JezK
Edit File: 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()