Struct NegativeCache 

pub struct NegativeCache { /* private fields */ }

A TTL-keyed negative result cache.

Implementations

impl NegativeCache

pub fn new(ttl_ms: u64) -> Self

Create a new NegativeCache with the given TTL in milliseconds.

pub fn insert_miss(&mut self, key: &str, now_ms: u64)

Record key as a known miss at timestamp now_ms.

If an entry for key already exists it is overwritten with the new timestamp (refreshing the TTL).

pub fn is_known_miss(&self, key: &str, now_ms: u64) -> bool

Returns true when key is a known miss that has not yet expired.

A miss entry at recorded_ms expires when now_ms >= recorded_ms + ttl_ms.

pub fn remove(&mut self, key: &str)

Remove the entry for key (e.g. after it has been successfully populated in the origin cache).

pub fn evict_expired(&mut self, now_ms: u64)

Prune all entries that have expired by now_ms.

pub fn len(&self) -> usize

Number of currently tracked negative entries (including expired ones that have not been pruned yet).

pub fn is_empty(&self) -> bool

Returns true when no entries are tracked.

pub fn ttl_ms(&self) -> u64

The configured TTL in milliseconds.

pub fn clear(&mut self)

Clear all entries.

Trait Implementations

impl Clone for NegativeCache

fn clone(&self) -> NegativeCache

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for NegativeCache

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

Formats the value using the given formatter.