SickRage/lib/shove/store/cassandra.py

73 lines
2.1 KiB
Python

# -*- coding: utf-8 -*-
'''
Cassandra-based object store
The shove psuedo-URL for a cassandra-based store is:
cassandra://<host>:<port>/<keyspace>/<columnFamily>
'''
import urlparse
try:
import pycassa
except ImportError:
raise ImportError('This store requires the pycassa library')
from shove import BaseStore
class CassandraStore(BaseStore):
'''Cassandra based store'''
init = 'cassandra://'
def __init__(self, engine, **kw):
super(CassandraStore, self).__init__(engine, **kw)
spliturl = urlparse.urlsplit(engine)
_, keyspace, column_family = spliturl[2].split('/')
try:
self._pool = pycassa.connect(keyspace, [spliturl[1]])
self._store = pycassa.ColumnFamily(self._pool, column_family)
except pycassa.InvalidRequestException:
from pycassa.system_manager import SystemManager
system_manager = SystemManager(spliturl[1])
system_manager.create_keyspace(
keyspace,
pycassa.system_manager.SIMPLE_STRATEGY,
{'replication_factor': str(kw.get('replication', 1))}
)
system_manager.create_column_family(keyspace, column_family)
self._pool = pycassa.connect(keyspace, [spliturl[1]])
self._store = pycassa.ColumnFamily(self._pool, column_family)
def __getitem__(self, key):
try:
item = self._store.get(key).get(key)
if item is not None:
return self.loads(item)
raise KeyError(key)
except pycassa.NotFoundException:
raise KeyError(key)
def __setitem__(self, key, value):
self._store.insert(key, dict(key=self.dumps(value)))
def __delitem__(self, key):
# beware eventual consistency
try:
self._store.remove(key)
except pycassa.NotFoundException:
raise KeyError(key)
def clear(self):
# beware eventual consistency
self._store.truncate()
def keys(self):
return list(i[0] for i in self._store.get_range())
__all__ = ['CassandraStore']