1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the 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 public interface ChannelFutureProgressListener extends ChannelFutureListener {
40
41 /**
42 * Invoked when the I/O operation associated with the {@link ChannelFuture}
43 * has been progressed.
44 *
45 * @param future the source {@link ChannelFuture} which called this
46 * callback
47 */
48 void operationProgressed(ChannelFuture future, long amount, long current, long total) throws Exception;
49 }