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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.directory.mavibot.btree.comparator;
21  
22  
23  import java.util.Comparator;
24  
25  
26  /**
27   * Compares int arrays
28   *
29   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
30   */
31  public class IntArrayComparator implements Comparator<int[]>
32  {
33      /** A static instance of a IntArrayComparator */
34      public static final IntArrayComparator INSTANCE = new IntArrayComparator();
35  
36      /**
37       * A private constructor of the IntArrayComparator class
38       */
39      private IntArrayComparator()
40      {
41      }
42  
43  
44      /**
45       * Compare two long arrays.
46       *
47       * @param intArray1 First int array
48       * @param intArray2 Second int array
49       * @return 1 if intArray1 > intArray2, 0 if intArray1 == intArray2, -1 if intArray1 < intArray2
50       */
51      public int compare( int[] intArray1, int[] intArray2 )
52      {
53          if ( intArray1 == intArray2 )
54          {
55              return 0;
56          }
57  
58          if ( intArray1 == null )
59          {
60              if ( intArray2 == null )
61              {
62                  return 0;
63              }
64              else
65              {
66                  return -1;
67              }
68          }
69          else
70          {
71              if ( intArray2 == null )
72              {
73                  return 1;
74              }
75              else
76              {
77                  if ( intArray1.length < intArray2.length )
78                  {
79                      int pos = 0;
80  
81                      for ( int int1 : intArray1 )
82                      {
83                          int int2 = intArray2[pos];
84  
85                          if ( int1 == int2 )
86                          {
87                              pos++;
88                          }
89                          else if ( int1 < int2 )
90                          {
91                              return -1;
92                          }
93                          else
94                          {
95                              return 1;
96                          }
97                      }
98  
99                      return -1;
100                 }
101                 else
102                 {
103                     int pos = 0;
104 
105                     for ( int int2 : intArray2 )
106                     {
107                         int int1 = intArray1[pos];
108 
109                         if ( int1 == int2 )
110                         {
111                             pos++;
112                         }
113                         else if ( int1 < int2 )
114                         {
115                             return -1;
116                         }
117                         else
118                         {
119                             return 1;
120                         }
121                     }
122 
123                     if ( pos < intArray1.length )
124                     {
125                         return 1;
126                     }
127                     else
128                     {
129                         return 0;
130                     }
131                 }
132             }
133         }
134     }
135 }