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.io; |
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20 | |
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21 | import java.io.*; |
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22 | import java.lang.reflect.Array; |
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23 | |
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24 | /** A Writable for 2D arrays containing a matrix of instances of a class. */ |
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25 | public class TwoDArrayWritable implements Writable { |
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26 | private Class valueClass; |
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27 | private Writable[][] values; |
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28 | |
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29 | public TwoDArrayWritable(Class valueClass) { |
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30 | this.valueClass = valueClass; |
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31 | } |
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32 | |
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33 | public TwoDArrayWritable(Class valueClass, Writable[][] values) { |
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34 | this(valueClass); |
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35 | this.values = values; |
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36 | } |
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37 | |
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38 | public Object toArray() { |
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39 | int dimensions[] = {values.length, 0}; |
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40 | Object result = Array.newInstance(valueClass, dimensions); |
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41 | for (int i = 0; i < values.length; i++) { |
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42 | Object resultRow = Array.newInstance(valueClass, values[i].length); |
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43 | Array.set(result, i, resultRow); |
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44 | for (int j = 0; j < values[i].length; j++) { |
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45 | Array.set(resultRow, j, values[i][j]); |
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46 | } |
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47 | } |
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48 | return result; |
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49 | } |
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50 | |
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51 | public void set(Writable[][] values) { this.values = values; } |
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52 | |
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53 | public Writable[][] get() { return values; } |
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54 | |
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55 | public void readFields(DataInput in) throws IOException { |
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56 | // construct matrix |
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57 | values = new Writable[in.readInt()][]; |
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58 | for (int i = 0; i < values.length; i++) { |
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59 | values[i] = new Writable[in.readInt()]; |
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60 | } |
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61 | |
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62 | // construct values |
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63 | for (int i = 0; i < values.length; i++) { |
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64 | for (int j = 0; j < values[i].length; j++) { |
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65 | Writable value; // construct value |
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66 | try { |
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67 | value = (Writable)valueClass.newInstance(); |
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68 | } catch (InstantiationException e) { |
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69 | throw new RuntimeException(e.toString()); |
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70 | } catch (IllegalAccessException e) { |
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71 | throw new RuntimeException(e.toString()); |
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72 | } |
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73 | value.readFields(in); // read a value |
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74 | values[i][j] = value; // store it in values |
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75 | } |
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76 | } |
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77 | } |
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78 | |
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79 | public void write(DataOutput out) throws IOException { |
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80 | out.writeInt(values.length); // write values |
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81 | for (int i = 0; i < values.length; i++) { |
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82 | out.writeInt(values[i].length); |
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83 | } |
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84 | for (int i = 0; i < values.length; i++) { |
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85 | for (int j = 0; j < values[i].length; j++) { |
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86 | values[i][j].write(out); |
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87 | } |
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88 | } |
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89 | } |
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90 | } |
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91 | |
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