Java nio live file reader in akka stream

LogFileReader.scala

import akka.streams.scaladsl._
import akka.util.ByteString
import java.nio.ByteBuffer
import java.nio.file.Path
import java.nio.channels.FileChannel

def logFileReader(path: Path, bufferSize: Int = 4096)
  Source.unfoldResource[ByteString, (ByteBuffer, FileChannel)](
    () => (ByteBuffer.allocateDirect(bufferSize), FileChannel.open(path, StandardOpenOption.READ)),
    {
      case (buf, chan) =>
        // ignore -1 (EOF) to watch the end
        val chunk =
          if (chan.read(buf) > 0) {
            buf.flip()
            val bs = ByteString(buf)
            buf.clear()
            bs
          } else ByteString.empty

        Some(chunk)
    },
    { case (_, chan) => chan.close() }
  )