Class: CharDet::UniversalDetector

Inherits:
Object
  • Object
show all
Defined in:
lib/rchardet/universaldetector.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ UniversalDetector

Returns a new instance of UniversalDetector.



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# File 'lib/rchardet/universaldetector.rb', line 38

def initialize
  @_highBitDetector = Regexp.new '[\x80-\xFF]', nil, 'n'
  @_escDetector = Regexp.new '(\033|\~\{)', nil, 'n'
  @_mEscCharSetProber = nil
  @_mCharSetProbers = []
  reset()
end

Instance Attribute Details

#result ⇒ Object

Returns the value of attribute result.



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# File 'lib/rchardet/universaldetector.rb', line 37

def result
  @result
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/rchardet/universaldetector.rb', line 135

def close
  return if @done
  if not @_mGotData
  	$stderr << "no data received!\n" if $debug
  	return
  end
  @done = true

  if @_mInputState == EPureAscii
  	@result = {'encoding' => 'ascii', 'confidence' => 1.0}
  	return @result
  end

  if @_mInputState == EHighbyte
  	confidences = {}
          @_mCharSetProbers.each{ |prober| confidences[prober] = prober.get_confidence }
  	maxProber = @_mCharSetProbers.max{ |a,b| confidences[a] <=> confidences[b] }
  	if maxProber and maxProber.get_confidence > MINIMUM_THRESHOLD
  	  @result = {'encoding' =>  maxProber.get_charset_name(),
  			       'confidence' =>  maxProber.get_confidence()}
  	  return @result
  	end
  end

  if $debug
  	$stderr << "no probers hit minimum threshhold\n" if $debug
  	for prober in @_mCharSetProbers[0]._mProbers
  	  next if not prober
  	  $stderr << "#{prober.get_charset_name} confidence = #{prober.get_confidence}\n" if $debug
  	end
  end
end

#feed(aBuf) ⇒ Object 



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# File 'lib/rchardet/universaldetector.rb', line 61

def feed(aBuf)
  # HACK: force internal encoding to be ascii-8bit (ruby 1.8 bytes)
  aBuf = aBuf.force_encoding('ASCII-8BIT') if aBuf.respond_to?(:force_encoding)
  return if @done

  aLen = aBuf.length
  return if not aLen

  if not @_mGotData
  	# If the data starts with BOM, we know it is UTF
  	if aBuf[0...3] == "\xEF\xBB\xBF"
  	  # EF BB BF  UTF-8 with BOM
  	  @result = {'encoding' => "UTF-8", 'confidence' => 1.0}
  	elsif aBuf[0...4] == "\xFF\xFE\x00\x00"
  	  # FF FE 00 00  UTF-32, little-endian BOM
  	  @result = {'encoding' => "UTF-32LE", 'confidence' => 1.0}
  	elsif aBuf[0...4] == "\x00\x00\xFE\xFF"
  	  # 00 00 FE FF  UTF-32, big-endian BOM
  	  @result = {'encoding' => "UTF-32BE", 'confidence' => 1.0}
  	elsif aBuf[0...4] == "\xFE\xFF\x00\x00"
  	  # FE FF 00 00  UCS-4, unusual octet order BOM (3412)
  	  @result = {'encoding' => "X-ISO-10646-UCS-4-3412", 'confidence' => 1.0}
  	elsif aBuf[0...4] == "\x00\x00\xFF\xFE"
  	  # 00 00 FF FE  UCS-4, unusual octet order BOM (2143)
  	  @result = {'encoding' =>  "X-ISO-10646-UCS-4-2143", 'confidence' =>  1.0}
  	elsif aBuf[0...2] == "\xFF\xFE"
  	  # FF FE  UTF-16, little endian BOM
  	  @result = {'encoding' =>  "UTF-16LE", 'confidence' =>  1.0}
  	elsif aBuf[0...2] == "\xFE\xFF"
  	  # FE FF  UTF-16, big endian BOM
  	  @result = {'encoding' =>  "UTF-16BE", 'confidence' =>  1.0}
  	end
  end

  @_mGotData = true
  if @result['encoding'] and (@result['confidence'] > 0.0)
  	@done = true
  	return
  end
  if @_mInputState == EPureAscii
  	if @_highBitDetector =~ (aBuf)
  	  @_mInputState = EHighbyte
  	elsif (@_mInputState == EPureAscii) and @_escDetector =~ (@_mLastChar + aBuf)
  	  @_mInputState = EEscAscii
  	end
  end
  
  @_mLastChar = aBuf[-1..-1]
  if @_mInputState == EEscAscii
  	if not @_mEscCharSetProber
  	  @_mEscCharSetProber = EscCharSetProber.new
  	end
  	if @_mEscCharSetProber.feed(aBuf) == EFoundIt
  	  @result = {'encoding' =>  self._mEscCharSetProber.get_charset_name(),
  			       'confidence' =>  @_mEscCharSetProber.get_confidence()
  	  }
  	  @done = true
  	end
  elsif @_mInputState == EHighbyte
  	if not @_mCharSetProbers or @_mCharSetProbers.empty?
  	  @_mCharSetProbers = [MBCSGroupProber.new(), SBCSGroupProber.new(), Latin1Prober.new()]
  	end
  	for prober in @_mCharSetProbers
  	  if prober.feed(aBuf) == EFoundIt
  	    @result = {'encoding' =>  prober.get_charset_name(),
  				   'confidence' =>  prober.get_confidence()}
  	    @done = true
  	    break
  	  end
  	end
  end

end

#reset ⇒ Object 



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# File 'lib/rchardet/universaldetector.rb', line 46

def reset
  @result = {'encoding' => nil, 'confidence' => 0.0}
  @done = false
  @_mStart = true
  @_mGotData = false
  @_mInputState = EPureAscii
  @_mLastChar = ''
  if @_mEscCharSetProber
   @_mEscCharSetProber.reset
  end
  for prober in @_mCharSetProbers
   prober.reset
  end
end