Spaces:
Runtime error
Runtime error
File size: 6,077 Bytes
0c87db7 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 |
######################## BEGIN LICENSE BLOCK ########################
# This code was modified from latin1prober.py by Rob Speer <[email protected]>.
# The Original Code is Mozilla Universal charset detector code.
#
# The Initial Developer of the Original Code is
# Netscape Communications Corporation.
# Portions created by the Initial Developer are Copyright (C) 2001
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
# Rob Speer - adapt to MacRoman encoding
# Mark Pilgrim - port to Python
# Shy Shalom - original C code
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
# 02110-1301 USA
######################### END LICENSE BLOCK #########################
from typing import List, Union
from .charsetprober import CharSetProber
from .enums import ProbingState
FREQ_CAT_NUM = 4
UDF = 0 # undefined
OTH = 1 # other
ASC = 2 # ascii capital letter
ASS = 3 # ascii small letter
ACV = 4 # accent capital vowel
ACO = 5 # accent capital other
ASV = 6 # accent small vowel
ASO = 7 # accent small other
ODD = 8 # character that is unlikely to appear
CLASS_NUM = 9 # total classes
# The change from Latin1 is that we explicitly look for extended characters
# that are infrequently-occurring symbols, and consider them to always be
# improbable. This should let MacRoman get out of the way of more likely
# encodings in most situations.
# fmt: off
MacRoman_CharToClass = (
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 00 - 07
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 08 - 0F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 10 - 17
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 18 - 1F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 20 - 27
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 28 - 2F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 30 - 37
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # 38 - 3F
OTH, ASC, ASC, ASC, ASC, ASC, ASC, ASC, # 40 - 47
ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, # 48 - 4F
ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC, # 50 - 57
ASC, ASC, ASC, OTH, OTH, OTH, OTH, OTH, # 58 - 5F
OTH, ASS, ASS, ASS, ASS, ASS, ASS, ASS, # 60 - 67
ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, # 68 - 6F
ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS, # 70 - 77
ASS, ASS, ASS, OTH, OTH, OTH, OTH, OTH, # 78 - 7F
ACV, ACV, ACO, ACV, ACO, ACV, ACV, ASV, # 80 - 87
ASV, ASV, ASV, ASV, ASV, ASO, ASV, ASV, # 88 - 8F
ASV, ASV, ASV, ASV, ASV, ASV, ASO, ASV, # 90 - 97
ASV, ASV, ASV, ASV, ASV, ASV, ASV, ASV, # 98 - 9F
OTH, OTH, OTH, OTH, OTH, OTH, OTH, ASO, # A0 - A7
OTH, OTH, ODD, ODD, OTH, OTH, ACV, ACV, # A8 - AF
OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH, # B0 - B7
OTH, OTH, OTH, OTH, OTH, OTH, ASV, ASV, # B8 - BF
OTH, OTH, ODD, OTH, ODD, OTH, OTH, OTH, # C0 - C7
OTH, OTH, OTH, ACV, ACV, ACV, ACV, ASV, # C8 - CF
OTH, OTH, OTH, OTH, OTH, OTH, OTH, ODD, # D0 - D7
ASV, ACV, ODD, OTH, OTH, OTH, OTH, OTH, # D8 - DF
OTH, OTH, OTH, OTH, OTH, ACV, ACV, ACV, # E0 - E7
ACV, ACV, ACV, ACV, ACV, ACV, ACV, ACV, # E8 - EF
ODD, ACV, ACV, ACV, ACV, ASV, ODD, ODD, # F0 - F7
ODD, ODD, ODD, ODD, ODD, ODD, ODD, ODD, # F8 - FF
)
# 0 : illegal
# 1 : very unlikely
# 2 : normal
# 3 : very likely
MacRomanClassModel = (
# UDF OTH ASC ASS ACV ACO ASV ASO ODD
0, 0, 0, 0, 0, 0, 0, 0, 0, # UDF
0, 3, 3, 3, 3, 3, 3, 3, 1, # OTH
0, 3, 3, 3, 3, 3, 3, 3, 1, # ASC
0, 3, 3, 3, 1, 1, 3, 3, 1, # ASS
0, 3, 3, 3, 1, 2, 1, 2, 1, # ACV
0, 3, 3, 3, 3, 3, 3, 3, 1, # ACO
0, 3, 1, 3, 1, 1, 1, 3, 1, # ASV
0, 3, 1, 3, 1, 1, 3, 3, 1, # ASO
0, 1, 1, 1, 1, 1, 1, 1, 1, # ODD
)
# fmt: on
class MacRomanProber(CharSetProber):
def __init__(self) -> None:
super().__init__()
self._last_char_class = OTH
self._freq_counter: List[int] = []
self.reset()
def reset(self) -> None:
self._last_char_class = OTH
self._freq_counter = [0] * FREQ_CAT_NUM
# express the prior that MacRoman is a somewhat rare encoding;
# this can be done by starting out in a slightly improbable state
# that must be overcome
self._freq_counter[2] = 10
super().reset()
@property
def charset_name(self) -> str:
return "MacRoman"
@property
def language(self) -> str:
return ""
def feed(self, byte_str: Union[bytes, bytearray]) -> ProbingState:
byte_str = self.remove_xml_tags(byte_str)
for c in byte_str:
char_class = MacRoman_CharToClass[c]
freq = MacRomanClassModel[(self._last_char_class * CLASS_NUM) + char_class]
if freq == 0:
self._state = ProbingState.NOT_ME
break
self._freq_counter[freq] += 1
self._last_char_class = char_class
return self.state
def get_confidence(self) -> float:
if self.state == ProbingState.NOT_ME:
return 0.01
total = sum(self._freq_counter)
confidence = (
0.0
if total < 0.01
else (self._freq_counter[3] - self._freq_counter[1] * 20.0) / total
)
confidence = max(confidence, 0.0)
# lower the confidence of MacRoman so that other more accurate
# detector can take priority.
confidence *= 0.73
return confidence
|