HTTP-TransparentCache version 0.1
============================

HTTP::TransparentCache is an implementation of http get that keeps a local 
cache of fetched pages to avoid fetching the same data from the server 
if it hasn't been updated. The cache is stored on disk and is thus 
persistent between invocations.

The http-headers If-Modified-Since and ETag are used to let the server
decide if the version in the cache is up-to-date or not.

LIMITATIONS

This module has a number of limitations that you should be aware of
before using it.

- Only get-requests are supported. No special http-headers or cookies 
  can be used.

- There is no upper limit to how much diskspace the cache requires. The
  only limiting mechanism is that data for urls that haven't been requested
  in the last MaxAge hours will be removed from the cache the next time
  the cache-object is created.

- The result of the http get is always stored in memory, and sometimes
  twice (or more depending on how LWP actually works). This means that 
  this module shouldn't be used to fetch extremely large files via http.

- If two different processes using the same cache-directory and try to
  fetch the same url at the same time, bad things can happen. Otherwise,
  it should be safe to share the cache-directory between several processes,
  since each object in the cache is stored in a separate file and there
  is no single file that is always read.

INSTALLATION

To install this module type the following:

   perl Makefile.PL
   make
   make test
   make install

DEPENDENCIES

LWP
Storable    (included with perl)
Digest::MD5 (included with perl)

All http-requests are made through the LWP module. Data is stored on disk
by the Storable module. Digest::MD5 is used for creating a hash of the
url.

COPYRIGHT AND LICENCE

Copyright (C) 2004 by Mattias Holmlund

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.4 or,
at your option, any later version of Perl 5 you may have available.