| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.giraph.graph; |
| |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableComparable; |
| |
| /** |
| * Handles all the situations that can arise upon creation/removal of |
| * vertices and edges. |
| * |
| * @param <I> Vertex id |
| * @param <V> Vertex data |
| * @param <E> Edge data |
| */ |
| @SuppressWarnings("rawtypes") |
| public interface VertexResolver<I extends WritableComparable, |
| V extends Writable, E extends Writable> { |
| /** |
| * A vertex may have been removed, created zero or more times and had |
| * zero or more messages sent to it. This method will handle all situations |
| * excluding the normal case (a vertex already exists and has zero or more |
| * messages sent it to). |
| * |
| * @param vertexId Vertex id (can be used for {@link Vertex}'s initialize()) |
| * @param vertex Original vertex or null if none |
| * @param vertexChanges Changes that happened to this vertex or null if none |
| * @param hasMessages True iff vertex received messages in the last superstep |
| * @return Vertex to be returned, if null, and a vertex currently exists |
| * it will be removed |
| */ |
| Vertex<I, V, E> resolve(I vertexId, |
| Vertex<I, V, E> vertex, |
| VertexChanges<I, V, E> vertexChanges, |
| boolean hasMessages); |
| } |