[freeciv-ai] (PR#6912) Optimize/reimplement CM: per-city caches

["Raimar Falke" <rf13@xxxxxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=6912 >

> [bhudson - Thu Nov 20 16:41:42 2003]:
> 
> This patch stores the cache on a per-city basis.  Once we do that, we
> can think about caching better between calls, which will make things
> faster (this patch doesn't make a huge difference right now: I can run 
a
> server-only game in 3:50 rather than 3:58, which is likely just noise)
.
> The memory usage is quite reasonable, and I've tested for leaks and
> found none in this code (hence all the recent leak patches in other 
code).
> 
> A reason why this isn't much faster is that cache1/cache2 (which 
compute
> the true results for an allocation of workers and specialists) are 
hard
> to cache across calls and expensive, while cache3 (store an allocation
> of workers and the unmodified results) is easy to cache but cheap to
> compute.  So we'll need to get smarter about not clearing 
cache1/cache2
> every time.

The patch is here 15% faster. I have however problems with the patch:
 - the indexing via city id is bad
 - storing the parameter in the cache struct is bad

  Raimar