001/*
002 * (C) Copyright 2014 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Florent Guillaume
018 */
019package org.nuxeo.ecm.core.api.model;
020
021/**
022 * Value holding a base {@link Long} value and a delta.
023 * <p>
024 * This is used when the actual intent of the value is to be an incremental update to an existing value.
025 *
026 * @since 6.0
027 */
028public class DeltaLong extends Delta {
029
030    private static final long serialVersionUID = 1L;
031
032    private final long base;
033
034    private final long delta;
035
036    /**
037     * A {@link DeltaLong} with the given base and delta.
038     */
039    public DeltaLong(long base, long delta) {
040        this.base = base;
041        this.delta = delta;
042    }
043
044    /**
045     * Constructs a {@link DeltaLong} from the given base number and delta, or a {@link Long} if the base is
046     * {@code null}.
047     * <p>
048     * The base number may be a {@link Long} or a {@link DeltaLong}. If it is a {@link DeltaLong} then the returned
049     * value will keep its base and just add deltas.
050     *
051     * @param base the base number
052     * @param delta the delta
053     * @return a new {@link DeltaLong} or {@link Long}
054     */
055    public static Number deltaOrLong(Number base, long delta) {
056        if (base == null) {
057            return Long.valueOf(delta);
058        } else if (base instanceof Long) {
059            return new DeltaLong(base.longValue(), delta);
060        } else if (base instanceof DeltaLong) {
061            DeltaLong dl = (DeltaLong) base;
062            if (delta == 0) {
063                return dl;
064            } else {
065                return new DeltaLong(dl.getBase(), dl.getDelta() + delta);
066            }
067        } else {
068            throw new IllegalArgumentException(base.getClass().getName());
069        }
070    }
071
072    @Override
073    public Delta add(Delta other) {
074        if (!(other instanceof DeltaLong)) {
075            throw new IllegalArgumentException("Cannot add " + getClass().getSimpleName() + " and "
076                    + other.getClass().getSimpleName());
077        }
078        return new DeltaLong(base, delta + ((DeltaLong) other).delta);
079    }
080
081    @Override
082    public Number add(Number other) {
083        if (!(other instanceof Long)) {
084            throw new IllegalArgumentException("Cannot add " + getClass().getSimpleName() + " and "
085                    + other.getClass().getSimpleName());
086        }
087        return Long.valueOf(((Long) other).longValue() + delta);
088    }
089
090    // @Override
091    public long getBase() {
092        return base;
093    }
094
095    // @Override
096    public long getDelta() {
097        return delta;
098    }
099
100    @Override
101    public Long getDeltaValue() {
102        return Long.valueOf(delta);
103    }
104
105    @Override
106    public Long getFullValue() {
107        return Long.valueOf(longValue());
108    }
109
110    @Override
111    public long longValue() {
112        return base + delta;
113    }
114
115    @Override
116    public int intValue() {
117        return (int) longValue();
118    }
119
120    @Override
121    public float floatValue() {
122        return (float) longValue();
123    }
124
125    @Override
126    public double doubleValue() {
127        return (double) longValue();
128    }
129
130    @Override
131    public String toString() {
132        return Long.toString(longValue());
133    }
134
135    @Override
136    public boolean equals(Object obj) {
137        if (obj instanceof DeltaLong) {
138            DeltaLong dl = (DeltaLong) obj;
139            return base == dl.base && delta == dl.delta;
140        }
141        return false;
142    }
143
144    @Override
145    public int hashCode() {
146        int result = 31 + (int) (base ^ (base >>> 32));
147        return 31 * result + (int) (delta ^ (delta >>> 32));
148    }
149
150}