TimedReconfigurationPlans.java

/*
 * Copyright (c) Fabien Hermenier
 *
 *        This file is part of Entropy.
 *
 *        Entropy 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 3 of the License, or
 *        (at your option) any later version.
 *
 *        Entropy 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 Entropy.  If not, see <http://www.gnu.org/licenses/>.
 */

package entropy.plan;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import entropy.configuration.Configuration;
import entropy.configuration.Configurations;
import entropy.configuration.ConfigurationsException;
import entropy.plan.action.Action;
import entropy.plan.action.ActionComparator;

/**
 * Common tools related to TimedReconfigurationPlan.
 *
 * @author Fabien Hermenier
 */
public final class TimedReconfigurationPlans {

    private static final ActionComparator cmp = new ActionComparator(ActionComparator.Type.start);

    /**
     * Utility class. No instantiation.
     */
    private TimedReconfigurationPlans() {
    }

    /**
     * Merge reconfiguration plans into a new plan.
     * Source configurations must be mergeable
     * TODO: There should be issues if the set of nodes are not disjoints (allowed by Configurations.merge) but have conflicting actions
     *
     * @param plans the plan to merge
     * @return the resulting plan
     * @throws TimedReconfigurationPlansException
     *          if source configurations were not mergeable.
     */
    public static TimedReconfigurationPlan merge(List<TimedReconfigurationPlan> plans) throws TimedReconfigurationPlansException {
        return merge(plans.toArray(new TimedReconfigurationPlan[plans.size()]));
    }

    /**
     * Merge reconfiguration plans into a new plan.
     * Source configurations must be mergeable
     * TODO: There should be issues if the set of nodes are not disjoints (allowed by Configurations.merge) but have conflicting actions
     *
     * @param plans the plan to merge
     * @return the resulting plan
     * @throws TimedReconfigurationPlansException
     *          if source configurations were not mergeable.
     */
    public static TimedReconfigurationPlan merge(TimedReconfigurationPlan... plans) throws TimedReconfigurationPlansException {
        Configuration[] srcs = new Configuration[plans.length];
        for (int i = 0; i < plans.length; i++) {
            srcs[i] = plans[i].getSource();
        }
        try {
            TimedReconfigurationPlan res = new DefaultTimedReconfigurationPlan(Configurations.merge(srcs));

            //Need to sort actions before merging
            List<Action> actions = new ArrayList<Action>();
            for (TimedReconfigurationPlan p : plans) {
                for (Action a : p) {
                    actions.add(a);
                }
            }
            Collections.sort(actions, cmp);
            for (Action a : actions) {
                if (!res.add(a)) {
                    throw new TimedReconfigurationPlansException("Unable to append action '" + a + "'");
                }

            }
            return res;
        } catch (ConfigurationsException e) {
            throw new TimedReconfigurationPlansException("Source configurations are not mergeable", e);
        }

    }
}