| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package com.datatorrent.lib.util; |
| |
| import java.io.Serializable; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import com.datatorrent.api.StreamCodec; |
| import com.datatorrent.lib.codec.JavaSerializationStreamCodec; |
| |
| /** |
| * This is an abstract operator that allows cloneKey and cloneValue to allow users to use mutable objects. |
| * <p></p> |
| * @displayName Base Key Value |
| * @category Algorithmic |
| * @tags key value abstract |
| * @since 0.3.2 |
| */ |
| public class BaseKeyValueOperator<K, V> extends BaseKeyOperator<K> |
| { |
| /** |
| * By default an immutable object is assumed. Override if V is mutable |
| * |
| * @param v |
| * @return v as is |
| */ |
| public V cloneValue(V v) |
| { |
| return v; |
| } |
| |
| /** |
| * By default an immutable object is assumed. Override if V is mutable |
| * |
| * @param kv |
| * @return v as is |
| */ |
| public KeyValPair<K, V> cloneKeyValPair(KeyValPair<K, V> kv) |
| { |
| return kv; |
| } |
| |
| /** |
| * Creates a HashMap<K,V> by using cloneKey(K) and cloneValue(V) |
| * |
| * @param tuple to be cloned |
| * @return HashMap<K,V> |
| */ |
| public HashMap<K, V> cloneTuple(Map<K, V> tuple) |
| { |
| if (tuple == null) { |
| return null; |
| } |
| HashMap<K, V> ret = new HashMap<K, V>(tuple.size()); |
| for (Map.Entry<K, V> e : tuple.entrySet()) { |
| ret.put(cloneKey(e.getKey()), cloneValue(e.getValue())); |
| } |
| return ret; |
| } |
| |
| /** |
| * Creates a HashMap<K,V>(1) by using cloneKey(K) and cloneValue(V) |
| * |
| * @param key key to be cloned |
| * @param val value to be cloned |
| * @return HashMap<K,V>(1) |
| */ |
| public HashMap<K, V> cloneTuple(K key, V val) |
| { |
| HashMap<K, V> ret = new HashMap<K, V>(1); |
| ret.put(cloneKey(key), cloneValue(val)); |
| return ret; |
| } |
| |
| /** |
| * A codec to enable partitioning to be done by key |
| */ |
| public StreamCodec<KeyValPair<K, V>> getKeyValPairStreamCodec() |
| { |
| return new DefaultPartitionCodec<K, V>(); |
| } |
| |
| public static class DefaultPartitionCodec<K, V> extends JavaSerializationStreamCodec<KeyValPair<K, V>> implements Serializable |
| { |
| /** |
| * A codec to enable partitioning to be done by key |
| */ |
| @Override |
| public int getPartition(KeyValPair<K, V> o) |
| { |
| return o.getKey().hashCode(); |
| } |
| |
| private static final long serialVersionUID = 201411031350L; |
| } |
| |
| } |