|
1
|
1 |
|
import re |
|
2
|
1 |
|
import functools |
|
3
|
|
|
|
|
4
|
|
|
|
|
5
|
1 |
|
class BitField(object): |
|
6
|
1 |
|
def __init__(self, enum): |
|
7
|
1 |
|
if not all(isinstance(member.value, int) for member in enum): |
|
8
|
1 |
|
msg = 'Enum {} members must have integer values'.format(repr(enum)) |
|
9
|
1 |
|
raise TypeError(msg) |
|
10
|
1 |
|
try: |
|
11
|
1 |
|
assert enum(0) |
|
12
|
1 |
|
msg = 'Cannot construct BitField from {} with a value for 0: {}' |
|
13
|
1 |
|
raise TypeError(msg.format(repr(enum), enum(0))) |
|
14
|
1 |
|
except ValueError: |
|
15
|
|
|
# A ValueError is raised if the enum does not have a value for 0 |
|
16
|
1 |
|
pass |
|
17
|
1 |
|
self.enum = enum |
|
18
|
|
|
|
|
19
|
|
|
# Determine the bit mask and length for this bitfield |
|
20
|
1 |
|
self.bit_mask = functools.reduce(lambda x, y: x | y, [e.value for e in self.enum]) |
|
21
|
1 |
|
self.bit_length = self.bit_mask.bit_length() |
|
22
|
|
|
|
|
23
|
1 |
|
def __repr__(self): |
|
24
|
1 |
|
return 'BitField({})'.format(self.enum) |
|
25
|
|
|
|
|
26
|
1 |
|
def __str__(self): |
|
27
|
|
|
return 'BitField({})'.format(self.enum) |
|
28
|
|
|
|
|
29
|
1 |
|
def find_value(self, item): |
|
30
|
|
|
""" |
|
31
|
|
|
Take a value and determine the enumeration value based on value or |
|
32
|
|
|
enum memeber name. |
|
33
|
|
|
""" |
|
34
|
|
|
# pylint: disable=too-many-branches |
|
35
|
1 |
|
if isinstance(item, str): |
|
36
|
|
|
# To make usage a bit nice/easier if the elements of the list are |
|
37
|
|
|
# strings assume that they are enum names and attempt to convert |
|
38
|
|
|
# them to the correct enumeration values. |
|
39
|
1 |
|
try: |
|
40
|
1 |
|
value = getattr(self.enum, item) |
|
41
|
1 |
|
except AttributeError: |
|
42
|
|
|
# This is the normal error to throw if the enum name is |
|
43
|
|
|
# not valid for this enumeration type. |
|
44
|
1 |
|
enum_name = re.match(r"<enum '(\S+)'>", str(self.enum)).group(1) |
|
45
|
1 |
|
msg = '{} is not a valid {}'.format(item, enum_name) |
|
46
|
1 |
|
raise ValueError(msg) |
|
47
|
1 |
|
elif isinstance(item, self.enum): |
|
48
|
1 |
|
value = item |
|
49
|
|
|
else: |
|
50
|
|
|
# Assume that the item is an integer value, convert it to an enum |
|
51
|
|
|
# value to ensure it is a valid value for this bitfield |
|
52
|
1 |
|
try: |
|
53
|
1 |
|
value = self.enum(item) |
|
54
|
1 |
|
except ValueError: |
|
55
|
|
|
# This value is not a valid enumeration value |
|
56
|
1 |
|
enum_name = re.match(r"<enum '(\S+)'>", str(self.enum)).group(1) |
|
57
|
1 |
|
msg = '{} is not a valid {}'.format(item, enum_name) |
|
58
|
1 |
|
raise ValueError(msg) |
|
59
|
|
|
|
|
60
|
1 |
|
return value |
|
61
|
|
|
|
|
62
|
1 |
|
def pack(self, arg): |
|
63
|
|
|
""" |
|
64
|
|
|
Take a list (or single value) and bitwise-or all the values together |
|
65
|
|
|
""" |
|
66
|
1 |
|
value = 0 |
|
67
|
1 |
|
if arg is not None: |
|
68
|
|
|
# Handle a variety of inputs: list or single, enum or raw |
|
69
|
1 |
|
if hasattr(arg, '__iter__'): |
|
70
|
1 |
|
arg_list = arg |
|
71
|
|
|
else: |
|
72
|
1 |
|
arg_list = [arg] |
|
73
|
|
|
|
|
74
|
1 |
|
for item in arg_list: |
|
75
|
1 |
|
value |= self.find_value(item).value |
|
76
|
|
|
|
|
77
|
1 |
|
return value |
|
78
|
|
|
|
|
79
|
1 |
|
def unpack(self, val): |
|
80
|
|
|
""" |
|
81
|
|
|
Take a single number and split it out into all values that are present |
|
82
|
|
|
""" |
|
83
|
1 |
|
return frozenset(e for e in self.enum if e.value & val) |
|
84
|
|
|
|
|
85
|
1 |
|
def make(self, arg): |
|
86
|
|
|
""" |
|
87
|
|
|
Take an input list and return a frozenset |
|
88
|
|
|
|
|
89
|
|
|
useful for testing |
|
90
|
|
|
""" |
|
91
|
|
|
values = [] |
|
92
|
|
|
if arg is not None: |
|
93
|
|
|
# Handle a variety of inputs: list or single, enum or raw |
|
94
|
|
|
if hasattr(arg, '__iter__'): |
|
95
|
|
|
arg_list = arg |
|
96
|
|
|
else: |
|
97
|
|
|
arg_list = [arg] |
|
98
|
|
|
|
|
99
|
|
|
for item in arg_list: |
|
100
|
|
|
values.append(self.find_value(item)) |
|
101
|
|
|
|
|
102
|
|
|
# return this list as a frozenset |
|
103
|
|
|
return frozenset(values) |
|
104
|
|
|
|
sprout42 /
StarStruct
