NAME
Apache::CacheContent - PerlFixupHandler class that caches dynamic
content
SYNOPSIS
* Make your method handler a subclass of Apache::CacheContent
* allow your web server process to write into portions of your document
root.
* Add a ttl() subroutine (optional)
* Add directives to your httpd.conf that are similar to these:
PerlModule MyHandler
# dynamic url
SetHandler perl-script
PerlHandler MyHandler->handler
# cached URL
SetHandler perl-script
PerlFixupHandler MyHandler->disk_cache
PerlSetVar CacheTTL 120 # in minutes...
DESCRIPTION
Note: This code is derived from the *Cookbook::CacheContent*
module, available as part of "The mod_perl Developer's
Cookbook"
The Apache::CacheContent module implements a PerlFixupHandler that helps
you to write handlers that can automatically cache generated web pages
to disk. This is a definite performance win for sites that end up
generating the exact same content for many users.
The module is written to use Apache's built-in file handling routines to
efficiently serve data to clients. This means that your code will not
need to worry about HTTP/1.X, byte ranges, if-modified-since, HEAD
requests, etc. It works by writing files into your DocumentRoot, so be
sure that your web server process can write there.
To use this you MUST use mod_perl method handlers. This means that your
version of mod_perl must support method handlers (the argument
EVERYTHING=1 to the mod_perl build will do this). Next you'll need to
have a content-generating mod_perl handler. If isn't a method handler
modify the *handler* subroutine to read:
sub handler ($$) {
my ($class, $r) = @_;
....
Next, make your handler a subclass of *Apache::CacheContent* by adding
an ISA entry:
@MyHandler::ISA = qw(Apache::CacheContent);
You may need to modify your handler code to only look at the *uri* of
the request. Remember, the cached content is independent of any query
string or form elements.
After this is done, you can activate your handler. To use your handler
in a fully dyamic way configure it as a PerlHandler in your httpd.conf,
like this:
PerlModule MyHandler
SetHandler perl-script
PerlHandler MyHandler->handler
So requests to *http://localhost/dynamic/foo.html* will call your
handler method directly. This is great for debugging and testing the
module. To activate the caching mechanism configure httpd.conf as
follows:
PerlModule MyHandler
SetHandler perl-script
PerlFixupHandler MyHandler->disk_cache
PerlSetVar CacheTTL 120 # in minutes..
Now when you access URLs like *http://localhost/cached/foo.html* the
content will be generated and stored in the file
*DocumentRoot*/cached/foo.html. Subsequent request for the same URL will
return the cached content, depending on the *CacheTTL* setting.
For further customization you can write your own *ttl* function that can
dynamically change the caching time based on the current request.
AUTHORS
Paul Lindner
Geoffrey Young
Randy Kobes
COPYRIGHT
Copyright (c) 2001, Paul Lindner, Geoffrey Young, Randy Kobes.
All rights reserved.
This module is free software. It may be used, redistributed and/or
modified under the same terms as Perl itself.
SEE ALSO
The example mod_perl method handler `CacheWeather'.
The mod_perl Developer's Cookbook
HISTORY
This code is derived from the *Cookbook::CacheContent* module, available
as part of "The mod_perl Developer's Cookbook".
For more information, visit
http://www.modperlcookbook.org/