| /* |
| * 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.compiler.rewriter.rules; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| import org.apache.vxquery.compiler.rewriter.rules.util.OperatorToolbox; |
| import org.apache.vxquery.functions.BuiltinOperators; |
| |
| import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression; |
| import org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator; |
| import org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalExpressionTag; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalOperatorTag; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable; |
| import org.apache.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression; |
| import org.apache.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AggregateOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AssignOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.SubplanOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.UnnestOperator; |
| import org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| /** |
| * The rule searches for unnest followed by subplan with the root operator an |
| * aggregate and removes the aggregate subplan. |
| * |
| * <pre> |
| * Before |
| * |
| * %PARENT_PLAN |
| * UNNEST( $v2 : iterate( $v1 ) ) |
| * SUBPLAN{ |
| * AGGREGATE( $v1 : sequence( %expression ) ) |
| * %NESTED_PLAN |
| * NESTEDTUPLESOURCE |
| * } |
| * %CHILD_PLAN |
| * |
| * where %PARENT_PLAN does not use $v1. |
| * |
| * After |
| * |
| * %PARENT_PLAN |
| * UNNEST( $v2 : iterate( $v3 ) ) |
| * ASSIGN( $v3 : %expression ) |
| * %NESTED_PLAN |
| * %CHILD_PLAN |
| * </pre> |
| */ |
| public class EliminateUnnestAggregateSubplanRule implements IAlgebraicRewriteRule { |
| @Override |
| public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) |
| throws AlgebricksException { |
| AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue(); |
| if (op.getOperatorTag() != LogicalOperatorTag.UNNEST) { |
| return false; |
| } |
| UnnestOperator unnest = (UnnestOperator) op; |
| |
| // Check to see if the expression is the iterate operator. |
| ILogicalExpression logicalExpression = (ILogicalExpression) unnest.getExpressionRef().getValue(); |
| if (logicalExpression.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| return false; |
| } |
| AbstractFunctionCallExpression functionCall = (AbstractFunctionCallExpression) logicalExpression; |
| if (!functionCall.getFunctionIdentifier().equals(BuiltinOperators.ITERATE.getFunctionIdentifier())) { |
| return false; |
| } |
| |
| AbstractLogicalOperator op2 = (AbstractLogicalOperator) unnest.getInputs().get(0).getValue(); |
| if (op2.getOperatorTag() != LogicalOperatorTag.SUBPLAN) { |
| return false; |
| } |
| SubplanOperator subplan = (SubplanOperator) op2; |
| |
| AbstractLogicalOperator subplanOp = (AbstractLogicalOperator) subplan.getNestedPlans().get(0).getRoots().get(0) |
| .getValue(); |
| if (subplanOp.getOperatorTag() != LogicalOperatorTag.AGGREGATE) { |
| return false; |
| } |
| AggregateOperator aggregate = (AggregateOperator) subplanOp; |
| |
| // Check to see if the expression is a function and op:sequence. |
| ILogicalExpression logicalExpression2 = (ILogicalExpression) aggregate.getExpressions().get(0).getValue(); |
| if (logicalExpression2.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| return false; |
| } |
| AbstractFunctionCallExpression functionCall2 = (AbstractFunctionCallExpression) logicalExpression2; |
| if (!functionCall2.getFunctionIdentifier().equals(BuiltinOperators.SEQUENCE.getFunctionIdentifier())) { |
| return false; |
| } |
| |
| // Make inline the arguments for the subplan. |
| AbstractLogicalOperator subplanEnd = OperatorToolbox.findLastSubplanOperator(subplanOp); |
| int count = 0; |
| for (Mutable<ILogicalOperator> input : subplan.getInputs()) { |
| subplanEnd.getInputs().get(count++).setValue(input.getValue()); |
| } |
| |
| // Replace search string with assign. |
| Mutable<ILogicalExpression> assignExpression = functionCall2.getArguments().get(0); |
| LogicalVariable assignVariable = context.newVar(); |
| AssignOperator aOp = new AssignOperator(assignVariable, assignExpression); |
| for (Mutable<ILogicalOperator> input : aggregate.getInputs()) { |
| aOp.getInputs().add(input); |
| } |
| functionCall.getArguments().get(0).setValue(new VariableReferenceExpression(assignVariable)); |
| unnest.getInputs().get(0).setValue(aOp); |
| context.computeAndSetTypeEnvironmentForOperator(aOp); |
| context.computeAndSetTypeEnvironmentForOperator(unnest); |
| return true; |
| } |
| |
| @Override |
| public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) { |
| return false; |
| } |
| } |