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.mapreduce; |
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20 | |
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21 | import java.io.IOException; |
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22 | |
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23 | import org.apache.hadoop.conf.Configuration; |
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24 | |
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25 | /** |
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26 | * The context that is given to the {@link Mapper}. |
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27 | * @param <KEYIN> the key input type to the Mapper |
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28 | * @param <VALUEIN> the value input type to the Mapper |
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29 | * @param <KEYOUT> the key output type from the Mapper |
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30 | * @param <VALUEOUT> the value output type from the Mapper |
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31 | */ |
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32 | public class MapContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> |
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33 | extends TaskInputOutputContext<KEYIN,VALUEIN,KEYOUT,VALUEOUT> { |
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34 | private RecordReader<KEYIN,VALUEIN> reader; |
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35 | private InputSplit split; |
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36 | |
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37 | public MapContext(Configuration conf, TaskAttemptID taskid, |
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38 | RecordReader<KEYIN,VALUEIN> reader, |
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39 | RecordWriter<KEYOUT,VALUEOUT> writer, |
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40 | OutputCommitter committer, |
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41 | StatusReporter reporter, |
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42 | InputSplit split) { |
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43 | super(conf, taskid, writer, committer, reporter); |
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44 | this.reader = reader; |
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45 | this.split = split; |
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46 | } |
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47 | |
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48 | /** |
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49 | * Get the input split for this map. |
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50 | */ |
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51 | public InputSplit getInputSplit() { |
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52 | return split; |
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53 | } |
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54 | |
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55 | @Override |
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56 | public KEYIN getCurrentKey() throws IOException, InterruptedException { |
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57 | return reader.getCurrentKey(); |
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58 | } |
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59 | |
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60 | @Override |
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61 | public VALUEIN getCurrentValue() throws IOException, InterruptedException { |
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62 | return reader.getCurrentValue(); |
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63 | } |
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64 | |
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65 | @Override |
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66 | public boolean nextKeyValue() throws IOException, InterruptedException { |
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67 | return reader.nextKeyValue(); |
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68 | } |
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69 | |
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70 | } |
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71 | |
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