Re: Cached pages

Hi Jorge,

On 11/04/16 16:23, Jorge Arellano Cid wrote:

>> Now, if if you use the same words on the index page, dillo doesn't run the
>> CGI, but produces the previous cached page - sure, a reload works, but that
>> doesn't seem logical.
>
>    Logic depends upon the considered facts.
>
>
>> Firefox doesn't do this, it runs the CGI each time, which is what I would
>> expect on something that produces dynamic content.
>
>    Cache policy is not trivial (e.g. check idempotency in HTTP).
>
>    For  instance,  if  you decide to try to reload whenever it may
> seem  useful,  you  start  having  problems when users go offline
> (i.e.  intermitent internet connections). BTW,  that's how we got
> "offline mode"; Good&Simple right? Hmmm, no. Unfortunately it was
> nearly  impossible  to  teach  the  proverbial grandma when to go
> offline  and  when  online.  Power users started to complain they
> were  not  able  to  go  back and forward fast on already visited
> pages,  and  that  pages  dissappeared. Why, the browser issued a
> reload  every  time, cleaning the cache, and guess what, websites
> used the opportunity to refresh advertisement.
>
>    At  some  point there were cache directives served in HTTP, but
> they  got  abused  by advertising again (i.e. always reload means
> more  money).  And  some  sites decided to serve their pages with
> always  reload  directives,  even some decided to issue automatic
> reloads  after  a  certain a mount of time (more clicks/visits on
> the stats, more money for payed advertisingt, etc...).
>
>    One  of  the  reasons why people love to have many open tabs is
> that  since  the  reload  mess inception (and some other stuff as
> custom navigation), it became hard to tell whether you'll be able
> to see the same page again by going back and forward. So tabs are
> a solution to the new problem.
>
>    As  you  may  see  from  this short sample, a cache policy must
> consider lots of cases.


First, I wasn't complaining, just curious (as 10CC sang, I don't like 
Dillo, I love it!) - and as I was debuggng a perl script, in normal use 
this wouldn't be an issue as the same input will always produce the same 
output, so a cached page is always correct.

Many thanks for a very detailed explanation of the way this issue got 
into a mess - I am sure you are the best person to steer Dillo away from it.

Regards,

Nick

-- 
Gosh that takes me back... or is it forward?  That's the trouble with
time travel, you never can tell."
		-- Doctor Who "Androids of Tara"