plugin_decorator.py

plugined_cache = {}
plugins = {}
def plugined(base_class):
	class_name = base_class.__name__
	if class_name in plugined_cache: 
		PluginedClass = plugined_cache[class_name]
	else:
		classes = plugins[class_name]+[base_class]
		classes.reverse()
		PluginedClass = type(class_name, tuple(classes), dict()) 
		plugined_cache[class_name] = PluginedClass
	return PluginedClass


def accept(base_class):
	class_name = base_class.__name__
	classes = plugins[class_name]
	classes.reverse()
	classes.append(base_class)
	PluginedClass = type(class_name, tuple(classes), dict()) 
	return PluginedClass


def to(class_name):
	if class_name not in plugins: plugins[class_name] = []

	def classDecorator(self):
		plugins[class_name].append(self)
		return self
	return classDecorator


@to("Request")
class RequestPlugin(object):
	def route1(self, req):
		return self.name, "Hello Plugin"

@to("Request")
class RequestPlugin2(object):
	def route2(self, req):
		return self.name, "Hello Plugin2"

@to("Request")
class RequestOverride(object):
	def route(self, req):
		back = super(RequestOverride, self).route(req)
		return self.name, "Overrided:", back


@accept
class Request(object):
	def __init__(self, name):
		self.name = name

	def route(self, req):
		return self.name, "Hello base"


import time
s = time.time()

for i in range(100000):
	request = Request("requester")
	back = request.route2("hello")
print "With 3 plugin", time.time()-s, back




class Request(object):
	def __init__(self, name):
		self.name = name

	def route(self, req):
		return self.name, "Hello base"

import time
s = time.time()

for i in range(100000):
	request = Request("requester")
	back = request.route("hello")
print "Without plugin", time.time()-s, back 

"""
With 3 plugin 0.201000213623 ('requester', 'Hello Plugin2')
Without plugin 0.198999881744 ('requester', 'Hello base')
"""