| /** |
| * 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 org.apache.hadoop.mapred.nativetask.serde; |
| |
| import java.io.IOException; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.io.Writable; |
| |
| @InterfaceAudience.Private |
| public class NativeSerialization { |
| |
| private final ConcurrentHashMap<String, Class<?>> map = |
| new ConcurrentHashMap<String, Class<?>>(); |
| |
| public boolean accept(Class<?> c) { |
| return Writable.class.isAssignableFrom(c); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public INativeSerializer<Writable> getSerializer(Class<?> c) throws IOException { |
| |
| if (null == c) { |
| return null; |
| } |
| if (!Writable.class.isAssignableFrom(c)) { |
| throw new IOException("Cannot serialize type " + c.getName() + |
| ", we only accept subclass of Writable"); |
| } |
| final String name = c.getName(); |
| final Class<?> serializer = map.get(name); |
| |
| if (null != serializer) { |
| try { |
| return (INativeSerializer<Writable>) serializer.newInstance(); |
| } catch (final Exception e) { |
| throw new IOException(e); |
| } |
| } |
| return new DefaultSerializer(); |
| } |
| |
| public void register(String klass, Class<?> serializer) throws IOException { |
| if (null == klass || null == serializer) { |
| throw new IOException("invalid arguments, klass or serializer is null"); |
| } |
| |
| if (!INativeSerializer.class.isAssignableFrom(serializer)) { |
| throw new IOException("Serializer is not assigable from INativeSerializer"); |
| } |
| |
| final Class<?> storedSerializer = map.get(klass); |
| if (null == storedSerializer) { |
| map.put(klass, serializer); |
| return; |
| } else { |
| if (!storedSerializer.getName().equals(serializer.getName())) { |
| throw new IOException("Error! Serializer already registered, existing: " + |
| storedSerializer.getName() + ", new: " + |
| serializer.getName()); |
| } |
| } |
| } |
| |
| public void reset() { |
| map.clear(); |
| } |
| |
| private static NativeSerialization instance = new NativeSerialization(); |
| |
| public static NativeSerialization getInstance() { |
| return instance; |
| } |
| } |