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Diffstat (limited to 'game/python-extra/chardet/universaldetector.py')
| -rw-r--r-- | game/python-extra/chardet/universaldetector.py | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/game/python-extra/chardet/universaldetector.py b/game/python-extra/chardet/universaldetector.py new file mode 100644 index 0000000..7b4e92d --- /dev/null +++ b/game/python-extra/chardet/universaldetector.py @@ -0,0 +1,286 @@ +######################## 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 +# +# 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 ######################### +""" +Module containing the UniversalDetector detector class, which is the primary +class a user of ``chardet`` should use. + +:author: Mark Pilgrim (initial port to Python) +:author: Shy Shalom (original C code) +:author: Dan Blanchard (major refactoring for 3.0) +:author: Ian Cordasco +""" + + +import codecs +import logging +import re + +from .charsetgroupprober import CharSetGroupProber +from .enums import InputState, LanguageFilter, ProbingState +from .escprober import EscCharSetProber +from .latin1prober import Latin1Prober +from .mbcsgroupprober import MBCSGroupProber +from .sbcsgroupprober import SBCSGroupProber + + +class UniversalDetector(object): + """ + The ``UniversalDetector`` class underlies the ``chardet.detect`` function + and coordinates all of the different charset probers. + + To get a ``dict`` containing an encoding and its confidence, you can simply + run: + + .. code:: + + u = UniversalDetector() + u.feed(some_bytes) + u.close() + detected = u.result + + """ + + MINIMUM_THRESHOLD = 0.20 + HIGH_BYTE_DETECTOR = re.compile(b'[\x80-\xFF]') + ESC_DETECTOR = re.compile(b'(\033|~{)') + WIN_BYTE_DETECTOR = re.compile(b'[\x80-\x9F]') + ISO_WIN_MAP = {'iso-8859-1': 'Windows-1252', + 'iso-8859-2': 'Windows-1250', + 'iso-8859-5': 'Windows-1251', + 'iso-8859-6': 'Windows-1256', + 'iso-8859-7': 'Windows-1253', + 'iso-8859-8': 'Windows-1255', + 'iso-8859-9': 'Windows-1254', + 'iso-8859-13': 'Windows-1257'} + + def __init__(self, lang_filter=LanguageFilter.ALL): + self._esc_charset_prober = None + self._charset_probers = [] + self.result = None + self.done = None + self._got_data = None + self._input_state = None + self._last_char = None + self.lang_filter = lang_filter + self.logger = logging.getLogger(__name__) + self._has_win_bytes = None + self.reset() + + def reset(self): + """ + Reset the UniversalDetector and all of its probers back to their + initial states. This is called by ``__init__``, so you only need to + call this directly in between analyses of different documents. + """ + self.result = {'encoding': None, 'confidence': 0.0, 'language': None} + self.done = False + self._got_data = False + self._has_win_bytes = False + self._input_state = InputState.PURE_ASCII + self._last_char = b'' + if self._esc_charset_prober: + self._esc_charset_prober.reset() + for prober in self._charset_probers: + prober.reset() + + def feed(self, byte_str): + """ + Takes a chunk of a document and feeds it through all of the relevant + charset probers. + + After calling ``feed``, you can check the value of the ``done`` + attribute to see if you need to continue feeding the + ``UniversalDetector`` more data, or if it has made a prediction + (in the ``result`` attribute). + + .. note:: + You should always call ``close`` when you're done feeding in your + document if ``done`` is not already ``True``. + """ + if self.done: + return + + if not len(byte_str): + return + + if not isinstance(byte_str, bytearray): + byte_str = bytearray(byte_str) + + # First check for known BOMs, since these are guaranteed to be correct + if not self._got_data: + # If the data starts with BOM, we know it is UTF + if byte_str.startswith(codecs.BOM_UTF8): + # EF BB BF UTF-8 with BOM + self.result = {'encoding': "UTF-8-SIG", + 'confidence': 1.0, + 'language': ''} + elif byte_str.startswith((codecs.BOM_UTF32_LE, + codecs.BOM_UTF32_BE)): + # FF FE 00 00 UTF-32, little-endian BOM + # 00 00 FE FF UTF-32, big-endian BOM + self.result = {'encoding': "UTF-32", + 'confidence': 1.0, + 'language': ''} + elif byte_str.startswith(b'\xFE\xFF\x00\x00'): + # FE FF 00 00 UCS-4, unusual octet order BOM (3412) + self.result = {'encoding': "X-ISO-10646-UCS-4-3412", + 'confidence': 1.0, + 'language': ''} + elif byte_str.startswith(b'\x00\x00\xFF\xFE'): + # 00 00 FF FE UCS-4, unusual octet order BOM (2143) + self.result = {'encoding': "X-ISO-10646-UCS-4-2143", + 'confidence': 1.0, + 'language': ''} + elif byte_str.startswith((codecs.BOM_LE, codecs.BOM_BE)): + # FF FE UTF-16, little endian BOM + # FE FF UTF-16, big endian BOM + self.result = {'encoding': "UTF-16", + 'confidence': 1.0, + 'language': ''} + + self._got_data = True + if self.result['encoding'] is not None: + self.done = True + return + + # If none of those matched and we've only see ASCII so far, check + # for high bytes and escape sequences + if self._input_state == InputState.PURE_ASCII: + if self.HIGH_BYTE_DETECTOR.search(byte_str): + self._input_state = InputState.HIGH_BYTE + elif self._input_state == InputState.PURE_ASCII and \ + self.ESC_DETECTOR.search(self._last_char + byte_str): + self._input_state = InputState.ESC_ASCII + + self._last_char = byte_str[-1:] + + # If we've seen escape sequences, use the EscCharSetProber, which + # uses a simple state machine to check for known escape sequences in + # HZ and ISO-2022 encodings, since those are the only encodings that + # use such sequences. + if self._input_state == InputState.ESC_ASCII: + if not self._esc_charset_prober: + self._esc_charset_prober = EscCharSetProber(self.lang_filter) + if self._esc_charset_prober.feed(byte_str) == ProbingState.FOUND_IT: + self.result = {'encoding': + self._esc_charset_prober.charset_name, + 'confidence': + self._esc_charset_prober.get_confidence(), + 'language': + self._esc_charset_prober.language} + self.done = True + # If we've seen high bytes (i.e., those with values greater than 127), + # we need to do more complicated checks using all our multi-byte and + # single-byte probers that are left. The single-byte probers + # use character bigram distributions to determine the encoding, whereas + # the multi-byte probers use a combination of character unigram and + # bigram distributions. + elif self._input_state == InputState.HIGH_BYTE: + if not self._charset_probers: + self._charset_probers = [MBCSGroupProber(self.lang_filter)] + # If we're checking non-CJK encodings, use single-byte prober + if self.lang_filter & LanguageFilter.NON_CJK: + self._charset_probers.append(SBCSGroupProber()) + self._charset_probers.append(Latin1Prober()) + for prober in self._charset_probers: + if prober.feed(byte_str) == ProbingState.FOUND_IT: + self.result = {'encoding': prober.charset_name, + 'confidence': prober.get_confidence(), + 'language': prober.language} + self.done = True + break + if self.WIN_BYTE_DETECTOR.search(byte_str): + self._has_win_bytes = True + + def close(self): + """ + Stop analyzing the current document and come up with a final + prediction. + + :returns: The ``result`` attribute, a ``dict`` with the keys + `encoding`, `confidence`, and `language`. + """ + # Don't bother with checks if we're already done + if self.done: + return self.result + self.done = True + + if not self._got_data: + self.logger.debug('no data received!') + + # Default to ASCII if it is all we've seen so far + elif self._input_state == InputState.PURE_ASCII: + self.result = {'encoding': 'ascii', + 'confidence': 1.0, + 'language': ''} + + # If we have seen non-ASCII, return the best that met MINIMUM_THRESHOLD + elif self._input_state == InputState.HIGH_BYTE: + prober_confidence = None + max_prober_confidence = 0.0 + max_prober = None + for prober in self._charset_probers: + if not prober: + continue + prober_confidence = prober.get_confidence() + if prober_confidence > max_prober_confidence: + max_prober_confidence = prober_confidence + max_prober = prober + if max_prober and (max_prober_confidence > self.MINIMUM_THRESHOLD): + charset_name = max_prober.charset_name + lower_charset_name = max_prober.charset_name.lower() + confidence = max_prober.get_confidence() + # Use Windows encoding name instead of ISO-8859 if we saw any + # extra Windows-specific bytes + if lower_charset_name.startswith('iso-8859'): + if self._has_win_bytes: + charset_name = self.ISO_WIN_MAP.get(lower_charset_name, + charset_name) + self.result = {'encoding': charset_name, + 'confidence': confidence, + 'language': max_prober.language} + + # Log all prober confidences if none met MINIMUM_THRESHOLD + if self.logger.getEffectiveLevel() == logging.DEBUG: + if self.result['encoding'] is None: + self.logger.debug('no probers hit minimum threshold') + for group_prober in self._charset_probers: + if not group_prober: + continue + if isinstance(group_prober, CharSetGroupProber): + for prober in group_prober.probers: + self.logger.debug('%s %s confidence = %s', + prober.charset_name, + prober.language, + prober.get_confidence()) + else: + self.logger.debug('%s %s confidence = %s', + prober.charset_name, + prober.language, + prober.get_confidence()) + return self.result |