[OSM-dev] OSM without segments - prototype

[Steve Coast]

This is super cool, its great that you and Frederik have taken the  
code and ran with it.

You even did a migration! Insane! :-)

On 16 Aug 2007, at 17:16, Gabriel Ebner wrote:

> Over the last few days I've developed working prototypes of the  
> server code and
> JOSM that do away with segments and make ways simple lists of nodes.
>
> What would that gain us?  First of all, big space savings (I  
> estimate 40%,
> I'll post accurate numbers when I'll have imported yesterdays's  
> planet and
> exported it again).
>
> Secondly, a major code simplification.  There are no more corner  
> cases like
> unordered ways and you don't have to keep track of segments which have
> effectively become cruft by now.  E.g, the split way action in JOSM  
> is now
> only half as long (including comments and boilerplate) as before.
>
> The only current use of ways that doesn't fall into the simple list  
> of nodes
> are areas with holes.  That however could be handled with entities  
> (or any
> other sort of superway).
>
> You can get the code from my website:
>
> $ git clone http://www.gabrielebner.at/repos/osm_nosegs/josm.git
> $ git clone http://www.gabrielebner.at/repos/osm_nosegs/planet.rb.git
> $ git clone http://www.gabrielebner.at/repos/osm_nosegs/rails_port.git
> $ cd rails_port; svn co http://svn.openstreetmap.org/sites/ 
> rails_port/vendor
>
> Then you just need to run rake db:migrate in the rails_port  
> directory (that
> takes about 4 hours on my machine), and you'll have a segments-free  
> database.
>
> Migration should cope with all sorts of ways in the current  
> database, but it
> does not convert historical ways.  Obviously it also deletes all  
> segments and
> their histories.
>
> In this prototype, a way looks like this now:
>   <way id="123">
>     <nd id="321"/>
>     <nd id="322"/>
>     <nd id="324"/>
>     <tag k="highway" v="unclassified"/>
>   </way>
>
> Unfortunately I don't have a server ready to run a demo version of  
> this, so
> if you want to try it out, you'll need to do it on your machine.
>
> Things still missing (I'll do the porting should this proposal be  
> adopted;
> except for Potlatch and the two controllers as I don't know that  
> code):
>   - amf_controller.rb and swf_controller.rb
>   - osmarender
>   - osm2pgsql
>   - Potlatch
>   - JOSM plugins: validator, UtilsPlugin
>   - export tools (garmin, google earth, ....)
>
>   Gabriel.
>
> BTW, is there any reason node tags are stored as a single string?   
> That way,
> things like "amenity"="restaurant;name=Gasthaus zur Post" lead to  
> unexpected
> results.
>
>
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>

have fun,

SteveC | steve at asklater.com | http://www.asklater.com/steve/