Coverage Summary for Class: IncidentEdgeSet (com.google.common.graph)

1 /*
2  * Copyright (C) 2019 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.graph;
18 
19 import java.util.AbstractSet;
20 import java.util.Set;
21 import javax.annotation.CheckForNull;
22 
23 /**
24  * Abstract base class for an incident edges set that allows different implementations of {@link
25  * AbstractSet#iterator()}.
26  */
27 @ElementTypesAreNonnullByDefault
28 abstract class IncidentEdgeSet<N> extends AbstractSet<EndpointPair<N>> {
29   final N node;
30   final BaseGraph<N> graph;
31 
32   IncidentEdgeSet(BaseGraph<N> graph, N node) {
33     this.graph = graph;
34     this.node = node;
35   }
36 
37   @Override
38   public boolean remove(@CheckForNull Object o) {
39     throw new UnsupportedOperationException();
40   }
41 
42   @Override
43   public int size() {
44     if (graph.isDirected()) {
45       return graph.inDegree(node)
46           + graph.outDegree(node)
47           - (graph.successors(node).contains(node) ? 1 : 0);
48     } else {
49       return graph.adjacentNodes(node).size();
50     }
51   }
52 
53   @Override
54   public boolean contains(@CheckForNull Object obj) {
55     if (!(obj instanceof EndpointPair)) {
56       return false;
57     }
58     EndpointPair<?> endpointPair = (EndpointPair<?>) obj;
59 
60     if (graph.isDirected()) {
61       if (!endpointPair.isOrdered()) {
62         return false;
63       }
64 
65       Object source = endpointPair.source();
66       Object target = endpointPair.target();
67       return (node.equals(source) && graph.successors(node).contains(target))
68           || (node.equals(target) && graph.predecessors(node).contains(source));
69     } else {
70       if (endpointPair.isOrdered()) {
71         return false;
72       }
73       Set<N> adjacent = graph.adjacentNodes(node);
74       Object nodeU = endpointPair.nodeU();
75       Object nodeV = endpointPair.nodeV();
76 
77       return (node.equals(nodeV) && adjacent.contains(nodeU))
78           || (node.equals(nodeU) && adjacent.contains(nodeV));
79     }
80   }
81 }