Stores

CacheKit “stores” are the underlying key/value containers used by policies. They provide:

• A capacity limit (by entries, weight, or other accounting)
• Basic operations (get/insert/remove/clear)
• Optional concurrency wrappers
• Metrics counters (hits/misses/inserts/updates/removes/evictions)

Most policies are generic over store traits defined in cachekit::store::traits:

• StoreCore<K, V>: read-only operations + metrics
• StoreMut<K, V>: mutation operations
• ConcurrentStore<K, V>: Send + Sync stores (typically via RwLock)

Store implementations

• HashMap store: simplest entry-count store; has concurrent and sharded variants.
• Slab store: stable EntryId handles via indirection; good for policy metadata.
• Weight store: enforces both entry count and total “weight” (e.g. bytes).
• Handle store: keyed by compact handles (IDs) instead of full keys.

Choosing a store (quick guide)

• Default: use the HashMap store.
• If the policy needs stable entry IDs: use the Slab store.
• If you want size-based capacity: use the Weight store.
• If you already have an interner / stable IDs for keys: use the Handle store.