[OSM-talk] Street Labels

Lars Aronsson lars at aronsson.se
Mon Mar 13 20:53:34 GMT 2006


Joerg Ostertag wrote:

> Last time I tried it online it was so extremly incredibly slow, 
> that I thought i can't handle it. This was the reason I decided 
> only to try it localy.

The slowness that has occasionally (a few days every month) been 
observed in the OSM editing applet (clicking the "Edit" tab on the 
website) has always depended on unusually long response times from 
the server, caused either by slow hardware or by various software 
bugs in the server, introduced by accident as the system is 
continously under development.  The execution speed of the Java 
code in the applet has never been the issue, as far as I can tell.

The Java applet undergoes very little development, so very few 
bugs are introduced there.  This is why it lacks so many features 
that are available in the stand-alone editors, such as adding 
class attributes for roads.

The defensive client programmer (whether applet or stand-alone) 
should never assume that client-server calls are responded to in 
zero time.  Instead, such calls should be made in a separate 
thread and if the response takes more than 1 or 2 seconds, a 
warning message should be given to the user that the server seems 
to be slow.  This shifts the blame from the client program to the 
server. The current Java applet gives no such warnings.

When a piece of software is self-aware enough to shift the blame 
to some other part of the system ("it wasn't me!"), I call that 
subject-oriented programming.


-- 
  Lars Aronsson (lars at aronsson.se)
  Aronsson Datateknik - http://aronsson.se




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