Module: TingYun::Support::Serialize::OkJson

Extended by:
OkJson
Included in:
OkJson
Defined in:
lib/ting_yun/support/serialize/ok_json.rb

Defined Under Namespace

Classes: Error, Utf8Error

Constant Summary collapse

Upstream =
'LTD7LBKLZWFF7OZK'
Utagx =

1000 0000

0x80
Utag2 =

1100 0000

0xc0
Utag3 =

1110 0000

0xe0
Utag4 =

1111 0000

0xf0
Utag5 =

1111 1000

0xF8
Umaskx =

0011 1111

0x3f
Umask2 =

0001 1111

0x1f
Umask3 =

0000 1111

0x0f
Umask4 =

0000 0111

0x07
Uchar1max =
(1<<7) - 1
Uchar2max =
(1<<11) - 1
Uchar3max =
(1<<16) - 1
Ucharerr =

unicode “replacement char”

0xFFFD
Ustrerr =

unicode “replacement char”

"\xef\xbf\xbd"
Usurrself =
0x10000
Usurr1 =
0xd800
Usurr2 =
0xdc00
Usurr3 =
0xe000
Spc =
Unesc =
{?b => ?\b, ?f => ?\f, ?n => ?\n, ?r => ?\r, ?t => ?\t}

Instance Method Summary collapse

Instance Method Details

#abbrev(s) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 284

def abbrev(s)
  t = s[0, 10]
  p = t['`']
  t = t[0, p] if p
  t = t + '...' if t.length < s.length
  '`' + t + '`'
end

#arrenc(a) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 478

def arrenc(a)
  '[' + a.map { |x| valenc(x) }.join(',') + ']'
end

#arrparse(ts) ⇒ Object

Parses an “array” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 143

def arrparse(ts)
  ts = eat('[', ts)
  arr = []

  if ts[0][0] == ']'
    return arr, ts[1..-1]
  end

  v, ts = valparse(ts)
  arr << v

  if ts[0][0] == ']'
    return arr, ts[1..-1]
  end

  loop do
    ts = eat(',', ts)

    v, ts = valparse(ts)
    arr << v

    if ts[0][0] == ']'
      return arr, ts[1..-1]
    end
  end
end

#decode(s) ⇒ Object

Decodes a json document in string s and returns the corresponding ruby value. String s must be valid UTF-8. If you have a string in some other encoding, convert it first.

String values in the resulting structure will be UTF-8.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 46

def decode(s)
  ts = lex(s)
  v, ts = textparse(ts)
  if ts.length > 0
    raise Error, 'trailing garbage'
  end
  v
end

#eat(typ, ts) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 171

def eat(typ, ts)
  if ts[0][0] != typ
    raise Error, "expected #{typ} (got #{ts[0].inspect})"
  end
  ts[1..-1]
end

#encode(x) ⇒ Object

Encodes x into a json text. It may contain only Array, Hash, String, Numeric, true, false, nil. (Note, this list excludes Symbol.) X itself must be an Array or a Hash. No other value can be encoded, and an error will be raised if x contains any other value, such as Nan, Infinity, Symbol, and Proc, or if a Hash key is not a String. Strings contained in x must be valid UTF-8.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 439

def encode(x)
  case x
    when Hash then
      objenc(x)
    when Array then
      arrenc(x)
    else
      raise Error, 'root value must be an Array or a Hash'
  end
end

#falsetok(s) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 254

def falsetok(s)
  ; s[0, 5] == 'false' ? [:val, 'false', false] : []
end

#hexdec4(s) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 395

def hexdec4(s)
  if s.length != 4
    raise Error, 'short'
  end
  (nibble(s[0])<<12) | (nibble(s[1])<<8) | (nibble(s[2])<<4) | nibble(s[3])
end

#keyenc(k) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 483

def keyenc(k)
  case k
    when String then
      strenc(k)
    else
      raise Error, "Hash key is not a string: #{k.inspect}"
  end
end

#lex(s) ⇒ Object

Scans s and returns a list of json tokens, excluding white space (as defined in RFC 4627).



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 181

def lex(s)
  ts = []
  while s.length > 0
    typ, lexeme, val = tok(s)
    if typ == nil
      raise Error, "invalid character at #{s[0, 10].inspect}"
    end
    if typ != :space
      ts << [typ, lexeme, val]
    end
    s = s[lexeme.length..-1]
  end
  ts
end

#nibble(c) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 416

def nibble(c)
  case true
    when ?0 <= c && c <= ?9 then
      c.ord - ?0.ord
    when ?a <= c && c <= ?z then
      c.ord - ?a.ord + 10
    when ?A <= c && c <= ?Z then
      c.ord - ?A.ord + 10
    else
      raise Error, "invalid hex code #{c}"
  end
end

#nulltok(s) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 246

def nulltok(s)
  ; s[0, 4] == 'null' ? [:val, 'null', nil] : []
end

#numenc(x) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 541

def numenc(x)
  if ((x.nan? || x.infinite?) rescue false)
    raise Error, "Numeric cannot be represented: #{x}"
  end
  "#{x}"
end

#numtok(s) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 259

def numtok(s)
  m = /-?([1-9][0-9]+|[0-9])([.][0-9]+)?([eE][+-]?[0-9]+)?/.match(s)
  if m && m.begin(0) == 0
    if m[3] && !m[2]
      [:val, m[0], Integer(m[1])*(10**Integer(m[3][1..-1]))]
    elsif m[2]
      [:val, m[0], Float(m[0])]
    else
      [:val, m[0], Integer(m[0])]
    end
  else
    []
  end
end

#objenc(x) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 473

def objenc(x)
  '{' + x.map { |k, v| keyenc(k) + ':' + valenc(v) }.join(',') + '}'
end

#objparse(ts) ⇒ Object

Parses an “object” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 100

def objparse(ts)
  ts = eat('{', ts)
  obj = {}

  if ts[0][0] == '}'
    return obj, ts[1..-1]
  end

  k, v, ts = pairparse(ts)
  obj[k] = v

  if ts[0][0] == '}'
    return obj, ts[1..-1]
  end

  loop do
    ts = eat(',', ts)

    k, v, ts = pairparse(ts)
    obj[k] = v

    if ts[0][0] == '}'
      return obj, ts[1..-1]
    end
  end
end

#pairparse(ts) ⇒ Object

Parses a “member” in the sense of RFC 4627. Returns the parsed values and any trailing tokens.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 130

def pairparse(ts)
  (typ, _, k), ts = ts[0], ts[1..-1]
  if typ != :str
    raise Error, "unexpected #{k.inspect}"
  end
  ts = eat(':', ts)
  v, ts = valparse(ts)
  [k, v, ts]
end

#strenc(s) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 493

def strenc(s)
  t = StringIO.new
  t.putc(?")
  r = 0

  # In ruby >= 1.9, s[r] is a codepoint, not a byte.
  rubydoesenc = s.class.method_defined?(:encoding)

  while r < s.length
    case s[r]
      when ?" then
        t.print('\\"')
      when ?\\ then
        t.print('\\\\')
      when ?\b then
        t.print('\\b')
      when ?\f then
        t.print('\\f')
      when ?\n then
        t.print('\\n')
      when ?\r then
        t.print('\\r')
      when ?\t then
        t.print('\\t')
      else
        c = s[r]
        case true
          when rubydoesenc
            begin
              c.ord # will raise an error if c is invalid UTF-8
              t.write(c)
            rescue
              t.write(Ustrerr)
            end
          when Spc <= c && c <= ?~
            t.putc(c)
          else
            n = ucharcopy(t, s, r) # ensure valid UTF-8 output
            r += n - 1 # r is incremented below
        end
    end
    r += 1
  end
  t.putc(?")
  t.string
end

#strtok(s) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 275

def strtok(s)
  m = /"([^"\\]|\\["\/\\bfnrt]|\\u[0-9a-fA-F]{4})*"/.match(s)
  if !m
    raise Error, "invalid string literal at #{abbrev(s)}"
  end
  [:str, m[0], unquote(m[0])]
end

#subst(u1, u2) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 403

def subst(u1, u2)
  if Usurr1 <= u1 && u1 < Usurr2 && Usurr2 <= u2 && u2 < Usurr3
    return ((u1-Usurr1)<<10) | (u2-Usurr2) + Usurrself
  end
  return Ucharerr
end

#surrogate?(u) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 411

def surrogate?(u)
  Usurr1 <= u && u < Usurr3
end

#textparse(ts) ⇒ Object

Parses a “json text” in the sense of RFC 4627. Returns the parsed value and any trailing tokens. Note: this is almost the same as valparse, except that it does not accept atomic values.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 60

def textparse(ts)
  if ts.length < 0
    raise Error, 'empty'
  end

  typ, _, val = ts[0]
  case typ
    when '{' then
      objparse(ts)
    when '[' then
      arrparse(ts)
    else
      raise Error, "unexpected #{val.inspect}"
  end
end

#tok(s) ⇒ Object

Scans the first token in s and returns a 3-element list, or nil if s does not begin with a valid token.

The first list element is one of ‘‘’, ‘:’, ‘,’, ‘[’, ‘]’, :val, :str, and :space.

The second element is the lexeme.

The third element is the value of the token for :val and :str, otherwise it is the lexeme.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 210

def tok(s)
  case s[0]
    when ?{ then
      ['{', s[0, 1], s[0, 1]]
    when ?} then
      ['}', s[0, 1], s[0, 1]]
    when ?: then
      [':', s[0, 1], s[0, 1]]
    when ?, then
      [',', s[0, 1], s[0, 1]]
    when ?[ then
      ['[', s[0, 1], s[0, 1]]
    when ?] then
      [']', s[0, 1], s[0, 1]]
    when ?n then
      nulltok(s)
    when ?t then
      truetok(s)
    when ?f then
      falsetok(s)
    when ?" then
      strtok(s)
    when Spc then
      [:space, s[0, 1], s[0, 1]]
    when ?\t then
      [:space, s[0, 1], s[0, 1]]
    when ?\n then
      [:space, s[0, 1], s[0, 1]]
    when ?\r then
      [:space, s[0, 1], s[0, 1]]
    else
      numtok(s)
  end
end

#truetok(s) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 250

def truetok(s)
  ; s[0, 4] == 'true' ? [:val, 'true', true] : []
end

#ucharcopy(t, s, i) ⇒ Object

Copies the valid UTF-8 bytes of a single character from string s at position i to I/O object t, and returns the number of bytes copied. If no valid UTF-8 char exists at position i, ucharcopy writes Ustrerr and returns 1.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 554

def ucharcopy(t, s, i)
  n = s.length - i
  raise Utf8Error if n < 1

  c0 = s[i].ord

  # 1-byte, 7-bit sequence?
  if c0 < Utagx
    t.putc(c0)
    return 1
  end

  raise Utf8Error if c0 < Utag2 # unexpected continuation byte?

  raise Utf8Error if n < 2 # need continuation byte
  c1 = s[i+1].ord
  raise Utf8Error if c1 < Utagx || Utag2 <= c1

  # 2-byte, 11-bit sequence?
  if c0 < Utag3
    raise Utf8Error if ((c0&Umask2)<<6 | (c1&Umaskx)) <= Uchar1max
    t.putc(c0)
    t.putc(c1)
    return 2
  end

  # need second continuation byte
  raise Utf8Error if n < 3

  c2 = s[i+2].ord
  raise Utf8Error if c2 < Utagx || Utag2 <= c2

  # 3-byte, 16-bit sequence?
  if c0 < Utag4
    u = (c0&Umask3)<<12 | (c1&Umaskx)<<6 | (c2&Umaskx)
    raise Utf8Error if u <= Uchar2max
    t.putc(c0)
    t.putc(c1)
    t.putc(c2)
    return 3
  end

  # need third continuation byte
  raise Utf8Error if n < 4
  c3 = s[i+3].ord
  raise Utf8Error if c3 < Utagx || Utag2 <= c3

  # 4-byte, 21-bit sequence?
  if c0 < Utag5
    u = (c0&Umask4)<<18 | (c1&Umaskx)<<12 | (c2&Umaskx)<<6 | (c3&Umaskx)
    raise Utf8Error if u <= Uchar3max
    t.putc(c0)
    t.putc(c1)
    t.putc(c2)
    t.putc(c3)
    return 4
  end

  raise Utf8Error
rescue Utf8Error
  t.write(Ustrerr)
  return 1
end

#ucharenc(a, i, u) ⇒ Object

Encodes unicode character u as UTF-8 bytes in string a at position i. Returns the number of bytes written.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 371

def ucharenc(a, i, u)
  case true
    when u <= Uchar1max
      a[i] = (u & 0xff).chr
      1
    when u <= Uchar2max
      a[i+0] = (Utag2 | ((u>>6)&0xff)).chr
      a[i+1] = (Utagx | (u&Umaskx)).chr
      2
    when u <= Uchar3max
      a[i+0] = (Utag3 | ((u>>12)&0xff)).chr
      a[i+1] = (Utagx | ((u>>6)&Umaskx)).chr
      a[i+2] = (Utagx | (u&Umaskx)).chr
      3
    else
      a[i+0] = (Utag4 | ((u>>18)&0xff)).chr
      a[i+1] = (Utagx | ((u>>12)&Umaskx)).chr
      a[i+2] = (Utagx | ((u>>6)&Umaskx)).chr
      a[i+3] = (Utagx | (u&Umaskx)).chr
      4
  end
end

#unquote(q) ⇒ Object

Converts a quoted json string literal q into a UTF-8-encoded string. The rules are different than for Ruby, so we cannot use eval. Unquote will raise an error if q contains control characters.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 296

def unquote(q)
  q = q[1...-1]
  a = q.dup # allocate a big enough string
  rubydoesenc = false
  # In ruby >= 1.9, a[w] is a codepoint, not a byte.
  if a.class.method_defined?(:force_encoding)
    a.force_encoding('UTF-8')
    rubydoesenc = true
  end
  r, w = 0, 0
  while r < q.length
    c = q[r]
    case true
      when c == ?\\
        r += 1
        if r >= q.length
          raise Error, "string literal ends with a \"\\\": \"#{q}\""
        end

        case q[r]
          when ?", ?\\, ?/, ?'
            a[w] = q[r]
            r += 1
            w += 1
          when ?b, ?f, ?n, ?r, ?t
            a[w] = Unesc[q[r]]
            r += 1
            w += 1
          when ?u
            r += 1
            uchar = begin
              hexdec4(q[r, 4])
            rescue RuntimeError => e
              raise Error, "invalid escape sequence \\u#{q[r, 4]}: #{e}"
            end
            r += 4
            if surrogate? uchar
              if q.length >= r+6
                uchar1 = hexdec4(q[r+2, 4])
                uchar = subst(uchar, uchar1)
                if uchar != Ucharerr
                  # A valid pair; consume.
                  r += 6
                end
              end
            end
            if rubydoesenc
              a[w] = '' << uchar
              w += 1
            else
              w += ucharenc(a, w, uchar)
            end
          else
            raise Error, "invalid escape char #{q[r]} in \"#{q}\""
        end
      when c == ?", c < Spc
        raise Error, "invalid character in string literal \"#{q}\""
      else
        # Copy anything else byte-for-byte.
        # Valid UTF-8 will remain valid UTF-8.
        # Invalid UTF-8 will remain invalid UTF-8.
        # In ruby >= 1.9, c is a codepoint, not a byte,
        # in which case this is still what we want.
        a[w] = c
        r += 1
        w += 1
    end
  end
  a[0, w]
end

#valenc(x) ⇒ Object



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 451

def valenc(x)
  case x
    when Hash then
      objenc(x)
    when Array then
      arrenc(x)
    when String then
      strenc(x)
    when Numeric then
      numenc(x)
    when true then
      "true"
    when false then
      "false"
    when nil then
      "null"
    else
      raise Error, "cannot encode #{x.class}: #{x.inspect}"
  end
end

#valparse(ts) ⇒ Object

Parses a “value” in the sense of RFC 4627. Returns the parsed value and any trailing tokens.



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# File 'lib/ting_yun/support/serialize/ok_json.rb', line 79

def valparse(ts)
  if ts.length < 0
    raise Error, 'empty'
  end

  typ, _, val = ts[0]
  case typ
    when '{' then
      objparse(ts)
    when '[' then
      arrparse(ts)
    when :val, :str then
      [val, ts[1..-1]]
    else
      raise Error, "unexpected #{val.inspect}"
  end
end