Use a Riak bucket as a Django session store

# Do with this what you will but don't blame me if anything bad happens.
import time

from django.conf import settings
from django.contrib.sessions.backends.base import SessionBase, CreateError

import riak

class SessionStore(SessionBase):
	
	def __init__(self, session_key=None):
		self._client = riak.RiakClient()
		self._bucket = self._client.bucket('sessions')
		super(SessionStore, self).__init__(session_key)

	def load(self):
		# Get the session from Riak.
		session = self._bucket.get(self.session_key)
		if session.exists():
			session_data = session.get_data()
			return self.decode(session_data['data'])
		else:
			self.create()
			return {}

	def create(self):
		while True:
			self.session_key = self._get_new_session_key()
			try:
				self.save(must_create=True)
			except CreateError:
				# The key wasn't unique, try again
				continue
			self.modified = True
			return
		
	def save(self,must_create=True):
		session_key = self.session_key
		session_data = self.encode(self._get_session(no_load=must_create))
		expire_date = time.mktime(self.get_expiry_date().timetuple())
		session = self._bucket.new(session_key, data={
			'data': session_data,
			'expire': expire_date,
		})
		# Save the object to Riak.
		session.store()

	def exists(self, session_key):
		session = self._bucket.get(session_key)
		return session.exists()
	
	def delete(self, session_key=None):
		sk = session_key
		# Get the object and delete it if found.
		if session_key is None:
			sk = self.session_key
		session = self._bucket.get(sk)
		if session.exists():
			session.delete()