#
# This file is part of pysnmp software.
#
# Copyright (c) 2005-2016, Ilya Etingof <ilya@glas.net>
# License: http://pysnmp.sf.net/license.html
#
from pysnmp import nextid
from pysnmp.proto import error


class Cache:
    __stateReference = nextid.Integer(0xffffff)

    def __init__(self):
        self.__cacheEntries = {}

    def push(self, **securityData):
        stateReference = self.__stateReference()
        self.__cacheEntries[stateReference] = securityData
        return stateReference

    def pop(self, stateReference):
        if stateReference in self.__cacheEntries:
            securityData = self.__cacheEntries[stateReference]
        else:
            raise error.ProtocolError(
                'Cache miss for stateReference=%s at %s' % (stateReference, self)
            )
        del self.__cacheEntries[stateReference]
        return securityData