| /* |
| * Copyright 2009-2010 by The Regents of the University of California |
| * Licensed 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 from |
| * |
| * 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 edu.uci.ics.hyracks.algebricks.core.algebra.expressions; |
| |
| import java.util.List; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| |
| import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.ILogicalExpression; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.functions.IFunctionInfo; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.visitors.ILogicalExpressionVisitor; |
| |
| /** |
| * |
| * An aggregate function may be executed in a "two step" mode. First the |
| * "step-one" aggregates are run and then the results are passed to the |
| * "step-two" aggregators. The convention is the following: |
| * |
| * 1. The step-one aggregate must be able to accept the same arguments as the |
| * original aggregate function call. |
| * |
| * 2. The step-two aggregate must be a unary function that accepts as input the |
| * output of the step-one aggregate. |
| * |
| */ |
| |
| public class AggregateFunctionCallExpression extends AbstractFunctionCallExpression { |
| |
| private boolean twoStep; |
| private IFunctionInfo stepOneAggregate; |
| private IFunctionInfo stepTwoAggregate; |
| |
| public AggregateFunctionCallExpression(IFunctionInfo finfo, boolean isTwoStep) { |
| super(FunctionKind.AGGREGATE, finfo); |
| this.twoStep = isTwoStep; |
| } |
| |
| public AggregateFunctionCallExpression(IFunctionInfo finfo, boolean isTwoStep, |
| List<Mutable<ILogicalExpression>> arguments) { |
| super(FunctionKind.AGGREGATE, finfo, arguments); |
| this.twoStep = isTwoStep; |
| } |
| |
| public AggregateFunctionCallExpression(IFunctionInfo finfo, boolean isTwoStep, |
| Mutable<ILogicalExpression>... expressions) { |
| super(FunctionKind.AGGREGATE, finfo, expressions); |
| this.twoStep = isTwoStep; |
| } |
| |
| public boolean isTwoStep() { |
| return twoStep; |
| } |
| |
| public void setTwoStep(boolean twoStep) { |
| this.twoStep = twoStep; |
| } |
| |
| @Override |
| public AggregateFunctionCallExpression cloneExpression() { |
| cloneAnnotations(); |
| List<Mutable<ILogicalExpression>> clonedArgs = cloneArguments(); |
| AggregateFunctionCallExpression fun = new AggregateFunctionCallExpression(finfo, twoStep, clonedArgs); |
| fun.setStepTwoAggregate(stepTwoAggregate); |
| fun.setStepOneAggregate(stepOneAggregate); |
| return fun; |
| } |
| |
| public void setStepOneAggregate(IFunctionInfo stepOneAggregate) { |
| this.stepOneAggregate = stepOneAggregate; |
| } |
| |
| public IFunctionInfo getStepOneAggregate() { |
| return stepOneAggregate; |
| } |
| |
| public void setStepTwoAggregate(IFunctionInfo stepTwoAggregate) { |
| this.stepTwoAggregate = stepTwoAggregate; |
| } |
| |
| public IFunctionInfo getStepTwoAggregate() { |
| return stepTwoAggregate; |
| } |
| |
| @Override |
| public <R, T> R accept(ILogicalExpressionVisitor<R, T> visitor, T arg) throws AlgebricksException { |
| return visitor.visitAggregateFunctionCallExpression(this, arg); |
| } |
| |
| } |