package org.eclipse.jetty.server;
   
   import java.io.IOException;
   
   import org.eclipse.jetty.http.HttpException;
   import org.eclipse.jetty.http.HttpStatus;
   import org.eclipse.jetty.io.AsyncEndPoint;
   import org.eclipse.jetty.io.Connection;
   import org.eclipse.jetty.io.EndPoint;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  public class AsyncHttpConnection extends HttpConnection
  {
      private static final Logger LOG = Log.getLogger(AsyncHttpConnection.class);
  
      public AsyncHttpConnection(Connector connector, EndPoint endpoint, Server server)
      {
          super(connector,endpoint,server);
      }
  
      public Connection handle() throws IOException
      {
          Connection connection = this;
          
          // Loop while more in buffer
          try
          {
              setCurrentConnection(this);
  
              boolean progress=true; 
              boolean more_in_buffer =false;
              
              while (_endp.isOpen() && (more_in_buffer || progress))
              {
                  progress=false;
                  try
                  {
                      LOG.debug("async request",_request);
                      
                      // Handle resumed request
                      if (_request._async.isAsync() && !_request._async.isComplete())
                          handleRequest();
                      
                      // else Parse more input
                      else if (!_parser.isComplete() && _parser.parseAvailable()>0)
                          progress=true;
  
                      // Generate more output
                      if (_generator.isCommitted() && !_generator.isComplete() && _generator.flushBuffer()>0)
                          progress=true;
                      
                      // Flush output from buffering endpoint
                      if (_endp.isBufferingOutput())
                          _endp.flush();
                  }
                  catch (HttpException e)
                  {
                      if (LOG.isDebugEnabled())
                      {
                          LOG.debug("uri="+_uri);
                          LOG.debug("fields="+_requestFields);
                          LOG.debug(e);
                      }
                      _generator.sendError(e.getStatus(), e.getReason(), null, true);
                      _parser.reset();
                      _endp.close();
                  }
                  finally
                  {
                      // Do we need to complete a half close?
                      if (_endp.isInputShutdown() && (_parser.isIdle() || _parser.isComplete()))
                      {
                          LOG.debug("complete half close {}",this);
                          more_in_buffer=false;
                          _endp.close();
                          reset(true);
                      }
                      
                      // else Is this request/response round complete?
                      else if (_parser.isComplete() && _generator.isComplete() && !_endp.isBufferingOutput())
                      {
                          // look for a switched connection instance?
                          if (_response.getStatus()==HttpStatus.SWITCHING_PROTOCOLS_101)
                          {
                              Connection switched=(Connection)_request.getAttribute("org.eclipse.jetty.io.Connection");
                              if (switched!=null)
                              {
                                  _parser.reset();
                                  _generator.reset(true);
                                  return switched;
                              }
                          }
                          
                          // Reset the parser/generator
                          // keep the buffers as we will cycle 
                          progress=true;
                          reset(false);
                          more_in_buffer = _parser.isMoreInBuffer() || _endp.isBufferingInput();
                     }
 
                     // else Are we suspended?
                     else if (_request.isAsyncStarted())
                     {
                         LOG.debug("suspended {}",this);
                         more_in_buffer=false;
                         progress=false;
                     }
                     else
                         more_in_buffer = _parser.isMoreInBuffer() || _endp.isBufferingInput();
                 }
             }
         }
         finally
         {
             setCurrentConnection(null);
             _parser.returnBuffers();
 
             // Are we write blocked
             if (_generator.isCommitted() && !_generator.isComplete())
                 ((AsyncEndPoint)_endp).scheduleWrite();
             else
                 _generator.returnBuffers();
         }
         return connection;
     }
 
 }