| /* |
| * Copyright 2009-2013 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 org.apache.vxquery.compiler.rewriter.rules; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.List; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| import org.apache.commons.lang3.mutable.MutableObject; |
| import org.apache.vxquery.compiler.rewriter.rules.util.ExpressionToolbox; |
| |
| 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.functions.AlgebricksBuiltinFunctions; |
| import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractBinaryJoinOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AbstractLogicalOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.AssignOperator; |
| import org.apache.hyracks.algebricks.core.algebra.operators.logical.visitors.VariableUtilities; |
| import org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule; |
| |
| public class PushFunctionsOntoEqJoinBranches 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 { |
| AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue(); |
| |
| if (op.getOperatorTag() != LogicalOperatorTag.INNERJOIN) { |
| return false; |
| } |
| AbstractBinaryJoinOperator join = (AbstractBinaryJoinOperator) op; |
| |
| ILogicalExpression expr = join.getCondition().getValue(); |
| if (expr.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| return false; |
| } |
| AbstractFunctionCallExpression fexp = (AbstractFunctionCallExpression) expr; |
| FunctionIdentifier fi = fexp.getFunctionIdentifier(); |
| if (!(fi.equals(AlgebricksBuiltinFunctions.AND) || fi.equals(AlgebricksBuiltinFunctions.EQ))) { |
| return false; |
| } |
| boolean modified = false; |
| List<Mutable<ILogicalExpression>> functionList = new ArrayList<Mutable<ILogicalExpression>>(); |
| List<Mutable<ILogicalExpression>> variableList = new ArrayList<Mutable<ILogicalExpression>>(); |
| functionList.clear(); |
| ExpressionToolbox.findAllFunctionExpressions(join.getCondition(), AlgebricksBuiltinFunctions.EQ, functionList); |
| Collection<LogicalVariable> producedVariables = new ArrayList<LogicalVariable>(); |
| for (Mutable<ILogicalExpression> searchM : functionList) { |
| ILogicalExpression search = searchM.getValue(); |
| if (search.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| continue; |
| } |
| AbstractFunctionCallExpression searchExp = (AbstractFunctionCallExpression) search; |
| // Go through all argument for EQ. |
| for (Mutable<ILogicalExpression> expressionM : searchExp.getArguments()) { |
| // Push on to branch when possible. |
| for (Mutable<ILogicalOperator> branch : join.getInputs()) { |
| producedVariables.clear(); |
| getProducedVariablesInDescendantsAndSelf(branch.getValue(), producedVariables); |
| variableList.clear(); |
| ExpressionToolbox.findVariableExpressions(expressionM, variableList); |
| boolean found = true; |
| for (Mutable<ILogicalExpression> searchVariableM : variableList) { |
| VariableReferenceExpression vre = (VariableReferenceExpression) searchVariableM.getValue(); |
| if (!producedVariables.contains(vre.getVariableReference())) { |
| found = false; |
| } |
| } |
| if (found) { |
| // push down |
| LogicalVariable assignVariable = context.newVar(); |
| AssignOperator aOp = new AssignOperator(assignVariable, new MutableObject<ILogicalExpression>(expressionM.getValue())); |
| aOp.getInputs().add(new MutableObject<ILogicalOperator>(branch.getValue())); |
| branch.setValue(aOp); |
| aOp.recomputeSchema(); |
| |
| expressionM.setValue(new VariableReferenceExpression(assignVariable)); |
| modified = true; |
| } |
| } |
| } |
| } |
| return modified; |
| } |
| |
| public static void getProducedVariablesInDescendantsAndSelf(ILogicalOperator op, Collection<LogicalVariable> vars) |
| throws AlgebricksException { |
| // DFS traversal |
| VariableUtilities.getProducedVariables(op, vars); |
| for (Mutable<ILogicalOperator> c : op.getInputs()) { |
| getProducedVariablesInDescendantsAndSelf(c.getValue(), vars); |
| } |
| } |
| |
| |
| } |