| /* |
| * 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.rya.accumulo.utils; |
| |
| import static java.util.Objects.requireNonNull; |
| |
| import org.apache.accumulo.core.security.ColumnVisibility; |
| |
| import com.google.common.base.Charsets; |
| |
| import edu.umd.cs.findbugs.annotations.DefaultAnnotation; |
| import edu.umd.cs.findbugs.annotations.NonNull; |
| |
| /** |
| * Simplifies Accumulo visibility expressions. |
| */ |
| @DefaultAnnotation(NonNull.class) |
| public class VisibilitySimplifier { |
| |
| /** |
| * Unions two visibility equations and then simplifies the result. |
| * |
| * @param vis1 - The first visibility equation that will be unioned. (not null) |
| * @param vis2 - The other visibility equation that will be unioned. (not null) |
| * @return A simplified form of the unioned visibility equations. |
| */ |
| public static String unionAndSimplify(final String vis1, final String vis2) { |
| requireNonNull(vis1); |
| requireNonNull(vis2); |
| |
| if(vis1.isEmpty()) { |
| return vis2; |
| } |
| |
| if(vis2.isEmpty()) { |
| return vis1; |
| } |
| |
| return simplify("(" + vis1 + ")&(" + vis2 + ")"); |
| } |
| |
| /** |
| * Simplifies an Accumulo visibility expression. |
| * |
| * @param visibility - The expression to simplify. (not null) |
| * @return A simplified form of {@code visibility}. |
| */ |
| public static String simplify(final String visibility) { |
| requireNonNull(visibility); |
| |
| String last = visibility; |
| String simplified = new String(new ColumnVisibility(visibility).flatten(), Charsets.UTF_8); |
| |
| while(!simplified.equals(last)) { |
| last = simplified; |
| simplified = new String(new ColumnVisibility(simplified).flatten(), Charsets.UTF_8); |
| } |
| |
| return simplified; |
| } |
| } |