Zygo Blaxell 4943a07cce crucible: cache: linked-list LRU implementation ...

We need a better cache expiration algorithm than "make a copy of
the entire thing, sort it while holding a lock, and delete half
the items in a single burst."

Replace the Lamport clock with a double-linked list.  Each insert
or lookup operation moves the affected item to the head of the list.
Each erase operation deletes one single item at the tail of the list.

Also sort out some iterator invalidation nonsense by doing erases before
inserts instead of "insert, erase, find the inserted item again because
we invalidated the found iterator during the erase."

The new implementation adds a second word-sized member to each Value
as well as a copy of the Key.  Hopefully the enlarged size is not
a deal-breaker.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>

2018-01-17 22:58:44 -05:00

..

crucible

crucible: cache: linked-list LRU implementation

2018-01-17 22:58:44 -05:00