initial vints_unpack

cassandra/cqltypes.py

@@ -48,7 +48,7 @@ from cassandra.marshal import (int8_pack, int8_unpack, int16_pack, int16_unpack,
                                uint16_pack, uint16_unpack, uint32_pack, uint32_unpack,
                                int32_pack, int32_unpack, int64_pack, int64_unpack,
                                float_pack, float_unpack, double_pack, double_unpack,
-                               varint_pack, varint_unpack)
+                               varint_pack, varint_unpack, vints_unpack)
 from cassandra import util
 
 apache_cassandra_type_prefix = 'org.apache.cassandra.db.marshal.'
@@ -660,6 +660,20 @@ class TimeType(_CassandraType):
         return int64_pack(nano)
 
 
+class DurationType(_CassandraType):
+    typename = 'duration'
+
+    @staticmethod
+    def deserialize(byts, protocol_version):
+        print vints_unpack(byts)
+        varint_unpack(byts)
+        return varint_unpack(byts)
+
+    @staticmethod
+    def serialize(byts, protocol_version):
+        return # ...
+
+
 class UTF8Type(_CassandraType):
     typename = 'text'
     empty_binary_ok = True

cassandra/marshal.py

@@ -84,3 +84,18 @@ def varint_pack(big):
         revbytes.append(0)
     revbytes.reverse()
     return six.binary_type(revbytes)
+
+
+def decode_zig_zag(n):
+    return (n >> 1) ^ -(n & 1)
+
+
+def vints_unpack(term):  # noqa
+    first_byte = ord(term[0])
+    if (first_byte & 128) == 0:
+        val = first_byte
+    else:
+        extra_bytes = 8 - (~first_byte & 0xff).bit_length()
+        # takes (8-extra_bytes) bits + extra_bytes
+
+    return decode_zig_zag(val)