Struct SemanticSimilarityCache 

pub struct SemanticSimilarityCache { /* private fields */ }

Pairwise cosine-similarity cache with LFU eviction and TTL staleness.

All public mutating methods are &mut self; no internal locking is performed — the caller is responsible for synchronisation when used from multiple threads.

Implementations

impl SemanticSimilarityCache

pub fn new(config: PairCacheConfig) -> Self

Create a new cache with the given PairCacheConfig.

pub fn get(&mut self, a: u64, b: u64) -> Option<f32>

Look up the cached similarity for the pair (a, b).

Returns None when:

• the pair is not in the cache, or
• the cached entry is stale (older than ttl_ticks).

On a hit the entry’s access_count is incremented.

pub fn insert(&mut self, a: u64, b: u64, similarity: f32)

Insert (or update) the similarity score for the pair (a, b).

When the cache is at capacity the entry with the lowest access_count is evicted first (LFU).

pub fn compute_and_cache( &mut self, a: u64, vec_a: &[f32], b: u64, vec_b: &[f32], ) -> f32

Compute the cosine similarity between vec_a and vec_b, cache the result under (a, b), and return the score.

If a == b the result is 1.0 without evaluating the vectors.

pub fn evict_stale(&mut self) -> usize

Remove all stale entries from the cache and return the number removed.

pub fn advance_tick(&mut self)

Advance the internal logical clock by one tick.

pub fn stats(&self) -> &PairCacheStats

Return a reference to the current aggregate statistics.

pub fn current_tick(&self) -> u64

Return the current tick value.

pub fn len(&self) -> usize

Return the number of entries currently stored in the cache.

pub fn is_empty(&self) -> bool

Return true when the cache contains no entries.