<?php
define('DRUPAL_ROOT', getcwd());
require_once DRUPAL_ROOT . '/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);

function no_op($text) {
  return $text;
}

error_reporting(E_ALL | E_STRICT);
define('ITERATIONS', 10000);
define('MILLION', 1000000);
define('SETS', 10);

$output_header = array();
$output_rows = array();

// Initialize theme system with a hook that isn't being benchmarked.
theme('placeholder', array('text' => 'hello'));

for ($set=0; $set < SETS; $set++) {
  // nothing
  $start = microtime(true);
  for ($i=0; $i < ITERATIONS; ++$i) {
  }
  $stop = microtime(true);
  if ($set == 0) {
    $output_header[] = 'nothing';
  }
  $output_rows[$set][] = MILLION*($stop - $start)/ITERATIONS;

  // l()
  $start = microtime(true);
  for ($i=0; $i < ITERATIONS; ++$i) {
    $output = l('text ' . $i, 'node');
  }
  $stop = microtime(true);
  if ($set == 0) {
    $output_header[] = 'l() = ' . $output;
  }
  $output_rows[$set][] = MILLION*($stop - $start)/ITERATIONS;
}

$summary_row = array();
for ($col=0; $col < count($output_rows[0]); $col++) {
  $a = array();
  foreach ($output_rows as $row) {
    $a[] = $row[$col];
  }
  $avg = average($a);
  $stdev = stdev($a);
  $summary_row[$col] = $avg . ' +/- ' . $stdev;
}
$output_rows[] = $summary_row;

print theme('table', array('header' => $output_header, 'rows' => $output_rows));

function average($a) {
  return array_sum($a) / count($a);
}

function stdev($a) {
  $avg = average($a);
  $variance = array();
  foreach ($a as $val) {
    $variance[] = pow($val-$avg, 2);
  }
  return sqrt(average($variance));
}