(PHP 5 >= 5.2.0, PHP 7, PECL swoole >= 1.9.0)
swoole_async_read — Read file stream asynchronously
$filename
   , callable $callback
   [, int $chunk_size = 65536
   [, int $offset = 0
  ]] ) : bool
filenameThe filename of the file being read.
callbackfilenameThe name of the file.
contentThe content readed from the file stream.
chunk_sizeThe chunk length.
offsetThe offset.
Whether the read is succeed.