| /* |
| * 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.impl.builtin; |
| |
| import java.io.IOException; |
| import java.lang.reflect.Type; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.data.SizeUtil; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.data.TupleFactory; |
| |
| /** |
| * UDF to get memory size of a tuple and extracts number of rows value from |
| * special tuple created by PoissonSampleLoader |
| * It is used by skewed join. |
| * |
| */ |
| |
| public class GetMemNumRows extends EvalFunc<Tuple>{ |
| |
| private TupleFactory factory; |
| |
| public GetMemNumRows() { |
| factory = TupleFactory.getInstance(); |
| } |
| |
| /** |
| * @param in - input tuple |
| * @return - tuple having size in memory of this tuple and numRows if this |
| * is specially marked tuple having number of rows field |
| */ |
| public Tuple exec(Tuple in) throws IOException { |
| if (in == null) { |
| return null; |
| } |
| long memSize = in.getMemorySize(); |
| long numRows = 0; |
| |
| |
| // if this is specially marked tuple, get the number of rows |
| int tSize = in.size(); |
| if(tSize >=2 && |
| PoissonSampleLoader.NUMROWS_TUPLE_MARKER.equals(in.get(tSize-2)) ){ |
| memSize -= SizeUtil.getPigObjMemSize(PoissonSampleLoader.NUMROWS_TUPLE_MARKER); |
| numRows = (Long)in.get(tSize-1); |
| } |
| |
| //create tuple to be returned |
| Tuple t = factory.newTuple(2); |
| t.set(0, memSize); |
| t.set(1, numRows); |
| return t; |
| } |
| |
| public Type getReturnType(){ |
| return Tuple.class; |
| } |
| } |