20 def is_internal_node(node):  argument
22 …return ((node.cast(long_type) & constants.LX_RADIX_TREE_ENTRY_MASK) == constants.LX_RADIX_TREE_INT…
24 def entry_to_node(node):  argument
26     node_type = node.type
27     indirect_ptr = node.cast(long_type) & ~constants.LX_RADIX_TREE_INTERNAL_NODE
30 def node_maxindex(node):  argument
31     return (constants.LX_RADIX_TREE_MAP_SIZE << node['shift']) - 1
35         node = root.dereference()
40     node = root['xa_head']
41     if node == 0:
44     if not (is_internal_node(node)):
47         return node
49     node = entry_to_node(node)
50     maxindex = node_maxindex(node)
55     shift = node['shift'] + constants.LX_RADIX_TREE_MAP_SHIFT
58         offset = (index >> node['shift']) & constants.LX_RADIX_TREE_MAP_MASK
59         slot = node['slots'][offset]
64         node = slot.cast(node.type.pointer()).dereference()
65         if node == 0:
72     return node