/*

 * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package sun.jvm.hotspot.utilities;

/** Derived from the example in Section 15.3 of CLR. */

import java.util.Comparator;

public class IntervalNode extends RBNode {

  private Interval   interval;

  private Comparator endpointComparator;

  private Object     minEndpoint;

  private Object     maxEndpoint;

  public IntervalNode(Interval interval, Comparator endpointComparator, Object data) {

    super(data);

    this.interval = interval;

    this.endpointComparator = endpointComparator;

  }

  public void copyFrom(RBNode arg) {

    IntervalNode argNode = (IntervalNode) arg;

    this.interval = argNode.interval;

  }

  public Interval getInterval() {

    return interval;

  }

  public Object getMinEndpoint() {

    return minEndpoint;

  }

  public Object getMaxEndpoint() {

    return maxEndpoint;

  }

  public boolean update() {

    Object newMaxEndpoint = computeMaxEndpoint();

    Object newMinEndpoint = computeMinEndpoint();

    if ((maxEndpoint != newMaxEndpoint) || (minEndpoint != newMinEndpoint)) {

      maxEndpoint = newMaxEndpoint;

      minEndpoint = newMinEndpoint;

      return true;

    }

    return false;

  }

  // Computes maximum endpoint without setting it in this node

  public Object computeMinEndpoint() {

    IntervalNode left = (IntervalNode) getLeft();

    if (left != null) {

      return left.getMinEndpoint();

    }

    return interval.getLowEndpoint();

  }

  // Computes maximum endpoint without setting it in this node

  public Object computeMaxEndpoint() {

    Object curMax = interval.getHighEndpoint();

    if (getLeft() != null) {

      IntervalNode left = (IntervalNode) getLeft();

      if (endpointComparator.compare(left.getMaxEndpoint(), curMax) > 0) {

        curMax = left.getMaxEndpoint();

      }

    }

    if (getRight() != null) {

      IntervalNode right = (IntervalNode) getRight();

      if (endpointComparator.compare(right.getMaxEndpoint(), curMax) > 0) {

        curMax = right.getMaxEndpoint();

      }

    }

    return curMax;

  }

  public String toString() {

    String res = interval.toString();

    Object d = getData();

    if (d != null) {

      res += " " + d;

    }

    return res;

  }

}