Coverage Summary for Class: ExplicitOrdering (com.google.common.collect)

1 /*
2  * Copyright (C) 2007 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.google.common.collect;
18 
19 import com.google.common.annotations.GwtCompatible;
20 import java.io.Serializable;
21 import java.util.List;
22 import org.checkerframework.checker.nullness.qual.Nullable;
23 
24 /** An ordering that compares objects according to a given order. */
25 @GwtCompatible(serializable = true)
26 final class ExplicitOrdering<T> extends Ordering<T> implements Serializable {
27   final ImmutableMap<T, Integer> rankMap;
28 
29   ExplicitOrdering(List<T> valuesInOrder) {
30     this(Maps.indexMap(valuesInOrder));
31   }
32 
33   ExplicitOrdering(ImmutableMap<T, Integer> rankMap) {
34     this.rankMap = rankMap;
35   }
36 
37   @Override
38   public int compare(T left, T right) {
39     return rank(left) - rank(right); // safe because both are nonnegative
40   }
41 
42   private int rank(T value) {
43     Integer rank = rankMap.get(value);
44     if (rank == null) {
45       throw new IncomparableValueException(value);
46     }
47     return rank;
48   }
49 
50   @Override
51   public boolean equals(@Nullable Object object) {
52     if (object instanceof ExplicitOrdering) {
53       ExplicitOrdering<?> that = (ExplicitOrdering<?>) object;
54       return this.rankMap.equals(that.rankMap);
55     }
56     return false;
57   }
58 
59   @Override
60   public int hashCode() {
61     return rankMap.hashCode();
62   }
63 
64   @Override
65   public String toString() {
66     return "Ordering.explicit(" + rankMap.keySet() + ")";
67   }
68 
69   private static final long serialVersionUID = 0;
70 }