ncclient:NETCONF Python client

# Copyright 2h009 Shikhar Bhushan

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#    http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

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'Locking-related NETCONF operations'

from copy import deepcopy

from rpc import RPC

# TODO:

# should have some way to parse session-id from a lock-denied error

class Lock(RPC):

    "*<lock>* RPC"

    SPEC = {

        'tag': 'lock',

        'subtree': {

            'tag': 'target',

            'subtree': {'tag': None }

        }

    }

    #REPLY_CLS = LockReply

    def request(self, target):

        """

        :arg target: see :ref:`source_target`

        :type target: string

        :rtype: :ref:`return`

        """

        spec = deepcopy(Lock.SPEC)

        spec['subtree']['subtree']['tag'] = target

        return self._request(spec)

class Unlock(RPC):

    "*<unlock>* RPC"

    SPEC = {

        'tag': 'unlock',

        'subtree': {

            'tag': 'target',

            'subtree': {'tag': None }

        }

    }

    def request(self, target):

        """

        :arg target: see :ref:`source_target`

        :type target: string

        :rtype: :ref:`return`

        """

        spec = deepcopy(Unlock.SPEC)

        spec['subtree']['subtree']['tag'] = target

        return self._request(spec)

class LockContext:

    """

    A context manager for the :class:`Lock` / :class:`Unlock` pair of RPC's.

    RPC errors are always raised as exceptions.

    Initialise with session instance (:class:`Session

    <ncclient.transport.Session>`) and lock target (:ref:`source_target`)

    """

    def __init__(self, session, target):

        self.session = session

        self.target = target

    def __enter__(self):

        reply = Lock(self.session).request(self.target)

        if not reply.ok: # an error locking should definitely always be raised

            raise reply.error

        else:

            return self

    def __exit__(self, *args):

        reply = Unlock(self.session).request(self.target)

        if not reply.ok:

            raise reply.error

        return False