Struct ccache::lru::LRUShared

pub struct LRUShared<'a, Hmap, E, K, V, CidT, Umeta, HB> where
    Hmap: HashMap<E, K, V, CidT, Umeta, HB>,
    E: EntryT<K, V, CidT, Umeta>,
    K: Hash,
    V: Val,
    CidT: Cid,
    Umeta: Meta<V>,
    HB: BuildHasher + Default,  { /* fields omitted */ }

Actual implementation of the LRU on a shared hashmap

Implementations

impl<'a, Hmap: HashMap<E, K, V, CidT, Umeta, HB>, E: EntryT<K, V, CidT, Umeta>, K: Hash, V: Val, CidT: Cid, Umeta: Meta<V>, HB: BuildHasher + Default> LRUShared<'a, Hmap, E, K, V, CidT, Umeta, HB>

pub fn new(
    entries: usize,
    cache_id: CidT,
    access_scan: Option<&'a dyn Fn(NonNull<E>)>
) -> Self

Build a LRU that works on someone else’s hasmap

In this case each cache should have a different Cid (Cache ID) so that everyone known whose elements is being used, and call the proper cache methods

pub fn set_scanf(&mut self, access_scan: Option<&'a dyn Fn(NonNull<E>)>)

change the scan callback

pub fn insert_shared(
    &mut self,
    hmap: &mut Hmap,
    maybe_old_entry: Option<&mut E>,
    new_entry_idx: usize
) -> InsertResultShared<E>

insert_shared does not actually insert anything.

It will only fix the LRU linked lists after something has been inserted by the parent.

Note that maybe_old_entry is != None if and only if the ols entry is part of the same cache

pub fn clear_shared(&mut self)

reset the LRU

pub fn remove_shared(&mut self, entry: &E)

remove the pointers to this element in the LRU.

Does not actually remove the element, that is done by the caller

pub fn make_head(&mut self, entry: &mut E)

make the key the head of the LRU.

pub fn get_cache_id(&self) -> CidT

get the LRU cache id

pub fn on_get(&mut self, entry: &mut E)

Used when composing caches, run the callback on the entry

This method should be passed down between parent/child cache and only the final cache which owns the element should execute it

pub fn start_scan(&mut self)

start the lazy scan
The scan will execute on the whole LRU but only once

pub fn is_scan_running(&self) -> bool

check if the scan is still running

pub fn capacity(&self) -> usize

get the LRU capacity

pub fn len(&self) -> usize

get the LRU usage