[jetty-users] jetty-9.1 -- ServletOutputStream.isReady() -- how much dat

[Richard Johnson <johnson.richard78@xxxxxxxxx>]

Hi everyone,

  I was looking into the Servlet-3.1 implementation for truly non-blocking IO.

  Found this article: http://webtide.intalio.com/2013/07/servlet-3-1-async-io-and-jetty/ by Simone Bordet.

  The Servlet-3.1 ServletOutputStream provides simple boolean isReady() method to find out is the stream
  is ready to receive some data to write to the client, but it is unclear how much data can be written without blocking.

  I.e. if we do large enough write in subsequent out.writ(buffer, 0, len), it would block? Or not?

  Can anybody clarify this?

Thank you,
Richard

Code snippet:

class StandardDataStream implements WriteListener {

....

  public void onWritePossible() throws IOException
  {
    byte[] buffer = new byte[4096];

    // while we are able to write without blocking
    while(out.isReady())
    {
      // read some content into the copy buffer
      int len=content.read(buffer);

      // If we are at EOF then complete
      if (len<0)
      {
        async.complete();
        return;
      }

      // write out the copy buffer.  
      out.write(buffer,0,len);
    }
  }