[Summary view] [Print] [Text view]

   1  <?php
   2  
   3  declare(strict_types=1);
   4  
   5  namespace MaxMind\Db\Reader;
   6  
   7  class Util
   8  {
   9      /**
  10       * @param resource    $stream
  11       * @param int<0, max> $numberOfBytes
  12       */
  13      public static function read($stream, int $offset, int $numberOfBytes): string
  14      {
  15          if ($numberOfBytes === 0) {
  16              return '';
  17          }
  18          if (fseek($stream, $offset) === 0) {
  19              $value = fread($stream, $numberOfBytes);
  20  
  21              // We check that the number of bytes read is equal to the number
  22              // asked for. We use ftell as getting the length of $value is
  23              // much slower.
  24              if ($value !== false && ftell($stream) - $offset === $numberOfBytes) {
  25                  return $value;
  26              }
  27          }
  28  
  29          throw new InvalidDatabaseException(
  30              'The MaxMind DB file contains bad data'
  31          );
  32      }
  33  }