Viewing file:  rbtree.py (4.25 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
# SPDX-License-Identifier: GPL-2.0
#
# Copyright 2019 Google LLC.
import gdb
from linux import utils
rb_root_type = utils.CachedType("struct rb_root")
rb_node_type = utils.CachedType("struct rb_node")
def rb_first(root):
if root.type == rb_root_type.get_type():
node = root.address.cast(rb_root_type.get_type().pointer())
elif root.type != rb_root_type.get_type().pointer():
raise gdb.GdbError("Must be struct rb_root not {}".format(root.type))
node = root['rb_node']
if node == 0:
return None
while node['rb_left']:
node = node['rb_left']
return node
def rb_last(root):
if root.type == rb_root_type.get_type():
node = root.address.cast(rb_root_type.get_type().pointer())
elif root.type != rb_root_type.get_type().pointer():
raise gdb.GdbError("Must be struct rb_root not {}".format(root.type))
node = root['rb_node']
if node == 0:
return None
while node['rb_right']:
node = node['rb_right']
return node
def rb_parent(node):
parent = gdb.Value(node['__rb_parent_color'] & ~3)
return parent.cast(rb_node_type.get_type().pointer())
def rb_empty_node(node):
return node['__rb_parent_color'] == node.address
def rb_next(node):
if node.type == rb_node_type.get_type():
node = node.address.cast(rb_node_type.get_type().pointer())
elif node.type != rb_node_type.get_type().pointer():
raise gdb.GdbError("Must be struct rb_node not {}".format(node.type))
if rb_empty_node(node):
return None
if node['rb_right']:
node = node['rb_right']
while node['rb_left']:
node = node['rb_left']
return node
parent = rb_parent(node)
while parent and node == parent['rb_right']:
node = parent
parent = rb_parent(node)
return parent
def rb_prev(node):
if node.type == rb_node_type.get_type():
node = node.address.cast(rb_node_type.get_type().pointer())
elif node.type != rb_node_type.get_type().pointer():
raise gdb.GdbError("Must be struct rb_node not {}".format(node.type))
if rb_empty_node(node):
return None
if node['rb_left']:
node = node['rb_left']
while node['rb_right']:
node = node['rb_right']
return node.dereference()
parent = rb_parent(node)
while parent and node == parent['rb_left'].dereference():
node = parent
parent = rb_parent(node)
return parent
class LxRbFirst(gdb.Function):
"""Lookup and return a node from an RBTree
$lx_rb_first(root): Return the node at the given index.
If index is omitted, the root node is dereferenced and returned."""
def __init__(self):
super(LxRbFirst, self).__init__("lx_rb_first")
def invoke(self, root):
result = rb_first(root)
if result is None:
raise gdb.GdbError("No entry in tree")
return result
LxRbFirst()
class LxRbLast(gdb.Function):
"""Lookup and return a node from an RBTree.
$lx_rb_last(root): Return the node at the given index.
If index is omitted, the root node is dereferenced and returned."""
def __init__(self):
super(LxRbLast, self).__init__("lx_rb_last")
def invoke(self, root):
result = rb_last(root)
if result is None:
raise gdb.GdbError("No entry in tree")
return result
LxRbLast()
class LxRbNext(gdb.Function):
"""Lookup and return a node from an RBTree.
$lx_rb_next(node): Return the node at the given index.
If index is omitted, the root node is dereferenced and returned."""
def __init__(self):
super(LxRbNext, self).__init__("lx_rb_next")
def invoke(self, node):
result = rb_next(node)
if result is None:
raise gdb.GdbError("No entry in tree")
return result
LxRbNext()
class LxRbPrev(gdb.Function):
"""Lookup and return a node from an RBTree.
$lx_rb_prev(node): Return the node at the given index.
If index is omitted, the root node is dereferenced and returned."""
def __init__(self):
super(LxRbPrev, self).__init__("lx_rb_prev")
def invoke(self, node):
result = rb_prev(node)
if result is None:
raise gdb.GdbError("No entry in tree")
return result
LxRbPrev()
|