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.