LonelyBuilder.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.vjob.builder;

import java.util.List;

import entropy.configuration.VirtualMachine;
import entropy.vjob.Lonely;
import entropy.vjob.VJobElement;
import entropy.vjob.VJobSet;

/**
 * A builder for the placement constraint Lonely.
 *
 * @author Fabien Hermenier
 */
public class LonelyBuilder implements PlacementConstraintBuilder {

    @Override
    public String getIdentifier() {
        return "lonely";
    }

    @Override
    public String getSignature() {
        return "lonely(<vmset>)";
    }

    /**
     * Build a constraint.
     *
     * @param args the parameters of the constraint. Must be one non-empty set of virtual machines.
     * @return the constraint
     * @throws entropy.vjob.builder.ConstraintBuilderException
     *          if an error occurred while building the constraint
     */
    @Override
    public Lonely buildConstraint(List<VJobElement> args) throws ConstraintBuilderException {
        if (args.size() != 1) {
            throw new ConstraintBuilderException(this);
        }
        try {
            VJobSet<VirtualMachine> vms1 = (VJobSet<VirtualMachine>) args.get(0);
            if (vms1.size() == 0) {
                throw new ConstraintBuilderException("Empty set not allowed");
            }
            return new Lonely(vms1);
        } catch (ClassCastException e) {
            throw new ConstraintBuilderException(getSignature(), e);
        }
    }

}