Provided by: libmemoize-memcached-perl_0.03-2_all 
NAME
Memoize::Memcached - use a memcached cache to memoize functions
SYNOPSIS
use Memoize::Memcached
memcached => {
servers => [ '127.0.0.1:11211' ],
};
memoize_memcached('foo');
# Function 'foo' is now memoized using the memcached server
# running on 127.0.0.1:11211 as the cache.
WARNING
The way "flush_cache" works with memcached can be dangerous. Please read the documentation below on
"flush_cache".
EXPORT
This module exports "memoize_memcached", "flush_cache", and "unmemoize". The "unmemoize" function is
just the one from Memoize, and is made available for convenience.
FUNCTIONS
memoize_memcached
This is the memcached equivalent of "memoize". It works very similarly, except for some difference in
options.
If the "LIST_CACHE" or "SCALAR_CACHE" options are passed in, "memoize_memcached" will complain and then
pass the request along to "memoize". The result will be a memoized function, but using whatever cache
you specified and NOT using memcached at all.
This function also accepts a "memcached" option, which expects a hashref. This is de-referenced and
passed directly into an internal function which sets up the memcached configuration for that function.
This contents of this hashref are mostly options passed to "Cache::Memcached", with a few exceptions.
The actual key used to look up memoize data in memcached is formed from the function name, the normalized
arguments, and some additional prefixes which can be set via the "memcached" option. These prefixes are
"key_prefix", "list_key_prefix", and "scalar_key_prefix".
The "key_prefix" defaults to "memoize-" if it's not passed in, or an undefined value is passed in.
The "list_key_prefix" and "scalar_key_prefix" options default to "list-" and "scalar-" respectively, by
the same criteria.
So, the default way the key is generated is:
"memoize-<function>-list-<normalized args>"
or
"memoize-<function>-scalar-<normalized args>"
The function and normalized args portion of this key are set internally, but the "memoize-" prefix and
the context portion can be configured with memcached options as follows:
"<key_prefix>-function-<list_key_prefix|scalar_key_prefix>-args"
Examples:
memoize_memcached('foo');
# keys generated will look like this:
# list context: memoize-foo-list-<argument signature>
# scalar context: memoize-foo-scalar-<argument signature>
memoize_memcached('foo',
memcached => {
servers => [ ... ],
key_prefix => '_M-',
list_key_prefix => 'L-',
scalar_key_prefix => 'S-',
},
;
# keys generated will look like this:
# list context: _M-foo-L-<argument signature>
# scalar context: _M-foo-S-<argument signature>
flush_cache
The behavior documented in "Memoize" is sort of implemented. A call to
"flush_cache('memoized_function')" will indeed clear the cache of all cached return values for that
function, BUT it will also clear the entire memcached cache, including all other memoized functions using
the same memcached cache, and even data unrelated to "Memoize::Memcached" in the same cache. It will
flush the entire cache.
There are 2 new ways to call this function:
flush_cache();
and
flush_cache(memoized_function => qw( an argument signature ));
The call without arguments will flush the entire memcached cache, just like the 1 argument version. This
includes unrelated data. Be careful.
The call with 2 or more arguments will flush only the cached return values (array and scalar contexts)
for a call to the function named by the first argument with an argument signature matching the second
argument to the end. Unlike the other 2 ways to call this function, when called this way only the
specified part of the cache is flushed.
I would recommended that only the 2 or more argument version of "flush_cache" be called unless you are
very sure of what you are doing.
GOTCHAS
The biggest gotcha is that you probably never want to call "flush_cache('memoized_function')". Because
of the way "CLEAR" is implemented against memcached, this call will flush the entire memcached cache.
Everything. Even stuff having nothing to do with "Memoize::Memcached". You are warned.
TO-DO
A more intuitive interface for handling different memcached server configurations would probably be
useful.
AUTHOR
David Trischuk, "<trischuk at gmail.com>"
BUGS
Please report any bugs or feature requests to "bug-memoize-memcached at rt.cpan.org", or through the web
interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Memoize-Memcached
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Memoize-Memcached>. I will be notified, and then you'll
automatically be notified of progress on your bug as I make changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc Memoize::Memcached
You can also look for information at:
• RT: CPAN's request tracker
http://rt.cpan.org/NoAuth/Bugs.html?Dist=Memoize-Memcached
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Memoize-Memcached>
• AnnoCPAN: Annotated CPAN documentation
http://annocpan.org/dist/Memoize-Memcached <http://annocpan.org/dist/Memoize-Memcached>
• CPAN Ratings
http://cpanratings.perl.org/d/Memoize-Memcached <http://cpanratings.perl.org/d/Memoize-Memcached>
• Search CPAN
http://search.cpan.org/dist/Memoize-Memcached <http://search.cpan.org/dist/Memoize-Memcached>
ACKNOWLEDGMENTS
The tied hash portion of this module is heavily based on "Cache::Memcached::Tie" by Andrew Kostenko.
COPYRIGHT & LICENSE
Copyright 2008 David Trischuk, all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl
itself.
perl v5.12.3 2011-05-14 Memoize::Memcached(3pm)