Antwort: [Mod_gzip] mod_gzip compression level

[Stephen Pierzchala]

I agree with Peter. Modding the level from 6 to 9 has had the following 
results for me:

http://www.pierzchala.com/compress/homepage2.html
No Compression        56380 bytes

http://www.pierzchala.com/compress/homepage2.html
mod_deflate        19818 bytes
     -- DeflateMemLevel 8

http://www.pierzchala.com:9280/compress/homepage2.html
mod_gzip           16333 bytes
     -- GZIP Level 6

http://www.pierzchala.com:9280/compress/homepage2.html
mod_gzip           16268 bytes
     -- GZIP Level 9

smp

***

Peter J. Cranstone wrote:
> Hi All,
> Peter here...
> 
> Kevin and I did a lot of testing wit mod_gzip and determined the best
> compression level "for the buck" was 6.
> 
> Changing it around made some differences but not enough to warrant a
> change to a higher level which will slow things down.
> 
> 
> Peter
> 
> 
> 
> -----Original Message-----
> From: mod_gzip-admin@lists.over.net
> [mailto:mod_gzip-admin@lists.over.net] On Behalf Of
> Michael.Schroepl@telekurs.de
> Sent: Wednesday, March 05, 2003 6:00 AM
> To: mod_gzip@lists.over.net
> Subject: Antwort: [Mod_gzip] mod_gzip compression level
> 
> 
> Hi,
> 
> 
> 
>>I have compiled  mod_gzip-1.3.26.1a with apache_1.3.27.
>>Is it possible to modify the compression level?
> 
> 
> We have tried to isolate the place inside the source code
> where the compression level has been set.
> 
> But after some discussion with Kevin Kiley it looked as if
> there is not such place where you can simply switch the
> compression level to any value you want. I don't remember
> the details, but maybe Kevin didn't implement some parts
> of the level 7-9 algorithm, as he decided to use level 6
> anyway ... on the other hand, it might rather be possible
> to use some lower level (if you want to save CPU load).
> 
> 
>>If so can you point me to a place that documents how to do it?
> 
> 
> If I knew how to do it, there would be such a document
> (and there would even be a configuration directive in
> mod_gzip 1.3.26.1a).
> 
> But if you are of the adventurous type, then take the source
> code and read mod_gzip_compress.c.
> 
> line 1197 reads like this:
>       gz1->level       = 6;
> So this one _might_ be the place to change the compression
> level ... but I don't guarantee that mod_gzip will still
> work correctly. This is undiscovered territory ...
> 
> Regards, Michael
> 
> 
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> 
> 

-- 

****

Stephen Pierzchala
stephen@pierzchala.com
http://www.pierzchala.com/