[Xastir] Online tigermaps display

[Daniel H. Brown]

On Mon, 22 Nov 2004, Curt, WE7U wrote:
>> I'm installing cygwin this morning, and will see if I see the same problem.
>> More in a bit.
>
> For anyone who hasn't guessed by now, Daniel Brown wrote some nice

Just "Dan" or N8YSZ is fine  :-)

> map caching code for online Tigermaps.  If you have the proper db
> libraries and header files installed, Xastir's configure will find
> them and automatically compile in the caching support.  The caching
> of course reduces our load on the Tigermap server, which improves
> its response for everyone else.
>
> If you've tried this map caching and have positive or negative
> comments about how it works, I'm sure Dan would like to hear them.
> It's the first implementation, but for what it does it does it fast!


I would appreciate any comments and suggestions for improvement.  I find it
works pretty well, for what it is - which is to say, a fairly quick "what
happens if we do this" bit of code.

I'm currently working on a couple improvements, specifically relating to
managing the amount of space the cache uses.  It currently only manages
things by throwing away maps that exceed a hard coded (6mo, by default)
expiration age.  Going forward, I'm working to implement, first off a space
usage limit and then based on that, both a "fifo" sort of queue, where the
oldest maps get aged off first and also a "LRU" algorithm to remove the
"least recently used" rather than just automatically tossing the oldest
cached map.  The way I have the code planned out, it isn't too much harder
to have the more complex (lru AND fifo) aging methodology.  I'm going to
try to get a patch for this out within the next week or so, based on how
much coding time I have over the holiday.

73
N8YSZ.

--
Dan Brown 
brown at brauhausdc.org