| /* |
| * 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 java.util.Iterator; |
| |
| import org.apache.pig.Algebraic; |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.data.DataAtom; |
| import org.apache.pig.data.DataBag; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.impl.logicalLayer.schema.AtomSchema; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| |
| |
| /** |
| * Generates the sum of the values of the first field of a tuple. |
| */ |
| public class SUM extends EvalFunc<DataAtom> implements Algebraic { |
| |
| @Override |
| public void exec(Tuple input, DataAtom output) throws IOException { |
| output.setValue(sum(input)); |
| } |
| |
| public String getInitial() { |
| return Initial.class.getName(); |
| } |
| |
| public String getIntermed() { |
| return Initial.class.getName(); |
| } |
| |
| public String getFinal() { |
| return Final.class.getName(); |
| } |
| |
| static public class Initial extends EvalFunc<Tuple> { |
| @Override |
| public void exec(Tuple input, Tuple output) throws IOException { |
| output.appendField(new DataAtom(sum(input))); |
| } |
| } |
| static public class Final extends EvalFunc<DataAtom> { |
| @Override |
| public void exec(Tuple input, DataAtom output) throws IOException { |
| output.setValue(sum(input)); |
| } |
| } |
| |
| static protected double sum(Tuple input) throws IOException { |
| DataBag values = input.getBagField(0); |
| |
| double sum = 0; |
| int i = 0; |
| Tuple t = null; |
| for (Iterator it = values.iterator(); it.hasNext();) { |
| try { |
| t = (Tuple) it.next(); |
| i++; |
| sum += t.getAtomField(0).numval(); |
| }catch(RuntimeException exp) { |
| StringBuilder msg = new StringBuilder(); |
| msg.append("iteration = "); |
| msg.append(i); |
| msg.append("bag size = "); |
| msg.append(values.size()); |
| msg.append(" partial sum = "); |
| msg.append(sum); |
| msg.append("\n"); |
| if (t != null) { |
| msg.append("previous tupple = "); |
| msg.append(t.toString()); |
| } |
| StringBuilder errorMsg = new StringBuilder(); |
| errorMsg.append(exp.getMessage()); |
| errorMsg.append(" additional info: "); |
| errorMsg.append(msg.toString()); |
| throw new RuntimeException(errorMsg.toString()); |
| //throw new RuntimeException(exp.getMessage() + " error processing: " + t.toString()); |
| } |
| } |
| |
| return sum; |
| } |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new AtomSchema("sum" + count++); |
| } |
| |
| private static int count = 1; |
| } |