Sithara Punnassery | ff11455 | 2017-01-10 11:40:55 -0800 | [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 | package org.onosproject.config; |
| 17 | |
| 18 | |
| 19 | import org.onosproject.config.model.ResourceIdentifier; |
| 20 | |
| 21 | import java.util.Set; |
| 22 | |
| 23 | /** |
| 24 | * Abstraction for Filters that can be used while traversing the dynamic config store. |
| 25 | * This abstraction allows to select entries of interest based on various criteria |
| 26 | * defined by this interface. |
| 27 | * NOTE: Only criteria based on {@code ResourceIdentifier} are supported currently. |
| 28 | * This is a placeholder for a filter; Set of ResourceIdentifier becomes inefficient when |
| 29 | * using a large number of filtering criteria; |
| 30 | */ |
| 31 | public interface Filter { |
| 32 | enum TraversalMode { |
| 33 | /** |
| 34 | * Traversal types. |
| 35 | */ |
| 36 | SUB_TREE(-1), |
| 37 | NODE_ONLY(0), |
| 38 | GIVEN_DEPTH; |
| 39 | |
| 40 | /** |
| 41 | * variable indicating the depth of traversal. |
| 42 | * depth = -1 => if the node is pointing to a subtree, the entire subtree will be traversed; |
| 43 | * if the node points to a leaf, just the leaf will be retrieved. |
| 44 | * depth = 0 => tree will not be traversed; will retrieve just the specific node, |
| 45 | * irrespective of it being a subtree root or a leaf node |
| 46 | * depth = any other integer => that many levels of the subtree will be traversed; |
| 47 | * if depth > the number of levels of children, the entire subtree will |
| 48 | * be traversed and end the traversal, without throwing any errors. |
| 49 | */ |
| 50 | int depth; |
| 51 | |
| 52 | TraversalMode() { |
| 53 | |
| 54 | } |
| 55 | |
| 56 | TraversalMode(int depth) { |
| 57 | this.depth = depth; |
| 58 | } |
| 59 | |
| 60 | int depth() { |
| 61 | return depth; |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Adds the traversal depth to the Filter object. |
| 67 | * Various interpretations of depth are as mentioned. |
| 68 | * Default traversal mode is to read just the given node(NODE_ONLY). |
| 69 | * |
| 70 | * @param depth new criteria |
| 71 | */ |
| 72 | void addDepth(TraversalMode depth); |
| 73 | |
| 74 | /** |
| 75 | * Adds new ResourceIdentifier filtering criteria to a Filter object. |
| 76 | * If the same ResourceIdentifier is already part of the criteria |
| 77 | * for the object, it will not be added again, but will not throw any exceptions. |
| 78 | * This will not check for the validity of the ResourceIdentifier. |
| 79 | * |
| 80 | * @param add new criteria |
| 81 | */ |
| 82 | void addCriteria(Set<ResourceIdentifier> add); |
| 83 | |
| 84 | /** |
| 85 | * Removes the given ResourceIdentifier filtering criteria from a Filter object. |
| 86 | * If the ResourceIdentifier was NOT already part of the criteria for |
| 87 | * the object, it will not be removed, but will not throw any exceptions. |
| 88 | * This will not check for the validity of the ResourceIdentifier. |
| 89 | * |
| 90 | * @param remove criteria to be removed |
| 91 | */ |
| 92 | void removeCriteria(Set<ResourceIdentifier> remove); |
| 93 | |
| 94 | /** |
| 95 | * Method to list all the ResourceIdentifier criteria that are in place for a Filter. |
| 96 | * |
| 97 | * @return Set of ResourceIdentifier criteria for this entity |
| 98 | */ |
| 99 | Set<ResourceIdentifier> getCriteria(); |
| 100 | |
| 101 | /** |
| 102 | * Method to create a filter that include all entries rejected by the criteria. |
| 103 | * |
| 104 | * @param original filter object with a criteria set |
| 105 | * @return Filter object with negated criteria set |
| 106 | * @throws InvalidFilterException if the received Filter object |
| 107 | * was null or if it had an empty criteria set |
| 108 | */ |
| 109 | Filter negateFilter(Filter original); |
| 110 | |
| 111 | /** |
| 112 | * Method to check if the Filter has an empty criteria set. |
| 113 | * |
| 114 | * @return {@code true} if criteria set is empty, {@code true} otherwise. |
| 115 | */ |
| 116 | boolean isEmptyFilter(); |
| 117 | } |