org.apache.lucene.util.mutable.MutableValueInt.java Source code

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Here is the source code for org.apache.lucene.util.mutable.MutableValueInt.java

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/*
 * 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.lucene.util.mutable;

/**
 * {@link MutableValue} implementation of type <code>int</code>.
 * When mutating instances of this object, the caller is responsible for ensuring 
 * that any instance where <code>exists</code> is set to <code>false</code> must also 
 * <code>value</code> set to <code>0</code> for proper operation.
 */
public class MutableValueInt extends MutableValue {
    public int value;

    @Override
    public Object toObject() {
        assert exists || 0 == value;
        return exists ? value : null;
    }

    @Override
    public void copy(MutableValue source) {
        MutableValueInt s = (MutableValueInt) source;
        value = s.value;
        exists = s.exists;
    }

    @Override
    public MutableValue duplicate() {
        MutableValueInt v = new MutableValueInt();
        v.value = this.value;
        v.exists = this.exists;
        return v;
    }

    @Override
    public boolean equalsSameType(Object other) {
        assert exists || 0 == value;
        MutableValueInt b = (MutableValueInt) other;
        return value == b.value && exists == b.exists;
    }

    @Override
    public int compareSameType(Object other) {
        assert exists || 0 == value;
        MutableValueInt b = (MutableValueInt) other;
        int ai = value;
        int bi = b.value;
        if (ai < bi)
            return -1;
        else if (ai > bi)
            return 1;

        if (exists == b.exists)
            return 0;
        return exists ? 1 : -1;
    }

    @Override
    public int hashCode() {
        assert exists || 0 == value;
        // TODO: if used in HashMap, it already mixes the value... maybe use a straight value?
        return (value >> 8) + (value >> 16);
    }
}