def _get_packed_fingerprint():
if node_t._packed_fingerprint is None:
node_t._packed_fingerprint = struct.pack(">Q", node_t._get_hash_recursive([]))
return node_t._packed_fingerprint
def _get_hash_recursive(parents):
if node_t in parents: return 0
newparents = parents + [node_t]
tmphash = (0x98ff4a363aeb7273+ node_t._get_hash_recursive(newparents)) & 0xffffffffffffffff
tmphash = (((tmphash<<1)&0xffffffffffffffff) + (tmphash>>63)) & 0xffffffffffffffff
return tmphash
