Gesendet: Mittwoch, 06. März 2013 um 23:08 Uhr Von: "Michael Tremer" michael.tremer@ipfire.org An: "Bernhard Bitsch" Bernhard.Bitsch@gmx.de Cc: "development@lists.ipfire.org" development@lists.ipfire.org Betreff: Re: Aw: Fwd: Update-Accelerator 3.0
On Wed, 2013-03-06 at 22:23 +0100, Bernhard Bitsch wrote:
I don't think we should make a new solution based on squid's caching, too.
The existing Update Accelerator is written as a rewriter module to squid.
This model is strong enough to realize the function " caching of frequent file requests ".
When we jump right ahead to discuss technical details, I would like someone to check out if we can easily control the cache to store our files, so that we don't have to manage our own one.
No problem. But this solution must give us th possibility to manage the file store from the WUI. I don't want to miss this feature.
My first idea for a redesign of the accelerator was generalize the conditions for caching.
In the moment all conditions can be described by the pattern
if URI match set of (sample URI's and RE'S)_1 & URI !match set of (sample URIs and RE's)_2 then
check(URI)fi
This can be enhanced if the sets of URI's and RE's are condensed to two regular expressions for each caching class, actually called "vendor".
Then the check for caching is just a loop over all classes.
A second enhancement can be achieved if the most requested checks are made first. The loop terminates by the first match.
The latest version of PCRE comes with a fast JIT compiler for regular expressions. We should take advantage of that instead of running thrugh loops.
The loops are not avoidable by a JIT compiler ( Perl does this too ). The storage application must loop over the various categories. At a short look on PCRE I could not find a possibility for efficiently assembling several single RE's/URI's to one. This is necessary if we want the user to extend the rule set. A main problem in the actual implementation is the extension by adding a new alternative.
- Bernhard