• NAME
• SUPPORTED PLATFORMS
• SYNOPSIS
• STATUS
• DESCRIPTION
• PREREQUISITES
• AUTHOR

NAME

Apache::GzipChain - compress HTML (or anything) in the OutputChain

SUPPORTED PLATFORMS

• Linux
• Solaris
• Windows

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, koenig@kulturbox.de based on code by Jan Pazdziora, adelton@fi.muni.cz