| /* |
| * 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.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.pig.FuncSpec; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.impl.logicalLayer.FrontendException; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| |
| |
| /** |
| * Generates the maximum of a set of values. This class implements |
| * {@link org.apache.pig.Algebraic}, so if possible the execution will |
| * performed in a distributed fashion. |
| * <p> |
| * MAX can operate on any numeric type and on chararrays. It can also operate on bytearrays, |
| * which it will cast to doubles. It expects a bag of |
| * tuples of one record each. If Pig knows from the schema that this function |
| * will be passed a bag of integers or longs, it will use a specially adapted version of |
| * MAX that uses integer arithmetic for comparing the data. The return type |
| * of MAX will match the input type. |
| * <p> |
| * MAX implements the {@link org.apache.pig.Accumulator} interface as well. |
| * While this will never be |
| * the preferred method of usage it is available in case the combiner can not be |
| * used for a given calculation. |
| */ |
| public class MAX extends AlgebraicByteArrayMathBase { |
| |
| public MAX() { |
| setOp(KNOWN_OP.MAX); |
| } |
| |
| public static class Intermediate extends AlgebraicByteArrayMathBase.Intermediate { |
| @Override |
| public KNOWN_OP getOp() { |
| return KNOWN_OP.MAX; |
| } |
| } |
| |
| public static class Final extends AlgebraicByteArrayMathBase.Final { |
| @Override |
| public KNOWN_OP getOp() { |
| return KNOWN_OP.MAX; |
| } |
| } |
| |
| /* (non-Javadoc) |
| * @see org.apache.pig.EvalFunc#getArgToFuncMapping() |
| */ |
| @Override |
| public List<FuncSpec> getArgToFuncMapping() throws FrontendException { |
| List<FuncSpec> funcList = new ArrayList<FuncSpec>(); |
| funcList.add(new FuncSpec(this.getClass().getName(), Schema.generateNestedSchema(DataType.BAG, DataType.BYTEARRAY))); |
| funcList.add(new FuncSpec(DoubleMax.class.getName(), Schema.generateNestedSchema(DataType.BAG, DataType.DOUBLE))); |
| funcList.add(new FuncSpec(FloatMax.class.getName(), Schema.generateNestedSchema(DataType.BAG, DataType.FLOAT))); |
| funcList.add(new FuncSpec(IntMax.class.getName(), Schema.generateNestedSchema(DataType.BAG, DataType.INTEGER))); |
| funcList.add(new FuncSpec(LongMax.class.getName(), Schema.generateNestedSchema(DataType.BAG, DataType.LONG))); |
| funcList.add(new FuncSpec(StringMax.class.getName(), Schema.generateNestedSchema(DataType.BAG, DataType.CHARARRAY))); |
| funcList.add(new FuncSpec(DateTimeMax.class.getName(), Schema.generateNestedSchema(DataType.BAG, DataType.DATETIME))); |
| funcList.add(new FuncSpec(BigDecimalMax.class.getName(), Schema.generateNestedSchema(DataType.BAG, DataType.BIGDECIMAL))); |
| funcList.add(new FuncSpec(BigIntegerMax.class.getName(), Schema.generateNestedSchema(DataType.BAG, DataType.BIGINTEGER))); |
| return funcList; |
| } |
| } |