Source code for chardet.sjisprober

######################## BEGIN LICENSE BLOCK ########################
# The Original Code is mozilla.org code.
#
# The Initial Developer of the Original Code is
# Netscape Communications Corporation.
# Portions created by the Initial Developer are Copyright (C) 1998
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
#   Mark Pilgrim - port to Python
#
# 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 .chardistribution import SJISDistributionAnalysis
from .codingstatemachine import CodingStateMachine
from .enums import MachineState, ProbingState
from .jpcntx import SJISContextAnalysis
from .mbcharsetprober import MultiByteCharSetProber
from .mbcssm import SJIS_SM_MODEL


[docs]class SJISProber(MultiByteCharSetProber): def __init__(self): super().__init__() self.coding_sm = CodingStateMachine(SJIS_SM_MODEL) self.distribution_analyzer = SJISDistributionAnalysis() self.context_analyzer = SJISContextAnalysis() self.reset()
[docs] def reset(self): super().reset() self.context_analyzer.reset()
@property def charset_name(self): return self.context_analyzer.charset_name @property def language(self): return "Japanese"
[docs] def feed(self, byte_str): for i in range(len(byte_str)): coding_state = self.coding_sm.next_state(byte_str[i]) if coding_state == MachineState.ERROR: self.logger.debug( "%s %s prober hit error at byte %s", self.charset_name, self.language, i, ) self._state = ProbingState.NOT_ME break elif coding_state == MachineState.ITS_ME: self._state = ProbingState.FOUND_IT break elif coding_state == MachineState.START: char_len = self.coding_sm.get_current_charlen() if i == 0: self._last_char[1] = byte_str[0] self.context_analyzer.feed( self._last_char[2 - char_len :], char_len ) self.distribution_analyzer.feed(self._last_char, char_len) else: self.context_analyzer.feed( byte_str[i + 1 - char_len : i + 3 - char_len], char_len ) self.distribution_analyzer.feed(byte_str[i - 1 : i + 1], char_len) self._last_char[0] = byte_str[-1] if self.state == ProbingState.DETECTING: if self.context_analyzer.got_enough_data() and ( self.get_confidence() > self.SHORTCUT_THRESHOLD ): self._state = ProbingState.FOUND_IT return self.state
[docs] def get_confidence(self): context_conf = self.context_analyzer.get_confidence() distrib_conf = self.distribution_analyzer.get_confidence() return max(context_conf, distrib_conf)