PyConquer

Here's a WSGI middleware component for using [http://projects.amor.org/misc/wiki/PyConquer pyconquer] with any CherryPy app. It's a great way to find threading problems, as well as profile call times. PyConquer was built to resolve some concurrency issues while I was writing {{{test_states.py}}}, and really helped me untangle the interaction between request threads, the main thread, and (the old CP 2) autoreload.

{{{
#!python
class WSGILogger(object):
    """A WSGI middleware app which wraps 'nextapp' with pyconquer."""
    
    def __init__(self, nextapp, path="pyconquer.log"):
        self.nextapp = nextapp
        self.path = path
        f = open(self.path, "wb")
        f.write("")
        f.close()
    
    def run(self, func, *args):
        """run(func, *args). Run func, dumping trace data into self.path."""
        import pyconquer
        tr = pyconquer.Logger(events = ['call', 'return', 'exception',
                                        'c_call', 'c_return', 'c_exception',
                                        ])
        tr.out = open(self.path, "ab")
        tr.time_calls = True
        try:
            tr.start()
            return func(*args)
        finally:
            tr.stop()
            tr.out.close()
    
    def __call__(self, environ, start_response):
        # Wrap the request in a function so we get a "total time".
        def gather():
            result = []
            for line in self.nextapp(environ, start_response):
                result.append(line)
            return result
        return self.run(gather)
}}}