efficent-second-use-test.js

(function() {

  /* globals require, describe, it, expect, console, d3 */
  'use strict';

  try {

    var locald3;
    var reuseOptimzedCloud;

    try {
      locald3 = d3;
      reuseOptimzedCloud = d3.layout.cloud;
    } catch (e) {
      locald3 = require("d3");
      reuseOptimzedCloud = require("../");
    }

    var calculateAndScaleMeaningfulWords = function(text) {
      var frequencyCount = {},
        whitespaceRegEx = /\s+/g,
        nonEnglishCharactersRegEx = /[^A-Za-z0-9]/g,
        LIMIT_WORDS_IN_CLOUD = 500,
        leastFrequentCount,
        mostFrequentCount;

      var isMeaningLess = function(word) {
        if (word.length <= 3) {
          return true;
        }
      };

      // Build frequency count
      text.split(whitespaceRegEx).map(function(word) {
        word = word.replace(nonEnglishCharactersRegEx, '');
        if (isMeaningLess(word)) {
          return;
        }
        frequencyCount[word] = (frequencyCount[word] || 0) + 1;
      });

      // Convert frequency count hash into an array with the x most frequent words
      frequencyCount = locald3.entries(frequencyCount).sort(function(a, b) {
        return b.value - a.value;
      }).slice(0, LIMIT_WORDS_IN_CLOUD);

      return frequencyCount;
    };

    var WIDTH = 960 * 1;
    var HEIGHT = 600 * 1;


    describe('efficient reuse', function() {

      var startTime,
        endTime,
        itterationTimes = [],
        calculateHowLongItTook,
        myReusedCloud,
        calculateMeaningfulWordsAndStartCloud;

      calculateHowLongItTook = function() {
        endTime = Date.now();
        console.log('Time', endTime - startTime);
        itterationTimes.push(endTime - startTime);
      };

      myReusedCloud = reuseOptimzedCloud()
        .padding(0)
        .size([WIDTH, HEIGHT])
        .font('Impact')
        .text(function(word) {
          return word.key;
        })
        .on('end', calculateHowLongItTook);


      calculateMeaningfulWordsAndStartCloud = function(text) {
        var frequencyCount = calculateAndScaleMeaningfulWords(text),
          leastFrequentCount,
          mostFrequentCount;

        // Make font size relative to the range between the most frequent and least frequent words
        leastFrequentCount = +frequencyCount[frequencyCount.length - 1].value || 1;
        mostFrequentCount = +frequencyCount[0].value;
        myReusedCloud.fontSize(function(wordNode) {
          return leastFrequentCount + (wordNode - leastFrequentCount) / (mostFrequentCount - leastFrequentCount);
        });

        // Set the words to this frequency count and render
        myReusedCloud.words(frequencyCount);
        myReusedCloud.start();
      };

      it('should take half as long on re-use of the cloud library', function() {

        // Run x itterations to see if it runs in linear time
        var NUMBER_OF_ITTERATIONS = 5;
        for (var i = 0; i < NUMBER_OF_ITTERATIONS; i++) {
          startTime = Date.now();
          calculateMeaningfulWordsAndStartCloud('this is a small cloud');
        }

        expect(itterationTimes.length).toEqual(NUMBER_OF_ITTERATIONS);

        expect(itterationTimes[0]).toBeGreaterThan(itterationTimes[1]);
        expect(itterationTimes[0]).toBeGreaterThan(itterationTimes[1] * 2);
      });

    });

  } catch (e) {
    console.log(e);
    console.log(e, e.stack);
  }

})();