Struct SlruCacheConfig 

pub struct SlruCacheConfig {
    pub capacity: NonZeroUsize,
    pub protected_capacity: NonZeroUsize,
    pub max_size: u64,
}

Configuration for an SLRU (Segmented LRU) cache.

SLRU divides the cache into two segments: a probationary segment for new entries and a protected segment for frequently accessed entries.

Fields

• capacity: Total number of entries the cache can hold. Each entry has memory overhead (~64-128 bytes) for keys, pointers, and metadata.
• protected_capacity: Size of the protected segment (must be < capacity). Typically 20% of total capacity for hot items.
• 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::SlruCacheConfig;
use cache_rs::SlruCache;
use core::num::NonZeroUsize;

// 10MB cache for ~1KB values, 20% protected
let config = SlruCacheConfig {
    capacity: NonZeroUsize::new(10_000).unwrap(),
    protected_capacity: NonZeroUsize::new(2_000).unwrap(),
    max_size: 10 * 1024 * 1024,  // 10MB
};
let cache: SlruCache<String, Vec<u8>> = SlruCache::init(config, None);

// Small cache for config values, 20% protected
let config = SlruCacheConfig {
    capacity: NonZeroUsize::new(500).unwrap(),
    protected_capacity: NonZeroUsize::new(100).unwrap(),
    max_size: 64 * 1024,  // 64KB is ample for small values
};
let cache: SlruCache<&str, i32> = SlruCache::init(config, None);

Fields

capacity: NonZeroUsize

Total capacity of the cache (protected + probationary). Account for ~64-128 bytes overhead per entry beyond value size.

protected_capacity: NonZeroUsize

Maximum size for the protected segment (must be < capacity). Typically 20% of capacity for frequently accessed “hot” items.

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 SlruCacheConfig

fn clone(&self) -> SlruCacheConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SlruCacheConfig

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

Formats the value using the given formatter.

impl Copy for SlruCacheConfig