| /* |
| * 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.asterix.optimizer.rules; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| import org.apache.commons.lang3.mutable.MutableObject; |
| |
| import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions; |
| 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.base.ILogicalOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.IOptimizationContext; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalExpressionTag; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ConstantExpression; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AggregateOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.AssignOperator; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities; |
| import edu.uci.ics.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| /** |
| * Pushes aggregate functions into a stand alone aggregate operator (no group by). |
| */ |
| public class PushAggFuncIntoStandaloneAggregateRule implements IAlgebraicRewriteRule { |
| |
| @Override |
| public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException { |
| return false; |
| } |
| |
| @Override |
| public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) |
| throws AlgebricksException { |
| // Pattern to match: assign <-- aggregate <-- !(group-by) |
| AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue(); |
| if (op.getOperatorTag() != LogicalOperatorTag.ASSIGN) { |
| return false; |
| } |
| Mutable<ILogicalOperator> opRef2 = op.getInputs().get(0); |
| AbstractLogicalOperator op2 = (AbstractLogicalOperator) opRef2.getValue(); |
| if (op2.getOperatorTag() != LogicalOperatorTag.AGGREGATE) { |
| return false; |
| } |
| // If there's a group by below the agg, then we want to have the agg pushed into the group by. |
| Mutable<ILogicalOperator> opRef3 = op2.getInputs().get(0); |
| AbstractLogicalOperator op3 = (AbstractLogicalOperator) opRef3.getValue(); |
| if (op3.getOperatorTag() == LogicalOperatorTag.GROUP) { |
| return false; |
| } |
| |
| AssignOperator assignOp = (AssignOperator) op; |
| AggregateOperator aggOp = (AggregateOperator) op2; |
| if (aggOp.getVariables().size() != 1) { |
| return false; |
| } |
| |
| // Make sure the agg expr is a listify. |
| ILogicalExpression aggExpr = aggOp.getExpressions().get(0).getValue(); |
| if (aggExpr.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| return false; |
| } |
| AbstractFunctionCallExpression origAggFuncExpr = (AbstractFunctionCallExpression) aggExpr; |
| if (origAggFuncExpr.getFunctionIdentifier() != AsterixBuiltinFunctions.LISTIFY) { |
| return false; |
| } |
| |
| LogicalVariable aggVar = aggOp.getVariables().get(0); |
| List<LogicalVariable> used = new LinkedList<LogicalVariable>(); |
| VariableUtilities.getUsedVariables(assignOp, used); |
| if (!used.contains(aggVar)) { |
| return false; |
| } |
| |
| Mutable<ILogicalExpression> srcAssignExprRef = fingAggFuncExprRef(assignOp.getExpressions(), aggVar); |
| if (srcAssignExprRef == null) { |
| return false; |
| } |
| AbstractFunctionCallExpression assignFuncExpr = (AbstractFunctionCallExpression) srcAssignExprRef.getValue(); |
| FunctionIdentifier aggFuncIdent = AsterixBuiltinFunctions.getAggregateFunction(assignFuncExpr.getFunctionIdentifier()); |
| |
| // Push the agg func into the agg op. |
| AbstractFunctionCallExpression aggOpExpr = (AbstractFunctionCallExpression) aggOp.getExpressions().get(0).getValue(); |
| List<Mutable<ILogicalExpression>> aggArgs = new ArrayList<Mutable<ILogicalExpression>>(); |
| aggArgs.add(aggOpExpr.getArguments().get(0)); |
| AggregateFunctionCallExpression aggFuncExpr = AsterixBuiltinFunctions.makeAggregateFunctionExpression(aggFuncIdent, aggArgs); |
| aggOp.getExpressions().get(0).setValue(aggFuncExpr); |
| |
| // The assign now just "renames" the variable to make sure the upstream plan still works. |
| srcAssignExprRef.setValue(new VariableReferenceExpression(aggVar)); |
| |
| // Create a new assign for a TRUE variable. |
| LogicalVariable trueVar = context.newVar(); |
| AssignOperator trueAssignOp = new AssignOperator(trueVar, new MutableObject<ILogicalExpression>(ConstantExpression.TRUE)); |
| |
| ILogicalOperator aggInput = aggOp.getInputs().get(0).getValue(); |
| aggOp.getInputs().get(0).setValue(trueAssignOp); |
| trueAssignOp.getInputs().add(new MutableObject<ILogicalOperator>(aggInput)); |
| |
| // Set partitioning variable. |
| aggOp.setPartitioningVariable(trueVar); |
| |
| context.computeAndSetTypeEnvironmentForOperator(trueAssignOp); |
| context.computeAndSetTypeEnvironmentForOperator(aggOp); |
| context.computeAndSetTypeEnvironmentForOperator(assignOp); |
| |
| return true; |
| } |
| |
| private Mutable<ILogicalExpression> fingAggFuncExprRef(List<Mutable<ILogicalExpression>> exprRefs, LogicalVariable aggVar) { |
| for (Mutable<ILogicalExpression> exprRef : exprRefs) { |
| ILogicalExpression expr = exprRef.getValue(); |
| if (expr.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| continue; |
| } |
| AbstractFunctionCallExpression funcExpr = (AbstractFunctionCallExpression) expr; |
| FunctionIdentifier funcIdent = AsterixBuiltinFunctions.getAggregateFunction(funcExpr.getFunctionIdentifier()); |
| if (funcIdent == null) { |
| // Recursively look in func args. |
| return fingAggFuncExprRef(funcExpr.getArguments(), aggVar); |
| } |
| // Check if this is the expr that uses aggVar. |
| Collection<LogicalVariable> usedVars = new HashSet<LogicalVariable>(); |
| funcExpr.getUsedVariables(usedVars); |
| if (usedVars.contains(aggVar)) { |
| return exprRef; |
| } |
| } |
| return null; |
| } |
| } |