| /* |
| * Copyright 2016-present Open Networking Foundation |
| * |
| * Licensed 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.onlab.graph; |
| |
| /** |
| * Default weigher returns identical weight for every graph edge. Basically it |
| * is a hop count weigher. |
| * Produces weights of {@link ScalarWeight} type. |
| * |
| * @param <V> vertex type |
| * @param <E> edge type |
| */ |
| public class DefaultEdgeWeigher<V extends Vertex, E extends Edge<V>> |
| implements EdgeWeigher<V, E> { |
| |
| /** |
| * Common weight value for any link. |
| */ |
| protected static final double HOP_WEIGHT_VALUE = 1; |
| /** |
| * Weight value for null path (without links). |
| */ |
| protected static final double NULL_WEIGHT_VALUE = 0; |
| |
| /** |
| * Default weight based on hop count. |
| * {@value #HOP_WEIGHT_VALUE} |
| */ |
| public static final ScalarWeight DEFAULT_HOP_WEIGHT = |
| new ScalarWeight(HOP_WEIGHT_VALUE); |
| |
| /** |
| * Default initial weight. |
| * {@value #NULL_WEIGHT_VALUE} |
| */ |
| public static final ScalarWeight DEFAULT_INITIAL_WEIGHT = |
| new ScalarWeight(NULL_WEIGHT_VALUE); |
| |
| @Override |
| public Weight weight(E edge) { |
| return DEFAULT_HOP_WEIGHT; |
| } |
| |
| @Override |
| public Weight getInitialWeight() { |
| return DEFAULT_INITIAL_WEIGHT; |
| } |
| |
| @Override |
| public Weight getNonViableWeight() { |
| return ScalarWeight.NON_VIABLE_WEIGHT; |
| } |
| } |