Prevent mod_deflate on zip file served by PHP

Question

I'm having some trouble prevent mod_deflate from jumping in on this scenario:

1. user running CodeIgniter (or any other framework that re-directs to index.php)
2. mod_deflate is active
3. zip file is served by a CodeIgniter controller (headers + readfile)

The thing is that Apache always detects the content as being php and therefor something like the lines bellow wont work as the server assumes the ZIP file as being a PHP one.

<FilesMatch "\.(xml|txt|html|php)$">
   SetOutputFilter DEFLATE
</FilesMatch>

Any ideas on how I can have Apache distinguish from an HTML file or a ZIP file both generated by the same index.php framework file.

Edit:
apache log

[Mon Jun 20 02:14:19 2011] [debug] 
mod_deflate.c(602): [client 192.168.0.5] 
Zlib: Compressed 50870209 to 50878224 : URL /index.php, 
referer: http://demo.dev/

Edit:
CI controller that serves the zip

header('Content-Type: application/zip');
header('Content-Transfer-Encoding: binary');
header("Content-Length: " . filesize($file_location)); 
header('Content-Disposition: attachment; filename="' . $file_title . '"'); 
readfile($file_location);

Answer 1

Even tough all answers should have been perfectly valid in a reasonable scenario (and were actually tested prior to making the question) the reason to why I've been unable to instruct Apache to deflate a file by MIME-Type remains unknown.

I was able to have it work as desired by forcing the following instructions into the script

apache_setenv('no-gzip', 1);
ini_set('zlib.output_compression', 0);

I do understand that this is a hot patch and is not addressing the problem's root but so far that will have to suffice. As there are others who may hit the same flag, the above code stays here for reference in what is a dirty fix.

Answer 2

You can either:

• use the deprecated AddOutputFilterByType and specify only the content types you do want to filter; or
• use the more powerful mod_filter. In FilterProvider you can provide a rule that excludes the filter when the zip content type (application/zip) is found in the response headers.

Answer 3

You can make use of mod_rewrite to change the mime-type of the request on the Apache level:

# Serve .zip request as zip-files
RewriteRule \.zip$ - [T=application/zip,E=no-gzip:1]

Place it above the rules of the framework, however this needs to make DEFLATE as well depended on mime-type and not file-extension as you do with <FilesMatch>.

Probably it works well together with

AddOutputFilterByType DEFLATE text/html

instead of the <FilesMatch> Directive.

Edit: Added the L flag which should be used in .htaccess context and additionally turned DEFLATE off via the no-gzip environment variable.

Answer 4

Try this (since your urls appear to end in .zip it might work for you):

<FilesMatch "\.(xml|txt|html|php)$">
   SetEnvIf Request_URI "\.zip$" no-gzip
   SetOutputFilter DEFLATE
</FilesMatch>

Answer 5

Instead of using

<FilesMatch "\.(xml|txt|html|php)$">
   SetOutputFilter DEFLATE
</FilesMatch>

Use this configuration for setting compression rules.

AddOutputFilterByType DEFLATE text/html text/plain text/css text/xml application/x-javascript application/javascript

This way, your output will be compressed only if content-type matches with above directives.

CI controller that serves the zip is already sending correct content-type header, so this will not get compressed.

header('Content-Type: application/zip');