| /* |
| * 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.Accumulator; |
| import org.apache.pig.PigException; |
| import org.apache.pig.backend.executionengine.ExecException; |
| import org.apache.pig.data.DataBag; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.data.TupleFactory; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| |
| |
| /** |
| * Core logic for applying an accumulative/algebraic math function to a |
| * bag of Longs. |
| */ |
| public abstract class AlgebraicLongMathBase extends AlgebraicMathBase<Long> implements Accumulator<Long> { |
| |
| protected static Long getSeed(KNOWN_OP op) { |
| switch (op) { |
| case SUM: return 0L; |
| case MIN: return Long.MAX_VALUE; |
| case MAX: return Long.MIN_VALUE; |
| default: return null; |
| } |
| } |
| |
| private static Long doWork(Long arg1, Long arg2, KNOWN_OP op) { |
| if (arg1 == null) { |
| return arg2; |
| } else if (arg2 == null) { |
| return arg1; |
| } else { |
| switch (op) { |
| case MAX: return Math.max(arg1, arg2); |
| case MIN: return Math.min(arg1, arg2); |
| case SUM: return arg1 + arg2; |
| default: return null; |
| } |
| } |
| } |
| |
| protected static Long doTupleWork(Tuple input, KnownOpProvider opProvider) throws ExecException { |
| DataBag values = (DataBag)input.get(0); |
| // if we were handed an empty bag, return NULL |
| // this is in compliance with SQL standard |
| if(values == null || values.size() == 0) { |
| return null; |
| } |
| Long sofar = AlgebraicLongMathBase.getSeed(opProvider.getOp()); |
| boolean sawNonNull = false; |
| for (Iterator<Tuple> it = values.iterator(); it.hasNext();) { |
| Tuple t = it.next(); |
| try { |
| // Note: use Number.longValue() instead of casting to Long |
| // to allow Integers, too. |
| Number n = ((Number)(t.get(0))); |
| if (n == null) continue; |
| Long d = n.longValue(); |
| sawNonNull = true; |
| sofar = doWork(sofar, d, opProvider.getOp()); |
| }catch(RuntimeException exp) { |
| int errCode = 2103; |
| throw new ExecException("Problem doing work on Longs", errCode, PigException.BUG, exp); |
| } |
| } |
| return sawNonNull ? sofar : null; |
| } |
| |
| @Override |
| public Long exec(Tuple input) throws IOException { |
| try { |
| return doTupleWork(input, opProvider); |
| } catch (ExecException ee) { |
| throw ee; |
| } catch (Exception e) { |
| int errCode = 2106; |
| throw new ExecException("Error executing function on Longs", errCode, PigException.BUG, e); |
| } |
| } |
| |
| static public abstract class Intermediate extends AlgebraicMathBase.Intermediate { |
| private static TupleFactory tfact = TupleFactory.getInstance(); |
| |
| @Override |
| public Tuple exec(Tuple input) throws IOException { |
| try { |
| return tfact.newTuple(doTupleWork(input, this)); |
| } catch (ExecException ee) { |
| throw ee; |
| } catch (Exception e) { |
| int errCode = 2106; |
| throw new ExecException("Error executing function on Longs", errCode, PigException.BUG, e); |
| } |
| } |
| } |
| |
| static public abstract class Final extends AlgebraicMathBase.Final<Long> { |
| @Override |
| public Long exec(Tuple input) throws IOException { |
| try { |
| return doTupleWork(input, this); |
| } catch (ExecException ee) { |
| throw ee; |
| } catch (Exception e) { |
| int errCode = 2106; |
| throw new ExecException("Error executing function on Longs", errCode, PigException.BUG, e); |
| } |
| } |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new Schema(new Schema.FieldSchema(null, DataType.LONG)); |
| } |
| |
| /* Accumulator interface implementation*/ |
| private Long intermediateVal = null; |
| |
| @Override |
| public void accumulate(Tuple b) throws IOException { |
| try { |
| Long curVal = doTupleWork(b, opProvider); |
| if (curVal == null) { |
| return; |
| } |
| if (intermediateVal == null) { |
| intermediateVal = getSeed(opProvider.getOp()); |
| } |
| intermediateVal = doWork(intermediateVal, curVal, opProvider.getOp()); |
| } catch (ExecException ee) { |
| throw ee; |
| } catch (Exception e) { |
| int errCode = 2106; |
| throw new ExecException("Error executing function on Longs", errCode, PigException.BUG, e); |
| } |
| } |
| |
| @Override |
| public void cleanup() { |
| intermediateVal = null; |
| } |
| |
| @Override |
| public Long getValue() { |
| return intermediateVal; |
| } |
| } |