de.unisb.cs.st.javalanche.mutation.runtime.MutationSwitcher.java Source code

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Here is the source code for de.unisb.cs.st.javalanche.mutation.runtime.MutationSwitcher.java

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/*
 * Copyright (C) 2011 Saarland University
 * 
 * This file is part of Javalanche.
 * 
 * Javalanche is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Javalanche 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 Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser Public License
 * along with Javalanche.  If not, see <http://www.gnu.org/licenses/>.
 */
package de.unisb.cs.st.javalanche.mutation.runtime;

import java.util.Collection;
import java.util.Iterator;

import org.apache.commons.lang.time.DurationFormatUtils;
import org.apache.commons.lang.time.StopWatch;
import org.apache.log4j.Logger;

import de.unisb.cs.st.javalanche.mutation.javaagent.MutationsForRun;
import de.unisb.cs.st.javalanche.mutation.results.Mutation;

/**
 * Class handles the activation and deactivation of the mutations during
 * runtime.
 * 
 * @author David Schuler
 * 
 */
public class MutationSwitcher {

    private static final String CURRENT_MUTATION_KEY = "javalanche.current.mutation";

    private static Logger logger = Logger.getLogger(MutationSwitcher.class);

    /**
     * The mutations that get activated in this run.
     */
    private Collection<Mutation> mutations;

    private Iterator<Mutation> iter;

    /**
     * Holds the currently activated mutation.
     */
    private Mutation currentMutation;

    private StopWatch stopWatch = new StopWatch();

    public MutationSwitcher() {
        mutations = MutationsForRun.getFromDefaultLocation().getMutations();
        logger.info(mutations);
        iter = mutations.iterator();
    }

    /**
     * Checks if there is a mutation to apply.
     * 
     * @return True, if next() will return a mutation.
     */
    public boolean hasNext() {
        return iter.hasNext();
    }

    /**
     * Takes the next mutation without a result and sets it as the current
     * mutation.
     * 
     * @return The mutation that is now the current mutation.
     */
    public Mutation next() {
        while (iter.hasNext()) {
            currentMutation = iter.next();
            if (currentMutation.getMutationResult() == null) {
                return currentMutation;
            } else {
                logger.info("Mutation already got Results");
            }
        }
        return currentMutation;
    }

    /**
     * Turns the current mutation on.
     */
    public void switchOn() {
        if (currentMutation != null) {
            logger.info("enabling mutation: " + currentMutation.getMutationVariable() + " in line "
                    + currentMutation.getLineNumber() + " - " + currentMutation.toString());
            stopWatch.reset();
            stopWatch.start();
            System.setProperty(currentMutation.getMutationVariable(), "1");
            System.setProperty(CURRENT_MUTATION_KEY, currentMutation.getId() + "");

        }
    }

    /**
     * Turns the current mutation off.
     */
    public void switchOff() {
        if (currentMutation != null) {
            System.clearProperty(currentMutation.getMutationVariable());
            System.clearProperty(CURRENT_MUTATION_KEY);
            stopWatch.stop();
            logger.info("Disabling mutation: " + currentMutation.getMutationVariable() + " Time active "
                    + DurationFormatUtils.formatDurationHMS(stopWatch.getTime()));
            currentMutation = null;
        }
    }

}