Enum EvictionPolicy 

#[non_exhaustive]
pub enum EvictionPolicy {
    Lru,
    Lfu,
    Fifo,
    Arc,
}

Which entry an eviction discards when the cache is full.

All four policies keep the cache within its capacity; they differ only in which entry they sacrifice to make room. The default is Lru, the best general-purpose choice for search workloads.

Examples

use iqdb_cache::EvictionPolicy;

assert_eq!(EvictionPolicy::default(), EvictionPolicy::Lru);

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Lru

Least Recently Used. Discards the entry untouched for the longest. The default: it adapts to shifting query hot-sets and is the strongest general default for search.

Lfu

Least Frequently Used. Discards the entry with the fewest lifetime hits, breaking ties by least-recently-used. Favors stable, skewed workloads where a few queries dominate.

Fifo

First In, First Out. Discards the oldest inserted entry regardless of access. The cheapest policy; a good fit when reuse is uniform.

Arc

Adaptive Replacement Cache. Balances recency and frequency automatically using ghost lists, tuning itself between LRU- and LFU-like behavior as the workload shifts.

Trait Implementations

impl Clone for EvictionPolicy

fn clone(&self) -> EvictionPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for EvictionPolicy

impl Debug for EvictionPolicy

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for EvictionPolicy

fn default() -> EvictionPolicy

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for EvictionPolicy

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for EvictionPolicy

impl Hash for EvictionPolicy

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for EvictionPolicy

fn eq(&self, other: &EvictionPolicy) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for EvictionPolicy

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for EvictionPolicy