Struct PageCache 

pub struct PageCache { /* private fields */ }

Bounded, MVCC-safe page cache with frequency-aware CLOCK eviction and an optional persistent backing directory.

Implementations

impl PageCache

pub fn new(capacity_bytes: u64) -> Self

pub fn stats(&self) -> CacheStats

Cumulative hit/miss counts since construction (or the last reset_stats). Cheap (Relaxed atomic loads).

pub fn reset_stats(&self)

Zero the hit/miss counters (e.g. to measure a single query’s locality).

pub fn with_persistence(self, dir: PathBuf) -> Self

Enable persistence: load any cached pages from <dir> and spill future evictions/inserts there. Files are raw page bytes (ciphertext when the table is encrypted).

pub fn insert(&mut self, page: CachedPage)

Insert a page (replaces any entry with the same key). Spills to the persistent backing directory when enabled.

pub fn get( &mut self, content_hash: &[u8; 32], snapshot: Snapshot, ) -> Option<Bytes>

Fetch the page visible to snapshot (the entry’s committed epoch must be <= snapshot.epoch), promoting its frequency. O(1).

pub fn try_get( &self, content_hash: &[u8; 32], snapshot: Snapshot, ) -> Option<Bytes>

Non-blocking probe used by the parallel (rayon) read path: returns a hit without contending on a write lock when one is held. Some on hit; None on miss (or if the value is not visible to snapshot). The caller treats any None as “fall through to disk”.

pub fn used_bytes(&self) -> u64

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn flush_to_disk(&self)

Flush all live entries to the persistent backing dir (best-effort).