[120] | 1 | /** |
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| 2 | * Copyright 2007 The Apache Software Foundation |
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| 3 | * |
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| 4 | * Licensed to the Apache Software Foundation (ASF) under one |
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| 5 | * or more contributor license agreements. See the NOTICE file |
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| 6 | * distributed with this work for additional information |
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| 7 | * regarding copyright ownership. The ASF licenses this file |
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| 8 | * to you under the Apache License, Version 2.0 (the |
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| 9 | * "License"); you may not use this file except in compliance |
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| 10 | * with the License. You may obtain a copy of the License at |
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| 11 | * |
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| 12 | * http://www.apache.org/licenses/LICENSE-2.0 |
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| 13 | * |
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| 14 | * Unless required by applicable law or agreed to in writing, software |
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| 15 | * distributed under the License is distributed on an "AS IS" BASIS, |
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| 16 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 17 | * See the License for the specific language governing permissions and |
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| 18 | * limitations under the License. |
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| 19 | */ |
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| 20 | package org.apache.hadoop.io; |
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| 21 | |
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| 22 | import java.io.DataInput; |
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| 23 | import java.io.DataOutput; |
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| 24 | import java.io.IOException; |
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| 25 | import java.util.Collection; |
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| 26 | import java.util.Comparator; |
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| 27 | import java.util.Map; |
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| 28 | import java.util.Set; |
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| 29 | import java.util.SortedMap; |
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| 30 | import java.util.TreeMap; |
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| 31 | |
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| 32 | import org.apache.hadoop.util.ReflectionUtils; |
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| 33 | |
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| 34 | /** |
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| 35 | * A Writable SortedMap. |
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| 36 | */ |
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| 37 | public class SortedMapWritable extends AbstractMapWritable |
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| 38 | implements SortedMap<WritableComparable, Writable> { |
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| 39 | |
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| 40 | private SortedMap<WritableComparable, Writable> instance; |
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| 41 | |
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| 42 | /** default constructor. */ |
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| 43 | public SortedMapWritable() { |
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| 44 | super(); |
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| 45 | this.instance = new TreeMap<WritableComparable, Writable>(); |
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| 46 | } |
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| 47 | |
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| 48 | /** |
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| 49 | * Copy constructor. |
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| 50 | * |
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| 51 | * @param other the map to copy from |
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| 52 | */ |
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| 53 | public SortedMapWritable(SortedMapWritable other) { |
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| 54 | this(); |
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| 55 | copy(other); |
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| 56 | } |
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| 57 | |
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| 58 | /** {@inheritDoc} */ |
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| 59 | public Comparator<? super WritableComparable> comparator() { |
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| 60 | // Returning null means we use the natural ordering of the keys |
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| 61 | return null; |
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| 62 | } |
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| 63 | |
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| 64 | /** {@inheritDoc} */ |
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| 65 | public WritableComparable firstKey() { |
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| 66 | return instance.firstKey(); |
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| 67 | } |
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| 68 | |
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| 69 | /** {@inheritDoc} */ |
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| 70 | public SortedMap<WritableComparable, Writable> |
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| 71 | headMap(WritableComparable toKey) { |
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| 72 | |
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| 73 | return instance.headMap(toKey); |
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| 74 | } |
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| 75 | |
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| 76 | /** {@inheritDoc} */ |
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| 77 | public WritableComparable lastKey() { |
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| 78 | return instance.lastKey(); |
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| 79 | } |
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| 80 | |
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| 81 | /** {@inheritDoc} */ |
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| 82 | public SortedMap<WritableComparable, Writable> |
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| 83 | subMap(WritableComparable fromKey, WritableComparable toKey) { |
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| 84 | |
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| 85 | return instance.subMap(fromKey, toKey); |
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| 86 | } |
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| 87 | |
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| 88 | /** {@inheritDoc} */ |
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| 89 | public SortedMap<WritableComparable, Writable> |
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| 90 | tailMap(WritableComparable fromKey) { |
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| 91 | |
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| 92 | return instance.tailMap(fromKey); |
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| 93 | } |
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| 94 | |
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| 95 | /** {@inheritDoc} */ |
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| 96 | public void clear() { |
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| 97 | instance.clear(); |
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| 98 | } |
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| 99 | |
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| 100 | /** {@inheritDoc} */ |
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| 101 | public boolean containsKey(Object key) { |
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| 102 | return instance.containsKey(key); |
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| 103 | } |
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| 104 | |
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| 105 | /** {@inheritDoc} */ |
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| 106 | public boolean containsValue(Object value) { |
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| 107 | return instance.containsValue(value); |
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| 108 | } |
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| 109 | |
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| 110 | /** {@inheritDoc} */ |
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| 111 | public Set<java.util.Map.Entry<WritableComparable, Writable>> entrySet() { |
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| 112 | return instance.entrySet(); |
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| 113 | } |
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| 114 | |
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| 115 | /** {@inheritDoc} */ |
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| 116 | public Writable get(Object key) { |
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| 117 | return instance.get(key); |
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| 118 | } |
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| 119 | |
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| 120 | /** {@inheritDoc} */ |
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| 121 | public boolean isEmpty() { |
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| 122 | return instance.isEmpty(); |
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| 123 | } |
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| 124 | |
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| 125 | /** {@inheritDoc} */ |
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| 126 | public Set<WritableComparable> keySet() { |
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| 127 | return instance.keySet(); |
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| 128 | } |
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| 129 | |
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| 130 | /** {@inheritDoc} */ |
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| 131 | public Writable put(WritableComparable key, Writable value) { |
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| 132 | addToMap(key.getClass()); |
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| 133 | addToMap(value.getClass()); |
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| 134 | return instance.put(key, value); |
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| 135 | } |
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| 136 | |
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| 137 | /** {@inheritDoc} */ |
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| 138 | public void putAll(Map<? extends WritableComparable, ? extends Writable> t) { |
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| 139 | for (Map.Entry<? extends WritableComparable, ? extends Writable> e: |
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| 140 | t.entrySet()) { |
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| 141 | |
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| 142 | instance.put(e.getKey(), e.getValue()); |
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| 143 | } |
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| 144 | } |
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| 145 | |
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| 146 | /** {@inheritDoc} */ |
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| 147 | public Writable remove(Object key) { |
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| 148 | return instance.remove(key); |
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| 149 | } |
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| 150 | |
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| 151 | /** {@inheritDoc} */ |
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| 152 | public int size() { |
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| 153 | return instance.size(); |
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| 154 | } |
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| 155 | |
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| 156 | /** {@inheritDoc} */ |
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| 157 | public Collection<Writable> values() { |
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| 158 | return instance.values(); |
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| 159 | } |
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| 160 | |
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| 161 | /** {@inheritDoc} */ |
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| 162 | @SuppressWarnings("unchecked") |
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| 163 | @Override |
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| 164 | public void readFields(DataInput in) throws IOException { |
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| 165 | super.readFields(in); |
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| 166 | |
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| 167 | // Read the number of entries in the map |
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| 168 | |
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| 169 | int entries = in.readInt(); |
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| 170 | |
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| 171 | // Then read each key/value pair |
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| 172 | |
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| 173 | for (int i = 0; i < entries; i++) { |
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| 174 | WritableComparable key = |
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| 175 | (WritableComparable) ReflectionUtils.newInstance(getClass( |
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| 176 | in.readByte()), getConf()); |
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| 177 | |
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| 178 | key.readFields(in); |
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| 179 | |
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| 180 | Writable value = (Writable) ReflectionUtils.newInstance(getClass( |
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| 181 | in.readByte()), getConf()); |
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| 182 | |
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| 183 | value.readFields(in); |
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| 184 | instance.put(key, value); |
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| 185 | } |
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| 186 | } |
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| 187 | |
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| 188 | /** {@inheritDoc} */ |
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| 189 | @Override |
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| 190 | public void write(DataOutput out) throws IOException { |
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| 191 | super.write(out); |
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| 192 | |
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| 193 | // Write out the number of entries in the map |
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| 194 | |
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| 195 | out.writeInt(instance.size()); |
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| 196 | |
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| 197 | // Then write out each key/value pair |
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| 198 | |
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| 199 | for (Map.Entry<WritableComparable, Writable> e: instance.entrySet()) { |
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| 200 | out.writeByte(getId(e.getKey().getClass())); |
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| 201 | e.getKey().write(out); |
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| 202 | out.writeByte(getId(e.getValue().getClass())); |
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| 203 | e.getValue().write(out); |
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| 204 | } |
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| 205 | } |
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| 206 | } |
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