Simple ULEB128 by Ruby

simple_uleb128.rb

#!/usr/bin/env ruby

# Unsigned LEB128 Converter
# https://en.wikipedia.org/wiki/LEB128

def leb128_encode( n )
  tmp = []
  while true do
    tmp.push( ((n & 0x7F) | 0x80 ).chr )
    if n <= 0x7F
      tmp.push( (tmp.pop.ord ^ 0x80).chr )
      break
    end
    n = (n >> 7)
  end
  puts tmp[0].bth
  tmp.join
end

def leb128_decode( bytes , offset = 0)
  bytes = bytes[offset..-1]
  n = 0
  cnt = 0
  bytes.each_byte {|b|
    n = n | ( ( b.ord & 0x7F ) << (7 * cnt) )
    cnt += 1
    if b.ord & 0x80 == 0
      return n, offset + cnt
    end
  }
end