Struct ResultCache 

pub struct ResultCache { /* private fields */ }

Thread-safe result cache with LRU eviction and TTL

Performance Characteristics

• Get: O(1) average, O(n) worst case for access order update
• Insert: O(1) average, O(n) worst case for eviction
• Memory: O(max_size * entry_size)

Thread Safety

Uses Arc<RwLock<_>> for interior mutability:

• Multiple concurrent readers
• Exclusive writer access
• Clone creates a new reference to same cache

Implementations

impl ResultCache

pub fn new(config: CacheConfig) -> Self

Create a new result cache with the given configuration

Example

use llm_shield_models::cache::{ResultCache, CacheConfig};
use std::time::Duration;

let cache = ResultCache::new(CacheConfig {
    max_size: 1000,
    ttl: Duration::from_secs(300),
});

pub fn get(&self, key: &str) -> Option<ScanResult>

Get a cached result by key

Returns None if:

• Key doesn’t exist
• Entry has expired (and removes it)

Updates LRU access order on cache hit.

pub fn insert(&self, key: String, result: ScanResult)

Insert or update a cache entry

If the cache is at capacity, evicts the least recently used entry. If the key already exists, updates it and refreshes the TTL.

pub fn clear(&self)

Clear all entries from the cache

This does not reset statistics.

pub fn len(&self) -> usize

Get the number of entries in the cache

Note: This includes expired entries that haven’t been lazily cleaned yet.

pub fn is_empty(&self) -> bool

Check if the cache is empty

pub fn stats(&self) -> CacheStats

Get cache statistics

pub fn reset_stats(&self)

Reset cache statistics

This does not affect cached entries.

pub fn hash_key(input: &str) -> String

Generate a deterministic hash key from input text

Useful for caching scan results based on input content.

Example

use llm_shield_models::cache::ResultCache;

let input = "some text to scan";
let key = ResultCache::hash_key(input);

Trait Implementations

impl Clone for ResultCache

fn clone(&self) -> Self

Clone creates a new reference to the same underlying cache

All clones share the same cache data and statistics.

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

Performs copy-assignment from source.