Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/chardet/utf8prober.py: 93%

1######################## BEGIN LICENSE BLOCK ######################## 

2# The Original Code is mozilla.org code. 

3# 

4# The Initial Developer of the Original Code is 

5# Netscape Communications Corporation. 

6# Portions created by the Initial Developer are Copyright (C) 1998 

7# the Initial Developer. All Rights Reserved. 

8# 

9# Contributor(s): 

10# Mark Pilgrim - port to Python 

11# 

12# This library is free software; you can redistribute it and/or 

13# modify it under the terms of the GNU Lesser General Public 

14# License as published by the Free Software Foundation; either 

15# version 2.1 of the License, or (at your option) any later version. 

16# 

17# This library is distributed in the hope that it will be useful, 

18# but WITHOUT ANY WARRANTY; without even the implied warranty of 

19# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 

20# Lesser General Public License for more details. 

21# 

22# You should have received a copy of the GNU Lesser General Public 

23# License along with this library; if not, see 

24# <https://www.gnu.org/licenses/>. 

25######################### END LICENSE BLOCK ######################### 

26 

27from typing import Union 

28 

29from .charsetprober import CharSetProber 

30from .codingstatemachine import CodingStateMachine 

31from .enums import MachineState, ProbingState 

32from .mbcssm import UTF8_SM_MODEL 

33 

34 

35class UTF8Prober(CharSetProber): 

36 ONE_CHAR_PROB = 0.5 

37 

38 def __init__(self) -> None: 

39 super().__init__() 

40 self.coding_sm = CodingStateMachine(UTF8_SM_MODEL) 

41 self._num_mb_chars = 0 

42 self.reset() 

43 

44 def reset(self) -> None: 

45 super().reset() 

46 self.coding_sm.reset() 

47 self._num_mb_chars = 0 

48 

49 @property 

50 def charset_name(self) -> str: 

51 return "utf-8" 

52 

53 @property 

54 def language(self) -> str: 

55 return "" 

56 

57 def feed(self, byte_str: Union[bytes, bytearray]) -> ProbingState: 

58 for c in byte_str: 

59 coding_state = self.coding_sm.next_state(c) 

60 if coding_state == MachineState.ERROR: 

61 self._state = ProbingState.NOT_ME 

62 break 

63 if coding_state == MachineState.ITS_ME: 

64 self._state = ProbingState.FOUND_IT 

65 break 

66 if coding_state == MachineState.START: 

67 if self.coding_sm.get_current_charlen() >= 2: 

68 self._num_mb_chars += 1 

69 

70 if self.state == ProbingState.DETECTING: 

71 if self.get_confidence() > self.SHORTCUT_THRESHOLD: 

72 self._state = ProbingState.FOUND_IT 

73 

74 return self.state 

75 

76 def get_confidence(self) -> float: 

77 unlike = 0.99 

78 if self._num_mb_chars < 6: 

79 unlike *= self.ONE_CHAR_PROB**self._num_mb_chars 

80 return 1.0 - unlike 

81 return unlike