| // 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.doris.common; |
| |
| import org.apache.doris.common.util.Daemon; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.base.Strings; |
| |
| import org.apache.logging.log4j.Logger; |
| import org.apache.logging.log4j.LogManager; |
| |
| import java.nio.file.FileSystems; |
| import java.nio.file.Path; |
| import java.nio.file.Paths; |
| import java.nio.file.StandardWatchEventKinds; |
| import java.nio.file.WatchEvent; |
| import java.nio.file.WatchKey; |
| import java.nio.file.WatchService; |
| import java.nio.file.WatchEvent.Kind; |
| |
| /* |
| * used for watch config changed |
| */ |
| public class ConfigWatcher extends Daemon { |
| private static final Logger LOG = LogManager.getLogger(ConfigWatcher.class); |
| |
| public final Path configPath; |
| |
| public ConfigWatcher(String configPathStr) { |
| super("config watcher"); |
| Preconditions.checkState(!Strings.isNullOrEmpty(configPathStr)); |
| configPath = Paths.get(configPathStr); |
| } |
| |
| @Override |
| protected void runOneCycle() { |
| LOG.debug("start config watcher loop"); |
| try { |
| WatchService watchService = FileSystems.getDefault().newWatchService(); |
| configPath.register(watchService, StandardWatchEventKinds.ENTRY_CREATE, |
| StandardWatchEventKinds.ENTRY_MODIFY, |
| StandardWatchEventKinds.ENTRY_DELETE); |
| // start an infinite loop |
| while (true) { |
| // retrieve and remove the next watch key |
| final WatchKey key = watchService.take(); |
| // get list of pending events for the watch key |
| for (WatchEvent<?> watchEvent : key.pollEvents()) { |
| // get the kind of event (create, modify, delete) |
| final Kind<?> kind = watchEvent.kind(); |
| if (kind == StandardWatchEventKinds.OVERFLOW) { |
| continue; |
| } |
| |
| final WatchEvent<Path> watchEventPath = (WatchEvent<Path>) watchEvent; |
| final Path filePath = watchEventPath.context(); |
| LOG.info("config watcher [" + kind + " -> " + filePath + "]"); |
| |
| if (kind == StandardWatchEventKinds.ENTRY_CREATE) { |
| handleCreate(filePath); |
| } else if (kind == StandardWatchEventKinds.ENTRY_MODIFY) { |
| handleModify(filePath); |
| } else if (kind == StandardWatchEventKinds.ENTRY_DELETE) { |
| handleDelete(filePath); |
| } |
| } |
| |
| // reset the key |
| boolean valid = key.reset(); |
| // exit loop if the key is not valid |
| if (!valid) { |
| LOG.warn("config watch key is not valid"); |
| break; |
| } |
| } // end while |
| } catch (Exception e) { |
| LOG.warn("config watcher got exception", e); |
| } |
| } |
| |
| private void handleCreate(Path filePath) { |
| // TODO(cmy): implement if needed |
| } |
| |
| private void handleDelete(Path filePath) { |
| // TODO(cmy): implement if needed |
| } |
| |
| private void handleModify(Path filePath) { |
| // TODO(cmy): implement if needed |
| } |
| |
| // for test |
| public static void main(String[] args) throws InterruptedException { |
| ConfigWatcher wathcer = new ConfigWatcher("./"); |
| wathcer.start(); |
| Thread.sleep(500000); |
| } |
| } |