[TYPO3-dev] t3lib_cache

[Daniel Bruessler]

Hello Ernesto,

yes, varchar is better. The tagging with "tx_testextension_table:5454" 
is a nice idea. But still I find it better to have a M:N ;-)

The current int-value can be used for more than one register! Just by 
multiplication. But that's not reaaaly nice.
first value: 10^0
second value: 10^3 or 10^4

Cheers!
Daniel

> Daniel Bruessler wrote: on 17.01.2008 13:12:
>> Hello Steffen,
>>
>> yes, sorry :-)
>>
>> So what's with these new functions:
>>
>> setCacheReg($value, $key='reg1')
>> clearCacheByPage ($uid)
>> clearCacheByReg ($value, $key='reg1', $pid=0)
>>
>> annotation: if $pid=0 the function clearCacheByReg this reg-value is 
>> cleared for any page.
>>
>> So for the moment it's just possible to have "reg1" or "reg2" as value 
>> (is there really a reg2? In the API I just found class-var 
>> "page_cache_reg1")
> 
> There is no reg2.
> 
> And what I was trying to suggest was that we just need one "tagging" 
> method for cached pages, and this doesn't need to be just an integer 
> (like reg1 currently is).
> 
> If we have an indexed varchar, this might be enough (e.g. 
> "tx_testextension_table:5454" would identify a cache tagged with this 
> table uid entry, so the extension knows where the single-view was 
> rendered). With this approach, currently only "one" extension can put 
> their information in this reg1 (later "ident" or something). The API for 
> it is pretty "dumb", just set $TSFE->page_cache_reg1. Meaning also that 
> the "latest called extension" wins.
> 
> To overcome that, maybe we could already think about many extensions 
> trying to do that. In order not to pollute the current cache_pages with 
> more fields, it might be interesting to create a cache_pages_ref table 
> like:
> 
> id int(11)  foreign key to cache_pages.id
> extkey varchar indexed
> ident varchar indexed
> 
> So that there is a 1-M relation between cached-pages and "tags" for this 
> cache entry. So it is then later easy to locate caches that affect 
> certain records. E.g. say we have a page with:
> 
> - news single view with uid=666 and
> - two product teasers with uid=777 and 888 on the left border (same page)
> 
> 1) cache_pages contains one rendered page with id=2323
> 2) cache_pages_ref contains two entries:
> 
> 2323, tt_news, 666
> 2323, product_ext, 777
> 2323, product_ext, 888
> 
> Say the extension product_ext knows that 888 product is "obsolet" or 
> something has changed or "whatever", it will then be able to find all 
> pages that display information about that record and delete all cache 
> related to it (here is where t3lib_cache API comes in).
> 
> The "ident" varchar might also be used in some other ways other than 
> storing the pure uid. Maybe there is a list of uids, maybe there is 
> nothing at all, maybe there are keywords like "latest_view". It's up to 
> the extensions author to think about how he wants to manage the TYPO3 
> page cache.
> 
> Cheers,
> Ernesto