Word Counting

extensions [mapreduce]

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;; Mapper
;;;; Read the line of a file, split it into words, emit word
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

to read-file [file-name words]
  ;;; Loop over all words
  foreach words
  [
    ;;;  emit: 
    mapreduce:emit ? "1" ; 
  ]
end 

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;; Reducer
;;;; Sum up the occurrences of a word
;;;;  key    the word
;;;;  accum  current count
;;;;  value  next value
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

to-report word-count [key acum value]
  report acum + read-from-string value
end 

to server
  mapreduce:acceptworkers
end 

to node
  mapreduce:node.connect "127.0.0.1" 9173
end 

to count-words
  let words []
  let runit true
  
  reset-ticks
  
  ;;; Tell MapReduce that a line has words, separated by spaces
  mapreduce:config.valueseparator " "
  ;;; Start the MapReduce computation
  let res mapreduce:mapreduce "read-file" "word-count" 0 data-set
  ;;; Wait or the computation to finish and display the progress
  while [mapreduce:running?] [
   every 0.5 [
       print mapreduce:map-progress
       print mapreduce:reduce-progress
       ; plot 1
       tick
     ]
  ]
  tick
  print "done"

  ;;; Print the result
  show mapreduce:result res
  tick
end