[OSM-dev] Rewrite of generate_tiles.py => mtilegenerator.py

[Martin Lesser]

Hi,

operating a own mapnik-tiles-generating server I needed a script which
re-renders expired tiles in an easy way based on the expired-list
osm2pgsql creates optionally. To avoid confusion and due to the rewrite
done I called it mtilegenerator.py. First information about it and the
code you may find on http://wiki.openstreetmap.org/wiki/User:Bettercom

Some changes made (which at least I need for calling the script from
other scripts):

* getopt-style driven (so probably not working on Win)
* creates symlinks for "naked" water- and land-tiles (a 302-redirect
  would be another improvement but this is a webserver-issue)
* tiles to be rendered may be defined via geographic X/Y or via
  Tilenumber (i.e. Z=10, X=300, Y=200)
* Overwriting existing tiles is an option
* When defining a range of zoomlevels to be rendered rendering is done
  like tiles at home: At first the tile at maxZoom-level is rendered and
  then all childs of it and so on. I will try to get some stats whether
  this could improve DB-performance (because the result of the query
  for the the parent tile still is in PG-cache).

HTH, cheers

Martin