Struct MultiTierBackend 

pub struct MultiTierBackend<L1, L2> { /* private fields */ }

Multi-tier cache backend combining fast L1 and persistent L2.

The multi-tier backend automatically promotes frequently accessed entries from L2 to L1 based on the configured promotion strategy.

Implementations

impl<L1, L2> MultiTierBackend<L1, L2>

where L1: CacheBackend, L2: CacheBackend,

pub fn new(l1: L1, l2: L2) -> Self

Creates a new multi-tier backend with default configuration.

pub fn builder() -> MultiTierBuilder<L1, L2>

Creates a builder for configuring the multi-tier backend.

pub fn l1(&self) -> &L1

Returns a reference to the L1 backend.

pub fn l2(&self) -> &L2

Returns a reference to the L2 backend.

pub fn stats(&self) -> &TierStats

Returns a reference to the current tier statistics.

Trait Implementations

impl<L1, L2> CacheBackend for MultiTierBackend<L1, L2>

where L1: CacheBackend, L2: CacheBackend,

async fn get_keys_by_tag(&self, tag: &str) -> Result<Vec<String>, CacheError>

Merges both tiers.

A tier that reports CacheError::Unsupported — the shared backends keep no tag index — contributes nothing rather than failing the whole call, so the common InMemoryBackend over RedisBackend arrangement keeps working off the L1 index. Only if neither tier has an index is the Unsupported error propagated.

async fn invalidate_by_tag(&self, tag: &str) -> Result<usize, CacheError>

Invalidates in both tiers, tolerating a tier without a tag index in the same way as get_keys_by_tag.

async fn list_tags(&self) -> Result<Vec<String>, CacheError>

Merges both tiers, tolerating a tier without a tag index in the same way as get_keys_by_tag.

async fn get(&self, key: &str) -> Result<Option<CacheRead>, CacheError>

Fetches a cached entry by key.

async fn set( &self, key: String, entry: CacheEntry, ttl: Duration, stale_for: Duration, ) -> Result<(), CacheError>

Stores an entry with a time-to-live and additional stale window.

async fn invalidate(&self, key: &str) -> Result<(), CacheError>

Invalidates the cache entry for key, if present.

fn invalidate_by_tags( &self, tags: &[String], ) -> impl Future<Output = Result<usize, CacheError>> + Send

Invalidates all cache entries associated with multiple tags.

impl<L1: Clone, L2: Clone> Clone for MultiTierBackend<L1, L2>

fn clone(&self) -> MultiTierBackend<L1, L2>

Returns a duplicate of the value.

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

Performs copy-assignment from source.