text: <?php
  namespace GuzzleHttp\Psr7;
  
  use Psr\Http\Message\StreamInterface;
  
  /**
   * Uses PHP's zlib.inflate filter to inflate deflate or gzipped content.
   *
   * This stream decorator skips the first 10 bytes of the given stream to remove
   * the gzip header, converts the provided stream to a PHP stream resource,
   * then appends the zlib.inflate filter. The stream is then converted back
   * to a Guzzle stream resource to be used as a Guzzle stream.
   *
   * @link http://tools.ietf.org/html/rfc1952
   * @link http://php.net/manual/en/filters.compression.php
   */
  class InflateStream implements StreamInterface
  {
      use StreamDecoratorTrait;
  
      public function __construct(StreamInterface $stream)
      {
          // read the first 10 bytes, ie. gzip header
          $header = $stream->read(10);
          $filenameHeaderLength = $this->getLengthOfPossibleFilenameHeader($stream, $header);
          // Skip the header, that is 10 + length of filename + 1 (nil) bytes
          $stream = new LimitStream($stream, -1, 10 + $filenameHeaderLength);
          $resource = StreamWrapper::getResource($stream);
          stream_filter_append($resource, 'zlib.inflate', STREAM_FILTER_READ);
          $this->stream = new Stream($resource);
      }
  
      /**
       * @param StreamInterface $stream
       * @param $header
       * @return int
       */
      private function getLengthOfPossibleFilenameHeader(StreamInterface $stream, $header)
      {
          $filename_header_length = 0;
  
          if (substr(bin2hex($header), 6, 2) === '08') {
              // we have a filename, read until nil
              $filename_header_length = 1;
              while ($stream->read(1) !== chr(0)) {
                  $filename_header_length++;
              }
          }
  
          return $filename_header_length;
      }
  }
  