Struct HybridArticleCache 

pub struct HybridArticleCache { /* private fields */ }

Hybrid article cache with memory and disk tiers

Uses foyer’s HybridCache for automatic memory→disk spillover. Hot articles stay in memory, cold articles spill to disk.

Supports tier-aware TTL: entries from higher tier backends get longer TTLs. Formula: effective_ttl = base_ttl * (2 ^ tier)

Note: Keys are stored as String (message ID without brackets) because foyer requires keys to implement the Code trait for disk serialization.

Implementations

impl HybridArticleCache

pub async fn new(config: HybridCacheConfig) -> Result<Self>

Create a new hybrid cache with the given configuration

This will create the disk cache directory if it doesn’t exist.

pub async fn upsert_ingest( &self, message_id: MessageId<'_>, buffer: impl Into<CacheIngestResponse>, backend: BackendId, tier: CacheTier, )

Insert or update an article in the cache

With WriteOnInsertion policy, articles are written to disk immediately in a background task (non-blocking).

UPSERT SEMANTICS: Never overwrites a larger semantic payload with a smaller one. A cached full article (220/222 response) must not be replaced by STAT availability.

The tier is stored with the entry for tier-aware TTL calculation.

pub async fn record_missing( &self, message_id: MessageId<'_>, backend_id: BackendId, )

Record that a backend doesn’t have an article (430 response)

pub async fn record_has_status( &self, message_id: MessageId<'_>, status_code: StatusCode, backend: BackendId, tier: CacheTier, )

Record successful backend availability without storing response payload bytes.

pub fn stats(&self) -> HybridCacheStats

Get cache statistics

pub async fn close(&self) -> Result<()>

Close the cache gracefully

Flushes pending writes to disk before returning. This waits for all enqueued disk writes to complete.

Trait Implementations

impl CacheStatsProvider for HybridArticleCache

fn display_stats(&self) -> CacheDisplayStats

Get statistics for TUI display

impl Debug for HybridArticleCache

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

Formats the value using the given formatter.