the contents of this cache.
pub fn iter_mut(&mut self) -> IterMut<(K, V)> {
pub fn iter_mut(&mut self) -> IterMut<K> {
self.entries.iter_mut()
}
/// Insert a given key and value in the cache.
pub fn insert(&mut self, key: K, val: V) {
/// Insert a given key in the cache.
pub fn insert(&mut self, key: K) {
if self.entries.len() == self.cache_size {
self.entries.remove(0);
}
self.entries.push((key, val));
}
/// Try to find a key in the cache.
pub fn find(&mut self, key: &K) -> Option<V> {
match self.entries.iter().position(|&(ref k, _)| key == k) {
Some(pos) => Some(self.touch(pos).clone()),
None => None,
}
}
/// Try to find a given key, or create a given item with that key executing
/// `blk`.
pub fn find_or_create<F>(&mut self, key: K, mut blk: F) -> V
where F: FnMut() -> V,
{
match self.entries.iter().position(|&(ref k, _)| *k == key) {
Some(pos) => self.touch(pos).clone(),
None => {
let val = blk();
self.insert(key, val.clone());
val
}
}
self.entries.push(key);
}
/// Evict all elements from the cache.