Struct lru_cache::LruCache [] [src]

pub struct LruCache<K: Eq + Hash, V, S: BuildHasher = RandomState> { /* fields omitted */ }

An LRU cache.

Methods

impl<K: Eq + Hash, V> LruCache<K, V>
[src]

Creates an empty cache that can hold at most capacity items.

Examples

use lru_cache::LruCache;
let mut cache: LruCache<i32, &str> = LruCache::new(10);Run

impl<K: Eq + Hash, V, S: BuildHasher> LruCache<K, V, S>
[src]

Creates an empty cache that can hold at most capacity items with the given hash builder.

Checks if the map contains the given key.

Examples

use lru_cache::LruCache;

let mut cache = LruCache::new(1);

cache.insert(1, "a");
assert_eq!(cache.contains_key(&1), true);Run

Inserts a key-value pair into the cache. If the key already existed, the old value is returned.

Examples

use lru_cache::LruCache;

let mut cache = LruCache::new(2);

cache.insert(1, "a");
cache.insert(2, "b");
assert_eq!(cache.get_mut(&1), Some(&mut "a"));
assert_eq!(cache.get_mut(&2), Some(&mut "b"));Run

Returns a mutable reference to the value corresponding to the given key in the cache, if any.

Examples

use lru_cache::LruCache;

let mut cache = LruCache::new(2);

cache.insert(1, "a");
cache.insert(2, "b");
cache.insert(2, "c");
cache.insert(3, "d");

assert_eq!(cache.get_mut(&1), None);
assert_eq!(cache.get_mut(&2), Some(&mut "c"));Run

Removes the given key from the cache and returns its corresponding value.

Examples

use lru_cache::LruCache;

let mut cache = LruCache::new(2);

cache.insert(2, "a");

assert_eq!(cache.remove(&1), None);
assert_eq!(cache.remove(&2), Some("a"));
assert_eq!(cache.remove(&2), None);
assert_eq!(cache.len(), 0);Run

Returns the maximum number of key-value pairs the cache can hold.

Examples

use lru_cache::LruCache;
let mut cache: LruCache<i32, &str> = LruCache::new(2);
assert_eq!(cache.capacity(), 2);Run

Sets the number of key-value pairs the cache can hold. Removes least-recently-used key-value pairs if necessary.

Examples

use lru_cache::LruCache;

let mut cache = LruCache::new(2);

cache.insert(1, "a");
cache.insert(2, "b");
cache.insert(3, "c");

assert_eq!(cache.get_mut(&1), None);
assert_eq!(cache.get_mut(&2), Some(&mut "b"));
assert_eq!(cache.get_mut(&3), Some(&mut "c"));

cache.set_capacity(3);
cache.insert(1, "a");
cache.insert(2, "b");

assert_eq!(cache.get_mut(&1), Some(&mut "a"));
assert_eq!(cache.get_mut(&2), Some(&mut "b"));
assert_eq!(cache.get_mut(&3), Some(&mut "c"));

cache.set_capacity(1);

assert_eq!(cache.get_mut(&1), None);
assert_eq!(cache.get_mut(&2), None);
assert_eq!(cache.get_mut(&3), Some(&mut "c"));Run

Removes and returns the least recently used key-value pair as a tuple.

Examples

use lru_cache::LruCache;

let mut cache = LruCache::new(2);

cache.insert(1, "a");
cache.insert(2, "b");

assert_eq!(cache.remove_lru(), Some((1, "a")));
assert_eq!(cache.len(), 1);Run

Returns the number of key-value pairs in the cache.

Returns true if the cache contains no key-value pairs.

Removes all key-value pairs from the cache.

Returns an iterator over the cache's key-value pairs in least- to most-recently-used order.

Accessing the cache through the iterator does not affect the cache's LRU state.

Examples

use lru_cache::LruCache;

let mut cache = LruCache::new(2);

cache.insert(1, 10);
cache.insert(2, 20);
cache.insert(3, 30);

let kvs: Vec<_> = cache.iter().collect();
assert_eq!(kvs, [(&2, &20), (&3, &30)]);Run

Returns an iterator over the cache's key-value pairs in least- to most-recently-used order, with mutable references to the values.

Accessing the cache through the iterator does not affect the cache's LRU state.

Examples

use lru_cache::LruCache;

let mut cache = LruCache::new(2);

cache.insert(1, 10);
cache.insert(2, 20);
cache.insert(3, 30);

let mut n = 2;

for (k, v) in cache.iter_mut() {
    assert_eq!(*k, n);
    assert_eq!(*v, n * 10);
    *v *= 10;
    n += 1;
}

assert_eq!(n, 4);
assert_eq!(cache.get_mut(&2), Some(&mut 200));
assert_eq!(cache.get_mut(&3), Some(&mut 300));Run

Trait Implementations

impl<K: Clone + Eq + Hash, V: Clone, S: Clone + BuildHasher> Clone for LruCache<K, V, S>
[src]

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

impl<K: Eq + Hash, V, S: BuildHasher> Extend<(K, V)> for LruCache<K, V, S>
[src]

Extends a collection with the contents of an iterator. Read more

impl<K: Debug + Eq + Hash, V: Debug, S: BuildHasher> Debug for LruCache<K, V, S>
[src]

Formats the value using the given formatter.

impl<K: Eq + Hash, V, S: BuildHasher> IntoIterator for LruCache<K, V, S>
[src]

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Creates an iterator from a value. Read more

impl<'a, K: Eq + Hash, V, S: BuildHasher> IntoIterator for &'a LruCache<K, V, S>
[src]

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Creates an iterator from a value. Read more

impl<'a, K: Eq + Hash, V, S: BuildHasher> IntoIterator for &'a mut LruCache<K, V, S>
[src]

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Creates an iterator from a value. Read more