org.gradoop.model.impl.algorithms.fsm.gspan.pojos.DFSCode.java Source code

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Here is the source code for org.gradoop.model.impl.algorithms.fsm.gspan.pojos.DFSCode.java

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/*
 * This file is part of Gradoop.
 *
 * Gradoop is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Gradoop 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Gradoop. If not, see <http://www.gnu.org/licenses/>.
 */

package org.gradoop.model.impl.algorithms.fsm.gspan.pojos;

import com.google.common.collect.Lists;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.builder.HashCodeBuilder;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * pojo representing a gSpan DFS code
 */
public class DFSCode implements Serializable {
    /**
     * list of steps
     */
    private final List<DFSStep> steps;

    /**
     * constructor
     * @param step initial step
     */
    public DFSCode(DFSStep step) {
        this.steps = new ArrayList<>();
        this.steps.add(step);
    }

    /**
     * constructor
     * @param steps initial steps
     */
    public DFSCode(ArrayList<DFSStep> steps) {
        this.steps = steps;
    }

    /**
     * empty constructor
     */
    public DFSCode() {
        this.steps = new ArrayList<>();
    }

    /**
     * determines vertex times of the rightmost DFS path
     * @return vertex times
     */
    public List<Integer> getRightMostPathVertexTimes() {

        Integer lastFromTime = null;
        Integer lastToTime = null;

        List<Integer> rightMostPath = null;

        for (DFSStep step : Lists.reverse(steps)) {

            if (step.isForward() || lastToTime == null && step.isLoop()) {
                int fromTime = step.getFromTime();
                int toTime = step.getToTime();

                if (lastToTime == null) {
                    // graph consists of a single loop
                    if (toTime == 0) {
                        rightMostPath = Lists.newArrayList(toTime);
                    } else {
                        rightMostPath = Lists.newArrayList(toTime, fromTime);
                    }
                } else if (lastFromTime == toTime) {
                    rightMostPath.add(fromTime);
                }

                if (fromTime == 0) {
                    break;
                }

                lastFromTime = fromTime;
                lastToTime = toTime;
            }
        }
        return rightMostPath;
    }

    public List<DFSStep> getSteps() {
        return steps;
    }

    @Override
    public String toString() {
        return "[" + StringUtils.join(steps, " ") + "]";
    }

    @Override
    public int hashCode() {

        HashCodeBuilder builder = new HashCodeBuilder();

        for (DFSStep step : steps) {
            builder.append(step.hashCode());
        }

        return builder.hashCode();
    }

    @Override
    public boolean equals(Object other) {

        Boolean equals = this == other;

        if (!equals && other != null && other instanceof DFSCode) {

            DFSCode otherCode = (DFSCode) other;

            if (this.getSteps().size() == otherCode.getSteps().size()) {

                Iterator<DFSStep> ownSteps = this.getSteps().iterator();
                Iterator<DFSStep> otherSteps = otherCode.getSteps().iterator();

                equals = true;

                while (otherSteps.hasNext() && equals) {
                    equals = ownSteps.next().equals(otherSteps.next());
                }
            }
        }

        return equals;
    }

    /**
     * deep copy methods
     * @param dfsCode input DFS code
     * @return deep copy of input
     */
    public static DFSCode deepCopy(DFSCode dfsCode) {
        return new DFSCode(Lists.newArrayList(dfsCode.getSteps()));
    }

    /**
     * Convenience method retrieving the size of an DFS code.
     * @return number of traversal steps
     */
    public int size() {
        return steps.size();
    }

    public DFSStep getLastStep() {
        return steps.get(steps.size() - 1);
    }

    public int getMinVertexLabel() {
        return steps.isEmpty() ? 0 : steps.get(0).getMinVertexLabel();
    }
}