Struct TieredBackend 

pub struct TieredBackend { /* private fields */ }

Three-tier read-through / write-through cache resolver.

Holds Arc<dyn StorageBackend> per tier, so any backend composes — the real deployment injects RedisBackend (L1), PgStorageBackend (L2), S3Storage (L3); tests inject in-memory mocks + a LocalStorage.

Implementations

impl TieredBackend

pub fn new( l1: Arc<dyn StorageBackend>, l2: Arc<dyn StorageBackend>, l3: Arc<dyn StorageBackend>, ) -> Self

Compose three tiers with the default WritePolicy::WriteThrough.

pub fn with_write_policy( l1: Arc<dyn StorageBackend>, l2: Arc<dyn StorageBackend>, l3: Arc<dyn StorageBackend>, write_policy: WritePolicy, ) -> Self

Compose three tiers with an explicit WritePolicy.

pub fn write_policy(&self) -> WritePolicy

The active write policy.

Trait Implementations

impl StorageBackend for TieredBackend

fn wipe_all<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<usize, CacheError>> + Send + 'async_trait>>

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

Fan the wipe out to EVERY tier (L1 hot + L2/L3 durable), so a cache-wipe clears all three at once. Best-effort per tier (mirrors delete): one tier’s failure is logged, never aborting the others — the whole point is to return the store to cold. Reports the largest per-tier narinfo count removed (the authoritative tiers’ full set).

fn get_narinfo<'life0, 'life1, 'async_trait>( &'life0 self, hash: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<Option<String>, CacheError>> + Send + 'async_trait>>

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

Retrieve narinfo text by store path hash.

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

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

Retrieve a NAR blob by its relative path.

fn put_narinfo<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, hash: &'life1 str, content: &'life2 str, ) -> Pin<Box<dyn Future<Output = Result<(), CacheError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Store narinfo text keyed by store path hash.

fn put_nar<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, path: &'life1 str, data: &'life2 [u8], ) -> Pin<Box<dyn Future<Output = Result<(), CacheError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Store a NAR blob at the given relative path.

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

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

Delete a store path’s narinfo and associated NAR blob.

fn list_narinfos<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<Vec<String>, CacheError>> + Send + 'async_trait>>

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

List all stored narinfo hashes.