Translate statcmp.py to JavaScript

test/stats/statcmp.js

@@ -0,0 +1,197 @@
+/*jslint node: true */
+
+'use strict';
+
+var fs = require('fs');
+
+try {
+  var ttest = require('ttest');
+} catch (e) {
+  console.log('\nttest is not installed -- to intall, run "npm install ttest"');
+  console.log('Continuing without significance test...\n');
+}
+
+var VALID_GROUP_BYS = ['browser', 'pdf', 'page', 'round', 'stat'];
+
+function parseOptions() {
+  var yargs = require('yargs')
+    .usage('Compare the results of two stats files.\n' +
+           'Usage:\n  $0 <BASELINE> <CURRENT> [options]')
+    .demand(2)
+    .string(['groupBy'])
+    .describe('groupBy', 'How statistics should grouped. Valid options: ' +
+              VALID_GROUP_BYS.join(' '))
+    .default('groupBy', 'browser,stat');
+  var result = yargs.argv;
+  result.baseline = result._[0];
+  result.current = result._[1];
+  if (result.groupBy) {
+    result.groupBy = result.groupBy.split(/[;, ]+/);
+  }
+  return result;
+}
+
+function group(stats, groupBy) {
+  var vals = [];
+  for (var i = 0; i < stats.length; i++) {
+    var stat = stats[i];
+    var keyArr = [];
+    for (var j = 0; j < groupBy.length; j++) {
+      keyArr.push(stat[groupBy[j]]);
+    }
+    var key = keyArr.join(',');
+    if (vals[key] === undefined) {
+      vals[key] = [];
+    }
+    vals[key].push(stat['time']);
+  }
+  return vals;
+}
+
+/*
+ * Flatten the stats so that there's one row per stats entry.
+ * Also, if results are not grouped by 'stat', keep only 'Overall' results.
+ */
+function flatten(stats) {
+  var rows = [];
+  stats.forEach(function(stat) {
+    stat['stats'].forEach(function(s) {
+      rows.push({
+        browser: stat['browser'],
+        page: stat['page'],
+        pdf: stat['pdf'],
+        round: stat['round'],
+        stat: s['name'],
+        time: s['end'] - s['start']
+      });
+    });
+  });
+  // Use only overall results if not grouped by 'stat'
+  if (options.groupBy.indexOf('stat') < 0) {
+    rows = rows.filter(function(s) { return s.stat === 'Overall'; });
+  }
+  return rows;
+}
+
+function pad(s, length, dir /* default: 'right' */) {
+  s = '' + s;
+  var spaces = new Array(Math.max(0, length - s.length + 1)).join(' ');
+  return dir === 'left' ? spaces + s : s + spaces;
+}
+
+function mean(array) {
+  function add(a, b) {
+    return a + b;
+  }
+  return array.reduce(add, 0) / array.length;
+}
+
+/* Comparator for row key sorting. */
+function compareRow(a, b) {
+  a = a.split(',');
+  b = b.split(',');
+  for (var i = 0; i < Math.min(a.length, b.length); i++) {
+    var intA = parseInt(a[i], 10);
+    var intB = parseInt(b[i], 10);
+    var ai = isNaN(intA) ? a[i] : intA;
+    var bi = isNaN(intB) ? b[i] : intB;
+    if (ai < bi) {
+      return -1;
+    }
+    if (ai > bi) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+/*
+ * Dump various stats in a table to compare the baseline and current results.
+ * T-test Refresher:
+ * If I understand t-test correctly, p is the probability that we'll observe
+ * another test that is as extreme as the current result assuming the null
+ * hypothesis is true. P is NOT the probability of the null hypothesis. The null
+ * hypothesis in this case is that the baseline and current results will be the
+ * same. It is generally accepted that you can reject the null hypothesis if the
+ * p-value is less than 0.05. So if p < 0.05 we can reject the results are the
+ * same which doesn't necessarily mean the results are faster/slower but it can
+ * be implied.
+ */
+function stat(baseline, current) {
+  var baselineGroup = group(baseline, options.groupBy);
+  var currentGroup = group(current, options.groupBy);
+
+  var keys = Object.keys(baselineGroup);
+  keys.sort(compareRow);
+
+  var labels = options.groupBy.slice(0);
+  labels.push('Count', 'Baseline(ms)', 'Current(ms)', '+/-', '% ');
+  if (ttest) {
+    labels.push('Result(P<.05)');
+  }
+  var i, row, rows = [];
+  // collect rows and measure column widths
+  var width = labels.map(function(s) { return s.length; });
+  rows.push(labels);
+  for (var k = 0; k < keys.length; k++) {
+    var key = keys[k];
+    var baselineMean = mean(baselineGroup[key]);
+    var currentMean = mean(currentGroup[key]);
+    row = key.split(',');
+    row.push('' + baselineGroup[key].length,
+             '' + Math.round(baselineMean),
+             '' + Math.round(currentMean),
+             '' + Math.round(currentMean - baselineMean),
+             (100 * (currentMean - baselineMean) / baselineMean).toFixed(2));
+    if (ttest) {
+      var p = (baselineGroup[key].length < 2) ? 1 :
+               ttest(baselineGroup[key], currentGroup[key]).pValue();
+      if (p < 0.05) {
+        row.push(currentMean < baselineMean ? 'faster' : 'slower');
+      } else {
+        row.push('');
+      }
+    }
+    for (i = 0; i < row.length; i++) {
+      width[i] = Math.max(width[i], row[i].length);
+    }
+    rows.push(row);
+  }
+
+  // add horizontal line
+  var hline = width.map(function(w) { return new Array(w+1).join('-'); });
+  rows.splice(1, 0, hline);
+
+  // print output
+  console.log('-- Grouped By ' + options.groupBy.join(', ') + ' --');
+  var groupCount = options.groupBy.length;
+  for (var r = 0; r < rows.length; r++) {
+    row = rows[r];
+    for (i = 0; i < row.length; i++) {
+      row[i] = pad(row[i], width[i], (i < groupCount) ? 'right' : 'left');
+    }
+    console.log(row.join(' | '));
+  }
+}
+
+function main() {
+  var baseline, current;
+  try {
+    var baselineFile = fs.readFileSync(options.baseline).toString();
+    baseline = flatten(JSON.parse(baselineFile));
+  } catch(e) {
+    console.log('Error reading file "' + options.baseline + '": ' + e);
+    process.exit(0);
+  }
+  try {
+    var currentFile = fs.readFileSync(options.current).toString();
+    current = flatten(JSON.parse(currentFile));
+  } catch(e) {
+    console.log('Error reading file "' + options.current + '": ' + e);
+    process.exit(0);
+  }
+  stat(baseline, current);
+}
+
+var options = parseOptions();
+main();