Trait Cache 

pub trait Cache: Send + Sync {
    // Required methods
    fn get<'life0, 'life1, 'async_trait>(
        &'life0 self,
        key: &'life1 str,
    ) -> Pin<Box<dyn Future<Output = Option<i64>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;
    fn set<'life0, 'life1, 'async_trait>(
        &'life0 self,
        key: &'life1 str,
        sv: i64,
        ttl: Duration,
    ) -> Pin<Box<dyn Future<Output = ()> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait,
             'life1: 'async_trait;
}

Best-effort cache of sv:{sub} values.

Promoted to the SDK in Phase 11.Z from chat-auth’s private SessionVersionCache trait (§3 Row 6 “replace, don’t layer”). The shape is identical: get returns None on miss OR transient cache error; the super::CompositeEpochRevocation composer falls through to its super::Fetcher in either case, so Cache impls don’t expose error variants. set is best-effort and swallows failures internally — a failed write only means the next call will fetch again.

key is the full sv:{sub} form (built via super::sv_cache_key) so the SDK port matches the canonical PAS↔consumer shared-cache contract documented in STANDARDS_SHARED_CACHE.md §3.1.

Implementations

• super::InProcessTtlCache — opinionated per-pod TTL map; default wiring for RCW/CTW (Slice 4/5).
• chat-auth-internal — KVRocks-backed reader (kept consumer-side because it depends on ppoppo-kvrocks, which is not in the SDK feature graph).
• 11.AB+ — SDK ships a KVRocks-backed Cache once KVROCKS_URL ACL extends to RCW/CTW.

Required Methods

fn get<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 str, ) -> Pin<Box<dyn Future<Output = Option<i64>> + Send + 'async_trait>>

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

Look up the cached sv for key ("sv:{sub}").

Returns None on miss OR transient cache error — the composer treats both identically (fall through to the authoritative fetcher), so callers don’t need separate error handling for cache unavailability.

fn set<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 str, sv: i64, ttl: Duration, ) -> Pin<Box<dyn Future<Output = ()> + Send + 'async_trait>>

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

Best-effort write-back after a successful fetch. Implementations SHOULD honor the ttl (Redis SETEX, KVRocks TTL, in-process expiration). Failures are swallowed — the next call will fetch again.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Cache for InProcessTtlCache

impl Cache for SharedCacheCache