1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 package org.apache.zookeeper.server.watch; 20 21 import java.io.PrintWriter; 22 import org.apache.zookeeper.Watcher; 23 import org.apache.zookeeper.Watcher.Event.EventType; 24 25 public interface IWatchManager { 26 27 /** 28 * Add watch to specific path. 29 * 30 * @param path znode path 31 * @param watcher watcher object reference 32 * 33 * @return true if the watcher added is not already present 34 */ addWatch(String path, Watcher watcher)35 boolean addWatch(String path, Watcher watcher); 36 37 /** 38 * Add watch to specific path. 39 * 40 * @param path znode path 41 * @param watcher watcher object reference 42 * @param watcherMode the watcher mode to use 43 * 44 * @return true if the watcher added is not already present 45 */ addWatch(String path, Watcher watcher, WatcherMode watcherMode)46 default boolean addWatch(String path, Watcher watcher, WatcherMode watcherMode) { 47 if (watcherMode == WatcherMode.DEFAULT_WATCHER_MODE) { 48 return addWatch(path, watcher); 49 } 50 throw new UnsupportedOperationException(); // custom implementations must defeat this 51 } 52 53 /** 54 * Checks the specified watcher exists for the given path. 55 * 56 * @param path znode path 57 * @param watcher watcher object reference 58 * 59 * @return true if the watcher exists, false otherwise 60 */ containsWatcher(String path, Watcher watcher)61 boolean containsWatcher(String path, Watcher watcher); 62 63 /** 64 * Removes the specified watcher for the given path. 65 * 66 * @param path znode path 67 * @param watcher watcher object reference 68 * 69 * @return true if the watcher successfully removed, false otherwise 70 */ removeWatcher(String path, Watcher watcher)71 boolean removeWatcher(String path, Watcher watcher); 72 73 /** 74 * The entry to remove the watcher when the cnxn is closed. 75 * 76 * @param watcher watcher object reference 77 */ removeWatcher(Watcher watcher)78 void removeWatcher(Watcher watcher); 79 80 /** 81 * Distribute the watch event for the given path. 82 * 83 * @param path znode path 84 * @param type the watch event type 85 * 86 * @return the watchers have been notified 87 */ triggerWatch(String path, EventType type)88 WatcherOrBitSet triggerWatch(String path, EventType type); 89 90 /** 91 * Distribute the watch event for the given path, but ignore those 92 * suppressed ones. 93 * 94 * @param path znode path 95 * @param type the watch event type 96 * @param suppress the suppressed watcher set 97 * 98 * @return the watchers have been notified 99 */ triggerWatch(String path, EventType type, WatcherOrBitSet suppress)100 WatcherOrBitSet triggerWatch(String path, EventType type, WatcherOrBitSet suppress); 101 102 /** 103 * Get the size of watchers. 104 * 105 * @return the watchers number managed in this class. 106 */ size()107 int size(); 108 109 /** 110 * Clean up the watch manager. 111 */ shutdown()112 void shutdown(); 113 114 /** 115 * Returns a watch summary. 116 * 117 * @return watch summary 118 * @see WatchesSummary 119 */ getWatchesSummary()120 WatchesSummary getWatchesSummary(); 121 122 /** 123 * Returns a watch report. 124 * 125 * @return watch report 126 * @see WatchesReport 127 */ getWatches()128 WatchesReport getWatches(); 129 130 /** 131 * Returns a watch report by path. 132 * 133 * @return watch report 134 * @see WatchesPathReport 135 */ getWatchesByPath()136 WatchesPathReport getWatchesByPath(); 137 138 /** 139 * String representation of watches. Warning, may be large! 140 * 141 * @param pwriter the writer to dump the watches 142 * @param byPath iff true output watches by paths, otw output 143 * watches by connection 144 * 145 */ dumpWatches(PrintWriter pwriter, boolean byPath)146 void dumpWatches(PrintWriter pwriter, boolean byPath); 147 148 /** 149 * Return the current number of recursive watchers 150 * 151 * @return qty 152 */ getRecursiveWatchQty()153 default int getRecursiveWatchQty() { 154 return 0; 155 } 156 } 157