PHP - read huge amount of files from directory

Question

I have a folder with huge amount pictures(10000 files at least) and I need to get names of all this files using PHP. The problem is when I use scandir() I got error about memory limit. Also, I tried to use code like this:

          $files = [];
          $dir = opendir($this->path);
          $i = 0;
          while(($file = readdir($dir)) !== false) {
              $files[] = $file;
              $i++;
              if ($i == 100)
                  break;
          }

This code works fine, but it's not what I need. When I try to get all files, script still crashes.

Besides I thought about saving state of pointer in $dir somehow for using it later through AJAX requests and getting all files, but I can't find any solution for that purpose.

Is there any method of set limit and offset for reading files? I mean like pagination.

Answer 1

You can use RecursiveDirectoryIterator with a Generator if memory is a huge issue.

function recursiveDirectoryIterator($path) {
  foreach (new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path)) as $file) {
    if (!$file->isDir()) {
      yield $file->getFilename() . $file->getExtension();
    }
  }
}

$start = microtime(true);
$instance = recursiveDirectoryIterator('../vendor');
$total_files = 0;
foreach($instance as $value) {
  // echo $value
  $total_files++;
}
echo "Mem peak usage: " . (memory_get_peak_usage(true)/1024/1024)." MiB";
echo "Total number of files: " . $total_files;
echo "Completed in: ", microtime(true) - $start, " seconds";

Here's what I got on my not-so-great laptop.