Struct LfudaCacheConfig 

pub struct LfudaCacheConfig {
    pub capacity: NonZeroUsize,
    pub initial_age: usize,
    pub max_size: u64,
}

Configuration for an LFUDA (Least Frequently Used with Dynamic Aging) cache.

LFUDA enhances LFU by using a dynamic aging mechanism that prevents old frequently-accessed items from permanently blocking new items.

Fields

• capacity: Maximum number of entries the cache can hold. Each entry has memory overhead (~64-128 bytes) for keys, pointers, and metadata.
• initial_age: Initial global age value (default: 0)
• 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::LfudaCacheConfig;
use cache_rs::LfudaCache;
use core::num::NonZeroUsize;

// 10MB cache for ~1KB average values → ~10,000 entries
let config = LfudaCacheConfig {
    capacity: NonZeroUsize::new(10_000).unwrap(),
    initial_age: 0,
    max_size: 10 * 1024 * 1024,  // 10MB
};
let cache: LfudaCache<String, Vec<u8>> = LfudaCache::init(config, None);

// Small cache for tiny values with initial age
let config = LfudaCacheConfig {
    capacity: NonZeroUsize::new(500).unwrap(),
    initial_age: 100,
    max_size: 64 * 1024,  // 64KB is ample for small values
};
let cache: LfudaCache<&str, i32> = LfudaCache::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.

initial_age: usize

Initial global age value

max_size: u64

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

Trait Implementations

impl Clone for LfudaCacheConfig

fn clone(&self) -> LfudaCacheConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LfudaCacheConfig

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

Formats the value using the given formatter.

impl Copy for LfudaCacheConfig