[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 | |
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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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