text: <?php
  
  /*
   * This file is part of the Symfony package.
   *
   * (c) Fabien Potencier <fabien@symfony.com>
   *
   * For the full copyright and license information, please view the LICENSE
   * file that was distributed with this source code.
   */
  
  namespace Symfony\Contracts\Cache;
  
  use Psr\Cache\CacheItemPoolInterface;
  use Psr\Cache\InvalidArgumentException;
  use Psr\Log\LoggerInterface;
  
  // Help opcache.preload discover always-needed symbols
  class_exists(InvalidArgumentException::class);
  
  /**
   * An implementation of CacheInterface for PSR-6 CacheItemPoolInterface classes.
   *
   * @author Nicolas Grekas <p@tchwork.com>
   */
  trait CacheTrait
  {
      /**
       * {@inheritdoc}
       */
      public function get(string $key, callable $callback, float $beta = null, array &$metadata = null)
      {
          return $this->doGet($this, $key, $callback, $beta, $metadata);
      }
  
      /**
       * {@inheritdoc}
       */
      public function delete(string $key): bool
      {
          return $this->deleteItem($key);
      }
  
      private function doGet(CacheItemPoolInterface $pool, string $key, callable $callback, ?float $beta, array &$metadata = null, LoggerInterface $logger = null)
      {
          if (0 > $beta = $beta ?? 1.0) {
              throw new class(sprintf('Argument "$beta" provided to "%s::get()" must be a positive number, %f given.', static::class, $beta)) extends \InvalidArgumentException implements InvalidArgumentException { };
          }
  
          $item = $pool->getItem($key);
          $recompute = !$item->isHit() || \INF === $beta;
          $metadata = $item instanceof ItemInterface ? $item->getMetadata() : [];
  
          if (!$recompute && $metadata) {
              $expiry = $metadata[ItemInterface::METADATA_EXPIRY] ?? false;
              $ctime = $metadata[ItemInterface::METADATA_CTIME] ?? false;
  
              if ($recompute = $ctime && $expiry && $expiry <= ($now = microtime(true)) - $ctime / 1000 * $beta * log(random_int(1, \PHP_INT_MAX) / \PHP_INT_MAX)) {
                  // force applying defaultLifetime to expiry
                  $item->expiresAt(null);
                  $logger && $logger->info('Item "{key}" elected for early recomputation {delta}s before its expiration', [
                      'key' => $key,
                      'delta' => sprintf('%.1f', $expiry - $now),
                  ]);
              }
          }
  
          if ($recompute) {
              $save = true;
              $item->set($callback($item, $save));
              if ($save) {
                  $pool->save($item);
              }
          }
  
          return $item->get();
      }
  }
  