Struct BlockCache 

pub struct BlockCache<R> { /* private fields */ }

Block-based caching layer that wraps any RangeReader.

This cache is critical for performance:

• TIFF parsing requires many small reads at scattered offsets
• Without caching, each read would be an S3 request
• Block cache amortizes these into fewer, larger requests

Features:

• Fixed-size block cache (default 256KB blocks)
• LRU eviction when cache reaches capacity
• Singleflight: concurrent requests for the same block share one fetch
• Handles reads spanning multiple blocks

Implementations

impl<R: RangeReader> BlockCache<R>

pub fn new(inner: R) -> Self

Create a new BlockCache wrapping the given reader.

Uses default block size (256KB) and cache capacity (100 blocks).

pub fn with_capacity(inner: R, block_size: usize, capacity: usize) -> Self

Create a new BlockCache with custom block size and capacity.

Arguments

• inner - The underlying reader to wrap
• block_size - Size of each cached block in bytes
• capacity - Maximum number of blocks to cache

Trait Implementations

impl<R: RangeReader + 'static> RangeReader for BlockCache<R>

fn read_exact_at<'life0, 'async_trait>( &'life0 self, offset: u64, len: usize, ) -> Pin<Box<dyn Future<Output = Result<Bytes, IoError>> + Send + 'async_trait>>

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

Read exactly len bytes starting at offset.

fn size(&self) -> u64

Get the total size of the resource in bytes.

fn identifier(&self) -> &str

Get a unique identifier for this resource (for logging and cache keys).