gzencode and stream http archive

function gzencode_http_zip($gzdata){
  $gzsize = strlen($gzdata);
  $gzcrc = crc32($gzdata);
  $gzdata = gzcompress($gzdata,9);
  $gzdata = substr($gzdata,0,strlen($gzdata)-4);
  $rawdata = "\x1f\x8b\x08\x00\x00\x00\x00\x00".$gzdata."\x00\xff\xff".pack('V',$gzcrc).pack('V',$gzsize);
  return $rawdata;
}