| /** |
| * 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.lib; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| |
| import org.apache.hadoop.conf.Configurable; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.mapred.InputFormat; |
| import org.apache.hadoop.mapred.InputSplit; |
| import org.apache.hadoop.mapred.Mapper; |
| import org.apache.hadoop.util.ReflectionUtils; |
| |
| /** |
| * An {@link InputSplit} that tags another InputSplit with extra data for use by |
| * {@link DelegatingInputFormat}s and {@link DelegatingMapper}s. |
| */ |
| class TaggedInputSplit implements Configurable, InputSplit { |
| |
| private Class<? extends InputSplit> inputSplitClass; |
| |
| private InputSplit inputSplit; |
| |
| private Class<? extends InputFormat> inputFormatClass; |
| |
| private Class<? extends Mapper> mapperClass; |
| |
| private Configuration conf; |
| |
| public TaggedInputSplit() { |
| // Default constructor. |
| } |
| |
| /** |
| * Creates a new TaggedInputSplit. |
| * |
| * @param inputSplit The InputSplit to be tagged |
| * @param conf The configuration to use |
| * @param inputFormatClass The InputFormat class to use for this job |
| * @param mapperClass The Mapper class to use for this job |
| */ |
| public TaggedInputSplit(InputSplit inputSplit, Configuration conf, |
| Class<? extends InputFormat> inputFormatClass, |
| Class<? extends Mapper> mapperClass) { |
| this.inputSplitClass = inputSplit.getClass(); |
| this.inputSplit = inputSplit; |
| this.conf = conf; |
| this.inputFormatClass = inputFormatClass; |
| this.mapperClass = mapperClass; |
| } |
| |
| /** |
| * Retrieves the original InputSplit. |
| * |
| * @return The InputSplit that was tagged |
| */ |
| public InputSplit getInputSplit() { |
| return inputSplit; |
| } |
| |
| /** |
| * Retrieves the InputFormat class to use for this split. |
| * |
| * @return The InputFormat class to use |
| */ |
| public Class<? extends InputFormat> getInputFormatClass() { |
| return inputFormatClass; |
| } |
| |
| /** |
| * Retrieves the Mapper class to use for this split. |
| * |
| * @return The Mapper class to use |
| */ |
| public Class<? extends Mapper> getMapperClass() { |
| return mapperClass; |
| } |
| |
| public long getLength() throws IOException { |
| return inputSplit.getLength(); |
| } |
| |
| public String[] getLocations() throws IOException { |
| return inputSplit.getLocations(); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public void readFields(DataInput in) throws IOException { |
| inputSplitClass = (Class<? extends InputSplit>) readClass(in); |
| inputSplit = (InputSplit) ReflectionUtils |
| .newInstance(inputSplitClass, conf); |
| inputSplit.readFields(in); |
| inputFormatClass = (Class<? extends InputFormat>) readClass(in); |
| mapperClass = (Class<? extends Mapper>) readClass(in); |
| } |
| |
| private Class<?> readClass(DataInput in) throws IOException { |
| String className = Text.readString(in); |
| try { |
| return conf.getClassByName(className); |
| } catch (ClassNotFoundException e) { |
| throw new RuntimeException("readObject can't find class", e); |
| } |
| } |
| |
| public void write(DataOutput out) throws IOException { |
| Text.writeString(out, inputSplitClass.getName()); |
| inputSplit.write(out); |
| Text.writeString(out, inputFormatClass.getName()); |
| Text.writeString(out, mapperClass.getName()); |
| } |
| |
| public Configuration getConf() { |
| return conf; |
| } |
| |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| } |
| |
| @Override |
| public String toString() { |
| return inputSplit.toString(); |
| } |
| |
| } |