Struct CacheMetadata 

pub struct CacheMetadata<M = ()> {
    pub size: u64,
    pub last_accessed: u64,
    pub create_time: u64,
    pub algorithm: M,
}

Metadata associated with a cache entry.

This struct holds common cache metadata (size, timestamps) plus algorithm-specific data via the M type parameter. Use () for algorithms that don’t need extra per-entry metadata (e.g., LRU).

Type Parameter

• M: Algorithm-specific metadata type (e.g., LfuMeta, GdsfMeta)

Examples

use cache_rs::entry::CacheMetadata;

// Metadata without algorithm-specific data (for LRU)
let meta: CacheMetadata<()> = CacheMetadata::new(1024);
assert_eq!(meta.size, 1024);

Fields

size: u64

Size of content this entry represents (user-provided). For count-based caches, use 1. For size-aware caches, use actual bytes (memory, disk, etc.)

last_accessed: u64

Last access timestamp (nanos since epoch or monotonic clock).

create_time: u64

Creation timestamp (nanos since epoch or monotonic clock).

algorithm: M

Algorithm-specific metadata (frequency, priority, segment, etc.)

Implementations

impl<M: Default> CacheMetadata<M>

pub fn new(size: u64) -> Self

Creates new cache metadata with the specified size.

The algorithm-specific metadata is initialized to its default value.

Arguments

• size - Size of the content this entry represents

impl<M> CacheMetadata<M>

pub fn with_algorithm(size: u64, algorithm: M) -> Self

Creates new cache metadata with the specified size and algorithm metadata.

Arguments

• size - Size of the content this entry represents
• algorithm - Algorithm-specific metadata

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.

Trait Implementations

impl<M: Clone> Clone for CacheMetadata<M>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<M: Debug> Debug for CacheMetadata<M>

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

Formats the value using the given formatter.