[osmosis-dev] preprocessing for turn-restrictions usins an osmosis-plugin

[marcus.wolschon at googlemail.com]

On Thu, 19 Feb 2009 23:26:20 +1100, Brett Henderson <brett at bretth.com>
wrote:
>> Maybe: 
>> DatasetReader => Dataset or RandomAccessData or Map
>> Dataset => DatasetFactory or RandomAccessFactory or MapFactory
>> DatasetSink => DatasetClient or RandomAccessClient or MapAccessClient
>>   as the task need not be a sink for data
>>   comming from the Dataset but be a source for data going into it or
>>   both.
>> with the tasks named:
>>  --get-XYZ-dataset or --access-XYZ or --XYZ-map
>>   
> Okay, this might sound pedantic but I don't feel all that strongly about 
> it.  The Dataset interface is what is passed between tasks. 

Yes, it is passed. But it is not read. --read-dataset for me implies 
that you read something and following modifications to affect only the
in-memory-copy but not the original.
A clear naming makes things intuitive, I don't care what name you
decide on in the end as long as the metapher fits.

> It 
> represents a set of data to be read (and now modified).  I'd rather not 
> call it DatasetFactory because that would imply that it can be used to 
> create datasets which is not the case, the data already exists (it may 
> be empty but it exists).  The issue I ran into when creating this is 
> that multiple threads may access the Dataset concurrently (I initially 
> created it to extract many bboxes concurrently).  Where the data is 
> backed by a database that means each thread requires its own 
> connection.  So each task must instantiate a connection when it starts 
> processing, and close it when it is done.  The DatasetReader provides 
> the means to hold that connection specific context.  The DatasetReader 
> name is no longer appropriate but I thought something equivalent would 
> be okay.  Is it really that confusing?

Actually..yes. "Dataset" implies a set of data to be accessed.
Returning it from a DatasetReaser implies that it is a temporary
construct reat from somewhere and to be written back at a later point
in time.

> As for the DatasetSink name, I merely named it that to align with the 
> rest of the Sink Source model.  I like the sound of DatasetClient.
> 
> What does "Map" in some of the above names represent?  Map as in 
> OpenStreetMap, or Map as in HashMap?

As in OpenStreetMap but you are right. I did not think about the
association with "to map A to B".



> You can code it if you like :-)  Do you have svn access?

Nope, no SVN-access.
Where can I get access? (Have to look in the OSM-wiki,
it "should" be in there somewhere.)

> I haven't been doing much lately other than writing emails.  I still 
> haven't done the writeable entity stuff although that shouldn't take 
> long once I get into it.  I want to get that done first, then I might 
> have time for this writeable Dataset stuff.  If you want to make a start 
> though it would be great.  The days of me having time to do it all 
> myself appear to be over.

First it will take me a few days, maybe a week, to make my algorithm
with the turn-restrictions working. I want this to be in my version 1.0 .
Then I can help you with the changes to osmosis, so I can turn it into
an osmosis-task later.

Marcus