handlers.SocketHandler and exceptions

[Vinay Sajip]

On Jan 17, 1:47 pm, writeson <doug.farr... at gmail.com> wrote:
> Mark,
>
>
>
> > Check out the traceback module.  It can translate the traceback into a
> > variety of formats (such as a string) that can be pickled.
>
> > --Mark
>
> Thanks for the reply. I was looking at the traceback module and
> thinking along the same lines you are. The problem I'm having with
> that is how to modify the behavior of the SocketHandler code so it
> would call the traceback module functions. The point at which the
> handlers.SocketHandler code fails is in the method makePickle(), and
> I'm not sure how to overload/override that method. I tried creating my
> own class:
>
> class MySocketHandler(handlers.SocketHandler):
>     def makePickle(self, record):
>         # perform new code that transforms a Traceback object into a
> string
>
> but so far I haven't figured out how to get theloggingmodule to use
> my class. In myloggingconfiguration file I tried something like
> this:
>
> [handler_local_server]
> class=mydirectory.MySocketHandler
> level=DEBUG
> formatter=general
> args=("localhost", handlers.DEFAULT_TCP_LOGGING_PORT + 1)
>
> but I can't seem to get theloggingmodule to include mydirectory in
> its search path for modules.
>
> So that's where I'm stuck now.
>
> Again, thanks for your response,
> Doug

What version of Python are you running? Recent versions should have a
fix for this. Here's the makePickle method of SocketHandler:

    def makePickle(self, record):
        """
        Pickles the record in binary format with a length prefix, and
        returns it ready for transmission across the socket.
        """
        ei = record.exc_info
        if ei:
            dummy = self.format(record) # just to get traceback text
into record.exc_text
            record.exc_info = None  # to avoid Unpickleable error
        s = cPickle.dumps(record.__dict__, 1)
        if ei:
            record.exc_info = ei  # for next handler
        slen = struct.pack(">L", len(s))
        return slen + s

Notice the code to avoid the Unpickleable error.

Best regards,

Vinay Sajip