1 /*

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

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

     4  *

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

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

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

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

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 package sun.jvm.hotspot.utilities;

    26 

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

    28 

    29 import java.util.Comparator;

    30 

    31 public class IntervalNode extends RBNode {

    32   private Interval   interval;

    33   private Comparator endpointComparator;

    34   private Object     minEndpoint;

    35   private Object     maxEndpoint;

    36 

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

    38     super(data);

    39     this.interval = interval;

    40     this.endpointComparator = endpointComparator;

    41   }

    42 

    43   public void copyFrom(RBNode arg) {

    44     IntervalNode argNode = (IntervalNode) arg;

    45     this.interval = argNode.interval;

    46   }

    47 

    48   public Interval getInterval() {

    49     return interval;

    50   }

    51 

    52   public Object getMinEndpoint() {

    53     return minEndpoint;

    54   }

    55 

    56   public Object getMaxEndpoint() {

    57     return maxEndpoint;

    58   }

    59 

    60   public boolean update() {

    61     Object newMaxEndpoint = computeMaxEndpoint();

    62     Object newMinEndpoint = computeMinEndpoint();

    63 

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

    65       maxEndpoint = newMaxEndpoint;

    66       minEndpoint = newMinEndpoint;

    67       return true;

    68     }

    69 

    70     return false;

    71   }

    72 

    73   // Computes maximum endpoint without setting it in this node

    74   public Object computeMinEndpoint() {

    75     IntervalNode left = (IntervalNode) getLeft();

    76     if (left != null) {

    77       return left.getMinEndpoint();

    78     }

    79     return interval.getLowEndpoint();

    80   }

    81 

    82   // Computes maximum endpoint without setting it in this node

    83   public Object computeMaxEndpoint() {

    84     Object curMax = interval.getHighEndpoint();

    85     if (getLeft() != null) {

    86       IntervalNode left = (IntervalNode) getLeft();

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

    88         curMax = left.getMaxEndpoint();

    89       }

    90     }

    91 

    92     if (getRight() != null) {

    93       IntervalNode right = (IntervalNode) getRight();

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

    95         curMax = right.getMaxEndpoint();

    96       }

    97     }

    98     return curMax;

    99   }

   100 

   101   public String toString() {

   102     String res = interval.toString();

   103     Object d = getData();

   104     if (d != null) {

   105       res += " " + d;

   106     }

   107     return res;

   108   }

   109 }