FileCache::getMultiple

public FileCache::getMultiple(array $filepaths)

public function getMultiple(array $filepaths) {
  $file_data = [];
  $remaining_cids = [];

  // First load from the static cache what we can.
  foreach ($filepaths as $filepath) {
    if (!file_exists($filepath)) {
      continue;
    }

    $realpath = realpath($filepath);
    // If the file exists but realpath returns nothing, it is using a stream
    // wrapper, those are not supported.
    if (empty($realpath)) {
      continue;
    }

    $cid = $this->prefix . ':' . $this->collection . ':' . $realpath;
    if (isset(static::$cached[$cid]) && static::$cached[$cid]['mtime'] == filemtime($filepath)) {
      $file_data[$filepath] = static::$cached[$cid]['data'];
    }
    else {
      // Collect a list of cache IDs that we still need to fetch from cache
      // backend.
      $remaining_cids[$cid] = $filepath;
    }
  }

  // If there are any cache IDs left to fetch from the cache backend.
  if ($remaining_cids && $this->cache) {
    $cache_results = $this->cache->fetch(array_keys($remaining_cids)) ? : [];
    foreach ($cache_results as $cid => $cached) {
      $filepath = $remaining_cids[$cid];
      if ($cached['mtime'] == filemtime($filepath)) {
        $file_data[$cached['filepath']] = $cached['data'];
        static::$cached[$cid] = $cached;
      }
    }
  }

  return $file_data;
}