Thomas Vachuska | 58de416 | 2015-09-10 16:15:33 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2015 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 | */ |
Thomas Vachuska | 6b33126 | 2015-04-27 11:09:07 -0700 | [diff] [blame] | 16 | package org.onlab.jdvue; |
| 17 | |
| 18 | import java.util.ArrayList; |
| 19 | import java.util.Collections; |
| 20 | import java.util.List; |
| 21 | import java.util.Objects; |
| 22 | |
Sho SHIMIZU | 43748e8 | 2015-08-25 10:05:08 -0700 | [diff] [blame] | 23 | import static com.google.common.base.MoreObjects.toStringHelper; |
Thomas Vachuska | 6b33126 | 2015-04-27 11:09:07 -0700 | [diff] [blame] | 24 | |
| 25 | /** |
| 26 | * Simple representation of a Java package dependency cycle. |
| 27 | */ |
| 28 | public class DependencyCycle { |
| 29 | |
| 30 | private final List<JavaPackage> cycle; |
| 31 | |
| 32 | /** |
| 33 | * Creates a normalized dependency cycle represented by the specified list |
| 34 | * of Java packages, which are expected to be given in order of dependency. |
| 35 | * List is assumed to be non-empty. |
| 36 | * |
| 37 | * @param cycle list of Java packages in the dependency cycle |
| 38 | * @param cause Java package that caused the cycle |
| 39 | */ |
| 40 | DependencyCycle(List<JavaPackage> cycle, JavaPackage cause) { |
| 41 | this.cycle = normalize(cycle, cause); |
| 42 | } |
| 43 | |
| 44 | /** |
| 45 | * Produces a normalized dependency cycle list. Normalization is performed |
| 46 | * by rotating the list so that the package with the least lexicographic |
| 47 | * name is at the start of the list. |
| 48 | * |
| 49 | * @param cycle list of Java packages in the dependency cycle |
| 50 | * @param cause Java package that caused the cycle |
| 51 | * @return normalized cycle |
| 52 | */ |
| 53 | private List<JavaPackage> normalize(List<JavaPackage> cycle, JavaPackage cause) { |
| 54 | int start = cycle.indexOf(cause); |
| 55 | List<JavaPackage> clone = new ArrayList<>(cycle.subList(start, cycle.size())); |
| 56 | int leastIndex = findIndexOfLeastName(clone); |
| 57 | Collections.rotate(clone, -leastIndex); |
| 58 | return Collections.unmodifiableList(clone); |
| 59 | } |
| 60 | |
| 61 | /** |
| 62 | * Returns the index of the Java package with the least name. |
| 63 | * |
| 64 | * @param cycle list of Java packages in the dependency cycle |
| 65 | * @return index of the least Java package name |
| 66 | */ |
| 67 | private int findIndexOfLeastName(List<JavaPackage> cycle) { |
| 68 | int leastIndex = 0; |
| 69 | String leastName = cycle.get(leastIndex).name(); |
| 70 | for (int i = 1, n = cycle.size(); i < n; i++) { |
| 71 | JavaPackage javaPackage = cycle.get(i); |
| 72 | if (leastName.compareTo(javaPackage.name()) > 0) { |
| 73 | leastIndex = i; |
| 74 | leastName = javaPackage.name(); |
| 75 | } |
| 76 | } |
| 77 | return leastIndex; |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Returns the normalized Java package dependency cycle |
| 82 | * |
| 83 | * @return list of packages in the dependency cycle |
| 84 | */ |
| 85 | public List<JavaPackage> getCycle() { |
| 86 | return cycle; |
| 87 | } |
| 88 | |
| 89 | /** |
| 90 | * Returns the dependency cycle in form of individual dependencies. |
| 91 | * |
| 92 | * @return list of dependencies forming the cycle |
| 93 | */ |
| 94 | public List<Dependency> getCycleSegments() { |
| 95 | List<Dependency> dependencies = new ArrayList<>(); |
| 96 | for (int i = 0, n = cycle.size(); i < n; i++) { |
| 97 | dependencies.add(new Dependency(cycle.get(i), cycle.get(i < n - 1 ? i + 1 : 0))); |
| 98 | } |
| 99 | return dependencies; |
| 100 | } |
| 101 | |
| 102 | @Override |
| 103 | public boolean equals(Object o) { |
| 104 | if (o instanceof DependencyCycle) { |
| 105 | DependencyCycle that = (DependencyCycle) o; |
| 106 | return Objects.equals(cycle, that.cycle); |
| 107 | } |
| 108 | return false; |
| 109 | } |
| 110 | |
| 111 | @Override |
| 112 | public int hashCode() { |
HIGUCHI Yuta | ca9cc8e | 2015-10-29 23:26:51 -0700 | [diff] [blame] | 113 | return cycle.hashCode(); |
Thomas Vachuska | 6b33126 | 2015-04-27 11:09:07 -0700 | [diff] [blame] | 114 | } |
| 115 | |
| 116 | @Override |
| 117 | public String toString() { |
| 118 | return toStringHelper(this).add("cycle", cycle).toString(); |
| 119 | } |
| 120 | |
| 121 | public String toShortString() { |
| 122 | StringBuilder sb = new StringBuilder("["); |
| 123 | for (JavaPackage javaPackage : cycle) { |
| 124 | sb.append(javaPackage.name()).append(", "); |
| 125 | } |
| 126 | if (sb.length() > 1) { |
| 127 | sb.delete(sb.length() - 2, sb.length()); |
| 128 | } |
| 129 | sb.append("]"); |
| 130 | return sb.toString(); |
| 131 | } |
| 132 | |
| 133 | } |