Struct CacheEntry 

pub struct CacheEntry<K, V, M = ()> {
    pub key: K,
    pub value: V,
    pub metadata: CacheMetadata<M>,
}

Unified cache entry holding key, value, and metadata.

The M parameter allows each algorithm to store its own metadata without affecting the core entry structure. Use () for algorithms that don’t need extra per-entry metadata (e.g., LRU).

Examples

use cache_rs::entry::CacheEntry;

// Create a simple entry for count-based caching
let entry: CacheEntry<&str, i32> = CacheEntry::new("key", 42, 1);
assert_eq!(entry.key, "key");
assert_eq!(entry.value, 42);
assert_eq!(entry.metadata.size, 1);

Fields

key: K

The cached key

value: V

The cached value (or reference/handle to external storage)

metadata: CacheMetadata<M>

Cache metadata including size, timestamps, and algorithm-specific data

Implementations

impl<K, V, M: Default> CacheEntry<K, V, M>

pub fn new(key: K, value: V, size: u64) -> Self

Creates a new cache entry without algorithm-specific metadata.

Use this constructor for algorithms like LRU that don’t need per-entry metadata beyond the basic key, value, and timestamps.

Arguments

• key - The cache key
• value - The cached value
• size - Size of the content this entry represents (use 1 for count-based caches)

Examples

use cache_rs::entry::CacheEntry;

// Count-based cache entry
let entry: CacheEntry<&str, String> = CacheEntry::new("user:123", "Alice".to_string(), 1);

// Size-aware cache entry
let data = vec![0u8; 1024];
let entry: CacheEntry<&str, Vec<u8>> = CacheEntry::new("file.bin", data, 1024);

impl<K, V, M> CacheEntry<K, V, M>

pub fn with_algorithm_metadata( key: K, value: V, size: u64, algorithm_meta: M, ) -> Self

Creates a new cache entry with algorithm-specific metadata.

Use this constructor for algorithms like LFU, LFUDA, SLRU, or GDSF that need to track additional per-entry state.

Arguments

• key - The cache key
• value - The cached value
• size - Size of the content this entry represents (use 1 for count-based caches)
• algorithm_meta - Algorithm-specific metadata

Examples

use cache_rs::entry::CacheEntry;
use cache_rs::lfu::LfuMeta;

let entry = CacheEntry::with_algorithm_metadata(
    "key".to_string(),
    vec![1, 2, 3],
    3,
    LfuMeta { frequency: 0 },
);
assert_eq!(entry.metadata.algorithm.frequency, 0);

pub fn touch(&mut self)

Updates the last_accessed timestamp to the current time.

pub fn age_nanos(&self) -> u64

Gets the age of this entry in nanoseconds.

pub fn idle_nanos(&self) -> u64

Gets the time since last access in nanoseconds.

pub fn size(&self) -> u64

Returns the size of the cached content.

Trait Implementations

impl<K: Clone, V: Clone, M: Clone> Clone for CacheEntry<K, V, M>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<K: Debug, V: Debug, M: Debug> Debug for CacheEntry<K, V, M>

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

Formats the value using the given formatter.