ncclient:NETCONF Python client

from weakref import WeakKeyDictionary, WeakValueDictionary

from ncclient.content.parsers import RootParser

from ncclient.content.common import qualify as _

from ncclient.content.common import BASE_NS

    _listeners = WeakKeyDictionary()

    _lock = Lock()

    def __init__(self, session):

        self._id = None

        self._reply = None # RPCReply

        self._reply_event = None

    @property

    def _listener(self):

        with self._lock:

            return self._listeners.setdefault(self._session, MessageListener())

    def _response_cb(self, raw):

        self._reply = RPCReply(raw)

        reply_event.set()

    def _do_request(self, op, reply_event=None):

        # get the listener instance for this session

        # <rpc-reply> with message id will reach response_cb

        self._listener.register(self._id, self._response_cb)

        # only effective the first time, transport.session.Subject internally

        # uses a set type for listeners

        self._session.add_listener(self._listener)

        req = RPCBuilder.build(self._id, op)

        self._session.send(req)

        if reply_event is not None: # if we were provided an Event to use

            self._reply_event = reply_event

        else: # otherwise, block till response received and return it

            self._reply_event = Event()

            self._reply.parse()

            return self._reply

    def request(self, *args, **kwds):

        try:

            return self._reply_event.isSet()

        except TypeError: # reply_event is None

            return False

    def __init__(self, raw):

        self._raw = raw

        self._parsed = False

        self._ok = None

        self._errs = []

    def __str__(self):

        return self._raw

    @property

    def raw(self):

        return self._raw

    def parse(self):

        #errs = RPCParser.parse(self._raw)

        #for raw, err_dict in errs:

        #    self._errs.append(RPCError(raw, err_dict))

        self._parsed = True

    @property

    def parsed(self):

        return self._parsed

    @property

    def ok(self):

        return True if self._parsed and not self._err else False

    @property

    def errors(self):

        return self._errs

    @property

    def raw(self):

        return self._raw

class RPCError(Exception): # raise it if you like

    def __init__(self, raw, err_dict):

        self._raw = raw

        self._dict = err_dict

    def __str__(self):

        # TODO

        return self._raw

    def __dict__(self):

        return self._dict

    @property

    def raw(self):

        return self._raw

    @property

    def type(self):

        return self._dict.get('type', None)

    @property

    def severity(self):

        return self._dict.get('severity', None)

    @property

    def tag(self):

        return self._dict.get('tag', None)

    @property

    def path(self):

        return self._dict.get('path', None)

    @property

    def message(self):

        return self._dict.get('message', None)

    @property

    def info(self):

        return self._dict.get('info', None)

class SessionListener:

    '''This is the glue between received data and the object it should be

    forwarded to.

    '''

    def __init__(self):

        # this dictionary takes care of <rpc-reply> elements received

        # { 'message-id': callback } dict

        self._id2cb = WeakValueDictionary()

        # this is a more generic dict takes care of other top-level elements

        # that may be received, e.g. <notification>'s

        # {'tag': callback} dict

        self._tag2cb = WeakValueDictionary() 

        # if we receive a SessionCloseError it might not be one we want to act on

        self._expecting_close = False

        self._errback = None # error event callback

        self._lock = Lock()

    def __str__(self):

        return 'SessionListener'

    def register(self, msgid, cb):

        with self._lock:

            self._id2cb[msgid] = cb

    def recognize(self, tag, cb):

        with self._lock:

            self._tag2cb[tag] = cb

    def expect_close(self):

        self._expecting_close = True

    @property

    def _recognized_elements(self):

        elems = [_('rpc-reply', BASE_NS)]

        with self._lock:

            elems.extend(self._tag2cb.keys())

        return elems

    def reply(self, raw):

        tag, attrs = RootParser.parse(raw, self._recognized_elements)

        try:

            cb = None

            if tag == _('rpc-reply', BASE_NS):

                try:

                    id = attrs[_('message-id', BASE_NS)]

                except KeyError:

                    logger.warning('<rpc-reply> w/o message-id attr received: %s'

                                   % raw)

                cb = self._id2cb.get(id, None)

            else:

                cb = self._tag2cb.get(tag, None)

            if cb is not None:

                cb(raw)

        except Exception as e:

            logger.warning('SessionListener.reply: %r' % e)

    def set_errback(self, errback):

        self._errback = errback

    def error(self, err):

        from ncclient.transport.error import SessionCloseError

        act = True

        if isinstance(err, SessionCloseError):

            logger.debug('session closed, expecting_close=%s' %

                         self._expecting_close)

            if self._expecting_close:

                act = False

        if act:

            logger.error('SessionListener.error: %r' % err)

            if self._errback is not None:

                errback(err)