Cache::Ref::CLOCK3pm

Usage

    my $c = Cache::Ref::CLOCK->new(
        size => $n,
        k    => $k,
    );

Overview

This algorithm is provides a second chance FIFO cache expiry policy using a circular buffer.

It is a very well accepted page replacement algorithm, but largely for reasons which are irrelevant in this context (cache hits don't need to be serialized in a multiprocessing context as they only require an idempotent operation (setting a bit to 1)).

Attributes

size

The size of the live entries.

k

This is the initial value given to all hit entries.

As the hand moves through the circular buffer it decrements the counters.

The default is 1, providing semantics similar to a second chance FIFO cache.

Larger values of "k" model LRU more accurately.

This is pretty silly though, as Cache::Ref::LRU is probably way more efficient for any "k" bigger than 1.

Copyright and license

This software is copyright (c) 2010 by Yuval Kogman.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.