1 | /** |
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2 | * Licensed to the Apache Software Foundation (ASF) under one |
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3 | * or more contributor license agreements. See the NOTICE file |
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4 | * distributed with this work for additional information |
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5 | * regarding copyright ownership. The ASF licenses this file |
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6 | * to you under the Apache License, Version 2.0 (the |
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7 | * "License"); you may not use this file except in compliance |
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8 | * with the License. You may obtain a copy of the License at |
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9 | * |
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10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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11 | * |
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12 | * Unless required by applicable law or agreed to in writing, software |
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13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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15 | * See the License for the specific language governing permissions and |
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16 | * limitations under the License. |
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17 | */ |
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18 | |
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19 | package org.apache.hadoop.mapred; |
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20 | |
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21 | import java.io.IOException; |
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22 | import java.util.concurrent.LinkedBlockingQueue; |
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23 | |
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24 | import org.apache.commons.logging.Log; |
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25 | import org.apache.commons.logging.LogFactory; |
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26 | |
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27 | import org.apache.hadoop.fs.FileSystem; |
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28 | import org.apache.hadoop.fs.Path; |
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29 | |
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30 | class CleanupQueue { |
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31 | |
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32 | public static final Log LOG = |
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33 | LogFactory.getLog(CleanupQueue.class); |
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34 | |
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35 | private static PathCleanupThread cleanupThread; |
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36 | |
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37 | /** |
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38 | * Create a singleton path-clean-up queue. It can be used to delete |
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39 | * paths(directories/files) in a separate thread. This constructor creates a |
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40 | * clean-up thread and also starts it as a daemon. Callers can instantiate one |
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41 | * CleanupQueue per JVM and can use it for deleting paths. Use |
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42 | * {@link CleanupQueue#addToQueue(JobConf, Path...)} to add paths for |
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43 | * deletion. |
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44 | */ |
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45 | public CleanupQueue() { |
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46 | synchronized (PathCleanupThread.class) { |
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47 | if (cleanupThread == null) { |
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48 | cleanupThread = new PathCleanupThread(); |
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49 | } |
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50 | } |
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51 | } |
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52 | |
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53 | public void addToQueue(JobConf conf, Path...paths) { |
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54 | cleanupThread.addToQueue(conf,paths); |
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55 | } |
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56 | |
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57 | private static class PathCleanupThread extends Thread { |
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58 | |
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59 | static class PathAndConf { |
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60 | JobConf conf; |
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61 | Path path; |
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62 | PathAndConf(JobConf conf, Path path) { |
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63 | this.conf = conf; |
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64 | this.path = path; |
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65 | } |
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66 | } |
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67 | // cleanup queue which deletes files/directories of the paths queued up. |
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68 | private LinkedBlockingQueue<PathAndConf> queue = new LinkedBlockingQueue<PathAndConf>(); |
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69 | |
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70 | public PathCleanupThread() { |
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71 | setName("Directory/File cleanup thread"); |
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72 | setDaemon(true); |
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73 | start(); |
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74 | } |
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75 | |
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76 | public void addToQueue(JobConf conf,Path... paths) { |
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77 | for (Path p : paths) { |
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78 | try { |
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79 | queue.put(new PathAndConf(conf,p)); |
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80 | } catch (InterruptedException ie) {} |
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81 | } |
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82 | } |
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83 | |
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84 | public void run() { |
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85 | LOG.debug(getName() + " started."); |
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86 | PathAndConf pathAndConf = null; |
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87 | while (true) { |
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88 | try { |
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89 | pathAndConf = queue.take(); |
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90 | // delete the path. |
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91 | FileSystem fs = pathAndConf.path.getFileSystem(pathAndConf.conf); |
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92 | fs.delete(pathAndConf.path, true); |
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93 | LOG.debug("DELETED " + pathAndConf.path); |
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94 | } catch (InterruptedException t) { |
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95 | return; |
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96 | } catch (Exception e) { |
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97 | LOG.warn("Error deleting path" + pathAndConf.path); |
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98 | } |
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99 | } |
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100 | } |
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101 | } |
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102 | } |
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