broker-plugins/amqp-1-0-protocol/src/main/java/org/apache/qpid/server/protocol/v1_0/type/UnsignedInteger.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.type;

public final class UnsignedInteger extends Number implements Comparable<UnsignedInteger>
{
    private final int _underlying;
    private static final UnsignedInteger[] cachedValues = new UnsignedInteger[256];

    static
    {
        for(int i = 0; i < 256; i++)
        {
            cachedValues[i] = new UnsignedInteger(i);
        }
    }

    public static final UnsignedInteger ZERO = cachedValues[0];
    public static final UnsignedInteger ONE = cachedValues[1];
    public static final UnsignedInteger MAX_VALUE = new UnsignedInteger(0xffffffff);


    public UnsignedInteger(int underlying)
    {
        _underlying = underlying;
    }

    @Override
    public int intValue()
    {
        return _underlying;
    }

    @Override
    public long longValue()
    {
        return ((long) _underlying) & 0xFFFFFFFFl;
    }

    @Override
    public float floatValue()
    {
        return (float) longValue();
    }

    @Override
    public double doubleValue()
    {
        return (double) longValue();
    }

    @Override
    public boolean equals(Object o)
    {
        if (this == o)
        {
            return true;
        }
        if (o == null || getClass() != o.getClass())
        {
            return false;
        }

        UnsignedInteger that = (UnsignedInteger) o;

        if (_underlying != that._underlying)
        {
            return false;
        }

        return true;
    }

    public int compareTo(UnsignedInteger o)
    {
        return Long.signum(longValue() - o.longValue());
    }

    @Override
    public int hashCode()
    {
        return _underlying;
    }

    @Override
    public String toString()
    {
        return String.valueOf(longValue());
    }

    public static UnsignedInteger valueOf(int underlying)
    {
        if((underlying & 0xFFFFFF00) == 0)
        {
            return cachedValues[underlying];
        }
        else
        {
            return new UnsignedInteger(underlying);
        }
    }

    public UnsignedInteger add(final UnsignedInteger i)
    {
        int val = _underlying + i._underlying;
        return UnsignedInteger.valueOf(val);
    }

    public UnsignedInteger subtract(final UnsignedInteger i)
    {
        int val = _underlying - i._underlying;
        return UnsignedInteger.valueOf(val);
    }

    public static UnsignedInteger valueOf(final String value)
    {
        long longVal = Long.parseLong(value);
        return valueOf(longVal);
    }

    public static UnsignedInteger valueOf(final long longVal)
    {
        if(longVal < 0L || longVal >= (1L<<32))
        {
            throw new NumberFormatException("Value \""+longVal+"\" lies outside the range [" + 0L + "-" + (1L<<32) +").");
        }
        return valueOf((int)longVal);
    }

}