[OSM-dev] [PATCH] osm2pgsql tile expiry
Martijn van Oosterhout
kleptog at gmail.com
Sun Feb 8 11:37:51 GMT 2009
Looks like a pretty cool idea. I only have a few small comments.
- The use of -o. Is there any other output osm2pgsql could produce
that would be more logical. Not really a big deal, the long option
expire-output is there which is good enough for me.
- There a whole new file added (expire-tiles.c) which seems to have
some kind of tree structure. Do you think you could add a comment at
the beginning what kind of structure it is and any relevent invariants
(like middle-ram.c does).
- Does middle.h need to include osmtypes.h?
- You've got a definition of EARTH_CIRCUMFERENCE. Does that match with
what's used in the projection code?
Other than that I have no objections (I assume it doesn't change
anything when not run in this mode).
Have a nice day,
On Sun, Feb 8, 2009 at 11:23 AM, Steve Hill <steve at nexusuk.org> wrote:
> I've been working on code to generate a list of dirty tiles while importing
> the deltas. The attached patch introduces 2 new commandline options: "-e
> <zoomlevel>" and "-o <dirty tile list output file>". So, specifying "-e 17
> -o /tmp/dirty_tiles" when importing a delta will cause osm2pgsql to generate
> a list of all zoom level 17 tiles which the delta has made dirty and store
> it in /tmp/dirty_tiles.
> Proviso: for polygons, it currently takes a simplistic approach of drawing a
> bounding box around the whole polygon and marking every tile in the box as
> dirty. If the bounding box is large (over 30x30Km) the polygon is treated
> as a line instead, so only the perimeter will be marked as dirty (this is so
> that huge polygons don't expire vast numbers of tiles and is based on the
> assumption that we probably aren't going to shade the area of massive
> The dirty tile list is maintained in memory as a binary tree and dumped to
> disk at the end of the run.
> I'm running this code on OpenPisteMap and it seems to be working ok. Does
> anyone have any objection to me committing these changes to the
> OpenStreetMap subversion server?
> - Steve
> xmpp:steve at nexusuk.org sip:steve at nexusuk.org http://www.nexusuk.org/
> Servatis a periculum, servatis a maleficum - Whisper, Evanescence
> dev mailing list
> dev at openstreetmap.org
Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/
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