def read(clasz, key, fetchmode=FetchMode.Property):
'''Read a Model from Cassandra'''
assert key and fetchmode, "specify key and fetchmode"
assert key.complete(), "your key has to be complete"
parent = ColumnParent(column_family = key.kind)
predicate = None
if fetchmode == FetchMode.Property:
if key.columns:
predicate = SlicePredicate(column_names = key.columns)
else:
type = Schema.ClassForModel(key.namespace, key.kind)
names = fields(type, Property).keys()
columns = list(names)
predicate = SlicePredicate(column_names = columns)
elif fetchmode == FetchMode.All:
range = SliceRange(start='', finish='', count = FETCHSIZE )
predicate = SlicePredicate(slice_range=range)
found = None
pool = poolFor(key.namespace)
with using(pool) as conn:
keyspace = keyspaceFor(key.namespace)
conn.client.set_keyspace(keyspace)
coscs = conn.client.get_slice(key.id, parent, predicate, clasz.consistency)
found = MetaModel.load(key, coscs)
return found
def delete(clasz, *keys):
'''Deletes a List of keys which represents Models'''
for key in keys:
assert key.complete(), "Your Key has to be complete to a delete"
path = ColumnPath(column_family = key.kind)
clock = time.time()
pool = poolFor(key.namespace)
with using(pool) as conn:
logging.info("DELETING %s FROM CASSANDRA" % key )
keyspace = keyspaceFor(key.namespace)
conn.client.set_keyspace(keyspace)
conn.client.remove(key.id, path, clock, clasz.consistency)
