Struct Recency 

struct Recency {
    next_tick: AtomicI64,
    dirty: Mutex<HashMap<i64, i64>>,
    pool: DbPool,
}

In-memory LRU recency tracker shared across all clones of a SqlStorage.

touch is called on the read path (pure, no DB write). drain is called inside insert_leaf to flush pending recency updates as part of the existing write transaction. Held in an Arc, so its Drop runs exactly once, when the last SqlStorage clone is dropped, flushing any touches that no insert_leaf persisted (graceful shutdown).

Fields

next_tick: AtomicI64

Monotonically increasing tick counter. Persisted maximum is seeded at connect time so ticks always exceed any value already stored in the DB after a restart.

dirty: Mutex<HashMap<i64, i64>>

height -> latest tick; flushed to DB by the next insert_leaf or by Drop.

pool: DbPool

Pool handle kept alive for the on-drop flush.

Implementations

impl Recency

fn touch(&self, height: i64)

fn drain(&self) -> Vec<(i64, i64)>

async fn flush(pool: DbPool, pending: Vec<(i64, i64)>)

Persist drained touches to last_used. Best-effort: a failure only degrades GC ranking, it never corrupts data.

Trait Implementations

impl Debug for Recency

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for Recency

Available on crate feature client only.

fn drop(&mut self)

Flush pending read-path touches to the DB on shutdown, best-effort.

Touches are otherwise only persisted by the next insert_leaf; without this, GC after a restart would rank recently-read leaves by a stale last_used and could evict them. Inside a tokio runtime the flush is spawned, not driven synchronously: blocking the current thread on the pool’s acquire path deadlocks a current-thread runtime, because acquire depends on tokio timers and tasks that cannot run while the thread is blocked. A spawned flush may be cancelled by runtime shutdown, losing the pending touches, which only degrades GC ranking. Outside a runtime the flush is driven to completion here.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.