NAME

Cache::AgainstFile::Base - base class for default backends

SYNOPSIS

 package Cache::AgainstFile::MyBackend;

 use Cache::AgainstFile::Base;
 @ISA = qw(Cache::AgainstFile::Base);
 
 ...implement methods...

 1;

This provides a default implementation for purging the cache, based on a list of stale files and a hashref of access times.

Classes inheriting from this base class should provide the following public methods:

$b = new Cache::AgainstFile::MyBackend(\&loader, \%options): This should call the base class constructor.
$data = $b->get($filename, @opts): Fetch an item from the cache. @opts should be passed after the filename to the loader coderef.
$n = $b->count(): Number of items in the cache
$bytes = $b->size(): Total size of the cache in bytes

They should also provide the following protected methods which are used to support purge():

$b->_remove(\@filenames): Remove a number of items from the cache
$hashref = $b->_accessed(): A hashref of filename => access time
@filenames = $b->_stale(): A list of cache items which are stale with respect to their original files