wsgi.py 文件源码

def pre_process_extensions(self, extensions, request, action_args):
        # List of callables for post-processing extensions
        post = []

        for ext in extensions:
            if inspect.isgeneratorfunction(ext):
                response = None

                # If it's a generator function, the part before the
                # yield is the preprocessing stage
                try:
                    with ResourceExceptionHandler():
                        gen = ext(req=request, **action_args)
                        response = next(gen)
                except Fault as ex:
                    response = ex

                # We had a response...
                if response:
                    return response, []

                # No response, queue up generator for post-processing
                post.append(gen)
            else:
                # Regular functions only perform post-processing
                post.append(ext)

        # Run post-processing in the reverse order
        return None, reversed(post)