[mkgmap-dev] [PATCH v2] Black/Whitelist

Tue Jan 5 23:26:44 GMT 2010

>>> Could someone please commit or deny the patch. It is open for a long
>>> time, no one has complained about it and I think it's a useful
>>> enhancement.
>>>
>>>       
>> Sorry, I don't see the use of a black/whitelist of tags.
>> The information of used tags should be contained in the style files, so
>> why should I have to manage another additional file?
>> Is it for speed/resource reasons?
>>
>> Regards,
>> Johann
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>>
>>     
>
> Johann,
>
> yes it speeds up the map generation by magnitude of times in case the 
> map uses only very few parameters. e.g. if you want to create a map that 
> visualizes the maxspeed (or maxheight, maxweight....) tag only its 
> useless to parse all other parameters.
>
> You are right that this information is also contained in the style files 
> and in future a better patch should automatically compile this 
> information from the style files.
>
> WanMil
>
>   
I'm not really inside the style code, so I don't completely understand 
the background of this.

But in my understanding the osm data has to be parsed from beginning to 
end. Before I can decide to dismiss an parameter, I have to read it in 
and parse it, haven't I ? If there is no action defined in the style 
file, no style rule is active and nothing else should be happening. So 
why handle it with extra code?

In my personal opinion I don't like another (superfluous) file, 
especially the blacklist file. And the whitelist *IS* the style file. No 
entrys here means no action!

But as I said, style file is not really my part. And i believe you, that 
it speeds up the process.

Regards,
Johann