[120] | 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 | package org.apache.hadoop.hdfs.server.namenode; |
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| 19 | |
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| 20 | import java.io.*; |
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| 21 | import java.net.*; |
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| 22 | import java.util.Iterator; |
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| 23 | import java.util.Map; |
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| 24 | import javax.servlet.http.HttpServletResponse; |
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| 25 | import javax.servlet.http.HttpServletRequest; |
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| 26 | |
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| 27 | import org.apache.hadoop.hdfs.protocol.FSConstants; |
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| 28 | import org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode.ErrorSimulator; |
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| 29 | |
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| 30 | /** |
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| 31 | * This class provides fetching a specified file from the NameNode. |
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| 32 | */ |
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| 33 | class TransferFsImage implements FSConstants { |
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| 34 | |
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| 35 | private boolean isGetImage; |
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| 36 | private boolean isGetEdit; |
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| 37 | private boolean isPutImage; |
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| 38 | private int remoteport; |
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| 39 | private String machineName; |
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| 40 | private CheckpointSignature token; |
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| 41 | |
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| 42 | /** |
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| 43 | * File downloader. |
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| 44 | * @param pmap key=value[] map that is passed to the http servlet as |
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| 45 | * url parameters |
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| 46 | * @param request the object from which this servelet reads the url contents |
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| 47 | * @param response the object into which this servelet writes the url contents |
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| 48 | * @throws IOException |
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| 49 | */ |
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| 50 | public TransferFsImage(Map<String,String[]> pmap, |
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| 51 | HttpServletRequest request, |
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| 52 | HttpServletResponse response |
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| 53 | ) throws IOException { |
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| 54 | isGetImage = isGetEdit = isPutImage = false; |
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| 55 | remoteport = 0; |
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| 56 | machineName = null; |
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| 57 | token = null; |
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| 58 | |
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| 59 | for (Iterator<String> it = pmap.keySet().iterator(); it.hasNext();) { |
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| 60 | String key = it.next(); |
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| 61 | if (key.equals("getimage")) { |
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| 62 | isGetImage = true; |
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| 63 | } else if (key.equals("getedit")) { |
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| 64 | isGetEdit = true; |
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| 65 | } else if (key.equals("putimage")) { |
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| 66 | isPutImage = true; |
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| 67 | } else if (key.equals("port")) { |
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| 68 | remoteport = new Integer(pmap.get("port")[0]).intValue(); |
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| 69 | } else if (key.equals("machine")) { |
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| 70 | machineName = pmap.get("machine")[0]; |
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| 71 | } else if (key.equals("token")) { |
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| 72 | token = new CheckpointSignature(pmap.get("token")[0]); |
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| 73 | } |
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| 74 | } |
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| 75 | |
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| 76 | int numGets = (isGetImage?1:0) + (isGetEdit?1:0); |
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| 77 | if ((numGets > 1) || (numGets == 0) && !isPutImage) { |
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| 78 | throw new IOException("Illegal parameters to TransferFsImage"); |
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| 79 | } |
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| 80 | } |
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| 81 | |
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| 82 | boolean getEdit() { |
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| 83 | return isGetEdit; |
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| 84 | } |
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| 85 | |
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| 86 | boolean getImage() { |
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| 87 | return isGetImage; |
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| 88 | } |
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| 89 | |
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| 90 | boolean putImage() { |
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| 91 | return isPutImage; |
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| 92 | } |
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| 93 | |
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| 94 | CheckpointSignature getToken() { |
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| 95 | return token; |
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| 96 | } |
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| 97 | |
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| 98 | String getInfoServer() throws IOException{ |
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| 99 | if (machineName == null || remoteport == 0) { |
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| 100 | throw new IOException ("MachineName and port undefined"); |
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| 101 | } |
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| 102 | return machineName + ":" + remoteport; |
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| 103 | } |
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| 104 | |
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| 105 | /** |
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| 106 | * A server-side method to respond to a getfile http request |
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| 107 | * Copies the contents of the local file into the output stream. |
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| 108 | */ |
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| 109 | static void getFileServer(OutputStream outstream, File localfile) |
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| 110 | throws IOException { |
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| 111 | byte buf[] = new byte[BUFFER_SIZE]; |
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| 112 | FileInputStream infile = null; |
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| 113 | try { |
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| 114 | infile = new FileInputStream(localfile); |
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| 115 | if (ErrorSimulator.getErrorSimulation(2) |
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| 116 | && localfile.getAbsolutePath().contains("secondary")) { |
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| 117 | // throw exception only when the secondary sends its image |
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| 118 | throw new IOException("If this exception is not caught by the " + |
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| 119 | "name-node fs image will be truncated."); |
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| 120 | } |
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| 121 | int num = 1; |
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| 122 | while (num > 0) { |
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| 123 | num = infile.read(buf); |
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| 124 | if (num <= 0) { |
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| 125 | break; |
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| 126 | } |
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| 127 | outstream.write(buf, 0, num); |
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| 128 | } |
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| 129 | } finally { |
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| 130 | if (infile != null) { |
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| 131 | infile.close(); |
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| 132 | } |
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| 133 | } |
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| 134 | } |
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| 135 | |
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| 136 | /** |
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| 137 | * Client-side Method to fetch file from a server |
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| 138 | * Copies the response from the URL to a list of local files. |
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| 139 | */ |
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| 140 | static void getFileClient(String fsName, String id, File[] localPath) |
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| 141 | throws IOException { |
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| 142 | byte[] buf = new byte[BUFFER_SIZE]; |
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| 143 | StringBuffer str = new StringBuffer("http://"+fsName+"/getimage?"); |
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| 144 | str.append(id); |
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| 145 | |
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| 146 | // |
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| 147 | // open connection to remote server |
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| 148 | // |
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| 149 | URL url = new URL(str.toString()); |
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| 150 | URLConnection connection = url.openConnection(); |
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| 151 | InputStream stream = connection.getInputStream(); |
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| 152 | FileOutputStream[] output = null; |
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| 153 | |
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| 154 | try { |
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| 155 | if (localPath != null) { |
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| 156 | output = new FileOutputStream[localPath.length]; |
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| 157 | for (int i = 0; i < output.length; i++) { |
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| 158 | output[i] = new FileOutputStream(localPath[i]); |
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| 159 | } |
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| 160 | } |
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| 161 | int num = 1; |
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| 162 | while (num > 0) { |
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| 163 | num = stream.read(buf); |
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| 164 | if (num > 0 && localPath != null) { |
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| 165 | for (int i = 0; i < output.length; i++) { |
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| 166 | output[i].write(buf, 0, num); |
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| 167 | } |
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| 168 | } |
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| 169 | } |
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| 170 | } finally { |
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| 171 | stream.close(); |
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| 172 | if (output != null) { |
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| 173 | for (int i = 0; i < output.length; i++) { |
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| 174 | if (output[i] != null) { |
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| 175 | output[i].close(); |
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| 176 | } |
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| 177 | } |
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| 178 | } |
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| 179 | } |
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| 180 | } |
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| 181 | } |
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