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LruCacheConfig

Struct LruCacheConfig 

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pub struct LruCacheConfig {
    pub capacity: NonZeroUsize,
    pub max_size: u64,
}
Expand description

Configuration for an LRU (Least Recently Used) cache.

LRU evicts the least recently accessed items when the cache reaches capacity.

§Fields

  • capacity: Maximum number of entries the cache can hold. Each entry has memory overhead (~64-128 bytes) for keys, pointers, and metadata.
  • max_size: Maximum total size in bytes for cached values. Set this based on your memory budget, not to u64::MAX. See module docs for sizing guidance.

§Sizing Recommendations

Always set meaningful values for both fields:

  • In-memory cache: max_size = memory budget for values; capacity = max_size / average_value_size
  • Disk-based cache: max_size = disk space allocation; capacity = max_size / average_object_size

§Examples

use cache_rs::config::LruCacheConfig;
use cache_rs::LruCache;
use core::num::NonZeroUsize;

// 10MB cache for ~1KB average values → ~10,000 entries
let config = LruCacheConfig {
    capacity: NonZeroUsize::new(10_000).unwrap(),
    max_size: 10 * 1024 * 1024,  // 10MB
};
let cache: LruCache<String, Vec<u8>> = LruCache::init(config, None);

// Small cache for tiny values (ints, bools) - capacity-limited
let config = LruCacheConfig {
    capacity: NonZeroUsize::new(500).unwrap(),
    max_size: 64 * 1024,  // 64KB is ample for small values
};
let cache: LruCache<&str, i32> = LruCache::init(config, None);

Fields§

§capacity: NonZeroUsize

Maximum number of key-value pairs the cache can hold. Account for ~64-128 bytes overhead per entry beyond value size.

§max_size: u64

Maximum total size in bytes for cached values. Set based on your memory/disk budget. Avoid using u64::MAX.

Trait Implementations§

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impl Clone for LruCacheConfig

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fn clone(&self) -> LruCacheConfig

Returns a duplicate of the value. Read more
1.0.0 · Source§

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

Performs copy-assignment from source. Read more
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impl Debug for LruCacheConfig

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

Formats the value using the given formatter. Read more
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impl Copy for LruCacheConfig

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dest. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.