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, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.apache.giraph.edge;
20
21 import org.apache.hadoop.io.Writable;
22 import org.apache.hadoop.io.WritableComparable;
23
24 /**
25 * Interface for data structures that store out-edges for a vertex.
26 *
27 * @param <I> Vertex id
28 * @param <E> Edge value
29 */
30 public interface OutEdges<I extends WritableComparable, E extends Writable>
31 extends Iterable<Edge<I, E>>, Writable {
32 /**
33 * Initialize the data structure and set the edges from an iterable.
34 * This method (or one of the two alternatives) must be called
35 * after instantiation, unless readFields() is called.
36 * Note: whether parallel edges are allowed or not depends on the
37 * implementation.
38 *
39 * @param edges Iterable of edges
40 */
41 void initialize(Iterable<Edge<I, E>> edges);
42
43 /**
44 * Initialize the data structure with the specified initial capacity.
45 * This method (or one of the two alternatives) must be called
46 * after instantiation, unless readFields() is called.
47 *
48 * @param capacity Initial capacity
49 */
50 void initialize(int capacity);
51
52 /**
53 * Initialize the data structure with the default initial capacity.
54 * This method (or one of the two alternatives) must be called
55 * after instantiation, unless readFields() is called.
56 *
57 */
58 void initialize();
59
60 /**
61 * Add an edge.
62 * Note: whether parallel edges are allowed or not depends on the
63 * implementation.
64 *
65 * @param edge Edge to add
66 */
67 void add(Edge<I, E> edge);
68
69 /**
70 * Remove all edges to the given target vertex.
71 * Note: the implementation will vary depending on whether parallel edges
72 * are allowed or not.
73 *
74 * @param targetVertexId Target vertex id
75 */
76 void remove(I targetVertexId);
77
78 /**
79 * Return the number of edges.
80 *
81 * @return Number of edges
82 */
83 int size();
84 }