/*
* 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;
}
}