delimiter/delimiter/processors/upper_bound.py

55 lines
1.6 KiB
Python

# -*- coding: utf-8 -*-
#
# 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.
import collections
from delimiter import exceptions
from delimiter import processor
BoundedResource = collections.namedtuple('BoundedResource',
['consumed', 'bound'])
class UpperBoundProcessor(processor.Processor):
"""Processes a limit given some upper bound."""
@staticmethod
def create(limit):
return {
'consumed': 0,
'bound': limit,
}
@staticmethod
def decode(details):
return BoundedResource(details['consumed'], details['bound'])
@staticmethod
def update(details, limit):
details = details.copy()
details['bound'] = limit
return details
@staticmethod
def process(details, amount):
consumed = details['consumed']
if consumed + amount > details['bound']:
raise exceptions.OverLimitException(
"Limit of '%s' can not be passed" % details['bound'])
else:
details = details.copy()
details['consumed'] = consumed + amount
return details