Hi Ticker, I fear the problem will not go away because the relation still has tags like name:en . Anyway, I work on a patch to remove the old-style support. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Ticker Berkin <rwb-mkgmap@jagit.co.uk> Gesendet: Mittwoch, 10. März 2021 16:04 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] tile takes very long time to generate Hi Gerd Having looked more closely at current OSM rules and what you said earlier in the thread about "old style" multipolygons and: https://wiki.openstreetmap.org/wiki/Old_style_multipolygons I'd agree that support for these should be removed. Then, with the appropriate --delete-tags-file=... the problem goes away. Ticker On Wed, 2021-03-10 at 12:47 +0000, Gerd Petermann wrote:
Hi Ticker,
reg. thetag handling I forgot to mention the --delete-tags-file option. This would allow to remove tags like place=sea or place=island while the input file is read, but the strange handling of MP tags makes this useless.
Gerd
________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Gerd Petermann <gpetermann_muenchen@hotmail.com> Gesendet: Mittwoch, 10. März 2021 13:42 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] tile takes very long time to generate
Hi Ticker,
I think it would be good if we could defer the actions in method MultiPolygonRelation.processElements() until the relation style rules were used. This would allow to remove rather useless relations like the place=sea or place=island MPs or maybe add a tag to tell mkgmap that only a POI is needed. No idea how much work that would be or what side effects it would have.
I've not yet checked why the mentioned MP takes soooo long, maybe it's because the MP contains some errors.
Gerd
________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Ticker Berkin <rwb-mkgmap@jagit.co.uk> Gesendet: Mittwoch, 10. März 2021 13:13 An: Development list for mkgmap Betreff: Re: [mkgmap-dev] tile takes very long time to generate
Hi
I'm not sure of all the rules regarding relations and resultant polygons and some of the MultiPolygonRelation.java code defeat me but some thoughts:
Even though the relation might not have any relevant tags, it is what causes all the significant inner and/or outer polygons to be create by mkgmap. It might have been necessary to use a relation because the closed way has too many points, etc.
mkgmap's OSM loading process drops any tags not referenced by the style. For relations it sets a flag to say if any tags have been dropped. Later, it doesn't bother processing the relation (building the multipolygons) if it *HAD* no tags. So, a relation tagged with just: [notUsedInStyle=someValue] will cause full processing, whereas without this, nothing will happen.
Much of the cost of MultiPolygon processing is the assembling of bits of way to make up the polygons. The rest of the cost is cutting inner polygons out of outer polygons. If the outer polygons really don't have tags used in the style, maybe this phase can be skipped.
In this example, the tag in question is "place"; this will occur in most styles.
In the above, I'm ignoring the special relation tag "type" and internal mkgmap:* tags.
Ticker
On Tue, 2021-03-09 at 15:27 +0000, Gerd Petermann wrote:
Hi all,
I sea no easy way to fix this. We'll have more and more monster multipolygons like r9488835. The current code in mkgmap r4607 processes a type=multipolygon before any rule from relations is used, so there is no easy way to tell mkgmap to ignore any MP with place=sea. Using a program like osmfilter on complete countries or continents also takes time, so maybe the best place to filter these killers would be in splitter, but we probably need some flexible syntax similar to the style rules. Another option would be a new mkgmap rule file for mkgmap that would be processed after reading the MP but before processing its geometry. This new rule file could allow actions like those in the finalize section of points/polygons.
Any ideas besides hard coded "quick&dirty" solutions?
Gerd
________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Bernhard Hiller <bhil@gmx.de> Gesendet: Dienstag, 9. März 2021 09:50 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] tile takes very long time to generate
Hi Karl, some time ago, I stumbled upon a tile which took 2 hours(!) on my machine. With the "--polygon-file" option, the time could be reduced to less than 100 s. See the old message in the archive: http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2017q1/026490.html and the thread "Performance with large files": http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2017q1/thread.html#26 46 3 Perhaps the trick helps in your case, too. Kind regards, Bernhard
Am 08.03.2021 um 06:53 schrieb 7770:
Hi.
I observe a situation that one of the very first tiles (often the first or the third) that mkgmap generates takes 20 - 30 minutes to generate, wheres the others take about 30 seconds each.
The map data produced by splitter is a total of around 700 files with splitter option --max-nodes=1275000.
sea and bouds are used for mkgmap.
At first i thought i am running low on memory but changing to max -jobs=1 (instead of the possible max of 2) did not make any change.
Is mkgmap doing something specific in the beginning that can explain this long time generating one of the very first tiles?
I can provide more details, let me know how i can best collect those details in case i need to set some parameters to have mkgmap to say more about what it is doing.
Regards Karl
_______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev