The current OSM server can hardly stand all the requests. Caches are needed. So little-osm is a start for any users that just want to read the data in their favourite application.
little-osm is an simple and primitive OSM server, aimed to be executed at anyone's home machine.
little-osm is intended as a read only server!
the README file contains partly incorrect instructions. The instructions below do work (at least on July, 11 2007)
- Get the Openstreetmap source code
- The little-osm codebase is under /applications/utils/little-osm/ in the main codebase
- Get ruby, rubygems and mysql ('gem install mysql', on Debian-based distros install the packages 'rubygems libmysql-ruby mysql-server', on Mandriva install the packages ruby, mysql and ruby-mysql)
- Get the planet.osm from somewhere. (http://josm.openstreetmap.de/wiki/Mirrors) and put this (unzipped) file in /applications/utils/little-osm/
- run 'mysql -u root < planet.sql' to create the table
- run 'ruby readxml.rb'. This will take awile. If you get errors after an hour, you have a corrupt planet.osm (Bugreport to user:Imi Imi)
- run the server with 'ruby server.rb'
What are differences?
There are some differences to the main server's map request:
- little-osm will order the objects in any arbitrary order.
- only nodes within the bbox are transfered. (The main OSM server also transfer nodes to line segments which have the other end in the bounding box.)
- segments, that cross the corners are transfered as well (but not their nodes). Some segments that actually do not cross the bbox could be also transfered.
|./readxml.rb||Script to convert a planet.osm into a mysql database|
|./planet.osm||here, you have to copy the planet.osm to read in.|
|test/*||Some unit tests.|
|api/||All API files reside here.|
The database in an very optimized format (for map-queries). It consist only of a single table:
CREATE TABLE `data` ( `uid` int(10) unsigned NOT NULL default '0', `tags` text, `time` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP, `reference` text, `min` point NOT NULL, `max` point NOT NULL, KEY `Index_1` (`uid`), spatial (`min`), spatial (`max`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
(see file applications/utils/little-osm/planet.sql)
- The uid is unique among all entries. It is the osm-id shifted by 3 bits, added 1 for segments and 2 for ways.
- The tags are an \n - seperated list of keys and values (key1\nvalue1\nkey2\n...).
- reference is empty for nodes, "from_id,to_id" for segments and "seg1,seg2,seg3..." for ways.
- The other coordinates are the bounding boxes for the object. For nodes, the bounding box is always only a point.