Hadoop Streaming API for Ruby

hadoop-streaming.rb

def emit(key, value, sep="\t")
  STDOUT.puts('' << key << sep << value)
end

def map(*options)
  options = [:split, "\t", 2] if options.empty?

  STDIN.each_line do |line|
    line.strip!
    key, value = line.send(*options)
    yield key, value
  end 
end

def reduce(*options)
  options = [:split, "\t", 2] if options.empty?

  current_key = nil 
  current_values = []

  STDIN.each_line do |line|
    line.strip!
    key, value = line.send(*options)

    if current_key != key && current_key != nil 
      yield current_key, current_values
      current_values.clear
    end 

    current_key = key 
    current_values << value
  end 

  yield current_key, current_values unless current_key.nil?
end