def _read_extended(self, offset):
next_byte = int_from_byte(self._buffer[offset])
type_num = next_byte + 7
if type_num < 7:
raise InvalidDatabaseError(
'Something went horribly wrong in the decoder. An '
'extended type resolved to a type number < 8 '
'({type})'.format(type=type_num))
return type_num, offset + 1
def _find_address_in_tree(self, ip_address):
packed = ip_address.packed
bit_count = len(packed) * 8
node = self._start_node(bit_count)
for i in range(bit_count):
if node >= self._metadata.node_count:
break
bit = 1 & (int_from_byte(packed[i >> 3]) >> 7 - (i % 8))
node = self._read_node(node, bit)
if node == self._metadata.node_count:
# Record is empty
return 0
elif node > self._metadata.node_count:
return node
raise InvalidDatabaseError('Invalid node in search tree')
def _find_address_in_tree(self, ip_address):
packed = ip_address.packed
bit_count = len(packed) * 8
node = self._start_node(bit_count)
for i in range(bit_count):
if node >= self._metadata.node_count:
break
bit = 1 & (int_from_byte(packed[i >> 3]) >> 7 - (i % 8))
node = self._read_node(node, bit)
if node == self._metadata.node_count:
# Record is empty
return 0
elif node > self._metadata.node_count:
return node
raise InvalidDatabaseError('Invalid node in search tree')
def _size_from_ctrl_byte(self, ctrl_byte, offset, type_num):
size = ctrl_byte & 0x1f
if type_num == 1 or size < 29:
return size, offset
if size == 29:
size = 29 + int_from_byte(self._buffer[offset])
return size, offset + 1
# Using unpack rather than int_from_bytes as it is faster
# here and below.
if size == 30:
new_offset = offset + 2
size_bytes = self._buffer[offset:new_offset]
size = 285 + struct.unpack(b'!H', size_bytes)[0]
return size, new_offset
new_offset = offset + 3
size_bytes = self._buffer[offset:new_offset]
size = struct.unpack(b'!I', b'\x00' + size_bytes)[0] + 65821
return size, new_offset
def decode(self, offset):
"""Decode a section of the data section starting at offset
Arguments:
offset -- the location of the data structure to decode
"""
new_offset = offset + 1
ctrl_byte = int_from_byte(self._buffer[offset])
type_num = ctrl_byte >> 5
# Extended type
if not type_num:
(type_num, new_offset) = self._read_extended(new_offset)
try:
decoder = self._type_decoder[type_num]
except KeyError:
raise InvalidDatabaseError('Unexpected type number ({type}) '
'encountered'.format(type=type_num))
(size, new_offset) = self._size_from_ctrl_byte(ctrl_byte, new_offset,
type_num)
return decoder(self, size, new_offset)
def test_byte(self):
# Python 2.6 doesn't support dictionary comprehension
b = dict((byte_from_int(0xc0 ^ int_from_byte(k[0])) + k[1:],
v.encode('utf-8')) for k, v in self.strings.items())
self.validate_type_decoding('byte', b)
def test_byte(self):
# Python 2.6 doesn't support dictionary comprehension
b = dict((byte_from_int(0xc0 ^ int_from_byte(k[0])) + k[1:],
v.encode('utf-8'))
for k, v in self.strings.items())
self.validate_type_decoding('byte', b)
