io.netty.channel.DefaultMessageSizeEstimator Maven / Gradle / Ivy
/*
* Copyright 2013 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.channel;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufHolder;
/**
* Default {@link MessageSizeEstimator} implementation which supports the estimation of the size of
* {@link ByteBuf}, {@link ByteBufHolder} and {@link FileRegion}.
*/
public final class DefaultMessageSizeEstimator implements MessageSizeEstimator {
private static final class HandleImpl implements Handle {
private final int unknownSize;
private HandleImpl(int unknownSize) {
this.unknownSize = unknownSize;
}
@Override
public int size(Object msg) {
if (msg instanceof ByteBuf) {
return ((ByteBuf) msg).readableBytes();
}
if (msg instanceof ByteBufHolder) {
return ((ByteBufHolder) msg).content().readableBytes();
}
if (msg instanceof FileRegion) {
return 0;
}
return unknownSize;
}
}
/**
* Return the default implementation which returns {@code 8} for unknown messages.
*/
public static final MessageSizeEstimator DEFAULT = new DefaultMessageSizeEstimator(8);
private final Handle handle;
/**
* Create a new instance
*
* @param unknownSize The size which is returned for unknown messages.
*/
public DefaultMessageSizeEstimator(int unknownSize) {
if (unknownSize < 0) {
throw new IllegalArgumentException("unknownSize: " + unknownSize + " (expected: >= 0)");
}
handle = new HandleImpl(unknownSize);
}
@Override
public Handle newHandle() {
return handle;
}
}