| 1 | /* |
| 2 | * Copyright (C) 2015 - EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com> |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU Lesser General Public License, version 2.1 only, |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This library is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License |
| 11 | * for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU Lesser General Public License |
| 14 | * along with this library; if not, write to the Free Software Foundation, |
| 15 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 16 | */ |
| 17 | |
| 18 | package org.lttng.ust.agent.context; |
| 19 | |
| 20 | import java.util.Set; |
| 21 | import java.util.concurrent.CopyOnWriteArraySet; |
| 22 | |
| 23 | /** |
| 24 | * The singleton manager of {@link IContextInfoRetriever} objects. |
| 25 | * |
| 26 | * @author Alexandre Montplaisir |
| 27 | */ |
| 28 | public final class ContextInfoManager { |
| 29 | |
| 30 | private static final ContextInfoManager INSTANCE = new ContextInfoManager(); |
| 31 | |
| 32 | private final Set<IContextInfoRetriever> cirs = new CopyOnWriteArraySet<IContextInfoRetriever>(); |
| 33 | |
| 34 | /** Singleton class, constructor should not be accessed directly */ |
| 35 | private ContextInfoManager() { |
| 36 | } |
| 37 | |
| 38 | /** |
| 39 | * Get the singleton instance. |
| 40 | * |
| 41 | * @return The singleton instance |
| 42 | * @deprecated The context-retrieving facilities are not yet implemented. |
| 43 | */ |
| 44 | @Deprecated |
| 45 | public static ContextInfoManager getInstance() { |
| 46 | return INSTANCE; |
| 47 | } |
| 48 | |
| 49 | /** |
| 50 | * Register a new context info retriever. |
| 51 | * |
| 52 | * This method has no effect if the exact same retriever is already |
| 53 | * registered. |
| 54 | * |
| 55 | * @param cir |
| 56 | * The context info retriever to register |
| 57 | */ |
| 58 | public void addContextInfoRetriever(IContextInfoRetriever cir) { |
| 59 | cirs.add(cir); |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Unregister a previously added context info retriever. |
| 64 | * |
| 65 | * This method has no effect if the retriever was not already registered. |
| 66 | * |
| 67 | * @param cir |
| 68 | * The context info retriever to unregister |
| 69 | */ |
| 70 | public void removeContextInfoRetriever(IContextInfoRetriever cir) { |
| 71 | cirs.remove(cir); |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Return a read-only view (does not support |
| 76 | * {@link java.util.Iterator#remove}) of the currently registered context |
| 77 | * info retrievers. |
| 78 | * |
| 79 | * @return The current context info retrievers |
| 80 | */ |
| 81 | public Iterable<IContextInfoRetriever> getContextInfoRetrievers() { |
| 82 | return cirs; |
| 83 | } |
| 84 | } |