| /* |
| * 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.pig.builtin; |
| |
| import java.io.IOException; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.PigConstants; |
| import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduce; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| |
| /** |
| * UniqueID generates a unique id for each records in the job. This unique id is |
| * stable in task retry. Any arguments to the function are ignored. |
| * Example: |
| * A = load 'mydata' as (name); |
| * B = foreach A generate name, UniqueID(); |
| * UniqueID takes the form "index-sequence" |
| */ |
| public class UniqueID extends EvalFunc<String> { |
| long sequence = 0; |
| @Override |
| public String exec(Tuple input) throws IOException { |
| String taskIndex = PigMapReduce.sJobConfInternal.get().get(PigConstants.TASK_INDEX); |
| String sequenceId = taskIndex + "-" + Long.toString(sequence); |
| sequence++; |
| return sequenceId; |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new Schema(new Schema.FieldSchema("uniqueid", DataType.CHARARRAY)); |
| } |
| } |