Revision.java

/**
 * Copyright (C) 2013-2014 Olaf Lessenich
 * Copyright (C) 2014-2015 University of Passau, Germany
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301  USA
 *
 * Contributors:
 *     Olaf Lessenich <lessenic@fim.uni-passau.de>
 *     Georg Seibt <seibt@fim.uni-passau.de>
 */
package de.fosd.jdime.config.merge;

import java.util.Arrays;
import java.util.Objects;
import java.util.function.Supplier;

import de.fosd.jdime.artifact.Artifact;

/**
 * This class represents a revision.
 *
 * @author Olaf Lessenich
 */
public class Revision {

    /**
     * A <code>Supplier</code> for an arbitrary number of names 'A',...,'Z','AA',...,'ZZ',...
     */
    public static final class SuccessiveNameSupplier implements Supplier<String> {
        private static final char A = 'A';
        private static final char Z = 'Z';
        private static final int NUM = Z - A + 1;

        private char[] name = {A};

        @Override
        public String get() {
            String res = String.valueOf(name);

            for (int i = name.length - 1; i >= 0 && inc(i--);) {
                if (i < 0) {
                    name = new char[name.length + 1];
                    Arrays.fill(name, A);
                }
            }

            return res;
        }

        /**
         * Increments the <code>char</code> at the given index in the <code>name</code> array mod <code>NUM</code> and
         * returns whether there was an overflow back to <code>A</code>.
         *
         * @param i
         *         the index to increment
         * @return whether there was an overflow
         */
        private boolean inc(int i) {
            name[i] = (char) (((name[i] - A + 1) % NUM) + A);
            return name[i] == A;
        }
    }

    /**
     * A <code>Supplier</code> for an arbitrary number of <code>Revision</code> named 'A',...,'Z','AA',...,'ZZ',...
     */
    public static final class SuccessiveRevSupplier implements Supplier<Revision> {

        private Supplier<String> nameSupplier = new SuccessiveNameSupplier();

        @Override
        public Revision get() {
            return new Revision(nameSupplier.get());
        }
    };

    /**
     * Name of the revision.
     */
    private String name;

    /**
     * Constructs a new <code>Revision</code> with the given name.
     *
     * @param name
     *         name of the revision
     */
    public Revision(String name) {
        this.name = name;
    }

    /**
     * Returns the name of the revision.
     *
     * @return the name
     */
    public String getName() {
        return name;
    }

    /**
     * Sets the name of the revision.
     *
     * @param name
     *         the name to set
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * Returns whether an artifact is contained in this revision.
     *
     * @param artifact
     *         artifact
     * @return true if the artifact is contained in this revision
     */
    public boolean contains(Artifact<?> artifact) {
        return artifact != null && artifact.hasMatching(this);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }

        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        Revision revision = (Revision) o;

        return Objects.equals(name, revision.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name);
    }

    @Override
    public String toString() {
        return name;
    }
}