[mkgmap-dev] Precompiled boundary files in one zip file

Sun Feb 12 21:41:06 GMT 2012

Hi WanMil,

> > I did not see any multi-threading problems while reading from zip, so I did
> > not code anything
> > special for this. You mentioned such problems, did you mean updating zip
> > files?
> 
> I remember that I read warnings that the Java zip file implementation is 
> not multithread capable. I'll have to search for them and will let you 
> know if I find them.

OK, I just found general comments like "it is not threadsave"
> 
> >
> > I don't think that we need a routine to write / create zip files, do we?
> 
> There will be one real improvement: The LocationHook first checks if the 
> bounds directory contains bounds file. The time checking that has been 
> improved much by your patch. But I still see quite high timings when 
> using multiple threads. If using a zip file this timing should be much 
> better because one just have to check if the on zip file is there.
> 
> A 2nd thing is that it is much easier to handle for users. That's what 
> Klaus alias toc-rox metioned.
> 
> So decide yourself. I would vote for using zip files (and it would also 
> be ok for me to drop the support for non zip files).

I like to use zip file as input, my question is if there is a need to write 
or update *.zip . I think it is sufficient to use a standalone zip program.

> 
> > I think we need a utility similar to BoundaryMerger to allow creating the
> > bnd files for planet in multiple steps, so that's what I am working on now.
> 
> Yes. Otherwise it is not possible to create boundaries for larger 
> regions if your computer does not have tons of GB.

Well, a special program to calculate only the bnd files would be an alternative, 
but I don't plan to code that.

Gerd

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