DataBlockSizeEstimator.java

/**
 * This file is part of Waarp Project.
 * 
 * Copyright 2009, Frederic Bregier, and individual contributors by the @author tags. See the
 * COPYRIGHT.txt in the distribution for a full listing of individual contributors.
 * 
 * All Waarp Project is free software: you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 * 
 * Waarp is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along with Waarp . If not, see
 * <http://www.gnu.org/licenses/>.
 */
package org.waarp.common.file;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufHolder;
import io.netty.channel.FileRegion;
import io.netty.channel.MessageSizeEstimator;

/**
 * DataBlock size estimator
 * 
 * @author Frederic Bregier
 * 
 */
public class DataBlockSizeEstimator implements MessageSizeEstimator {

    private final Handle handle;

    /**
     * 
     */
    public DataBlockSizeEstimator() {
        handle = new HandleImpl();
    }

    private static final class HandleImpl implements Handle {
        private HandleImpl() {
        }

        @Override
        public int size(Object msg) {
            if (!(msg instanceof DataBlock)) {
                // Type unimplemented
                if (msg instanceof ByteBuf) {
                    return ((ByteBuf) msg).readableBytes();
                }
                if (msg instanceof ByteBufHolder) {
                    return ((ByteBufHolder) msg).content().readableBytes();
                }
                if (msg instanceof FileRegion) {
                    return 0;
                }
            }
            DataBlock dataBlock = (DataBlock) msg;
            return dataBlock.getByteCount();
        }
    }

    @Override
    public Handle newHandle() {
        return handle;
    }

}