Class: Erlang::Encoder

Inherits:
Object
  • Object
show all
Includes:
Erlang::External::Types, Terms
Defined in:
lib/rinterface/erlang/encoder.rb

Constant Summary

Constants included from Erlang::External::Types

Erlang::External::Types::ATOM, Erlang::External::Types::BIN, Erlang::External::Types::FLOAT, Erlang::External::Types::FUN, Erlang::External::Types::INT, Erlang::External::Types::LARGE_BIGNUM, Erlang::External::Types::LARGE_TUPLE, Erlang::External::Types::LIST, Erlang::External::Types::NEW_FLOAT, Erlang::External::Types::NEW_FUN, Erlang::External::Types::NEW_REF, Erlang::External::Types::NIL, Erlang::External::Types::PID, Erlang::External::Types::PORT, Erlang::External::Types::REF, Erlang::External::Types::SMALL_BIGNUM, Erlang::External::Types::SMALL_INT, Erlang::External::Types::SMALL_TUPLE, Erlang::External::Types::STRING

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Encoder

Returns a new instance of Encoder.



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# File 'lib/rinterface/erlang/encoder.rb', line 7

def initialize
  @out = StringIO.new('', 'w')
end

Instance Attribute Details

#out ⇒ Object

Returns the value of attribute out.



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# File 'lib/rinterface/erlang/encoder.rb', line 6

def out
  @out
end

Instance Method Details

#rewind ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 11

def rewind
  @out.rewind
end

#term_to_binary(obj) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 15

def term_to_binary obj
  write_1 External::VERSION
  write_any_raw obj
end

#write_1(byte) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 34

def write_1(byte)
  @out.write([byte].pack("C"))
end

#write_2(short) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 38

def write_2(short)
  @out.write([short].pack("n"))
end

#write_4(long) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 42

def write_4(long)
  @out.write([long].pack("N"))
end

#write_any_raw(obj) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 20

def write_any_raw obj
  case obj
  when Symbol then write_symbol(obj)
  when Fixnum, Bignum then write_integer(obj)
  when Float then write_double(obj)
  when Array then write_tuple(obj)
  when String then write_binary(obj)
  when Pid then write_pid(obj)
  when List then write_list(obj)
  else
    raise "Failed encoding!"
  end
end

#write_binary(data) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 100

def write_binary(data)
  write_1 BIN
  write_4 data.length
  write_string data
end

#write_double(num) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 68

def write_double(num)
  write_1 NEW_FLOAT
  @out.write([num].pack('G'))
end

#write_integer(num) ⇒ Object

TODO: Bignum support



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# File 'lib/rinterface/erlang/encoder.rb', line 58

def write_integer(num)
  if 0 <= num && num < 256
    write_1 SMALL_INT
    write_1 num
  else
    write_1 INT
    write_4 num
  end
end

#write_list(list) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 92

def write_list(list)
  len = list.data.size
  write_1(108)
  write_4(len)
  list.data.each{ |i| write_any_raw i }
  write_1(106)
end

#write_pid(pid) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 84

def write_pid(pid)
  write_1(103)
  write_symbol(pid.node)
  write_4((pid.node_id & 0x7fff))
  write_4((pid.serial & 0x1fff))
  write_1((pid.creation & 0x3))
end

#write_string(string) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 46

def write_string(string)
  @out.write(string)
end

#write_symbol(sym) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 50

def write_symbol(sym)
  data = sym.to_s
  write_1 ATOM
  write_2 data.length
  write_string data
end

#write_tuple(data) ⇒ Object 



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# File 'lib/rinterface/erlang/encoder.rb', line 73

def write_tuple(data)
  if data.length < 256
    write_1 SMALL_TUPLE
    write_1 data.length
  else
    write_1 LARGE_TUPLE
    write_4 data.length
  end
  data.each{|e| write_any_raw e }
end