making script preformance more efficient

Question

I have a script that makes thumbnails of the pictures in a directory. But it's execution takes too long (about 170 images in the directory).

The script is called by ajax request. After 70% completion, I receive an error probably due to time out (takes about 3-4 minutes).

How can I solve this issue?

function createThumbs( $pathToImages, $pathToThumbs, $thumbWidth ) 
{
 // open the directory
 $dir = opendir( $pathToImages );

 // loop through it, looking for any/all JPG files:
while (false !== ($fname = readdir( $dir ))) {
// parse path for the extension
$info = pathinfo($pathToImages . $fname);
// continue only if this is a JPEG image
if ( strtolower($info['extension']) == 'jpg' ) 
{

  // load image and get image size
  $img = imagecreatefromjpeg( "{$pathToImages}{$fname}" );
  $width = imagesx( $img );
  $height = imagesy( $img );

  // calculate thumbnail size
  $new_width = $thumbWidth;
  $new_height = floor( $height * ( $thumbWidth / $width ) );

  // create a new temporary image
  $tmp_img = imagecreatetruecolor( $new_width, $new_height );

  // copy and resize old image into new image 
  imagecopyresampled( $tmp_img, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height );

  // save thumbnail into a file
   imagejpeg( $tmp_img, "{$pathToThumbs}thumb_{$fname}" );
   }
  }
   // close the directory
  closedir( $dir );
  }

  createThumbs($directory,$directory."/thumbs/",150);

ajax call;

   var ajaxr=$.ajax({
  type: "POST",
  url: "after_upload.php",
  timeout:600,
  beforeSend: function() {
  $("#result").html('<div align="center"><h2>מבצע עיבוד נתונים יקח זמן ,חכה..תכין קפה בנתיים      ותעשן סיגריה</h2><div><img src="loader.gif"/><div dir="rtl" style="margin:15px;">טוען מידע וממיר תמונות... <button id="cancel" style="padding:5px;">בטל פעולה ותחזור חזרה [X]</button></div></div>  </div>');
                        },
  success: function(data){
       $("#result").html(data);
  },
  error: function(xhr, textStatus, errorThrown) {
                             $("#result").html(textStatus);
                        }
  });

now,increased the time out to 3000 in ajax call and it instantly,for some reason return timeout error.if i remove time out property from the call ..it preforms the call and script executes..but only 70% of job is done..done returned empty error...

UPDATE:..i preformed everythin to make script execution time better now:console return 404 Not Found..

Answer 1

Make the creation of the thumbnail run in a loop and after every loop remove the previous resource from the server memory.

imagedestroy($thumb);
imagedestroy($source);

This would greatly help, I just finished something very similar.