[freeciv-ai] (PR#9802) generic_city_refresh speedup via caching

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://rt.freeciv.org/Ticket/Display.html?id=9802 >

> [bhudson - Wed Aug 25 01:26:21 2004]:
> 
> The major cost in the CM (>50%) is generic_city_refresh ; that's why
> we maintain all the
> fancy caches which distribute assumptions about game rules.  Looking
> at why this one
> function was so slow, I discovered it's because it computes a bunch of
> stuff that doesn't
> change across calls withing the CM -- which buildings exist, distance
> to the capital, etc etc.

Assuming the effects patch gets committed soon, I'd rather wait until
that's done (your patch touches some building effects code).  But if
nothing happens on it soon (~1 week) we should go forward with this. 
This code is a bit complicated so if there's a way to split it up that
would be helpful.

jason