[Freeciv-Dev] Re: [RFC] Caching AI values

[Gregory Berkolaiko <Gregory.Berkolaiko@xxxxxxxxxxxx>]

On Wed, 3 Apr 2002, Raimar Falke wrote:

> On Sat, Mar 23, 2002 at 03:09:07PM +0000, Gregory Berkolaiko wrote:
> > 
> > But first a couple of examples:
> > ======================================================================
> 
> > Cached value: list of all own refuelling points of the type FUEL_CITY
> > (basically the list of all cities)
> 
> IMHO the speed improvement for this is very small if only cities are
> included. The problem are the airbases. To get these you have to
> iterate over the whole map. What about a global airbase list? 
> Mantained by set_special and clear_special.

Yes, this is very good idea.
Still if you have 10 bombers and you consider them one-by-one, it make 
sense to build the list only once.

> > Counter increment: hooked up on events 
> > --CITY_LOSS, 
> > --CITY_ACQUISITION
> > 
> > Cached value: list of all friendly refuelling points
> > (basically the list of all cities + non-occupied airbases + ally cities)
> > Counter increment: hooked up on events 
> > --CITY_ACQUISITION, 
> > --ENEMY_DESTROYED (it could have been occupying an air-base), 
> > --END_OF_PHASE (assuming that city loss can occur only during the enemy 
> >                 movement phase)
> > Note the event ENEMY_DESTROYED is higly unlikely to change the cached 
> > value, so we can skip it here.
> 
> Same as above.
> 
> > So, ideally, 
> > 1. The counters would be subscribed to certain events.
> > 2. This "subscription" can be hardcoded.  
> > 3. Counter <-> cached value relation can be flexible: one counter can 
> > expire several caches.
> > 
> > Other possibly useful cached values: 
> 
> > enemy cities on the continent (useful for global invasion
> > management, diplomat code etc)
> 
> It has to be tested how much faster this would be compared to a
> for each player:
>  if enemy player:
>   for each city:
>    if city.continent==continent:

Same as above: you have 100 units, why do this cycle 100 times if you can 
just cache the list?

> > enemy targets reachable by unittype around a city (useful for
> > bombers etc)
> 
> for each unittype:
>  for area accessible with this unittype around city:
>   if tile has enemy unit:
> 
> should be fast.

and same here yet again
besides you don't just count enemy targets, you calculate the want, which 
uses win_chance

> > wonders built on a continent (useful for caravans and not building
> > too many wonders at the same time).
> 
> Same as the first: list of cities for a certain player and continent.

In this case it might be faster.


G.