Update of 3rd party library chardet

This commit is contained in:
Miroslav Stampar
2022-03-03 18:03:01 +01:00
parent 75905e0cd9
commit bacf18832a
42 changed files with 2025 additions and 2959 deletions

View File

@@ -26,95 +26,107 @@
# 02110-1301 USA
######################### END LICENSE BLOCK #########################
import sys
from . import constants
from .charsetprober import CharSetProber
from .compat import wrap_ord
SAMPLE_SIZE = 64
SB_ENOUGH_REL_THRESHOLD = 1024
POSITIVE_SHORTCUT_THRESHOLD = 0.95
NEGATIVE_SHORTCUT_THRESHOLD = 0.05
SYMBOL_CAT_ORDER = 250
NUMBER_OF_SEQ_CAT = 4
POSITIVE_CAT = NUMBER_OF_SEQ_CAT - 1
#NEGATIVE_CAT = 0
from .enums import CharacterCategory, ProbingState, SequenceLikelihood
class SingleByteCharSetProber(CharSetProber):
def __init__(self, model, reversed=False, nameProber=None):
CharSetProber.__init__(self)
self._mModel = model
SAMPLE_SIZE = 64
SB_ENOUGH_REL_THRESHOLD = 1024 # 0.25 * SAMPLE_SIZE^2
POSITIVE_SHORTCUT_THRESHOLD = 0.95
NEGATIVE_SHORTCUT_THRESHOLD = 0.05
def __init__(self, model, reversed=False, name_prober=None):
super(SingleByteCharSetProber, self).__init__()
self._model = model
# TRUE if we need to reverse every pair in the model lookup
self._mReversed = reversed
self._reversed = reversed
# Optional auxiliary prober for name decision
self._mNameProber = nameProber
self._name_prober = name_prober
self._last_order = None
self._seq_counters = None
self._total_seqs = None
self._total_char = None
self._freq_char = None
self.reset()
def reset(self):
CharSetProber.reset(self)
super(SingleByteCharSetProber, self).reset()
# char order of last character
self._mLastOrder = 255
self._mSeqCounters = [0] * NUMBER_OF_SEQ_CAT
self._mTotalSeqs = 0
self._mTotalChar = 0
self._last_order = 255
self._seq_counters = [0] * SequenceLikelihood.get_num_categories()
self._total_seqs = 0
self._total_char = 0
# characters that fall in our sampling range
self._mFreqChar = 0
self._freq_char = 0
def get_charset_name(self):
if self._mNameProber:
return self._mNameProber.get_charset_name()
@property
def charset_name(self):
if self._name_prober:
return self._name_prober.charset_name
else:
return self._mModel['charsetName']
return self._model['charset_name']
def feed(self, aBuf):
if not self._mModel['keepEnglishLetter']:
aBuf = self.filter_without_english_letters(aBuf)
aLen = len(aBuf)
if not aLen:
return self.get_state()
for c in aBuf:
order = self._mModel['charToOrderMap'][wrap_ord(c)]
if order < SYMBOL_CAT_ORDER:
self._mTotalChar += 1
if order < SAMPLE_SIZE:
self._mFreqChar += 1
if self._mLastOrder < SAMPLE_SIZE:
self._mTotalSeqs += 1
if not self._mReversed:
i = (self._mLastOrder * SAMPLE_SIZE) + order
model = self._mModel['precedenceMatrix'][i]
@property
def language(self):
if self._name_prober:
return self._name_prober.language
else:
return self._model.get('language')
def feed(self, byte_str):
if not self._model['keep_english_letter']:
byte_str = self.filter_international_words(byte_str)
if not byte_str:
return self.state
char_to_order_map = self._model['char_to_order_map']
for i, c in enumerate(byte_str):
# XXX: Order is in range 1-64, so one would think we want 0-63 here,
# but that leads to 27 more test failures than before.
order = char_to_order_map[c]
# XXX: This was SYMBOL_CAT_ORDER before, with a value of 250, but
# CharacterCategory.SYMBOL is actually 253, so we use CONTROL
# to make it closer to the original intent. The only difference
# is whether or not we count digits and control characters for
# _total_char purposes.
if order < CharacterCategory.CONTROL:
self._total_char += 1
if order < self.SAMPLE_SIZE:
self._freq_char += 1
if self._last_order < self.SAMPLE_SIZE:
self._total_seqs += 1
if not self._reversed:
i = (self._last_order * self.SAMPLE_SIZE) + order
model = self._model['precedence_matrix'][i]
else: # reverse the order of the letters in the lookup
i = (order * SAMPLE_SIZE) + self._mLastOrder
model = self._mModel['precedenceMatrix'][i]
self._mSeqCounters[model] += 1
self._mLastOrder = order
i = (order * self.SAMPLE_SIZE) + self._last_order
model = self._model['precedence_matrix'][i]
self._seq_counters[model] += 1
self._last_order = order
if self.get_state() == constants.eDetecting:
if self._mTotalSeqs > SB_ENOUGH_REL_THRESHOLD:
cf = self.get_confidence()
if cf > POSITIVE_SHORTCUT_THRESHOLD:
if constants._debug:
sys.stderr.write('%s confidence = %s, we have a'
'winner\n' %
(self._mModel['charsetName'], cf))
self._mState = constants.eFoundIt
elif cf < NEGATIVE_SHORTCUT_THRESHOLD:
if constants._debug:
sys.stderr.write('%s confidence = %s, below negative'
'shortcut threshhold %s\n' %
(self._mModel['charsetName'], cf,
NEGATIVE_SHORTCUT_THRESHOLD))
self._mState = constants.eNotMe
charset_name = self._model['charset_name']
if self.state == ProbingState.DETECTING:
if self._total_seqs > self.SB_ENOUGH_REL_THRESHOLD:
confidence = self.get_confidence()
if confidence > self.POSITIVE_SHORTCUT_THRESHOLD:
self.logger.debug('%s confidence = %s, we have a winner',
charset_name, confidence)
self._state = ProbingState.FOUND_IT
elif confidence < self.NEGATIVE_SHORTCUT_THRESHOLD:
self.logger.debug('%s confidence = %s, below negative '
'shortcut threshhold %s', charset_name,
confidence,
self.NEGATIVE_SHORTCUT_THRESHOLD)
self._state = ProbingState.NOT_ME
return self.get_state()
return self.state
def get_confidence(self):
r = 0.01
if self._mTotalSeqs > 0:
r = ((1.0 * self._mSeqCounters[POSITIVE_CAT]) / self._mTotalSeqs
/ self._mModel['mTypicalPositiveRatio'])
r = r * self._mFreqChar / self._mTotalChar
if self._total_seqs > 0:
r = ((1.0 * self._seq_counters[SequenceLikelihood.POSITIVE]) /
self._total_seqs / self._model['typical_positive_ratio'])
r = r * self._freq_char / self._total_char
if r >= 1.0:
r = 0.99
return r