Struct Resident 

pub struct Resident<R, K> { /* private fields */ }

Entries in the order they were placed, each owned by one run and named by its address on disk.

A hit does not reorder: the model trims first in, first out, and only placing an address again moves it to the newest end.

Implementations

impl<R: Ord + Clone, K: Ord + Clone> Resident<R, K>

pub fn new(budget_bytes: usize) -> Self

An empty cache that never holds more than budget_bytes.

pub fn insert<E>( &mut self, owner: &R, key: &K, load: impl FnOnce(&K) -> Result<Vec<u8>, E>, ) -> Result<(), E>

Reads key from disk through load and places it, then drops the oldest entries until the cache is within its budget. A frozen run is not placed; an entry larger than the budget is not kept. A failed load changes nothing and its error is returned.

pub fn read<E>( &mut self, owner: &R, key: &K, load: impl FnOnce(&K) -> Result<Vec<u8>, E>, ) -> Result<Arc<[u8]>, E>

Answers the cached bytes on a hit; on a miss reads them through load, places them as Self::insert does, and answers them.

pub fn evict_oldest(&mut self)

Drops the oldest entry, when the system asks for memory back or a beat evicts.

pub fn freeze(&mut self, owner: &R)

Drops every entry of owner and places nothing for it afterwards.

pub fn resident_bytes(&self) -> usize

The bytes the cache holds now.