| /* |
| * 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.solr.cloud.autoscaling.sim; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.Set; |
| import java.util.SortedSet; |
| import java.util.TreeSet; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.apache.solr.common.cloud.LiveNodesListener; |
| |
| /** |
| * This class represents a set of live nodes and allows adding listeners to track their state. |
| */ |
| public class LiveNodesSet implements Iterable<String> { |
| |
| private final Set<String> set = ConcurrentHashMap.newKeySet(); |
| private final Set<LiveNodesListener> listeners = ConcurrentHashMap.newKeySet(); |
| |
| public Set<String> get() { |
| return Collections.unmodifiableSet(set); |
| } |
| |
| public int size() { |
| return set.size(); |
| } |
| |
| public void registerLiveNodesListener(LiveNodesListener listener) { |
| listeners.add(listener); |
| } |
| |
| public void removeLiveNodesListener(LiveNodesListener listener) { |
| listeners.remove(listener); |
| } |
| |
| private void fireListeners(SortedSet<String> oldNodes, SortedSet<String> newNodes) { |
| for (LiveNodesListener listener : listeners) { |
| listener.onChange(oldNodes, newNodes); |
| } |
| } |
| |
| public boolean isEmpty() { |
| return set.isEmpty(); |
| } |
| |
| public boolean contains(String id) { |
| return set.contains(id); |
| } |
| |
| public synchronized boolean add(String id) { |
| if (set.contains(id)) { |
| return false; |
| } |
| TreeSet<String> oldNodes = new TreeSet<>(set); |
| set.add(id); |
| TreeSet<String> newNodes = new TreeSet<>(set); |
| fireListeners(oldNodes, newNodes); |
| return true; |
| } |
| |
| public synchronized boolean addAll(Collection<String> nodes) { |
| TreeSet<String> oldNodes = new TreeSet<>(set); |
| boolean changed = set.addAll(nodes); |
| TreeSet<String> newNodes = new TreeSet<>(set); |
| if (changed) { |
| fireListeners(oldNodes, newNodes); |
| } |
| return changed; |
| } |
| |
| public synchronized boolean remove(String id) { |
| if (!set.contains(id)) { |
| return false; |
| } |
| TreeSet<String> oldNodes = new TreeSet<>(set); |
| set.remove(id); |
| TreeSet<String> newNodes = new TreeSet<>(set); |
| fireListeners(oldNodes, newNodes); |
| return true; |
| } |
| |
| public synchronized void clear() { |
| TreeSet<String> oldNodes = new TreeSet<>(set); |
| set.clear(); |
| fireListeners(oldNodes, Collections.emptySortedSet()); |
| } |
| |
| @Override |
| public Iterator<String> iterator() { |
| return set.iterator(); |
| } |
| } |