| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| KryoWritableWrapper |
|
| 0.0;0 |
| 1 | /* | |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one | |
| 3 | * or more contributor license agreements. See the NOTICE file | |
| 4 | * distributed with this work for additional information | |
| 5 | * regarding copyright ownership. The ASF licenses this file | |
| 6 | * to you under the Apache License, Version 2.0 (the | |
| 7 | * "License"); you may not use this file except in compliance | |
| 8 | * with the License. You may obtain a copy of the License at | |
| 9 | * | |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 11 | * | |
| 12 | * Unless required by applicable law or agreed to in writing, software | |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, | |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 15 | * See the License for the specific language governing permissions and | |
| 16 | * limitations under the License. | |
| 17 | */ | |
| 18 | package org.apache.giraph.writable.kryo; | |
| 19 | ||
| 20 | import java.io.DataInput; | |
| 21 | import java.io.DataOutput; | |
| 22 | import java.io.IOException; | |
| 23 | ||
| 24 | import org.apache.giraph.utils.WritableUtils; | |
| 25 | import org.apache.hadoop.io.Writable; | |
| 26 | ||
| 27 | /** | |
| 28 | * Generic wrapper object, making any object writable. | |
| 29 | * | |
| 30 | * Uses Kryo inside for serialization. | |
| 31 | * Current configuration is not optimized for performance, | |
| 32 | * but Writable interface doesn't allow much room for it. | |
| 33 | * | |
| 34 | * Note - Java8 lambdas need to implement Serializable to work. | |
| 35 | * | |
| 36 | * @param <T> Object type | |
| 37 | */ | |
| 38 | public class KryoWritableWrapper<T> implements Writable { | |
| 39 | /** Wrapped object */ | |
| 40 | private T object; | |
| 41 | ||
| 42 | /** | |
| 43 | * Create wrapper given an object. | |
| 44 | * @param object Object instance | |
| 45 | */ | |
| 46 | 0 | public KryoWritableWrapper(T object) { |
| 47 | 0 | this.object = object; |
| 48 | 0 | } |
| 49 | ||
| 50 | /** | |
| 51 | * Creates wrapper initialized with null. | |
| 52 | */ | |
| 53 | 0 | public KryoWritableWrapper() { |
| 54 | 0 | } |
| 55 | ||
| 56 | /** | |
| 57 | * Unwrap the object value | |
| 58 | * @return Object value | |
| 59 | */ | |
| 60 | public T get() { | |
| 61 | 0 | return object; |
| 62 | } | |
| 63 | ||
| 64 | /** | |
| 65 | * Set wrapped object value | |
| 66 | * @param object New object value | |
| 67 | */ | |
| 68 | public void set(T object) { | |
| 69 | 0 | this.object = object; |
| 70 | 0 | } |
| 71 | ||
| 72 | @Override | |
| 73 | public void readFields(DataInput in) throws java.io.IOException { | |
| 74 | 0 | object = HadoopKryo.readClassAndObj(in); |
| 75 | 0 | } |
| 76 | ||
| 77 | @Override | |
| 78 | public void write(DataOutput out) throws IOException { | |
| 79 | 0 | HadoopKryo.writeClassAndObj(out, object); |
| 80 | 0 | } |
| 81 | ||
| 82 | /** | |
| 83 | * Returns Writable instance, wrapping given object only | |
| 84 | * if it is not already writable. | |
| 85 | * | |
| 86 | * @param object Object to potentially wrap | |
| 87 | * @return Writable object holding argument | |
| 88 | */ | |
| 89 | public static Writable wrapIfNeeded(Object object) { | |
| 90 | 0 | if (object instanceof Writable) { |
| 91 | 0 | return (Writable) object; |
| 92 | } else { | |
| 93 | 0 | return new KryoWritableWrapper<>(object); |
| 94 | } | |
| 95 | } | |
| 96 | ||
| 97 | /** | |
| 98 | * Unwrap Writable object if it was wrapped initially, | |
| 99 | * inverse of wrapIfNeeded function. | |
| 100 | * @param value Potentially wrapped value | |
| 101 | * @return Original unwrapped value | |
| 102 | * @param <T> Type of returned object. | |
| 103 | */ | |
| 104 | public static <T> T unwrapIfNeeded(Writable value) { | |
| 105 | 0 | if (value instanceof KryoWritableWrapper) { |
| 106 | 0 | return ((KryoWritableWrapper<T>) value).get(); |
| 107 | } else { | |
| 108 | 0 | return (T) value; |
| 109 | } | |
| 110 | } | |
| 111 | ||
| 112 | /** | |
| 113 | * Wrap object with KryoWritableWrapper, create a writable copy of it, | |
| 114 | * and then unwrap it, allowing any object to be copied. | |
| 115 | * | |
| 116 | * @param object Object to copy | |
| 117 | * @return copy of the object | |
| 118 | * @param <T> Type of the object | |
| 119 | */ | |
| 120 | public static <T> T wrapAndCopy(T object) { | |
| 121 | 0 | return WritableUtils.createCopy(new KryoWritableWrapper<>(object)).get(); |
| 122 | } | |
| 123 | ||
| 124 | /** | |
| 125 | * Converting the object to byte array. | |
| 126 | * @param object Object | |
| 127 | * @param <T> Type | |
| 128 | * @return byte array | |
| 129 | */ | |
| 130 | public static <T> byte [] convertToByteArray(T object) { | |
| 131 | 0 | KryoWritableWrapper<T> wrapper = |
| 132 | new KryoWritableWrapper<>(object); | |
| 133 | 0 | return WritableUtils.toByteArray(wrapper); |
| 134 | } | |
| 135 | ||
| 136 | /** | |
| 137 | * Converting from byte array | |
| 138 | * @param arr byte array | |
| 139 | * @param <T> type | |
| 140 | * @return original object | |
| 141 | */ | |
| 142 | public static <T> T convertFromByteArray(byte [] arr) { | |
| 143 | 0 | KryoWritableWrapper<T> wrapper = |
| 144 | new KryoWritableWrapper<>(); | |
| 145 | 0 | WritableUtils.fromByteArray(arr, wrapper); |
| 146 | 0 | return wrapper.get(); |
| 147 | } | |
| 148 | } |