<?php
 
  class MemoryUsageInformation {
    private $real_usage;
    private $statistics = array();
 
    // Memory Usage Information constructor
    public function __construct($real_usage = false) {
      $this->real_usage = $real_usage;
    }
 
    // Returns current memory usage with or without styling
    public function getCurrentMemoryUsage($with_style = true) {
      $mem = memory_get_usage($this->real_usage);
      return ($with_style) ? $this->byteFormat($mem) : $mem;
    }
 
    // Returns peak of memory usage
    public function getPeakMemoryUsage($with_style = true) {
      $mem = memory_get_peak_usage($this->real_usage);
      return ($with_style) ? $this->byteFormat($mem) : $mem;
    }
 
    // Set memory usage with info
    public function setMemoryUsage($info = '') {
      $this->statistics[] = array('time' => time(), 
                                  'info' => $info, 
                                  'memory_usage' => $this->getCurrentMemoryUsage());
    }
 
    // Print all memory usage info and memory limit and 
    public function printMemoryUsageInformation() {
      foreach ($this->statistics as $satistic) {
        echo  "Time: " . $satistic['time'] . 
              " | Memory Usage: " . $satistic['memory_usage'] . 
              " | Info: " . $satistic['info'];
        echo "\n";
      }
      echo "\n\n";
      echo "Peak of memory usage: " . $this->getPeakMemoryUsage();
      echo "\n\n";
    }
 
    // Set start with default info or some custom info
    public function setStart($info = 'Initial Memory Usage') {
      $this->setMemoryUsage($info);
    }
 
    // Set end with default info or some custom info
    public function setEnd($info = 'Memory Usage at the End') {
      $this->setMemoryUsage($info);
    }
 
    // Byte formatting
    private function byteFormat($bytes, $unit = "", $decimals = 2) {
	    $units = array('B' => 0, 'KB' => 1, 'MB' => 2, 'GB' => 3, 'TB' => 4, 
			    'PB' => 5, 'EB' => 6, 'ZB' => 7, 'YB' => 8);
 
	    $value = 0;
	    if ($bytes > 0) {
		    // Generate automatic prefix by bytes 
		    // If wrong prefix given
		    if (!array_key_exists($unit, $units)) {
			    $pow = floor(log($bytes)/log(1024));
			    $unit = array_search($pow, $units);
		    }
 
		    // Calculate byte value by prefix
		    $value = ($bytes/pow(1024,floor($units[$unit])));
	    }
 
	    // If decimals is not numeric or decimals is less than 0 
	    // then set default value
	    if (!is_numeric($decimals) || $decimals < 0) {
		    $decimals = 2;
	    }
 
	    // Format output
	    return sprintf('%.' . $decimals . 'f '.$unit, $value);
    }
  }
 
?>

<?php
 
  // Create new MemoryUsageInformation class
  $m = new MemoryUsageInformation(true);
 
  // Set start
  $m->setStart();
 
  // Create example array
  $a = array();
 
  // Set memory usage before loop
  $m->setMemoryUsage('Before Loop');
 
  // Fill array with
  for($i = 0; $i < 100000; $i++) {
    $a[$i] = uniqid();
  }
 
  // Set memory usage after loop
  $m->setMemoryUsage('After Loop');
 
  // Unset array
  unset($a);
 
  // Set memory usage after unset
  $m->setMemoryUsage('After Unset');
 
  // Set end
  $m->setEnd();
 
  // Print memory usage statistics
  $m->printMemoryUsageInformation();

Time: 1321095944 | Memory Usage: 768.00 KB | Info: Initial Memory Usage
Time: 1321095944 | Memory Usage: 768.00 KB | Info: Before Loop
Time: 1321095951 | Memory Usage: 24.25 MB | Info: After Loop
Time: 1321095951 | Memory Usage: 1.25 MB | Info: After Unset
Time: 1321095951 | Memory Usage: 1.25 MB | Info: Memory Usage at the End
 
Peak of memory usage: 24.25 MB