Hi, The following is an announcement of Cache::Cache 1.0. Please read the summary below for more details.
I want to ask a special favor of the modperl community (who tend to get a lot of mileage out of this code) -- I'm concerned with the use of Digest::MD5, particularly version 2.16, which is used by the code to generate unique filenames in the file-based cache. I've been seeing some pretty ugly bugs with the the MD5 code, and this has been confirmed on a few mailing lists and CPAN bug reports. Please let me know if you notice any weird behavior with your system after upgrading to version 1.0. (All unit test pass consistently, but under certain conditions, such as when XML::DOM is loaded, I think that Digest::MD5 may always return the same hash, no matter what the key.) Note that you can simply run Digest::MD5 2.12 and not 2.16 if you have any issues in production. So don't worry about upgrading to version 1.0 of Cache::Cache. I'm thinking of switching to Digest::SHA1 in version 1.01 to avoid this until a new version of Digest::MD5 is released. Does anyone know of a reason to avoid that? (SHA1 is slightly slower, but very little time in spent generating keys anyway, so it may not be a big deal.) For more information on the MD5 issue, please see: http://rt.cpan.org/NoAuth/Bug.html?id=362. Thanks to everyone for your help. Cheers, -DeWitt Summary: The Cache modules are designed to assist a developer in persisting data for a specified period of time. Often these modules are used in web applications to store data locally to save repeated and redundant expensive calls to remote machines or databases. People have also been known to use Cache::Cache for its straightforward interface in sharing data between runs of an application or invocations of a CGI-style script or simply as an easy to use abstraction of the filesystem or shared memory. Release Notes: Release of Cache::Cache version 1.0. This version fixes outstanding issues on Win32 platforms and other minor bug fixes. Project Homepage: http://perl-cache.sourceforge.net/ Tar/GZ: http://prdownloads.sourceforge.net/perl-cache/Cache-Cache-1.0.tar.gz http://www.cpan.org/authors/id/D/DC/DCLINTON/Cache-Cache-1.0.tar.gz Changelog: http://sourceforge.net/project/shownotes.php?release_id=83292 CVS tree (viewcvs): http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/perl-cache/ The following is the Cache-Cache-1.0 README file: Copyright (C) 2001 DeWitt Clinton All Rights Reserved You may distribute under the terms of either the GNU General Public License or the Artistic License, as specified in the Perl README file. NAME Cache::Cache DESCRIPTION The Cache modules are designed to assist a developer in persisting data for a specified period of time. Often these modules are used in web applications to store data locally to save repeated and redundant expensive calls to remote machines or databases. People have also been known to use Cache::Cache for its straightforward interface in sharing data between runs of an application or invocations of a CGI-style script or simply as an easy to use abstraction of the filesystem or shared memory. The Cache package provides Cache::Cache, a generic interface for creating persistent data stores. This interface is implemented by the Cache::MemoryCache, Cache::SharedMemoryCache, Cache::FileCache, Cache::SizeAwareFileCache, Cache::SizeAwareMemoryCache, and Cache::SizeAwareSharedMemoryCache classes. This work aggregates and extends the obsolete File::Cache and IPC::Cache projects. REQUIREMENTS Digest::MD5 Error File::Spec File::Path IPC::ShareLite Storable INSTALLATION perl Makefile.PL make make test make install USAGE First, choose the best type of cache implementation for your needs. The simplest cache is the MemoryCache, which is suitable for applications that are serving multiple sequential requests, and wish to avoid making redundant expensive queries, such as an Apache/mod_perl application talking to a database. If you wish to share that data between processes, then perhaps the SharedMemoryCache is appropriate, although its behavior is tightly bound to the underlying IPC mechanism, which varies from system to system, and is unsuitable for large objects or large numbers of objects. When the SharedMemoryCache is not acceptable, then FileCache offers all of the same functionality with similar performance metrics, and it is not limited in terms of the number of objects or their size. If you wish to maintain a strict limit on the size of a file system based cache, then the SizeAwareFileCache is the way to go. Similarly, the SizeAwareMemoryCache and the SizeAwareSharedMemoryCache add size management functionality to the MemoryCache and SharedMemoryCache classes respectively. Using a cache is simple. Here is some sample code for instantiating and using a file system based cache. use Cache::FileCache; my $cache = new Cache::FileCache( ); my $customer = $cache->get( $name ); if ( not defined $customer ) { $customer = get_customer_from_db( $name ); $cache->set( $name, $customer, "10 minutes" ); } return $customer; Please refer to the perldoc for Cache::Cache and the related implementations for complete documentation. INCOMPATIBLE CHANGES Cache::Cache 0.99 contains the following incompatible changes: * Error::Simple is thrown on exceptions * the get_identifiers method has been deprecated in favor of the get_keys method * the internal format of object in a FileCache has been modified, necessitating a clearing of the cache while upgrading (make test does this for the standard cache root) SEE ALSO The project homepage at http://perl-cache.sourceforge.net AUTHOR Original author: DeWitt Clinton <[EMAIL PROTECTED]> Copyright (C) 2001 DeWitt Clinton
