[Openstreetmap-dev] Source overview

Nick Whitelegg Nick.Whitelegg at solent.ac.uk
Mon Dec 5 19:04:08 GMT 2005






>+ ruby may be overkill for generating tiles. just running gpx.rbx or
>streets.rbx on its own takes overly long -- even "+" is implemented as
>an OO method in ruby. I implemented the same code in perl/GD and there
>was a significant speedup, but still not great - there's the initial
>compile/startup cost. Perhaps we should be looking at something with as
>little overhead as possible - like C.

Can't really comment on Ruby but PHP/GD is adequately fast as long as there
aren't too many streets in the current area. I suspect though that
optimising the database queries (something I didn't spend a lot of time on)
would help though.

Is C used much these days for web apps? One disadvantage with C over an
Apache module is the need to launch a separate process -- I haven't seen
any compelling evidence on the web to use C over a scripting language.

>I tried ImageMagick over Cairo. Even with the kludge of saving out to
>a file, Cairo is slightly faster than ImageMagick. GD I suspect is
>better than both.

One thing I could do on the dev machine with very little effort is to
convert my existing Freemap code to work with OSM - that uses PHP and GD.



>+ There are ways to get Mapserver talking directly to mysql, with
>Mapserver rendering the geometries directly. This could be very very
>good, but will require some MapScript coding to test.

Have had negative feedback from Steve on Mapserver regarding bloatedness.
Without knowing much about Mapserver, might this also reduce flexibility,
you're effectively scripting Mapserver rather than using a general purpose
language to speak to the database direct?

Nick








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