Coverage for d7a/alp/operands/length.py: 90%

41 statements  

« prev     ^ index     » next       coverage.py v7.5.0, created at 2024-05-24 08:03 +0200

1# 

2# Copyright (c) 2015-2021 University of Antwerp, Aloxy NV. 

3# 

4# This file is part of pyd7a. 

5# See https://github.com/Sub-IoT/pyd7a for further info. 

6# 

7# Licensed under the Apache License, Version 2.0 (the "License"); 

8# you may not use this file except in compliance with the License. 

9# You may obtain a copy of the License at 

10# 

11# http://www.apache.org/licenses/LICENSE-2.0 

12# 

13# Unless required by applicable law or agreed to in writing, software 

14# distributed under the License is distributed on an "AS IS" BASIS, 

15# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 

16# See the License for the specific language governing permissions and 

17# limitations under the License. 

18# 

19import struct 

20 

21from d7a.support.schema import Validatable, Types 

22 

23 

24class Length(Validatable): 

25 

26 SCHEMA = [ 

27 { 

28 "value": Types.INTEGER(min=0, max=0x3FFFFFFF) 

29 } 

30 ] 

31 

32 def __init__(self, value=0): 

33 self.value = value 

34 super(Length, self).__init__() 

35 

36 @staticmethod 

37 def parse(s): 

38 size = s.read("uint:2") # + 1 = already read 

39 value = s.read("uint:" + str(6 + (size * 8))) 

40 return Length(value=value) 

41 

42 def __iter__(self): 

43 byte = 0 

44 size = 1 

45 if self.value > 0x3F: 

46 size = 2 

47 if self.value > 0x3FFF: 

48 size = 3 

49 if self.value > 0x3FFFFF: 

50 size = 4 

51 

52 byte += (size - 1) << 6 

53 

54 if size == 1: 

55 byte += self.value 

56 yield byte 

57 else: 

58 length_bytes = bytearray(struct.pack(">I", self.value)) 

59 if size == 2: length_bytes = length_bytes[2:] 

60 elif size == 3: length_bytes = length_bytes[1:] 

61 

62 byte += length_bytes[0] 

63 yield byte 

64 for byte in length_bytes[1:]: yield byte 

65 

66 def __str__(self): 

67 return str(self.value) 

68 

69 def __eq__(self, other): 

70 if isinstance(other, self.__class__): 

71 return self.value == other.value 

72 elif isinstance(other, int): 

73 return self.value == other 

74 else: 

75 return False 

76 

77 def __ne__(self, other): 

78 return not self.__eq__(other)