[mkgmap-dev] possible bug? mkgmap freezes with lines only routing style

Sat Oct 29 14:57:25 BST 2011

Hi

I would like some opinions please from those that make maps.

If you have a style that say sets the name of every path to 'Path'

   eg: highway=path | highway=footway | highway=track {name 'Path' }

or anything similar that results in thousands of roads with the same
name, then mkgmap appears to freeze.

The code that is slow is creating a list of roads that will be used
when you search for an address in MapSource or on the device.

I can fix this in various ways, but I want to ask how useful it is to
have thousands of roads with the same name appear as a result of a
search?

For a start in mapsource, you only see a few of the results anyway.

Should I drop the name completely from the index when there are more
than say 500 roads with the same name in the same city?

There is a branch called simplify-sorted-roads where I am trying out 
different approaches to the problem, if anyone else wants to try it out
or look at it.

> I can confirm that behaviour. Although in real mkgmap does not freeze
> (endless loop) but is working very very hard. Possibly the mkgmap code
> is not very optimal for the special test case.
>
> @Steve, the code requires a very long time in the
> NETFile.simplifySortedRoads method because I think there are many roads
> with the same name. I think I remember a similar discussion some time
> ago? The method seems to perform a brute force method to detect
> connected roads with the same name. Can you have a look on it?

..Steve