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Cache-Ref-0.04
River stage two • 2 direct dependents • 26 total dependents
1 ++
/ Cache::Ref::CLOCK

NAME

Cache::Ref::CLOCK - CLOCK cache replacement algorithm

SYNOPSIS

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

DESCRIPTION

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.

AUTHOR

Yuval Kogman

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.