Struct MokaCache 

pub struct MokaCache { /* private fields */ }

Byte-weighed TTL cache over moka (DW-037 response-cache backend).

Bounds, honestly stated:

• Bytes, not entries: max_capacity is interpreted through a weigher counting key + value bytes plus a fixed per-entry overhead (ENTRY_OVERHEAD_BYTES), so the store is bounded by MEMORY, the property a gateway cache actually needs (entry-count bounds let N one-byte-below-the-cap entries allocate N times the cap).
• Time-to-idle (MokaCache::TIME_TO_IDLE): entries nobody looks at for an hour are evicted even when still nominally fresh — a cold entry costs memory and a future miss, nothing else.
• Per-entry TTL via CacheStore::set_with_ttl: the hint rides the stored pair and drives moka’s Expiry policy (plus 60 s of slack over the hint, so the envelope’s read-side expiry always fires first and the backend only reclaims what the policy already abandoned).

All eviction (size, idle, TTL) is approximate and concurrent — moka maintains shards internally; no global lock sits on the hot path.

Implementations

impl MokaCache

pub const TIME_TO_IDLE: Duration

Idle-eviction window (see the type docs).

pub const TTL_SLACK: Duration

Slack added to every TTL hint (see the type docs).

pub fn with_max_bytes(max_bytes: u64) -> Self

Cache bounded to max_bytes of key+value+overhead bytes.

Trait Implementations

impl CacheStore for MokaCache

fn get<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<Option<Vec<u8>>, ExtensionsError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Fetch the value for key, if present.

fn set<'life0, 'async_trait>( &'life0 self, key: String, value: Vec<u8>, ) -> Pin<Box<dyn Future<Output = Result<(), ExtensionsError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Store value under key, overwriting any previous value.

fn delete<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<bool, ExtensionsError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Remove key; returns whether a value existed.

fn set_with_ttl<'life0, 'async_trait>( &'life0 self, key: String, value: Vec<u8>, ttl: Duration, ) -> Pin<Box<dyn Future<Output = Result<(), ExtensionsError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Store value under key with a per-entry lifetime hint (DW-037). Backends that cannot honor a per-entry TTL implement the default (store without the hint); every reader re-checks expiry from the value itself, so correctness never depends on this. Defaulted, not abstract: existing implementations stay valid backends without a change (extend, do not break).

fn entry_count(&self) -> Option<u64>

Approximate number of live entries, when the backend can report it cheaply (DW-037 metrics gauge; None = not reportable). An estimate is acceptable — the consumer renders it as a gauge.

impl Debug for MokaCache

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

Formats the value using the given formatter.

impl Default for MokaCache

fn default() -> Self

Returns the “default value” for a type.