Module sccache::lru_disk_cache::lru_cache

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Expand description

A cache that holds a limited number of key-value pairs. When the capacity of the cache is exceeded, the least-recently-used (where “used” means a look-up or putting the pair into the cache) pair is automatically removed.

§Examples

ⓘ
use lru_cache::LruCache;

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

cache.insert(1, 10);
cache.insert(2, 20);
cache.insert(3, 30);
assert!(cache.get_mut(&1).is_none());
assert_eq!(*cache.get_mut(&2).unwrap(), 20);
assert_eq!(*cache.get_mut(&3).unwrap(), 30);

cache.insert(2, 22);
assert_eq!(*cache.get_mut(&2).unwrap(), 22);

cache.insert(6, 60);
assert!(cache.get_mut(&3).is_none());

cache.set_capacity(1);
assert!(cache.get_mut(&2).is_none());

The cache can also be limited by an arbitrary metric calculated from its key-value pairs, see LruCache::with_meter for more information. If the heapsize feature is enabled, this crate provides one such alternate metric—HeapSize. Custom metrics can be written by implementing the Meter trait.

Structs§

  • Count
    Size limit based on a simple count of cache items.
  • IntoIter
    An iterator over a cache’s key-value pairs in least- to most-recently-used order.
  • Iter
    An iterator over a cache’s key-value pairs in least- to most-recently-used order.
  • IterMut
    An iterator over a cache’s key-value pairs in least- to most-recently-used order with mutable references to the values.
  • LruCache
    An LRU cache.

Traits§