Struct TwoLevelCache 

pub struct TwoLevelCache<TKey, TValue: Clone> { /* private fields */ }

Provides a lightweight two-level cache for storing key-value pairs, supporting fast retrieval and optional eviction handling.

The cache maintains a primary entry for the most recently added item and a secondary array for additional items, up to the specified capacity. When the cache exceeds its capacity, evicted values are passed to the eviction action. It is optimized for scenarios where a small number of items are frequently accessed.

Implementations

impl<TKey: PartialEq + Clone + 'static, TValue: Clone> TwoLevelCache<TKey, TValue>

pub fn new() -> Self

Creates a cache with the default secondary capacity (3), no eviction action and the default comparer.

pub fn with_secondary_size(secondary_size: i32) -> Self

Creates a cache with the given secondary capacity.

Panics

When secondary_size is negative (upstream throws ArgumentOutOfRangeException).

pub fn with_options( secondary_size: i32, eviction_action: Option<Box<dyn Fn(&TValue) + Send>>, comparer: Option<Box<dyn Fn(&TKey, &TKey) -> bool + Send>>, ) -> Self

Creates a cache with the given secondary capacity, eviction action and key comparer (None compares with ==).

Panics

When secondary_size is negative (upstream throws ArgumentOutOfRangeException).

impl<TKey: Clone, TValue: Clone> TwoLevelCache<TKey, TValue>

pub fn try_get(&self, key: &TKey) -> Option<TValue>

Looks up the value stored for key.

pub fn get_or_add( &mut self, key: TKey, factory: impl FnOnce(&TKey) -> TValue, ) -> TValue

Returns the value stored for key, creating and storing it with factory when the key is not in the cache.

pub fn clear_and_dispose(&mut self)

Removes every entry, passing each value to the eviction action.

Trait Implementations

impl<TKey: PartialEq + Clone + 'static, TValue: Clone> Default for TwoLevelCache<TKey, TValue>

fn default() -> Self

Returns the “default value” for a type.