Function counter_age

src/models/lru_cache.rs:17–24

Calculates counter age, while considering a possibility of wraparound (with the assumption that wraparound will happen at most once) `global_value` > `item_value` indicates that wraparound has happened. In that case, the age is calculated taking that into consideration.

(global_value: u32, item_value: u32)

// consideration.
//
fn counter_age(global_value: u32, item_value: u32) -> u32 {
    if global_value >= item_value {
        global_value - item_value
    } else {
        // until wrap around + after wraparound
        (u32::MAX - item_value) + global_value
    }
}

pub struct EvictionIndex {
    inner: [AtomicU64; 256],