Synnefo » snf-ganeti

import inspect

import types

    self._method_invocations = {}

  def _RecordMethodInvocation(self, name, arg_dict):

    """ Records the invocation of a C{GanetiRAPIClient} method, noting the

    argument and the method names.

    """

    if name not in self._method_invocations:

      self._method_invocations[name] = set()

    for named_arg in arg_dict:

      self._method_invocations[name].add(named_arg)

  def _InvokerCreator(self, fn, name):

    """ Returns an invoker function that will invoke the given function

    with any arguments passed to the invoker at a later time, while

    catching any specific non-fatal errors we would like to know more

    about.

    @type fn arbitrary function

    @param fn The function to invoke later.

    @type name string

    @param name The name of the function, for debugging purposes.

    @rtype function

    """

    def decoratedFn(*args, **kwargs):

      result = None

      try:

        print "Using method %s" % name

        self._RecordMethodInvocation(name, kwargs)

        result = fn(*args, **kwargs)

      except GanetiApiError as e:

        print "RAPI error while performing function %s : %s" % \

              (name, str(e))

      return result

    return decoratedFn

    # We also want to expose non-methods

    if hasattr(self._client, attr) and \

       not isinstance(getattr(self._client, attr), types.MethodType):

      return getattr(self._client, attr)

      return self._InvokerCreator(self._client.__getattribute__(attr), attr)

  def _OutputMethodInvocationDetails(self):

    """ Attempts to output as much information as possible about the methods

    that have and have not been invoked, including which arguments have not

    been used.

    """

    print "\nMethod usage:\n"

    for method in [n for n in dir(self._client)

                     if not n.startswith('_') and

                        isinstance(self.__getattr__(n), types.FunctionType)]:

      if method not in self._method_invocations:

        print "Method unused: %s" % method

      else:

        arg_spec, _, _, default_arg_spec = \

          inspect.getargspec(getattr(self._client, method))

        default_args = []

        if default_arg_spec is not None:

          default_args = arg_spec[-len(default_arg_spec):]

        used_arg_set = self._method_invocations[method]

        unused_args = [arg for arg in default_args if arg not in used_arg_set]

        if unused_args:

          print "Method %s used, but arguments unused: %s" % \

                (method, ", ".join(unused_args))

  # The method invoked has the naming of the protected method, and pylint does

  # not like this. Disabling the warning is healthier than explicitly adding and

  # maintaining an exception for this method in the wrapper.

  # pylint: disable=W0212

  client._OutputMethodInvocationDetails()

  # pylint: enable=W0212