NAME
Apache::GzipChain - compress HTML (or anything) in the OutputChain
SYNOPSIS
In the configuration of your apache add something like
<Files *.html>
SetHandler perl-script
PerlHandler Apache::OutputChain Apache::GzipChain Apache::PassFile
</Files>
STATUS
This module is alpha software. Occasional SEGV have been observed. Use
with caution!
You currently cannot mix perl's own `print' statements that print to
STDOUT and the `print' or `write_client' methods in Apache.pm. If you do
that, you will very likely encounter empty documents and probably core
dumps too.
DESCRIPTION
This module compresses any output from another perl handler if and only
if the browser understands gzip encoding. To determine if the browser is
able to understand us we check both its *Accept-Encoding* header and its
*User-Agent* header. We check the latter because too few browsers send
the *Accept-Encoding* header currently. Instead I have set up an enquiry
form at
http://www.kulturbox.de/perl/test/content-encoding-gzip where
many users already have checked their browsers' abilities and left a
message. Thus we can test a regular expression against the *User-Agent*
header.
The module seems to work without influencing the other handlers. The
only thing that can be noticed by the other handler is that the response
header 'Content-Encoding' has been set. If GzipChain decides not to do
any compression, it just declines and doesn't even register itself for
the output chain.
GzipChain compresses every single buffer content it receives via the
output chain separately according to the GZIP specification (RFC 1952).
The compression ratio therefore suffers if the other module sends its
data in very small chunks. It is recommended that you use as few print
statements as possible in conjunction with the GzipChain. The
Apache::PassFile module is an example of an efficient file reader for
this purpose.
PREREQUISITES
Compress::Zlib, Apache::OutputChain
AUTHOR
Andreas Koenig,
[email protected] based on code by Jan Pazdziora,
[email protected]
