org.btrplace.plan.DependencyBasedPlanApplier Maven / Gradle / Ivy

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/*
 * Copyright (c) 2016 University Nice Sophia Antipolis
 *
 * This file is part of btrplace.
 * 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 3 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 program.  If not, see .
 */

package org.btrplace.plan;

import org.btrplace.model.Model;
import org.btrplace.plan.event.Action;

import java.util.HashSet;
import java.util.Set;

/**
 * A plan applier that relies on the dependencies between the actions composing the plan.
 * Only unblocked actions are executed. Once executed, the unblocked actions are executed.
 * 
 * This process is repeated until all the actions are executed. This process is ensure to finish
 * iff their is no cyclic dependencies.
 *
 * @author Fabien Hermenier
 */
public class DependencyBasedPlanApplier extends DefaultPlanApplier {

    @Override
    public Model apply(ReconfigurationPlan p) {
        int nbCommitted = 0;
        ReconfigurationPlanMonitor rpm = new DefaultReconfigurationPlanMonitor(p);
        Set feasible = new HashSet<>();
        for (Action a : p.getActions()) {
            if (!rpm.isBlocked(a)) {
                feasible.add(a);
            }
        }
        while (nbCommitted != p.getSize()) {
            Set newFeasible = new HashSet<>();
            for (Action a : feasible) {
                Set s = rpm.commit(a);
                fireAction(a);
                newFeasible.addAll(s);
                nbCommitted++;
            }
            feasible = newFeasible;
        }

        return rpm.getCurrentModel();
    }

    @Override
    public String toString(ReconfigurationPlan p) {
        StringBuilder b = new StringBuilder();
        for (Action a : p) {
            b.append(String.format("%s -> %s%n", p.getDirectDependencies(a), a));
        }
        return b.toString();
    }

}