1 /*
2 * Copyright 2009 Red Hat, Inc.
3 *
4 * Red Hat licenses this file to you under the Apache License, version 2.0
5 * (the "License"); you may not use this file except in compliance with the
6 * License. You may obtain a copy of the License at:
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package org.jboss.netty.channel;
17
18
19 /**
20 * Listens to the progress of a time-consuming I/O operation such as a large
21 * file transfer. If this listener is added to a {@link ChannelFuture} of an
22 * I/O operation that supports progress notification, the listener's
23 * {@link #operationProgressed(ChannelFuture, long, long, long)} method will be
24 * called back by an I/O thread. If the operation does not support progress
25 * notification, {@link #operationProgressed(ChannelFuture, long, long, long)}
26 * will not be invoked. Like a usual {@link ChannelFutureListener} that this
27 * interface extends, {@link #operationComplete(ChannelFuture)} will be called
28 * when the future is marked as complete.
29 *
30 * <h3>Return the control to the caller quickly</h3>
31 *
32 * {@link #operationProgressed(ChannelFuture, long, long, long)} and
33 * {@link #operationComplete(ChannelFuture)} is directly called by an I/O
34 * thread. Therefore, performing a time consuming task or a blocking operation
35 * in the handler method can cause an unexpected pause during I/O. If you need
36 * to perform a blocking operation on I/O completion, try to execute the
37 * operation in a different thread using a thread pool.
38 *
39 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
40 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
41 *
42 * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
43 */
44 public interface ChannelFutureProgressListener extends ChannelFutureListener {
45
46 /**
47 * Invoked when the I/O operation associated with the {@link ChannelFuture}
48 * has been progressed.
49 *
50 * @param future the source {@link ChannelFuture} which called this
51 * callback
52 */
53 void operationProgressed(ChannelFuture future, long amount, long current, long total) throws Exception;
54 }