| /** |
| * 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.hadoop.hdfs.server.federation.store.driver.impl; |
| |
| import java.io.BufferedReader; |
| import java.io.BufferedWriter; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| import java.io.OutputStreamWriter; |
| import java.nio.charset.StandardCharsets; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| |
| import org.apache.commons.lang.ArrayUtils; |
| import org.apache.hadoop.hdfs.server.federation.router.RBFConfigKeys; |
| import org.apache.hadoop.hdfs.server.federation.store.records.BaseRecord; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import com.google.common.io.Files; |
| |
| /** |
| * StateStoreDriver implementation based on a local file. |
| */ |
| public class StateStoreFileImpl extends StateStoreFileBaseImpl { |
| |
| private static final Logger LOG = |
| LoggerFactory.getLogger(StateStoreFileImpl.class); |
| |
| /** Configuration keys. */ |
| public static final String FEDERATION_STORE_FILE_DIRECTORY = |
| RBFConfigKeys.FEDERATION_STORE_PREFIX + "driver.file.directory"; |
| |
| /** Root directory for the state store. */ |
| private String rootDirectory; |
| |
| |
| @Override |
| protected boolean exists(String path) { |
| File test = new File(path); |
| return test.exists(); |
| } |
| |
| @Override |
| protected boolean mkdir(String path) { |
| File dir = new File(path); |
| return dir.mkdirs(); |
| } |
| |
| @Override |
| protected boolean rename(String src, String dst) { |
| try { |
| Files.move(new File(src), new File(dst)); |
| return true; |
| } catch (IOException e) { |
| LOG.error("Cannot rename {} to {}", src, dst, e); |
| return false; |
| } |
| } |
| |
| @Override |
| protected boolean remove(String path) { |
| File file = new File(path); |
| return file.delete(); |
| } |
| |
| @Override |
| protected String getRootDir() { |
| if (this.rootDirectory == null) { |
| String dir = getConf().get(FEDERATION_STORE_FILE_DIRECTORY); |
| if (dir == null) { |
| File tempDir = Files.createTempDir(); |
| dir = tempDir.getAbsolutePath(); |
| LOG.warn("The root directory is not available, using {}", dir); |
| } |
| this.rootDirectory = dir; |
| } |
| return this.rootDirectory; |
| } |
| |
| @Override |
| protected <T extends BaseRecord> BufferedReader getReader(String filename) { |
| BufferedReader reader = null; |
| try { |
| LOG.debug("Loading file: {}", filename); |
| File file = new File(filename); |
| FileInputStream fis = new FileInputStream(file); |
| InputStreamReader isr = |
| new InputStreamReader(fis, StandardCharsets.UTF_8); |
| reader = new BufferedReader(isr); |
| } catch (Exception ex) { |
| LOG.error("Cannot open read stream for record {}", filename, ex); |
| } |
| return reader; |
| } |
| |
| @Override |
| protected <T extends BaseRecord> BufferedWriter getWriter(String filename) { |
| BufferedWriter writer = null; |
| try { |
| LOG.debug("Writing file: {}", filename); |
| File file = new File(filename); |
| FileOutputStream fos = new FileOutputStream(file, false); |
| OutputStreamWriter osw = |
| new OutputStreamWriter(fos, StandardCharsets.UTF_8); |
| writer = new BufferedWriter(osw); |
| } catch (IOException e) { |
| LOG.error("Cannot open write stream for record {}", filename, e); |
| } |
| return writer; |
| } |
| |
| @Override |
| public void close() throws Exception { |
| setInitialized(false); |
| } |
| |
| @Override |
| protected List<String> getChildren(String path) { |
| File dir = new File(path); |
| File[] files = dir.listFiles(); |
| if (ArrayUtils.isNotEmpty(files)) { |
| List<String> ret = new ArrayList<>(files.length); |
| for (File file : files) { |
| String filename = file.getName(); |
| ret.add(filename); |
| } |
| return ret; |
| } |
| return Collections.emptyList(); |
| } |
| } |