quota.py

from zope.app import zapi

from zope.interface import implements
from interfaces import IQuota,IQuotaContained,IQuotaSize
from zope.app.intid.interfaces import IIntIds

from persistent import Persistent
from zope.app.container.contained import Contained
from BTrees.IOBTree import IOBTree

class Quota(Contained,Persistent):
    __doc__ = IQuota.__doc__
    
    def __init__(self) :
        self.osz = IOBTree()
    

    implements(IQuota,IQuotaContained)

    # See quota.interfaces.IQuota
    quota = 0

    # See quota.interfaces.IQuota
    size = 0
    
    def handleAdded(self, object): 
        size = IQuotaSize(object).size
        self.osz[zapi.getUtility(IIntIds, context=self).getId(object)] = size
        self.size+=size
        if self.size > self.quota :
            raise ValueError
 
    def handleModified(self, object): 
        size = IQuotaSize(object).size
        try :
            self.size-=self.osz[zapi.getUtility(IIntIds, context=self).getId(object)]
        except KeyError :
            pass            
        self.osz[zapi.getUtility(IIntIds, context=self).getId(object)] = size
        self.size+=size
        if self.size > self.quota :
            raise ValueError
 
    def handleRemoved(self, object): 
        self.size-=IQuotaSize(object).size
        try :
            del(self.osz[zapi.getUtility(IIntIds, context=self).getId(object)])
        except KeyError :
            pass