I have very little experience with caching mechanisms and I'm learning as I go.

How would one clear a cache within a given scope, where the scope is a named cache for a user, for a virtual host, or a server?

I'm curious about what causes Lasso's built in caching mechanism to run slowly. There may be a good reason for their implementation, like it does some things that are considered useful (at the expense of speediness) which could be adopted by Knop. Or it could be sloppiness.

--steve


On Tuesday, December 11, 2007, inbox_js@solve.se (Johan Solve) pronounced:

>To reduce the overheads from configuring navigation, database objects, language
>strings etc that's happening over and over again on every page load I'm experimenting
>with caching mechanisms.
>
>My current idea consists of two custom tags and it looks like this when used:
>
>if: !(knop_cachefetch: -type='lang');
> var: 'lang_nav_key'=(knop_lang: -default='sv');
> $lang_nav_key -> addlanguage(-language='sv', -strings=(map:
> 'hem'='hem',
> 'loggain'='loggain',
> ...
> knop_cachestore: -type='lang', -expires=1200;
>/if;
>
>
>knop_cachestore stores all page variables of the specified type in a global variable.
>It's a rather brutal approach but it gives a very nice automatic and transparent
>feeling, almost nothing to configure and it just works.
>
>knop_cachefetch tries to recreate all those page variables again from the global
>variable, if there's a cached version available. It returns true if it was successful
>and false if there wasn't a cached copy available.
>
>
>So the idea is to call knop_cachefetch first to try to have all knop object instances
>recreated as page vars, and if knop_cachefetch returns false then configure the knop
>objects the normal way and call knop_cachestore to cache them for the next page load.
>
>
>Some example timings for a project I'm working on -
>Without caching:
>Created langauge strings 23 ms
>Created database objects 73 ms
>Created navigation 142 ms
>
>With caching:
>Created langauge strings 5 ms
>Created database objects 8 ms
>Created navigation 7 ms
>
>Really nice...
>
>
>The cache can be forced to refresh simply by adding one more condition to cache_fetch:
>if: $cache_refresh || !(knop_cachefetch: -type='database');
>...
>
>
>The caching can also be done per visitor by specifying a session name to use for cache
>storage.
>
>if: !(knop_cachefetch: -type='nav', -session=$session_name);
> var: 'nav'=(knop_nav:
> -default=($lang_nav_key -> hem),
> -root=$siteroot,
> -navmethod=$navmethod);
> $nav -> insert(-key=($lang_nav_key -> hem), -label=($lang_nav_label -> hem),
>-url='/');
> ...
> knop_cachestore: -type='nav', -expires=1200, -session=$session_name;
>/if;
>
>
>I'm not using Lasso's built in cache tags for this since they seem to have too much
>overhead and are way too slow, but I do use thread locking to provide a thread safe
>caching mechanism.
>
>The global variable used for caching is named uniquely for the current site (based on
>server_name and response_localpath - response_filepath) and it's also possible to
>specify a -name to further isolate the cache storage if needed (for example if
>multiple sites are running in the same virtual root and hostname).
>
>
>Comments? Objections?
>
>

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
Steve Piercy Web Site Builder Soquel, CA
<web@StevePiercy.com> <http://www.StevePiercy.com/>

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