| /* |
| * 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.ExpressionToolbox; |
| import org.apache.vxquery.context.RootStaticContextImpl; |
| import org.apache.vxquery.context.StaticContextImpl; |
| import org.apache.vxquery.datamodel.accessors.TaggedValuePointable; |
| import org.apache.vxquery.functions.BuiltinOperators; |
| import org.apache.vxquery.types.Quantifier; |
| import org.apache.vxquery.types.SequenceType; |
| |
| 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.expressions.AbstractFunctionCallExpression; |
| import org.apache.hyracks.algebricks.core.algebra.expressions.ConstantExpression; |
| 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; |
| import org.apache.hyracks.data.std.primitive.IntegerPointable; |
| |
| /** |
| * The rule searches for subplans that only have one item per tuple. |
| * |
| * <pre> |
| * Before |
| * |
| * %PARENT_PLAN |
| * SUBPLAN{ |
| * AGGREGATE($v2, sequence(%expression($v1)) ) |
| * UNNEST($v1, iterate($v0) ) |
| * NESTEDTUPLESOURCE |
| * } |
| * %CHILD_PLAN |
| * |
| * Where |$v0| == 1 |
| * |
| * After |
| * |
| * %PARENT_PLAN |
| * ASSIGN($v2, %expression($v0) ) |
| * %CHILD_PLAN |
| * </pre> |
| * |
| * @author prestonc |
| */ |
| public class EliminateSubplanForSingleItemsRule implements IAlgebraicRewriteRule { |
| final StaticContextImpl dCtx = new StaticContextImpl(RootStaticContextImpl.INSTANCE); |
| final int ARG_DATA = 0; |
| final int ARG_TYPE = 1; |
| |
| public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) { |
| return false; |
| } |
| |
| public boolean rewritePre(Mutable<ILogicalOperator> opRef, IOptimizationContext context) throws AlgebricksException { |
| AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue(); |
| if (op.getOperatorTag() != LogicalOperatorTag.SUBPLAN) { |
| return false; |
| } |
| SubplanOperator subplan = (SubplanOperator) op; |
| |
| // AGGREGATE($v2, sequence(%expression($v1)) ) |
| AbstractLogicalOperator subplanOp1 = (AbstractLogicalOperator) subplan.getNestedPlans().get(0).getRoots() |
| .get(0).getValue(); |
| if (subplanOp1.getOperatorTag() != LogicalOperatorTag.AGGREGATE) { |
| return false; |
| } |
| AggregateOperator aggregate = (AggregateOperator) subplanOp1; |
| |
| // Check to see if the expression is a function and op:sequence. |
| ILogicalExpression logicalExpression1 = (ILogicalExpression) aggregate.getExpressions().get(0).getValue(); |
| if (logicalExpression1.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| return false; |
| } |
| AbstractFunctionCallExpression functionCall1 = (AbstractFunctionCallExpression) logicalExpression1; |
| if (!functionCall1.getFunctionIdentifier().equals(BuiltinOperators.SEQUENCE.getFunctionIdentifier())) { |
| return false; |
| } |
| |
| Mutable<ILogicalExpression> lvm1 = ExpressionToolbox.findVariableExpression(aggregate.getExpressions().get(0)); |
| if (lvm1 == null) { |
| return false; |
| } |
| VariableReferenceExpression vre1 = (VariableReferenceExpression) lvm1.getValue(); |
| |
| // UNNEST($v1, iterate($v0) ) |
| AbstractLogicalOperator subplanOp2 = (AbstractLogicalOperator) subplanOp1.getInputs().get(0).getValue(); |
| if (subplanOp2.getOperatorTag() != LogicalOperatorTag.UNNEST) { |
| return false; |
| } |
| UnnestOperator subplanUnnest = (UnnestOperator) subplanOp2; |
| |
| // Check to see if the expression is the iterate operator. |
| ILogicalExpression logicalExpression2 = (ILogicalExpression) subplanUnnest.getExpressionRef().getValue(); |
| if (logicalExpression2.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| return false; |
| } |
| AbstractFunctionCallExpression functionCall2 = (AbstractFunctionCallExpression) logicalExpression2; |
| if (!functionCall2.getFunctionIdentifier().equals(BuiltinOperators.ITERATE.getFunctionIdentifier())) { |
| return false; |
| } |
| |
| if (subplanUnnest.getVariable() != vre1.getVariableReference()) { |
| return false; |
| } |
| Mutable<ILogicalExpression> lvm2 = ExpressionToolbox.findVariableExpression(subplanUnnest.getExpressionRef()); |
| if (lvm2 == null) { |
| return false; |
| } |
| VariableReferenceExpression vre2 = (VariableReferenceExpression) lvm2.getValue(); |
| |
| // NESTEDTUPLESOURCE |
| AbstractLogicalOperator subplanOp3 = (AbstractLogicalOperator) subplanOp2.getInputs().get(0).getValue(); |
| if (subplanOp3.getOperatorTag() != LogicalOperatorTag.NESTEDTUPLESOURCE) { |
| return false; |
| } |
| |
| // Ensure input is from a UNNEST operator. |
| AbstractLogicalOperator subplanInput = (AbstractLogicalOperator) subplan.getInputs().get(0).getValue(); |
| if (subplanInput.getOperatorTag() != LogicalOperatorTag.ASSIGN) { |
| return false; |
| } |
| AssignOperator assign = (AssignOperator) subplanInput; |
| if (!assign.getVariables().contains(vre2.getVariableReference())) { |
| return false; |
| } |
| |
| // Check to see if the expression is the iterate operator. |
| ILogicalExpression logicalExpression3 = (ILogicalExpression) assign.getExpressions().get(0).getValue(); |
| if (logicalExpression3.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) { |
| return false; |
| } |
| AbstractFunctionCallExpression functionCall3 = (AbstractFunctionCallExpression) logicalExpression3; |
| if (!functionCall3.getFunctionIdentifier().equals(BuiltinOperators.TREAT.getFunctionIdentifier())) { |
| return false; |
| } |
| |
| // Find the treat type. |
| ILogicalExpression argType = functionCall3.getArguments().get(ARG_TYPE).getValue(); |
| if (argType.getExpressionTag() != LogicalExpressionTag.CONSTANT) { |
| return false; |
| } |
| TaggedValuePointable tvp = (TaggedValuePointable) TaggedValuePointable.FACTORY.createPointable(); |
| ExpressionToolbox.getConstantAsPointable((ConstantExpression) argType, tvp); |
| |
| IntegerPointable pTypeCode = (IntegerPointable) IntegerPointable.FACTORY.createPointable(); |
| tvp.getValue(pTypeCode); |
| SequenceType sType = dCtx.lookupSequenceType(pTypeCode.getInteger()); |
| if (sType.getQuantifier() != Quantifier.QUANT_ONE) { |
| return false; |
| } |
| |
| // Create replacement assign operator. |
| lvm1.setValue(vre2); |
| AssignOperator replacementAssign = new AssignOperator(aggregate.getVariables().get(0), functionCall1 |
| .getArguments().get(0)); |
| replacementAssign.getInputs().addAll(subplan.getInputs()); |
| opRef.setValue(replacementAssign); |
| |
| return false; |
| } |
| |
| } |