[Zope] Detecting dropped client connection?

[Dieter Maurer]

Stuart Bishop writes:
 > I have a method that generates a large database report (around 4MB).
 > It takes around 5 minutes to generate, but I can happily stream it
 > to the client using RESPONSE.write().
 > 
 > What I have noticed, however, is that if the client drops the connection,
 > my method just keeps processing oblivious wasting ram, cycles but most
 > importantly a Zope thread. Is there a call I can make for my code to 
 > check
 > if the connection is still valid, allowing it to die if nothing is
 > listening to it?
Difficult....

  The connection shutdown in recognized in a ZServer thread.
  A series of producers is used to interface this thread with
  the Zope thread.
  You would need to enchance the producers with a method,
  say "abortProcessing" which modifies the producer's state
  such that when the Zope thread delivers data for the next
  time, an exception is raised, aborting the thread execution.


Dieter