Struct SharedLRUCache 

pub struct SharedLRUCache<K: Copy + Eq + Default + 'static, V: Copy + Default + 'static> { /* private fields */ }

Implementations

impl<K: Copy + Eq + Default + 'static, V: Copy + Default + 'static> SharedLRUCache<K, V>

pub fn create( base_path: impl AsRef<Path>, capacity: u32, ) -> Result<Self, LRUError>

Create a new LRU cache with capacity entries.

SIZING: the underlying SharedHashMap is sized to 8x capacity to absorb tombstone accumulation (open-addressing leaves a tombstone on every remove; LRU caches do many removes via eviction). The linked list region is sized to capacity + 2 (one sentinel head + capacity nodes + 1 spare for the pop-then-push transition during update).

pub fn open( base_path: impl AsRef<Path>, capacity: u32, ) -> Result<Self, LRUError>

pub fn capacity(&self) -> u32

pub fn len(&self) -> usize

Current number of entries.

pub fn is_empty(&self) -> bool

pub fn get(&self, key: &K) -> Option<V>

Lock-free lookup. Does NOT promote k to MRU position. Use get_and_touch or touch for strict LRU semantics.

pub fn contains_key(&self, key: &K) -> bool

True if key is present (lock-free).

pub fn touch(&self, key: &K) -> bool

Promote key to MRU position. Writer-side. Returns true if the key was present and was promoted.

pub fn get_and_touch(&self, key: &K) -> Option<V>

Look up and promote in one call. Writer-side.

pub fn put(&self, key: K, value: V) -> Result<Option<V>, LRUError>

Insert / update. Writer-side. If the cache is at capacity AND key is new, evicts the LRU entry first. Returns the previous value if key was present.

pub fn remove(&self, key: &K) -> Option<V>

Remove a key. Writer-side. Returns the value if present.

pub fn evict_oldest(&self) -> Option<(K, V)>

Evict the LRU (least-recently-used) entry. Writer-side. Returns (key, value) of the evicted entry, or None if empty.

pub fn snapshot_mru_first(&self) -> Vec<(K, V)>

Snapshot all entries from MRU (front) to LRU (back). Lock-free; not stable under concurrent writers.

pub fn snapshot_lru_first(&self) -> Vec<(K, V)>

Snapshot all entries from LRU (back) to MRU (front).

pub fn flush(&self) -> Result<(), LRUError>

pub fn flush_async(&self) -> Result<(), LRUError>

Trait Implementations

impl<K: Copy + Eq + Default + Send + Sync + 'static, V: Copy + Default + Send + Sync + 'static> AdaptiveInstance for SharedLRUCache<K, V>

fn header(&self) -> &HandshakeHeader

fn ring(&self) -> &ObservationRing

fn make_policy(&self) -> Box<dyn Policy>

fn apply_migration(&self, new_tag: u32)

Called by the sidecar when the policy returns a new strategy tag. Default implementation: just set the tag on the header. Primitives that need heavier migration (data-layout swap) override this to perform the swap before (or after) updating the tag.