Andrey Komarov | 2398d96 | 2016-09-26 15:11:23 +0300 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2016-present Open Networking Laboratory |
| 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 org.onlab.graph; |
| 18 | |
| 19 | /** |
| 20 | * Abstraction of a graph edge weight. |
| 21 | */ |
| 22 | public interface Weight extends Comparable<Weight> { |
| 23 | |
| 24 | /** |
| 25 | * Merges the given weight with this one returning a new aggregated |
| 26 | * weight. |
| 27 | * |
| 28 | * @param otherWeight weight to add |
| 29 | * @return aggregated weight |
| 30 | */ |
| 31 | Weight merge(Weight otherWeight); |
| 32 | |
| 33 | /** |
| 34 | * Subtracts the given weight from this one and produces a new weight. |
| 35 | * |
| 36 | * @param otherWeight weight to subtract |
| 37 | * @return residual weight |
| 38 | */ |
| 39 | Weight subtract(Weight otherWeight); |
| 40 | |
| 41 | /** |
| 42 | * Returns true if the weighted subject (link/path) can be traversed; false otherwise. |
| 43 | * |
| 44 | * @return true if weight is adequate, false if weight is infinite |
| 45 | */ |
| 46 | boolean isViable(); |
| 47 | |
| 48 | /** |
| 49 | * Returns true if the weight is negative (means that aggregated |
| 50 | * path cost will decrease if we add weighted subject to it). |
| 51 | * |
| 52 | * @return true if the weight is negative, false otherwise |
| 53 | */ |
| 54 | boolean isNegative(); |
| 55 | } |