[OSM-dev] [PATCH] osm2pgsql tile expiry

Martijn van Oosterhout kleptog at gmail.com
Sun Feb 8 12:07:52 GMT 2009

I just realised. You have also created a parse_wkt, which opens up the
path to limited relation processing even in non-slim mode. (It doesn't
solve the problem completely, since the whole problem is that non-slim
doesn't store most of the info required, but for certain types of
relations it might be sufficient.)

On Sun, Feb 8, 2009 at 12:37 PM, Martijn van Oosterhout
<kleptog at gmail.com> wrote:
> 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
>> polygons).
>> 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
>> http://lists.openstreetmap.org/listinfo/dev
> --
> Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/

Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/

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