Coverage for ion/core/intercept/interceptor : 91.67%

#!/usr/bin/env python 

""" 

@file ion/core/intercept/interceptor.py 

@author Michael Meisinger 

@brief capability container interceptor system (security, governance) 

""" 

from twisted.internet import defer 

import ion.util.ionlog 

log = ion.util.ionlog.getLogger(__name__) 

from ion.core import ioninit 

from ion.core.process.cprocess import ContainerProcess, Invocation 

from ion.core.exception import ConfigurationError 

import ion.util.procutils as pu 

# Configuration 

CONF = ioninit.config(__name__) 

msg_sign = CONF.getValue('msg_sign', True) 

class Interceptor(ContainerProcess): 

    """ 

    Interceptor that processes messages as the come along and passes them on. 

    """ 

class EnvelopeInterceptor(Interceptor): 

    """ 

    Interceptor that can process messages in the in-path and out-path. Just a 

    wrapper for code to keep both complementing actions together. 

    Note: There is NO guanantee that for one incoming message there is one 

    outgoing message 

    """ 

    def process(self, invocation): 

        """ 

        @param invocation container object for parameters 

        @retval invocation instance, may be modified 

        """ 

        if invocation.path == Invocation.PATH_IN: 

            return defer.maybeDeferred(self.before, invocation) 

        elif invocation.path == Invocation.PATH_OUT: 

            return defer.maybeDeferred(self.after, invocation) 

        else: 

            raise ConfigurationError("Illegal EnvelopeInterceptor path: %s" % invocation.path) 

    def before(self, invocation): 

        return invocation 

    def after(self, invocation): 

        return invocation 

class PassThroughInterceptor(EnvelopeInterceptor): 

    """ 

    Interceptor that drops messages. 

    """ 

    def before(self, invocation): 

        invocation.proceed() 

        return invocation 

    def after(self, invocation): 

        invocation.proceed() 

        return invocation 

class DropInterceptor(EnvelopeInterceptor): 

    """ 

    Interceptor that drops messages. 

    """ 

    def before(self, invocation): 

        invocation.drop() 

        return invocation 

    def after(self, invocation): 

        invocation.drop() 

        return invocation