Added Cassandra backend.

beaker_extensions/cassandra.py

@@ -0,0 +1,75 @@
+import logging
+from beaker.exceptions import InvalidCacheBackendError, MissingCacheParameter
+
+from beaker_extensions.nosql import Container
+from beaker_extensions.nosql import NoSqlManager
+from beaker_extensions.nosql import pickle
+
+try:
+    import pycassa
+except ImportError:
+    raise InvalidCacheBackendError("Cassandra cache backend requires the 'pycassa' library")
+
+log = logging.getLogger(__name__)
+
+class CassandraManager(NoSqlManager):
+    """
+    Cassandra backend for beaker.
+
+    Configuration example:
+        beaker.session.type = cassandra
+        beaker.session.url = localhost:9160
+        beaker.session.keyspace = Keyspace1
+        beaker.session.column_family = beaker
+
+    The default column_family is 'beaker'.
+    If it doesn't exist under given keyspace, it is created automatically.
+    """
+    def __init__(self, namespace, url=None, data_dir=None, lock_dir=None, keyspace=None, column_family=None, **params):
+        if not keyspace:
+            raise MissingCacheParameter("keyspace is required")
+        self.keyspace = keyspace
+        self.column_family = column_family or 'beaker'
+        NoSqlManager.__init__(self, namespace, url=url, data_dir=data_dir, lock_dir=lock_dir, **params)
+
+    def open_connection(self, host, port, **params):
+        self.pool = pycassa.ConnectionPool(self.keyspace)
+        try:
+            self.cf = pycassa.ColumnFamily(self.pool, self.column_family)
+        except pycassa.NotFoundException:
+            log.info("Creating new %s ColumnFamily." % self.column_family)
+            system_manager = pycassa.system_manager.SystemManager()
+            system_manager.create_column_family(self.keyspace, self.column_family)
+            self.cf = pycassa.ColumnFamily(self.pool, self.column_family)
+
+    def __contains__(self, key):        
+        return self.cf.get_count(self._format_key(key)) > 0
+
+    def set_value(self, key, value, expiretime=None):
+        key = self._format_key(key)
+        self.cf.insert(key, {'data': pickle.dumps(value)}, ttl=expiretime)
+
+    def __getitem__(self, key):
+        try:
+            result = self.cf.get(key)
+            return result['data']
+        except pycassa.NotFoundException:
+            return None
+
+    def __delitem__(self, key):        
+        key = self._format_key(key)
+        self.cf.remove(self._format_key(key))
+
+    def _format_key(self, key):
+        return '%s:%s' % (self.namespace, key.replace(' ', '\302\267'))
+
+    def do_remove(self):
+        for key, empty in cf.get_range(column_count=0, filter_empty=False):
+            cf.remove(key)
+
+    def keys(self):
+        return list(key for key, empty in self.cf.get_range(column_count=0, filter_empty=False))
+
+
+class CassandraContainer(Container):
+    namespace_manager = CassandraManager

setup.py

@@ -28,5 +28,6 @@
       riak = beaker_extensions.riak:RiakManager
       dynomite = beaker_extensions.dynomite_:DynomiteManager
       ringo = beaker_extensions.ringo:RingoManager
+      cassandra = beaker_extensions.cassandra:CassandraManager
       """,
       )