neutron/neutron/plugins/brocade/vlanbm.py

61 lines
2.0 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright 2013 Brocade Communications System, Inc.
# All rights reserved.
#
# 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, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
# Authors:
# Shiv Haris (sharis@brocade.com)
# Varma Bhupatiraju (vbhupati@#brocade.com)
"""A Vlan Bitmap class to handle allocation/de-allocation of vlan ids."""
from six import moves
from neutron.common import constants
from neutron.plugins.brocade.db import models as brocade_db
MIN_VLAN = constants.MIN_VLAN_TAG + 1
MAX_VLAN = constants.MAX_VLAN_TAG
class VlanBitmap(object):
"""Setup a vlan bitmap for allocation/de-allocation."""
# Keep track of the vlans that have been allocated/de-allocated
# uses a bitmap to do this
def __init__(self, ctxt):
"""Initialize the vlan as a set."""
self.vlans = set(int(net['vlan'])
for net in brocade_db.get_networks(ctxt)
if net['vlan']
)
def get_next_vlan(self, vlan_id=None):
"""Try to get a specific vlan if requested or get the next vlan."""
min_vlan_search = vlan_id or MIN_VLAN
max_vlan_search = (vlan_id and vlan_id + 1) or MAX_VLAN
for vlan in moves.xrange(min_vlan_search, max_vlan_search):
if vlan not in self.vlans:
self.vlans.add(vlan)
return vlan
def release_vlan(self, vlan_id):
"""Return the vlan to the pool."""
if vlan_id in self.vlans:
self.vlans.remove(vlan_id)