| /** |
| * 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.mrql; |
| |
| import java.util.List; |
| import java.io.Serializable; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.spark.api.java.JavaRDD; |
| import org.apache.spark.api.java.function.Function2; |
| |
| |
| final public class RDDDataSource extends DataSource implements Serializable { |
| public JavaRDD<MRData> rdd; |
| |
| RDDDataSource ( JavaRDD<MRData> rdd ) { |
| super(); |
| this.rdd = rdd; |
| } |
| |
| @Override |
| public long size ( Configuration conf ) { |
| return rdd.count(); |
| } |
| |
| /** return the first num values */ |
| @Override |
| public List<MRData> take ( int num ) { |
| return (num < 0) ? rdd.collect() : rdd.take(num); |
| } |
| |
| /** accumulate all dataset values */ |
| @Override |
| public MRData reduce ( final MRData zero, final Function acc ) { |
| return rdd.aggregate(zero,new Function2<MRData,MRData,MRData>() { |
| Tuple t = new Tuple(new Tuple(),new Tuple()); |
| public MRData call ( MRData x, MRData y ) { |
| t.set(0,x).set(1,y); |
| return acc.eval(t); |
| } |
| },new Function2<MRData,MRData,MRData>() { |
| Tuple t = new Tuple(new Tuple(),new Tuple()); |
| public MRData call ( MRData x, MRData y ) { |
| return (y.equals(zero)) ? x : y; |
| } |
| }); |
| } |
| } |