def getNodePosition(cls, start, height=None) -> int:
"""
Calculates node position based on start and height
:param start: The sequence number of the first leaf under this tree.
:param height: Height of this node in the merkle tree
:return: the node's position
"""
pwr = highest_bit_set(start) - 1
height = height or pwr
if count_bits_set(start) == 1:
adj = height - pwr
return start - 1 + adj
else:
c = pow(2, pwr)
return cls.getNodePosition(c, pwr) + \
cls.getNodePosition(start - c, height)
def getNodePosition(cls, start, height=None) -> int:
"""
Calculates node position based on start and height
:param start: The sequence number of the first leaf under this tree.
:param height: Height of this node in the merkle tree
:return: the node's position
"""
pwr = highest_bit_set(start) - 1
height = height or pwr
if count_bits_set(start) == 1:
adj = height - pwr
return start - 1 + adj
else:
c = pow(2, pwr)
return cls.getNodePosition(c, pwr) + \
cls.getNodePosition(start - c, height)
def getPath(cls, seqNo, offset=0):
"""
Get the audit path of the leaf at the position specified by serNo.
:param seqNo: sequence number of the leaf to calculate the path for
:param offset: the sequence number of the node from where the path
should begin.
:return: tuple of leafs and nodes
"""
if offset >= seqNo:
raise ValueError("Offset should be less than serial number")
pwr = highest_bit_set(seqNo - 1 - offset) - 1
if pwr <= 0:
if seqNo % 2 == 0:
return [seqNo - 1], []
else:
return [], []
c = pow(2, pwr) + offset
leafs, nodes = cls.getPath(seqNo, c)
nodes.append(cls.getNodePosition(c, pwr))
return leafs, nodes
def getPath(cls, seqNo, offset=0):
"""
Get the audit path of the leaf at the position specified by serNo.
:param seqNo: sequence number of the leaf to calculate the path for
:param offset: the sequence number of the node from where the path
should begin.
:return: tuple of leafs and nodes
"""
if offset >= seqNo:
raise ValueError("Offset should be less than serial number")
pwr = highest_bit_set(seqNo - 1 - offset) - 1
if pwr <= 0:
if seqNo % 2 == 0:
return [seqNo - 1], []
else:
return [], []
c = pow(2, pwr) + offset
leafs, nodes = cls.getPath(seqNo, c)
nodes.append(cls.getNodePosition(c, pwr))
return leafs, nodes