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Diffstat (limited to 'requests/packages/chardet/universaldetector.py')
-rw-r--r-- | requests/packages/chardet/universaldetector.py | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/requests/packages/chardet/universaldetector.py b/requests/packages/chardet/universaldetector.py new file mode 100644 index 0000000..9a03ad3 --- /dev/null +++ b/requests/packages/chardet/universaldetector.py @@ -0,0 +1,170 @@ +######################## 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 ######################### + +from . import constants +import sys +import codecs +from .latin1prober import Latin1Prober # windows-1252 +from .mbcsgroupprober import MBCSGroupProber # multi-byte character sets +from .sbcsgroupprober import SBCSGroupProber # single-byte character sets +from .escprober import EscCharSetProber # ISO-2122, etc. +import re + +MINIMUM_THRESHOLD = 0.20 +ePureAscii = 0 +eEscAscii = 1 +eHighbyte = 2 + + +class UniversalDetector: + def __init__(self): + self._highBitDetector = re.compile(b'[\x80-\xFF]') + self._escDetector = re.compile(b'(\033|~{)') + self._mEscCharSetProber = None + self._mCharSetProbers = [] + self.reset() + + def reset(self): + self.result = {'encoding': None, 'confidence': 0.0} + self.done = False + self._mStart = True + self._mGotData = False + self._mInputState = ePureAscii + self._mLastChar = b'' + if self._mEscCharSetProber: + self._mEscCharSetProber.reset() + for prober in self._mCharSetProbers: + prober.reset() + + def feed(self, aBuf): + if self.done: + return + + aLen = len(aBuf) + if not aLen: + return + + if not self._mGotData: + # If the data starts with BOM, we know it is UTF + if aBuf[:3] == codecs.BOM: + # EF BB BF UTF-8 with BOM + self.result = {'encoding': "UTF-8", 'confidence': 1.0} + elif aBuf[:4] == codecs.BOM_UTF32_LE: + # FF FE 00 00 UTF-32, little-endian BOM + self.result = {'encoding': "UTF-32LE", 'confidence': 1.0} + elif aBuf[:4] == codecs.BOM_UTF32_BE: + # 00 00 FE FF UTF-32, big-endian BOM + self.result = {'encoding': "UTF-32BE", 'confidence': 1.0} + elif aBuf[:4] == 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 + } + elif aBuf[:4] == 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 + } + elif aBuf[:2] == codecs.BOM_LE: + # FF FE UTF-16, little endian BOM + self.result = {'encoding': "UTF-16LE", 'confidence': 1.0} + elif aBuf[:2] == codecs.BOM_BE: + # FE FF UTF-16, big endian BOM + self.result = {'encoding': "UTF-16BE", 'confidence': 1.0} + + self._mGotData = True + if self.result['encoding'] and (self.result['confidence'] > 0.0): + self.done = True + return + + if self._mInputState == ePureAscii: + if self._highBitDetector.search(aBuf): + self._mInputState = eHighbyte + elif ((self._mInputState == ePureAscii) and + self._escDetector.search(self._mLastChar + aBuf)): + self._mInputState = eEscAscii + + self._mLastChar = aBuf[-1:] + + if self._mInputState == eEscAscii: + if not self._mEscCharSetProber: + self._mEscCharSetProber = EscCharSetProber() + if self._mEscCharSetProber.feed(aBuf) == constants.eFoundIt: + self.result = {'encoding': self._mEscCharSetProber.get_charset_name(), + 'confidence': self._mEscCharSetProber.get_confidence()} + self.done = True + elif self._mInputState == eHighbyte: + if not self._mCharSetProbers: + self._mCharSetProbers = [MBCSGroupProber(), SBCSGroupProber(), + Latin1Prober()] + for prober in self._mCharSetProbers: + if prober.feed(aBuf) == constants.eFoundIt: + self.result = {'encoding': prober.get_charset_name(), + 'confidence': prober.get_confidence()} + self.done = True + break + + def close(self): + if self.done: + return + if not self._mGotData: + if constants._debug: + sys.stderr.write('no data received!\n') + return + self.done = True + + if self._mInputState == ePureAscii: + self.result = {'encoding': 'ascii', 'confidence': 1.0} + return self.result + + if self._mInputState == eHighbyte: + proberConfidence = None + maxProberConfidence = 0.0 + maxProber = None + for prober in self._mCharSetProbers: + if not prober: + continue + proberConfidence = prober.get_confidence() + if proberConfidence > maxProberConfidence: + maxProberConfidence = proberConfidence + maxProber = prober + if maxProber and (maxProberConfidence > MINIMUM_THRESHOLD): + self.result = {'encoding': maxProber.get_charset_name(), + 'confidence': maxProber.get_confidence()} + return self.result + + if constants._debug: + sys.stderr.write('no probers hit minimum threshhold\n') + for prober in self._mCharSetProbers[0].mProbers: + if not prober: + continue + sys.stderr.write('%s confidence = %s\n' % + (prober.get_charset_name(), + prober.get_confidence())) |