Karl Newman wrote: > On Sun, Feb 1, 2009 at 1:55 PM, Frederik Ramm <[email protected] > <mailto:[email protected]>> wrote: > > Hi, > > (f'up set to osmosis-dev) > > > Karl Newman wrote: > > Anyway, the tee can choke things up with all the temporary > files. It would > be nice to be able to share the stored node and ways files > between tee > tasks, but I haven't created that infrastructure yet. > > > It would be even better to have an extended --bp task that somehow > takes a list of disjoint polygons and uses some kind of point > location algorithm to determine which node belongs to which > polygon. The rationale being of course that with the classic > --bp/--tee approach, each node is duplicated n times and tested > against each of the polygons which is a waste of time, especially > with a large input file and many polygons (e.g. split up the US > into counties or so). > > Does the task and stream model that osmosis uses theoretically > support tasks where the number of output streams they create is > not fixed, but dependent on their parameters? So that e.g. a "bp > file=a.poly file=b.poly" (or "bp files=a.poly,b.poly") creates two > entity streams and so on? > > Bye > Frederik > > > What you're asking is possible. The number of input and output pipes > has to be known at invocation because the pipes are connected before > any tasks are run, but if it's a parameter passed to the task, then > the task can report to the pipeline manager how many output pipes it > has. The tricky part might be connecting the downstream tasks. It > might be confusing because of the stack-based pipeline ordering. If you want to see how this works, check out the SinkMultiSource interface which defines a task with a single input and multiple outputs. It is implemented by the EntityTee class which is the --tee task. It is integrated into the pipeline by the SinkMultiSourceManager class.
The SinkMultiSource interface defines a method called getSourceCount which allow tasks to tell the manager how many pipe outputs they have. It is called by SinkMultiSourceManager during pipeline startup. _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
