1 /*
2 * Copyright 2013 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 io.netty.channel;
17
18 /**
19 * Responsible to estimate size of a message. The size represent how much memory the message will ca. reserve in
20 * memory.
21 */
22 public interface MessageSizeEstimator {
23
24 /**
25 * Creates a new handle. The handle provides the actual operations.
26 */
27 Handle newHandle();
28
29 interface Handle {
30
31 /**
32 * Calculate the size of the given message.
33 *
34 * @param msg The message for which the size should be calculated
35 * @return size The size in bytes. The returned size must be >= 0
36 */
37 int size(Object msg);
38 }
39 }