1######################## BEGIN LICENSE BLOCK ########################
2# The Original Code is Mozilla Communicator client 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, write to the Free Software
24# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
25# 02110-1301 USA
26######################### END LICENSE BLOCK #########################
27
28from typing import List, Optional, Union
29
30from .charsetprober import CharSetProber
31from .enums import LanguageFilter, ProbingState
32
33
34class CharSetGroupProber(CharSetProber):
35 def __init__(self, lang_filter: LanguageFilter = LanguageFilter.NONE) -> None:
36 super().__init__(lang_filter=lang_filter)
37 self._active_num = 0
38 self.probers: List[CharSetProber] = []
39 self._best_guess_prober: Optional[CharSetProber] = None
40
41 def reset(self) -> None:
42 super().reset()
43 self._active_num = 0
44 for prober in self.probers:
45 prober.reset()
46 prober.active = True
47 self._active_num += 1
48 self._best_guess_prober = None
49
50 @property
51 def charset_name(self) -> Optional[str]:
52 if not self._best_guess_prober:
53 self.get_confidence()
54 if not self._best_guess_prober:
55 return None
56 return self._best_guess_prober.charset_name
57
58 @property
59 def language(self) -> Optional[str]:
60 if not self._best_guess_prober:
61 self.get_confidence()
62 if not self._best_guess_prober:
63 return None
64 return self._best_guess_prober.language
65
66 def feed(self, byte_str: Union[bytes, bytearray]) -> ProbingState:
67 for prober in self.probers:
68 if not prober.active:
69 continue
70 state = prober.feed(byte_str)
71 if not state:
72 continue
73 if state == ProbingState.FOUND_IT:
74 self._best_guess_prober = prober
75 self._state = ProbingState.FOUND_IT
76 return self.state
77 if state == ProbingState.NOT_ME:
78 prober.active = False
79 self._active_num -= 1
80 if self._active_num <= 0:
81 self._state = ProbingState.NOT_ME
82 return self.state
83 return self.state
84
85 def get_confidence(self) -> float:
86 state = self.state
87 if state == ProbingState.FOUND_IT:
88 return 0.99
89 if state == ProbingState.NOT_ME:
90 return 0.01
91 best_conf = 0.0
92 self._best_guess_prober = None
93 for prober in self.probers:
94 if not prober.active:
95 self.logger.debug("%s not active", prober.charset_name)
96 continue
97 conf = prober.get_confidence()
98 self.logger.debug(
99 "%s %s confidence = %s", prober.charset_name, prober.language, conf
100 )
101 if best_conf < conf:
102 best_conf = conf
103 self._best_guess_prober = prober
104 if not self._best_guess_prober:
105 return 0.0
106 return best_conf