[OSM-dev] pbf2osm development has started [code to test!]

Stefan de Konink stefan at konink.de
Thu Sep 30 10:44:17 BST 2010

Hash: SHA512

Op 30-09-10 06:30, Scott Crosby schreef:
>     Also Osmosis currently implements deflate, not bzip2/lzma. (At the
>     time of writing I implemented bzip2 as well, but couldn't test it.)
> If I can find a lzma/bzip2 java code, its ready to plug them in.
> Although, I'm thinking that with the cost of bzip2 decompression, the
> only interesting case is lzma.


> I would be happy to help in the design and algorithms of a geometric
> index, but I don't have the time to program it. Are you interested in
> coding this? If done properly, geometric sorting code can do much much
> more than make a planet.osm.pbf indexable.

Always interesting in coding stuff ;)

> They can make very cheap tileservers. PrimitiveBlocks are independently
> decodable blobs; they can be stored in a database. Given a bbox query,
> select out all of the blobs that intersect it, concatenate them
> together, add a header, and thats a conforming *.osm.pbf file. Depending
> on the precision used and whether metadata is kept, that entire database
> can be cached into 6-10GB of RAM. 
> I would like to see this happen. 

We should pull in the guy that did this for the BZ2 planet.

> This may be a new way to distribute the planet: A set of PrimitiveBlock
> tiles sitting in an Sqlite database..... Actually, now that I think of
> it, this may be the superior approach compared to using my hooks to hack
> an index into the *.osm.pbf format.
>     - allow the use of the bbox
> What exactly do you mean by this: ?

Filter output by applying a bbox (the expensive way). Extract nodes
within a bbox, sort them on ID, extract all ways, validate per item if
any of the nd's are selected. Append remaining nodes to a miss list.
Same operation for relations. Run lookup for missing ways, fetch missing
node list.

>      + based on the index

The 'open index' that is not implemented should be implemented.

> And this: ?
>      + based on geos like solution

Allow the user to make non-rectangle selections.

>     My personal interest is going for output that support output that
>     can be used to 'copy into' data into a database. And extend the
>     current protocol for diff support. (Hence: replacing osmsucker-ykw)
> What kinds of extensions are you thinking of?

What we discussed {create,modify,delete}.

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