clru/
config.rs

1use crate::weight::{WeightScale, ZeroWeightScale};
2use std::collections::hash_map::RandomState;
3use std::hash::BuildHasher;
4use std::marker::PhantomData;
5use std::num::NonZeroUsize;
6
7/// A configuration structure used to create an LRU cache.
8pub struct CLruCacheConfig<K, V, S = RandomState, W = ZeroWeightScale> {
9    pub(crate) capacity: NonZeroUsize,
10    pub(crate) hash_builder: S,
11    pub(crate) reserve: Option<usize>,
12    pub(crate) scale: W,
13    _marker: PhantomData<(K, V)>,
14}
15
16impl<K, V> CLruCacheConfig<K, V> {
17    /// Creates a new configuration that will create an LRU cache
18    /// that will hold at most `capacity` elements and default parameters.
19    pub fn new(capacity: NonZeroUsize) -> Self {
20        Self {
21            capacity,
22            hash_builder: RandomState::default(),
23            reserve: None,
24            scale: ZeroWeightScale,
25            _marker: PhantomData,
26        }
27    }
28}
29
30impl<K, V, S: BuildHasher, W: WeightScale<K, V>> CLruCacheConfig<K, V, S, W> {
31    /// Configure the provided hash builder.
32    pub fn with_hasher<O: BuildHasher>(self, hash_builder: O) -> CLruCacheConfig<K, V, O, W> {
33        let Self {
34            capacity,
35            reserve,
36            scale,
37            _marker,
38            ..
39        } = self;
40        CLruCacheConfig {
41            capacity,
42            hash_builder,
43            reserve,
44            scale,
45            _marker,
46        }
47    }
48
49    /// Configure the amount of pre-allocated memory in order to hold at least `reserve` elements
50    /// without reallocating.
51    pub fn with_memory(mut self, reserve: usize) -> Self {
52        self.reserve = Some(reserve);
53        self
54    }
55
56    /// Configure the provided scale.
57    pub fn with_scale<O: WeightScale<K, V>>(self, scale: O) -> CLruCacheConfig<K, V, S, O> {
58        let Self {
59            capacity,
60            hash_builder,
61            reserve,
62            ..
63        } = self;
64        CLruCacheConfig {
65            capacity,
66            hash_builder,
67            reserve,
68            scale,
69            _marker: PhantomData,
70        }
71    }
72}
clru/config.rs

clru/
config.rs
