A least-recently-used cache for Key -> Value computations
It currently keeps the last 8 associations, but this can be
changed to anywhere between 2 and 16 by changing LRUCache.Retained.
Implementation: We keep a ring of eight places, linked
with the next data structure. The ring models a priority queue.
last points to the last element of the queue, and
next(last) to the first one. Lookups compare keys
sequentially from first to last. Elements with successful lookup
get promoted to be first in the queue. Elements are evicted
at the last position.
- Companion:
- object
Value members
Concrete methods
Enter key/value in cache at position last.
As a side effect, sets last to lastButOne.
If lastButOne was set by a preceding unsuccessful lookup
for the same key, this means that the new element is now the
first in the queue. If there was no preceding lookup, the element
is inserted at a random position in the queue.
Enter key/value in cache at position last.
As a side effect, sets last to lastButOne.
If lastButOne was set by a preceding unsuccessful lookup
for the same key, this means that the new element is now the
first in the queue. If there was no preceding lookup, the element
is inserted at a random position in the queue.
Invalidate key. The invalidated element becomes the last in the queue.
Invalidate key. The invalidated element becomes the last in the queue.