Struct BufferRing 

pub struct BufferRing<K, V>
where
    K: Clone + Eq + Hash,
    V: Clone,
{ /* private fields */ }

Fixed-capacity circular cache.

Inserting into a full ring evicts the slot at the current hand position and returns the evicted (key, value) so the caller can flush it (e.g. through the pager’s double-write buffer for BulkWrite strategies).

Implementations

impl<K, V> BufferRing<K, V>

where K: Clone + Eq + Hash, V: Clone,

pub fn new(capacity: usize) -> Self

Create a new ring with the given fixed capacity. capacity is clamped to at least 1.

pub fn capacity(&self) -> usize

Configured ring capacity.

pub fn len(&self) -> usize

Number of occupied slots.

pub fn is_empty(&self) -> bool

Whether the ring has zero occupied slots.

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

Look up a key. Does NOT update any recency / visited state.

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

Insert a (key, value) pair. If the ring is full, the slot at the current hand position is evicted and the hand advances. Returns the evicted (key, value) if any.

If key is already present in the ring, its slot is updated in place and None is returned.

pub fn clear(&self)

Drop every slot. Used by clear_cursors-style cleanup paths.