NAME

       PPI::Cache - The PPI Document Caching Layer

SYNOPSIS

         # Set the cache
         use PPI::Cache path => '/var/cache/ppi-cache';

         # Manually create a cache
         my $Cache = PPI::Cache->new(
             path     => '/var/cache/perl/class-PPI',
             readonly => 1,
         );

DESCRIPTION

       "PPI::Cache" provides the default caching functionality for PPI.

       It integrates automatically with PPI itself. Once enabled, any attempt to load a document
       from the filesystem will be cached via cache.

       Please note that creating a PPI::Document from raw source or something other object will
       not be cached.

   Using PPI::Cache
       The most common way of using "PPI::Cache" is to provide parameters to the "use" statement
       at the beginning of your program.

         # Load the class but do not set a cache
         use PPI::Cache;

         # Use a fairly normal cache location
         use PPI::Cache path => '/var/cache/ppi-cache';

       Any of the arguments that can be provided to the "new" constructor can also be provided to
       "use".

METHODS

   new param => $value, ...
       The "new" constructor creates a new standalone cache object.

       It takes a number of parameters to control the cache.

       path
           The "path" param sets the base directory for the cache. It must already exist, and
           must be writable.

       readonly
           The "readonly" param is a true/false flag that allows the use of an existing cache by
           a less-privileged user (such as the web user).

           Existing documents will be retrieved from the cache, but new documents will not be
           written to it.

       Returns a new "PPI::Cache" object, or dies on error.

   path
       The "path" accessor returns the path on the local filesystem that is the root of the
       cache.

   readonly
       The "readonly" accessor returns true if documents should not be written to the cache.

   get_document $md5sum | \$source
       The "get_document" method checks to see if a Document is stored in the cache and retrieves
       it if so.

   store_document $Document
       The "store_document" method takes a PPI::Document as argument and explicitly adds it to
       the cache.

       Returns true if saved, or "undef" (or dies) on error.

       FIXME (make this return either one or the other, not both)

TO DO

       - Finish the basic functionality

       - Add support for use PPI::Cache auto-setting $PPI::Document::CACHE

SUPPORT

       See the support section in the main module.

AUTHOR

       Adam Kennedy <adamk@cpan.org>

COPYRIGHT

       Copyright 2005 - 2011 Adam Kennedy.

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

       The full text of the license can be found in the LICENSE file included with this module.