| /** |
| * 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.fs; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.util.Shell; |
| |
| import java.io.BufferedReader; |
| import java.io.File; |
| import java.io.IOException; |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| /** Filesystem disk space usage statistics. Uses the unix 'du' program*/ |
| @InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"}) |
| @InterfaceStability.Evolving |
| public class DU extends Shell { |
| private String dirPath; |
| |
| private AtomicLong used = new AtomicLong(); |
| private volatile boolean shouldRun = true; |
| private Thread refreshUsed; |
| private IOException duException = null; |
| private long refreshInterval; |
| |
| /** |
| * Keeps track of disk usage. |
| * @param path the path to check disk usage in |
| * @param interval refresh the disk usage at this interval |
| * @throws IOException if we fail to refresh the disk usage |
| */ |
| public DU(File path, long interval) throws IOException { |
| super(0); |
| |
| //we set the Shell interval to 0 so it will always run our command |
| //and use this one to set the thread sleep interval |
| this.refreshInterval = interval; |
| this.dirPath = path.getCanonicalPath(); |
| |
| //populate the used variable |
| run(); |
| } |
| |
| /** |
| * Keeps track of disk usage. |
| * @param path the path to check disk usage in |
| * @param conf configuration object |
| * @throws IOException if we fail to refresh the disk usage |
| */ |
| public DU(File path, Configuration conf) throws IOException { |
| this(path, 600000L); |
| //10 minutes default refresh interval |
| } |
| |
| /** |
| * This thread refreshes the "used" variable. |
| * |
| * Future improvements could be to not permanently |
| * run this thread, instead run when getUsed is called. |
| **/ |
| class DURefreshThread implements Runnable { |
| |
| public void run() { |
| |
| while(shouldRun) { |
| |
| try { |
| Thread.sleep(refreshInterval); |
| |
| try { |
| //update the used variable |
| DU.this.run(); |
| } catch (IOException e) { |
| synchronized (DU.this) { |
| //save the latest exception so we can return it in getUsed() |
| duException = e; |
| } |
| |
| LOG.warn("Could not get disk usage information", e); |
| } |
| } catch (InterruptedException e) { |
| } |
| } |
| } |
| } |
| |
| /** |
| * Decrease how much disk space we use. |
| * @param value decrease by this value |
| */ |
| public void decDfsUsed(long value) { |
| used.addAndGet(-value); |
| } |
| |
| /** |
| * Increase how much disk space we use. |
| * @param value increase by this value |
| */ |
| public void incDfsUsed(long value) { |
| used.addAndGet(value); |
| } |
| |
| /** |
| * @return disk space used |
| * @throws IOException if the shell command fails |
| */ |
| public long getUsed() throws IOException { |
| //if the updating thread isn't started, update on demand |
| if(refreshUsed == null) { |
| run(); |
| } else { |
| synchronized (DU.this) { |
| //if an exception was thrown in the last run, rethrow |
| if(duException != null) { |
| IOException tmp = duException; |
| duException = null; |
| throw tmp; |
| } |
| } |
| } |
| |
| return used.longValue(); |
| } |
| |
| /** |
| * @return the path of which we're keeping track of disk usage |
| */ |
| public String getDirPath() { |
| return dirPath; |
| } |
| |
| /** |
| * Start the disk usage checking thread. |
| */ |
| public void start() { |
| //only start the thread if the interval is sane |
| if(refreshInterval > 0) { |
| refreshUsed = new Thread(new DURefreshThread(), |
| "refreshUsed-"+dirPath); |
| refreshUsed.setDaemon(true); |
| refreshUsed.start(); |
| } |
| } |
| |
| /** |
| * Shut down the refreshing thread. |
| */ |
| public void shutdown() { |
| this.shouldRun = false; |
| |
| if(this.refreshUsed != null) { |
| this.refreshUsed.interrupt(); |
| } |
| } |
| |
| public String toString() { |
| return |
| "du -sk " + dirPath +"\n" + |
| used + "\t" + dirPath; |
| } |
| |
| protected String[] getExecString() { |
| return new String[] {"du", "-sk", dirPath}; |
| } |
| |
| protected void parseExecResult(BufferedReader lines) throws IOException { |
| String line = lines.readLine(); |
| if (line == null) { |
| throw new IOException("Expecting a line not the end of stream"); |
| } |
| String[] tokens = line.split("\t"); |
| if(tokens.length == 0) { |
| throw new IOException("Illegal du output"); |
| } |
| this.used.set(Long.parseLong(tokens[0])*1024); |
| } |
| |
| public static void main(String[] args) throws Exception { |
| String path = "."; |
| if (args.length > 0) { |
| path = args[0]; |
| } |
| |
| System.out.println(new DU(new File(path), new Configuration()).toString()); |
| } |
| } |