|
1
|
1 |
|
import re |
|
2
|
1 |
|
import collections |
|
3
|
1 |
|
import functools |
|
4
|
1 |
|
import starstruct.bitfield |
|
5
|
|
|
|
|
6
|
|
|
|
|
7
|
1 |
|
class PackedBitField(object): |
|
8
|
|
|
""" |
|
9
|
|
|
A class that is used to bitwise pack/unpack one or more enumerations or |
|
10
|
|
|
bitfields to/from an integer value |
|
11
|
|
|
""" |
|
12
|
1 |
|
def __init__(self, *args): |
|
13
|
|
|
# Ensure that there are no duplicate enum or bitfield types in the list |
|
14
|
1 |
|
member_bitfields = (k for k in args if isinstance(k, starstruct.bitfield.BitField)) |
|
15
|
1 |
|
all_enums = args + tuple(b.enum for b in member_bitfields) |
|
16
|
1 |
|
if len(all_enums) != len(set(all_enums)): |
|
17
|
1 |
|
msg = 'Duplicate fields not allowed: {}'.format(args) |
|
18
|
1 |
|
raise TypeError(msg) |
|
19
|
|
|
|
|
20
|
|
|
# Ensure that all fields are either bitfields, or enums with all |
|
21
|
|
|
# members of each enumeration type are integers |
|
22
|
1 |
|
member_enums = (k for k in args if not isinstance(k, starstruct.bitfield.BitField)) |
|
23
|
1 |
|
for key in member_enums: |
|
24
|
1 |
|
if not all(isinstance(member.value, int) for member in key): |
|
25
|
1 |
|
msg = 'Enum {} members must have integer values'.format(repr(key)) |
|
26
|
1 |
|
raise TypeError(msg) |
|
27
|
|
|
|
|
28
|
|
|
# Allow enum to be a list of enumerations that need bitpacked sequentially |
|
29
|
1 |
|
self._fields = collections.OrderedDict(zip(args, [{}] * len(args))) |
|
30
|
|
|
|
|
31
|
|
|
# Determine the bits required for the enumeration so they can all be |
|
32
|
|
|
# packed correctly. Assume that the furthest right enumeration should |
|
33
|
|
|
# have a bit offset of 0. |
|
34
|
1 |
|
total_width = 0 |
|
35
|
1 |
|
for key in reversed(self._fields): |
|
|
|
|
|
|
36
|
1 |
|
if isinstance(key, starstruct.bitfield.BitField): |
|
37
|
1 |
|
all_bits = key.bit_mask |
|
38
|
|
|
else: |
|
39
|
1 |
|
all_bits = functools.reduce(lambda x, y: x | y, [k.value for k in key]) |
|
40
|
|
|
|
|
41
|
1 |
|
self._fields[key] = { |
|
42
|
|
|
'offset': total_width, |
|
43
|
|
|
'mask': all_bits << total_width, |
|
44
|
|
|
'width': all_bits.bit_length(), |
|
45
|
|
|
} |
|
46
|
|
|
|
|
47
|
1 |
|
total_width += self._fields[key]['width'] |
|
48
|
|
|
|
|
49
|
|
|
# Track the bit mask and bit length attributes just like BitField |
|
50
|
1 |
|
self.bit_mask = functools.reduce(lambda x, y: x | y, [v['mask'] for v in self._fields.values()]) |
|
51
|
1 |
|
self.bit_length = total_width |
|
52
|
|
|
|
|
53
|
1 |
|
def __repr__(self): |
|
54
|
|
|
return 'PackedBitField({})'.format(list(self._fields)) |
|
55
|
|
|
|
|
56
|
1 |
|
def __str__(self): |
|
57
|
1 |
|
return 'PackedBitField({})'.format(list(self._fields)) |
|
58
|
|
|
|
|
59
|
1 |
|
def find_value(self, item): |
|
60
|
|
|
""" |
|
61
|
|
|
Take a value, determine if it matches one, and only one, of the member fields |
|
62
|
|
|
""" |
|
63
|
|
|
# pylint: disable=too-many-branches |
|
64
|
|
|
|
|
65
|
|
|
# Split the member fields into bitfields and enums |
|
66
|
1 |
|
member_enums = [k for k in self._fields if not isinstance(k, starstruct.bitfield.BitField)] |
|
67
|
1 |
|
member_bitfields = [k for k in self._fields if isinstance(k, starstruct.bitfield.BitField)] |
|
68
|
|
|
|
|
69
|
|
|
# See if the supplied value is an enum or bitfield value |
|
70
|
1 |
|
matches = [] |
|
71
|
1 |
|
for key in member_bitfields: |
|
72
|
1 |
|
try: |
|
73
|
1 |
|
matches.append((key.find_value(item), key)) |
|
74
|
1 |
|
except ValueError: |
|
75
|
|
|
# This just means it isn't a member of this bitfield |
|
76
|
1 |
|
pass |
|
77
|
|
|
|
|
78
|
|
|
# Also check for matches in the enums. This helps guard against |
|
79
|
|
|
# ambiguous inputs where the bitfield and enum types overlap. |
|
80
|
1 |
|
if isinstance(item, tuple(member_enums)): |
|
81
|
1 |
|
for key in member_enums: |
|
82
|
1 |
|
if isinstance(item, key): |
|
83
|
|
|
# This is guaranteed a unique match, so return now |
|
84
|
1 |
|
return (item, key) |
|
85
|
1 |
|
elif isinstance(item, str): |
|
86
|
|
|
# If it's a string, then check it against the enum fields |
|
87
|
|
|
# (bitfields should already have been validated) |
|
88
|
1 |
|
for key in member_enums: |
|
89
|
1 |
|
try: |
|
90
|
1 |
|
matches.append((getattr(key, item), key)) |
|
91
|
1 |
|
except AttributeError: |
|
92
|
|
|
# This is the normal error to throw if the enum name is |
|
93
|
|
|
# not valid for this enumeration type. Check the next enum. |
|
94
|
1 |
|
pass |
|
95
|
|
|
else: |
|
96
|
|
|
# Lastly, assume that the item is an integer value, attempt to |
|
97
|
|
|
# convert it to one of the enum values to ensure it is a valid |
|
98
|
|
|
# value. But if it matches more than one member field, we are |
|
99
|
|
|
# unable to pack this properly. |
|
100
|
1 |
|
for key in member_enums: |
|
101
|
1 |
|
try: |
|
102
|
1 |
|
matches.append((key(item), key)) |
|
103
|
1 |
|
except ValueError: |
|
104
|
|
|
# This just means that the value is not valid for a |
|
105
|
|
|
# specific enum type, check all enums for a match before |
|
106
|
|
|
# raising a ValueError |
|
107
|
1 |
|
pass |
|
108
|
|
|
|
|
109
|
1 |
|
if len(matches) == 1: |
|
110
|
1 |
|
return matches[0] |
|
111
|
1 |
|
elif len(matches) < 1: |
|
112
|
1 |
|
msg = '{} is not a valid {}'.format(item, list(self._fields)) |
|
113
|
1 |
|
raise ValueError(msg) |
|
114
|
1 |
|
elif len(matches) > 1: |
|
115
|
1 |
|
msg = '{} is not a unique {}'.format(item, list(self._fields)) |
|
116
|
1 |
|
raise ValueError(msg) |
|
117
|
|
|
|
|
118
|
1 |
|
def pack(self, arg): |
|
119
|
|
|
""" |
|
120
|
|
|
Take a list (or single value) and bitwise-or all the values together |
|
121
|
|
|
""" |
|
122
|
1 |
|
value = 0 |
|
123
|
1 |
|
if arg is not None: |
|
124
|
|
|
# Handle a variety of inputs: list or single, enum or raw |
|
125
|
1 |
|
if hasattr(arg, '__iter__'): |
|
126
|
1 |
|
arg_list = arg |
|
127
|
|
|
else: |
|
128
|
1 |
|
arg_list = [arg] |
|
129
|
|
|
|
|
130
|
1 |
|
for item in arg_list: |
|
131
|
1 |
|
(enum_val, key) = self.find_value(item) |
|
132
|
1 |
|
value |= (enum_val.value << self._fields[key]['offset']) |
|
133
|
|
|
|
|
134
|
1 |
|
return value |
|
135
|
|
|
|
|
136
|
1 |
|
def unpack(self, val): |
|
137
|
|
|
""" |
|
138
|
|
|
Take a single number and split it out into all values that are present |
|
139
|
|
|
""" |
|
140
|
1 |
|
values = [] |
|
141
|
1 |
|
for key in self._fields: |
|
142
|
1 |
|
enum_specific_bits = (val & self._fields[key]['mask']) >> self._fields[key]['offset'] |
|
143
|
1 |
|
if isinstance(key, starstruct.bitfield.BitField): |
|
144
|
1 |
|
values.extend(key.unpack(enum_specific_bits)) |
|
145
|
|
|
else: |
|
146
|
1 |
|
try: |
|
147
|
1 |
|
values.append(key(enum_specific_bits)) |
|
148
|
1 |
|
except ValueError: |
|
149
|
1 |
|
enum_name = re.match(r"<enum '(\S+)'>", str(key)).group(1) |
|
150
|
1 |
|
msg = '{} is not a valid {}'.format(enum_specific_bits, enum_name) |
|
151
|
1 |
|
raise ValueError(msg) |
|
152
|
1 |
|
return frozenset(values) |
|
153
|
|
|
|
|
154
|
1 |
|
def make(self, arg): |
|
155
|
|
|
""" |
|
156
|
|
|
Take an input list and return a frozenset |
|
157
|
|
|
|
|
158
|
|
|
useful for testing |
|
159
|
|
|
""" |
|
160
|
|
|
values = [] |
|
161
|
|
|
if arg is not None: |
|
162
|
|
|
# Handle a variety of inputs: list or single, enum or raw |
|
163
|
|
|
if hasattr(arg, '__iter__'): |
|
164
|
|
|
arg_list = arg |
|
165
|
|
|
else: |
|
166
|
|
|
arg_list = [arg] |
|
167
|
|
|
|
|
168
|
|
|
for item in arg_list: |
|
169
|
|
|
values.append(self.find_value(item)[0]) |
|
170
|
|
|
|
|
171
|
|
|
# return this list as a frozenset |
|
172
|
|
|
return frozenset(values) |
|
173
|
|
|
|
sprout42 /
StarStruct
Loading history...