| /* |
| * 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.vxquery.runtime.functions.aggregate; |
| |
| import java.io.DataOutput; |
| import java.io.IOException; |
| |
| import org.apache.hyracks.algebricks.runtime.base.IAggregateEvaluator; |
| import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator; |
| import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory; |
| import org.apache.hyracks.api.exceptions.HyracksDataException; |
| import org.apache.hyracks.data.std.api.IPointable; |
| import org.apache.hyracks.data.std.util.ArrayBackedValueStorage; |
| import org.apache.vxquery.datamodel.accessors.TaggedValuePointable; |
| import org.apache.vxquery.datamodel.values.ValueTag; |
| import org.apache.vxquery.datamodel.values.XDMConstants; |
| import org.apache.vxquery.exceptions.ErrorCode; |
| import org.apache.vxquery.exceptions.SystemException; |
| import org.apache.vxquery.runtime.functions.arithmetic.AddOperation; |
| import org.apache.vxquery.runtime.functions.arithmetic.DivideOperation; |
| import org.apache.vxquery.runtime.functions.base.AbstractTaggedValueArgumentAggregateEvaluator; |
| import org.apache.vxquery.runtime.functions.base.AbstractTaggedValueArgumentAggregateEvaluatorFactory; |
| import org.apache.vxquery.runtime.functions.util.ArithmeticHelper; |
| |
| public class FnAvgAggregateEvaluatorFactory extends AbstractTaggedValueArgumentAggregateEvaluatorFactory { |
| private static final long serialVersionUID = 1L; |
| |
| public FnAvgAggregateEvaluatorFactory(IScalarEvaluatorFactory[] args) { |
| super(args); |
| } |
| |
| @Override |
| protected IAggregateEvaluator createEvaluator(IScalarEvaluator[] args) throws HyracksDataException { |
| final TaggedValuePointable tvpCount = (TaggedValuePointable) TaggedValuePointable.FACTORY.createPointable(); |
| final ArrayBackedValueStorage abvsSum = new ArrayBackedValueStorage(); |
| final DataOutput dOutSum = abvsSum.getDataOutput(); |
| final ArrayBackedValueStorage abvsCount = new ArrayBackedValueStorage(); |
| final DataOutput dOutCount = abvsCount.getDataOutput(); |
| final AddOperation aOpAdd = new AddOperation(); |
| final ArithmeticHelper add = new ArithmeticHelper(aOpAdd, dCtx); |
| final DivideOperation aOpDivide = new DivideOperation(); |
| final ArithmeticHelper divide = new ArithmeticHelper(aOpDivide, dCtx); |
| |
| return new AbstractTaggedValueArgumentAggregateEvaluator(args) { |
| long count; |
| TaggedValuePointable tvpSum = (TaggedValuePointable) TaggedValuePointable.FACTORY.createPointable(); |
| |
| @Override |
| public void init() throws HyracksDataException { |
| count = 0; |
| } |
| |
| @Override |
| public void finishPartial(IPointable result) throws HyracksDataException { |
| finish(result); |
| } |
| |
| @Override |
| public void finish(IPointable result) throws HyracksDataException { |
| if (count == 0) { |
| XDMConstants.setEmptySequence(result); |
| } else { |
| // Set count as a TaggedValuePointable. |
| try { |
| abvsCount.reset(); |
| dOutCount.write(ValueTag.XS_INTEGER_TAG); |
| dOutCount.writeLong(count); |
| tvpCount.set(abvsCount); |
| |
| divide.compute(tvpSum, tvpCount, tvpSum); |
| result.set(tvpSum); |
| } catch (Exception e) { |
| throw new HyracksDataException(e); |
| } |
| } |
| } |
| |
| @Override |
| protected void step(TaggedValuePointable[] args) throws HyracksDataException { |
| TaggedValuePointable tvp = args[0]; |
| if (count == 0) { |
| // Init. |
| try { |
| abvsSum.reset(); |
| dOutSum.write(tvp.getByteArray(), tvp.getStartOffset(), tvp.getLength()); |
| tvpSum.set(abvsSum); |
| } catch (IOException e) { |
| throw new SystemException(ErrorCode.SYSE0001, e.toString()); |
| } |
| } else { |
| add.compute(tvp, tvpSum, tvpSum); |
| } |
| count++; |
| } |
| }; |
| } |
| } |