Struct BucketTable 

pub struct BucketTable<V> { /* private fields */ }

Lock-free fixed-capacity concurrent map: byte-key -> Arc<V>.

Implementations

impl<V> BucketTable<V>

pub fn with_max_keys(max_keys: usize) -> Self

Build a table sized for at most max_keys live entries. CAP is the next power of two at or above ceil(max_keys * 4 / 3), then bumped to guarantee CAP > max_keys so a probe that misses always hits an Empty slot.

This is the only constructor: a single-parameter type does not earn a separate new + builder surface (the principle-4 fluent-surface exception for one mandatory parameter), so with_max_keys is both the terse and the fluent form.

pub fn len(&self) -> usize

Advisory live-entry count (Relaxed).

pub fn is_empty(&self) -> bool

pub fn get_or_insert(&self, key: &[u8], make: impl FnOnce() -> V) -> Arc<V>

Return the shared handle for key, inserting one made by make if absent. Concurrent callers racing the same key converge on one published handle via a single install CAS (the loser re-probes onto the winner’s entry). make runs at most once per call — lazily, only on a confirmed miss, and the built Full is reused across CAS retries — and never on a read hit. If make panics nothing has been installed, so the table is left unchanged (no stranded slot).

pub fn get(&self, key: &[u8], hash: u64) -> Option<Arc<V>>

Read-only lookup: the shared handle for key, or None if absent. Stops at the first Empty (proof of absence), probing past Tomb and non-matching Full. This is the hot path — a lock-free load per slot and an Arc clone on a hit, no allocation.

pub fn evict_one_lru(&self, metric: impl Fn(&V) -> u64)

Evict the Full slot whose metric is the strict minimum. Ties resolve to the LOWEST slot index (deterministic — a divergence from dashmap’s nondeterministic iteration-order tie-break, documented intentionally). Best-effort: if the victim changed underneath the CAS it is skipped (matches dashmap’s non-atomic evict).

pub fn clear(&self)

Tombstone every currently published entry.

This is a best-effort concurrent clear: entries racing with a clear may survive if they are installed after their slot is scanned. Reads remain lock-free, and each successful removal uses the same CAS as eviction so a racing insert is never deleted accidentally.

pub fn sweep_idle(&self, now: u64, ttl: u64, metric: impl Fn(&V) -> u64)

Tombstone every Full slot whose metric is strictly less than now - ttl. A value exactly equal to the cutoff survives.