######################## 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 typing import Optional, Union from .charsetprober import CharSetProber from .codingstatemachine import CodingStateMachine from .enums import LanguageFilter, MachineState, ProbingState from .escsm import ( HZ_SM_MODEL, ISO2022CN_SM_MODEL, ISO2022JP_SM_MODEL, ISO2022KR_SM_MODEL, ) class EscCharSetProber(CharSetProber): """ This CharSetProber uses a "code scheme" approach for detecting encodings, whereby easily recognizable escape or shift sequences are relied on to identify these encodings. """ def __init__(self, lang_filter: LanguageFilter = LanguageFilter.NONE) -> None: super().__init__(lang_filter=lang_filter) self.coding_sm = [] if self.lang_filter & LanguageFilter.CHINESE_SIMPLIFIED: self.coding_sm.append(CodingStateMachine(HZ_SM_MODEL)) self.coding_sm.append(CodingStateMachine(ISO2022CN_SM_MODEL)) if self.lang_filter & LanguageFilter.JAPANESE: self.coding_sm.append(CodingStateMachine(ISO2022JP_SM_MODEL)) if self.lang_filter & LanguageFilter.KOREAN: self.coding_sm.append(CodingStateMachine(ISO2022KR_SM_MODEL)) self.active_sm_count = 0 self._detected_charset: Optional[str] = None self._detected_language: Optional[str] = None self._state = ProbingState.DETECTING self.reset() def reset(self) -> None: super().reset() for coding_sm in self.coding_sm: coding_sm.active = True coding_sm.reset() self.active_sm_count = len(self.coding_sm) self._detected_charset = None self._detected_language = None @property def charset_name(self) -> Optional[str]: return self._detected_charset @property def language(self) -> Optional[str]: return self._detected_language def get_confidence(self) -> float: return 0.99 if self._detected_charset else 0.00 def feed(self, byte_str: Union[bytes, bytearray]) -> ProbingState: for c in byte_str: for coding_sm in self.coding_sm: if not coding_sm.active: continue coding_state = coding_sm.next_state(c) if coding_state == MachineState.ERROR: coding_sm.active = False self.active_sm_count -= 1 if self.active_sm_count <= 0: self._state = ProbingState.NOT_ME return self.state elif coding_state == MachineState.ITS_ME: self._state = ProbingState.FOUND_IT self._detected_charset = coding_sm.get_coding_state_machine() self._detected_language = coding_sm.language return self.state return self.state