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

Cache::Ref::CLOCK(3pm) User Contributed Perl Documentation Cache::Ref::CLOCK(3pm)

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 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.
2010-09-23 perl v5.12.4