Trait CacheEntryAccess

Source

pub trait CacheEntryAccess<Key, Value>: Cache {
    // Required methods
    fn read(&self, key: &Key) -> Option<Value>;
    fn compute(&mut self, key: &Key) -> Value;
}

Expand description

Trait for Cachees that are internally a list of key-value pairs that are computed once and can be trivially returned without holding the lock.

Implementing this is required for crate::Memoizers::read_or_compute.

If computing a value needs data beyond the persistent cache key, use an accessor type for Key that contains both the stable key and borrowed inputs for the miss path. Self::read should only use the stable key, while Self::compute may use the additional inputs.

Required Methods§

Source

fn read(&self, key: &Key) -> Option<Value>

Reads the cache entry for the given key, if it exists.

Source

fn compute(&mut self, key: &Key) -> Value

Computes the cache entry for the given key and returns it.

crate::Memoizers::read_or_compute calls this while holding the cache’s write lock after checking the key a second time, so concurrent misses are guaranteed not to repeat the computation.