Current File : //lib/python3/dist-packages/chardet/mbcharsetprober.py
######################## BEGIN LICENSE BLOCK ########################
# 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):
# Mark Pilgrim - port to Python
# Shy Shalom - original C code
# Proofpoint, Inc.
#
# 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 Optional, Union
from .chardistribution import CharDistributionAnalysis
from .charsetprober import CharSetProber
from .codingstatemachine import CodingStateMachine
from .enums import LanguageFilter, MachineState, ProbingState
class MultiByteCharSetProber(CharSetProber):
"""
MultiByteCharSetProber
"""
def __init__(self, lang_filter: LanguageFilter = LanguageFilter.NONE) -> None:
super().__init__(lang_filter=lang_filter)
self.distribution_analyzer: Optional[CharDistributionAnalysis] = None
self.coding_sm: Optional[CodingStateMachine] = None
self._last_char = bytearray(b"\0\0")
def reset(self) -> None:
super().reset()
if self.coding_sm:
self.coding_sm.reset()
if self.distribution_analyzer:
self.distribution_analyzer.reset()
self._last_char = bytearray(b"\0\0")
def feed(self, byte_str: Union[bytes, bytearray]) -> ProbingState:
assert self.coding_sm is not None
assert self.distribution_analyzer is not None
for i, byte in enumerate(byte_str):
coding_state = self.coding_sm.next_state(byte)
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
if coding_state == MachineState.ITS_ME:
self._state = ProbingState.FOUND_IT
break
if coding_state == MachineState.START:
char_len = self.coding_sm.get_current_charlen()
if i == 0:
self._last_char[1] = byte
self.distribution_analyzer.feed(self._last_char, char_len)
else:
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.distribution_analyzer.got_enough_data() and (
self.get_confidence() > self.SHORTCUT_THRESHOLD
):
self._state = ProbingState.FOUND_IT
return self.state
def get_confidence(self) -> float:
assert self.distribution_analyzer is not None
return self.distribution_analyzer.get_confidence()
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