broker-plugins/amqp-1-0-protocol/src/main/java/org/apache/qpid/server/protocol/v1_0/codec/SimpleVariableWidthWriter.java

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.qpid.server.protocol.v1_0.codec;

import org.apache.qpid.bytebuffer.QpidByteBuffer;

public abstract class SimpleVariableWidthWriter<V> extends VariableWidthWriter<V>
{
    private byte[] _buf;


    public void setValue(V value)
    {
        _buf = getByteArray(value);
        super.setValue(value);
    }

    protected int getLength()
    {
        return _buf.length;
    }

    protected void writeBytes(QpidByteBuffer buf, int offset, int length)
    {
        buf.put(_buf, getOffset()+offset, length);
    }

    @Override
    protected void clearValue()
    {
        _buf = null;
    }

    @Override
    protected boolean hasValue()
    {
        return _buf != null;
    }

    public boolean isCacheable()
    {
        return true;
    }

    protected abstract byte[] getByteArray(V value);

    protected abstract int getOffset();

}