Struct CachedReader 

pub struct CachedReader<K: Ord, R: ?Sized> { /* private fields */ }

An async read-through adapter over a RangeReader.

Implementations

impl<K: Ord, R: ?Sized> CachedReader<K, R>

pub fn new(source: Arc<R>, cache: RangeCache<K>, config: ReaderConfig) -> Self

Wraps source with the provided cache and concurrency policy.

pub const fn cache(&self) -> &RangeCache<K>

Returns the shared cache.

pub const fn source(&self) -> &Arc<R>

Returns the wrapped source.

pub const fn config(&self) -> ReaderConfig

Returns the reader configuration.

impl<K, R> CachedReader<K, R>

where K: Ord + Clone, R: RangeReader<K> + ?Sized,

pub async fn read( &self, key: &K, range: Range<usize>, ) -> Result<Bytes, ReadError<R::Error>>

Reads a range, fetching and caching only its missing gaps.

Identical in-flight key-and-gap requests share one source fetch. Other overlapping requests remain independent. Responses rejected by the cache capacity policy are still returned to the caller.

Errors

Returns a validation error, source error, or ReadError::ShortRead. Source failures and invalid response lengths are never cached.

Panics

Panics only if the privately owned fetch semaphore is unexpectedly closed or an internal read-plan coverage invariant is violated.

Trait Implementations

impl<K: Ord, R: ?Sized> Clone for CachedReader<K, R>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<K, R> RangeReader<K> for CachedReader<K, R>

where K: Ord + Clone + Send + Sync, R: RangeReader<K> + ?Sized,

type Error = ReadError<<R as RangeReader<K>>::Error>

Source-specific error.

fn read_range<'life0, 'life1, 'async_trait>( &'life0 self, key: &'life1 K, range: Range<usize>, ) -> Pin<Box<dyn Future<Output = Result<Bytes, Self::Error>> + Send + 'async_trait>>

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

Reads the requested byte range for key.