Module: Puppet::Util::Puppetdb::CharEncoding

Defined in:
lib/puppet/util/puppetdb/char_encoding.rb

Constant Summary collapse

Utf8CharLens =

Some of this code is modeled after:

https://github.com/brianmario/utf8/blob/ef10c033/ext/utf8/utf8proc.c
https://github.com/brianmario/utf8/blob/ef10c033/ext/utf8/string_utf8.c

[
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
    4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
]
Utf8ReplacementChar = 
[ 0xEF, 0xBF, 0xBD ].pack("c*")

Class Method Summary collapse

Class Method Details

.get_byte(str, index) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 197

def self.get_byte(str, index)
  # This method is a hack to allow this code to work with either ruby 1.8
  #  or 1.9.  In production this code path should never be exercised by
  #  1.9 because it has a much more sane way to accomplish our goal, but
  #  for testing, it is useful to be able to run the 1.8 codepath in 1.9.
  if @has_get_byte
    str.getbyte(index)
  else
    str[index]
  end
end

.get_char_len(byte) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 107

def self.get_char_len(byte)
  Utf8CharLens[byte]
end

.iconv_to_utf8(str) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

TODO:

we’re not using this anymore, but I wanted to leave it around for a little while just to make sure that the new code pans out.



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 99

def self.iconv_to_utf8(str)
  iconv = Iconv.new('UTF-8//IGNORE', 'UTF-8')

  # http://po-ru.com/diary/fixing-invalid-utf-8-in-ruby-revisited/
  iconv.iconv(str + " ")[0..-2]
end

.is_valid_multibyte_suffix(byte, additional_bytes) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 182

def self.is_valid_multibyte_suffix(byte, additional_bytes)
  # This is heinous, but the UTF-8 spec says that codepoints greater than
  #  0x10FFFF are illegal.  The first character that is over that limit is
  #  0xF490bfbf, so if the first byte is F4 then we have to check for
  #  that condition.
  if byte == 0xF4
    val = additional_bytes.inject(0) { |result, b | (result << 8) + b}
    if val >= 0x90bfbf
      return false
    end
  end
  additional_bytes.all? { |b| ((b & 0xC0) == 0x80) }
end

.ruby18_clean_utf8(str) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 79

def self.ruby18_clean_utf8(str)
  #iconv_to_utf8(str)
  #ruby18_manually_clean_utf8(str)

  # So, we've tried doing this UTF8 cleaning for ruby 1.8 a few different
  # ways.  Doing it via IConv, we don't do a good job of handling characters
  # whose codepoints would exceed the legal maximum for UTF-8.  Doing it via
  # our manual scrubbing process is slower and doesn't catch overlong
  # encodings.  Since this code really shouldn't even exist in the first place
  # we've decided to simply compose the two scrubbing methods for now, rather
  # than trying to add detection of overlong encodings.  It'd be a non-trivial
  # chunk of code, and it'd have to do a lot of bitwise arithmetic (which Ruby
  # is not blazingly fast at).
  ruby18_manually_clean_utf8(iconv_to_utf8(str))
end

.ruby18_handle_multibyte_char(result_str, byte, str, i, char_len, strip = true) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 154

def self.ruby18_handle_multibyte_char(result_str, byte, str, i, char_len, strip = true)
  # keeping an array of bytes for now because we need to do some
  #  bitwise math on them.
  char_additional_bytes = []

  # If we don't have enough bytes left to read the full character, we
  #  put on a replacement character and bail.
  if i + (char_len - 1) > str.length
    result_str.concat(Utf8ReplacementChar) unless strip
    return
  end

  # we've already read the first byte, so we need to set up a range
  #  from 0 to (n-2); e.g. if it's a 2-byte char, we will have a range
  #  from 0 to 0 which will result in reading 1 more byte
  (0..char_len - 2).each do |x|
    char_additional_bytes << get_byte(str, i + x)
  end

  if (is_valid_multibyte_suffix(byte, char_additional_bytes))
    result_str << byte
    result_str.concat(char_additional_bytes.pack("c*"))
  else
    result_str.concat(Utf8ReplacementChar) unless strip
  end
end

.ruby18_manually_clean_utf8(str, strip = true) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Manually cleans a string by stripping any byte sequences that are not valid UTF-8 characters. If you’d prefer for the invalid bytes to be replaced with the unicode replacement character rather than being stripped, you may pass ‘false` for the optional second parameter (`strip`, which defaults to `true`).



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 118

def self.ruby18_manually_clean_utf8(str, strip = true)

  # This is a hack to allow this code to work with either ruby 1.8 or 1.9,
  # which is useful for debugging and benchmarking.  For more info see the
  # comments in the #get_byte method below.
  @has_get_byte = str.respond_to?(:getbyte)


  i = 0
  len = str.length
  result = ""

  while i < len
    byte = get_byte(str, i)

    i += 1

    char_len = get_char_len(byte)
    case char_len
    when 0
      result.concat(Utf8ReplacementChar) unless strip
    when 1
      result << byte
    when 2..4
      ruby18_handle_multibyte_char(result, byte, str, i,  char_len, strip)
      i += char_len - 1
    else
      raise Puppet::DevError, "Unhandled UTF8 char length: '#{char_len}'"
    end

  end

  result
end

.utf8_string(str) ⇒ Object 



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 35

def self.utf8_string(str)
  if RUBY_VERSION =~ /1.8/
    # Ruby 1.8 doesn't have String#encode and related methods, and there
    #  appears to be a bug in iconv that will interpret some byte sequences
    #  as 6-byte characters.  Thus, we are forced to resort to some unfortunate
    #  manual chicanery.
    warn_if_changed(str, ruby18_clean_utf8(str))
  elsif str.encoding == Encoding::UTF_8
    # If we get here, we're in ruby 1.9+, so we have the string encoding methods
    #  available.  However, just because  a ruby String object is already
    #  marked as UTF-8, that doesn't guarantee that its contents are actually
    #  valid; and if you call ruby's ".encode" method with an encoding of
    #  "utf-8" for a String that ruby already believes is UTF-8, ruby
    #  seems to optimize that to be a no-op.  So, we have to do some more
    #  complex handling...

    # If the string already has valid encoding then we're fine.
    return str if str.valid_encoding?

    # If not, we basically have to walk over the characters and replace
    #  them by hand.
    warn_if_changed(str, str.each_char.map { |c| c.valid_encoding? ? c : "\ufffd"}.join)
  else
    # if we get here, we're ruby 1.9 and the current string is *not* encoded
    #  as UTF-8.  Thus we can actually rely on ruby's "encode" method.
    begin
      str.encode('UTF-8')
    rescue Encoding::InvalidByteSequenceError, Encoding::UndefinedConversionError => e
      # If we got an exception, the string is either invalid or not
      # convertible to UTF-8, so drop those bytes.
      warn_if_changed(str, str.encode('UTF-8', :invalid => :replace, :undef => :replace))
    end
  end
end

.warn_if_changed(str, converted_str) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/puppet/util/puppetdb/char_encoding.rb', line 71

def self.warn_if_changed(str, converted_str)
  if converted_str != str
    Puppet.warning "Ignoring invalid UTF-8 byte sequences in data to be sent to PuppetDB"
  end
  converted_str
end