Trait Backend 

pub trait Backend: Sync + Send {
    // Required methods
    fn read<'life0, 'life1, 'async_trait>(
        &'life0 self,
        key: &'life1 CacheKey,
    ) -> Pin<Box<dyn Future<Output = Result<Option<CacheValue<Bytes>>, BackendError>> + Send + 'async_trait>>
       where 'life0: 'async_trait,
             'life1: 'async_trait,
             Self: 'async_trait;
    fn write<'life0, 'life1, 'async_trait>(
        &'life0 self,
        key: &'life1 CacheKey,
        value: CacheValue<Bytes>,
    ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>
       where 'life0: 'async_trait,
             'life1: 'async_trait,
             Self: 'async_trait;
    fn remove<'life0, 'life1, 'async_trait>(
        &'life0 self,
        key: &'life1 CacheKey,
    ) -> Pin<Box<dyn Future<Output = Result<DeleteStatus, BackendError>> + Send + 'async_trait>>
       where 'life0: 'async_trait,
             'life1: 'async_trait,
             Self: 'async_trait;

    // Provided methods
    fn label(&self) -> BackendLabel { ... }
    fn value_format(&self) -> &dyn Format { ... }
    fn key_format(&self) -> &CacheKeyFormat { ... }
    fn compressor(&self) -> &dyn Compressor { ... }
}

Low-level cache storage trait for raw byte operations.

Implement this trait to create a custom cache backend. The trait operates on raw bytes (CacheValue<Raw>), with serialization handled by CacheBackend.

Dyn-Compatibility

This trait is dyn-compatible. Blanket implementations are provided for:

• &dyn Backend
• Box<dyn Backend>
• Arc<dyn Backend + Send> (UnsyncBackend)
• Arc<dyn Backend + Send + Sync> (SyncBackend)

Required Methods

fn read<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<Option<CacheValue<Bytes>>, BackendError>> + Send + 'async_trait>>

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

Read raw cached data by key.

Returns Ok(Some(value)) on hit, Ok(None) on miss.

fn write<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, value: CacheValue<Bytes>, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

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

Write raw data to cache.

fn remove<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<DeleteStatus, BackendError>> + Send + 'async_trait>>

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

Remove data from cache.

Provided Methods

fn label(&self) -> BackendLabel

Backend label for metrics and source path composition.

Used to build hierarchical paths like "composition.moka" in CompositionBackend.

fn value_format(&self) -> &dyn Format

Serialization format for cached values. Default: BincodeFormat.

fn key_format(&self) -> &CacheKeyFormat

Key serialization format. Default: CacheKeyFormat::Bitcode.

fn compressor(&self) -> &dyn Compressor

Compressor for cached values. Default: PassthroughCompressor.

Trait Implementations

impl Backend for &dyn Backend

fn read<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<Option<CacheValue<Bytes>>, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, &dyn Backend: 'async_trait,

Read raw cached data by key.

fn write<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, value: CacheValue<Bytes>, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, &dyn Backend: 'async_trait,

Write raw data to cache.

fn remove<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<DeleteStatus, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, &dyn Backend: 'async_trait,

Remove data from cache.

fn label(&self) -> BackendLabel

Backend label for metrics and source path composition.

fn value_format(&self) -> &dyn Format

Serialization format for cached values. Default: BincodeFormat.

fn key_format(&self) -> &CacheKeyFormat

Key serialization format. Default: CacheKeyFormat::Bitcode.

fn compressor(&self) -> &dyn Compressor

Compressor for cached values. Default: PassthroughCompressor.

impl Backend for Box<dyn Backend>

fn read<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<Option<CacheValue<Bytes>>, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Box<dyn Backend>: 'async_trait,

Read raw cached data by key.

fn write<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, value: CacheValue<Bytes>, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Box<dyn Backend>: 'async_trait,

Write raw data to cache.

fn remove<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<DeleteStatus, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Box<dyn Backend>: 'async_trait,

Remove data from cache.

fn label(&self) -> BackendLabel

Backend label for metrics and source path composition.

fn value_format(&self) -> &dyn Format

Serialization format for cached values. Default: BincodeFormat.

fn key_format(&self) -> &CacheKeyFormat

Key serialization format. Default: CacheKeyFormat::Bitcode.

fn compressor(&self) -> &dyn Compressor

Compressor for cached values. Default: PassthroughCompressor.

impl CacheBackend for &dyn Backend

fn get<T>( &self, key: &CacheKey, ctx: &mut SmallBox<dyn Context, S4>, ) -> impl Future<Output = Result<Option<CacheValue<<T as CacheableResponse>::Cached>>, BackendError>> + Send

where T: CacheableResponse, <T as CacheableResponse>::Cached: Cacheable,

Retrieve a typed value from cache.

fn set<T>( &self, key: &CacheKey, value: &CacheValue<<T as CacheableResponse>::Cached>, ctx: &mut SmallBox<dyn Context, S4>, ) -> impl Future<Output = Result<(), BackendError>> + Send

where T: CacheableResponse, <T as CacheableResponse>::Cached: Cacheable,

Store a typed value in cache.

fn delete( &self, key: &CacheKey, _ctx: &mut SmallBox<dyn Context, S4>, ) -> impl Future<Output = Result<DeleteStatus, BackendError>> + Send

Delete a value from cache.

impl CacheBackend for Box<dyn Backend>

fn get<T>( &self, key: &CacheKey, ctx: &mut SmallBox<dyn Context, S4>, ) -> impl Future<Output = Result<Option<CacheValue<<T as CacheableResponse>::Cached>>, BackendError>> + Send

where T: CacheableResponse, <T as CacheableResponse>::Cached: Cacheable,

Retrieve a typed value from cache.

fn set<T>( &self, key: &CacheKey, value: &CacheValue<<T as CacheableResponse>::Cached>, ctx: &mut SmallBox<dyn Context, S4>, ) -> impl Future<Output = Result<(), BackendError>> + Send

where T: CacheableResponse, <T as CacheableResponse>::Cached: Cacheable,

Store a typed value in cache.

fn delete( &self, key: &CacheKey, _ctx: &mut SmallBox<dyn Context, S4>, ) -> impl Future<Output = Result<DeleteStatus, BackendError>> + Send

Delete a value from cache.

Dyn Compatibility

This trait is dyn compatible.

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

Implementations on Foreign Types

impl Backend for Arc<dyn Backend + Send>

fn read<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<Option<CacheValue<Bytes>>, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Arc<dyn Backend + Send>: 'async_trait,

fn write<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, value: CacheValue<Bytes>, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Arc<dyn Backend + Send>: 'async_trait,

fn remove<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<DeleteStatus, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Arc<dyn Backend + Send>: 'async_trait,

fn label(&self) -> BackendLabel

fn value_format(&self) -> &dyn Format

fn key_format(&self) -> &CacheKeyFormat

fn compressor(&self) -> &dyn Compressor

impl Backend for Arc<dyn Backend + Sync + Send>

fn read<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<Option<CacheValue<Bytes>>, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Arc<dyn Backend + Sync + Send>: 'async_trait,

fn write<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, value: CacheValue<Bytes>, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Arc<dyn Backend + Sync + Send>: 'async_trait,

fn remove<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<DeleteStatus, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Arc<dyn Backend + Sync + Send>: 'async_trait,

fn label(&self) -> BackendLabel

fn value_format(&self) -> &dyn Format

fn key_format(&self) -> &CacheKeyFormat

fn compressor(&self) -> &dyn Compressor

impl Backend for Box<dyn Backend>

fn read<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<Option<CacheValue<Bytes>>, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Box<dyn Backend>: 'async_trait,

fn write<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, value: CacheValue<Bytes>, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Box<dyn Backend>: 'async_trait,

fn remove<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 CacheKey, ) -> Pin<Box<dyn Future<Output = Result<DeleteStatus, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Box<dyn Backend>: 'async_trait,

fn label(&self) -> BackendLabel

fn value_format(&self) -> &dyn Format

fn key_format(&self) -> &CacheKeyFormat

fn compressor(&self) -> &dyn Compressor

Implementors

impl Backend for &dyn Backend

impl<L1, L2, O, R, W> Backend for CompositionBackend<L1, L2, O, R, W>

where L1: Backend + Clone + Send + Sync + 'static, L2: Backend + Clone + Send + Sync + 'static, O: Offload<'static>, R: CompositionReadPolicy, W: CompositionWritePolicy,