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

2# The Original Code is Mozilla Universal charset detector 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) 2001 

7# the Initial Developer. All Rights Reserved. 

8# 

9# Contributor(s): 

10# Mark Pilgrim - port to Python 

11# Shy Shalom - original C code 

12# Proofpoint, Inc. 

13# 

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

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

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

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

18# 

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

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

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

22# Lesser General Public License for more details. 

23# 

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

25# License along with this library; if not, write to the Free Software 

26# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 

27# 02110-1301 USA 

28######################### END LICENSE BLOCK ######################### 

29 

30from .charsetprober import CharSetProber 

31from .enums import ProbingState, MachineState 

32 

33 

34class MultiByteCharSetProber(CharSetProber): 

35 """ 

36 MultiByteCharSetProber 

37 """ 

38 

39 def __init__(self, lang_filter=None): 

40 super(MultiByteCharSetProber, self).__init__(lang_filter=lang_filter) 

41 self.distribution_analyzer = None 

42 self.coding_sm = None 

43 self._last_char = [0, 0] 

44 

45 def reset(self): 

46 super(MultiByteCharSetProber, self).reset() 

47 if self.coding_sm: 

48 self.coding_sm.reset() 

49 if self.distribution_analyzer: 

50 self.distribution_analyzer.reset() 

51 self._last_char = [0, 0] 

52 

53 @property 

54 def charset_name(self): 

55 raise NotImplementedError 

56 

57 @property 

58 def language(self): 

59 raise NotImplementedError 

60 

61 def feed(self, byte_str): 

62 for i in range(len(byte_str)): 

63 coding_state = self.coding_sm.next_state(byte_str[i]) 

64 if coding_state == MachineState.ERROR: 

65 self.logger.debug('%s %s prober hit error at byte %s', 

66 self.charset_name, self.language, i) 

67 self._state = ProbingState.NOT_ME 

68 break 

69 elif coding_state == MachineState.ITS_ME: 

70 self._state = ProbingState.FOUND_IT 

71 break 

72 elif coding_state == MachineState.START: 

73 char_len = self.coding_sm.get_current_charlen() 

74 if i == 0: 

75 self._last_char[1] = byte_str[0] 

76 self.distribution_analyzer.feed(self._last_char, char_len) 

77 else: 

78 self.distribution_analyzer.feed(byte_str[i - 1:i + 1], 

79 char_len) 

80 

81 self._last_char[0] = byte_str[-1] 

82 

83 if self.state == ProbingState.DETECTING: 

84 if (self.distribution_analyzer.got_enough_data() and 

85 (self.get_confidence() > self.SHORTCUT_THRESHOLD)): 

86 self._state = ProbingState.FOUND_IT 

87 

88 return self.state 

89 

90 def get_confidence(self): 

91 return self.distribution_analyzer.get_confidence()