| /* |
| * 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.asterix.graphix.lang.rewrite.visitor; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.stream.Collectors; |
| |
| import org.apache.asterix.common.exceptions.CompilationException; |
| import org.apache.asterix.common.exceptions.ErrorCode; |
| import org.apache.asterix.common.functions.FunctionSignature; |
| import org.apache.asterix.common.metadata.DataverseName; |
| import org.apache.asterix.lang.common.base.Clause; |
| import org.apache.asterix.lang.common.base.Expression; |
| import org.apache.asterix.lang.common.base.ILangExpression; |
| import org.apache.asterix.lang.common.clause.LetClause; |
| import org.apache.asterix.lang.common.clause.WhereClause; |
| import org.apache.asterix.lang.common.expression.CallExpr; |
| import org.apache.asterix.lang.common.expression.LiteralExpr; |
| import org.apache.asterix.lang.common.expression.VariableExpr; |
| import org.apache.asterix.lang.common.literal.StringLiteral; |
| import org.apache.asterix.lang.sqlpp.clause.AbstractBinaryCorrelateClause; |
| import org.apache.asterix.lang.sqlpp.clause.FromClause; |
| import org.apache.asterix.lang.sqlpp.clause.FromTerm; |
| import org.apache.asterix.lang.sqlpp.clause.Projection; |
| import org.apache.asterix.lang.sqlpp.clause.SelectBlock; |
| import org.apache.asterix.lang.sqlpp.clause.SelectClause; |
| import org.apache.asterix.lang.sqlpp.clause.SelectRegular; |
| import org.apache.asterix.lang.sqlpp.clause.SelectSetOperation; |
| import org.apache.asterix.lang.sqlpp.clause.UnnestClause; |
| import org.apache.asterix.lang.sqlpp.expression.SelectExpression; |
| import org.apache.asterix.lang.sqlpp.struct.SetOperationInput; |
| import org.apache.asterix.lang.sqlpp.util.FunctionMapUtil; |
| import org.apache.asterix.lang.sqlpp.visitor.base.AbstractSqlppSimpleExpressionVisitor; |
| import org.apache.asterix.om.functions.BuiltinFunctions; |
| import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier; |
| |
| /** |
| * Perform an analysis of a normalized graph element body (i.e. no Graphix AST nodes) to determine if we can inline |
| * this graph element body with the greater SELECT-BLOCK node during lowering. |
| * <ol> |
| * <li>Is this a dataset CALL-EXPR? If so, we can inline this directly.</li> |
| * <li>Is this expression a SELECT-EXPR containing a single FROM-TERM w/ possibly only UNNEST clauses? If so, we can |
| * inline this expression.</li> |
| * <li>Are there are LET-WHERE expressions? We can inline these if the two questions are true.</li> |
| * <li>Are there any aggregate functions (or any aggregation)? If so, we cannot inline this expression.</li> |
| * <li>Are there any UNION-ALLs? If so, we cannot inline this expression.</li> |
| * <li>Are there any ORDER-BY or LIMIT clauses? If so, we cannot inline this expression.</li> |
| * </ol> |
| */ |
| public class ElementBodyAnalysisVisitor extends AbstractSqlppSimpleExpressionVisitor { |
| private final ElementBodyAnalysisContext elementBodyAnalysisContext = new ElementBodyAnalysisContext(); |
| |
| public static class ElementBodyAnalysisContext { |
| private List<AbstractBinaryCorrelateClause> unnestClauses = null; |
| private List<LetClause> letClauses = null; |
| private List<WhereClause> whereClauses = null; |
| private List<Projection> selectClauseProjections = null; |
| private VariableExpr fromTermVariable = null; |
| private Expression selectElement = null; |
| |
| // At a minimum, this field must be defined. |
| private CallExpr datasetCallExpression = null; |
| private DataverseName dataverseName = null; |
| private String datasetName = null; |
| |
| // We take an optimistic approach, and look for cases where we _cannot_ inline our body. |
| private boolean isExpressionInline = true; |
| |
| public DataverseName getDataverseName() { |
| return dataverseName; |
| } |
| |
| public String getDatasetName() { |
| return datasetName; |
| } |
| |
| public boolean isExpressionInline() { |
| return isExpressionInline; |
| } |
| |
| public List<LetClause> getLetClauses() { |
| return letClauses; |
| } |
| |
| public List<WhereClause> getWhereClauses() { |
| return whereClauses; |
| } |
| |
| public List<Projection> getSelectClauseProjections() { |
| return selectClauseProjections; |
| } |
| |
| public List<AbstractBinaryCorrelateClause> getUnnestClauses() { |
| return unnestClauses; |
| } |
| |
| public VariableExpr getFromTermVariable() { |
| return fromTermVariable; |
| } |
| |
| public Expression getSelectElement() { |
| return selectElement; |
| } |
| |
| public CallExpr getDatasetCallExpression() { |
| return datasetCallExpression; |
| } |
| |
| public boolean isSelectClauseInline() { |
| if (selectElement == null && selectClauseProjections == null) { |
| return true; |
| |
| } else if (selectElement != null && selectElement.getKind() == Expression.Kind.VARIABLE_EXPRESSION) { |
| VariableExpr selectElementVariableExpr = (VariableExpr) selectElement; |
| return selectElementVariableExpr.getVar() == fromTermVariable.getVar(); |
| } |
| return false; |
| } |
| } |
| |
| @Override |
| public Expression visit(CallExpr callExpr, ILangExpression arg) throws CompilationException { |
| FunctionSignature functionSignature = callExpr.getFunctionSignature(); |
| FunctionIdentifier functionIdentifier = functionSignature.createFunctionIdentifier(); |
| if (functionIdentifier.equals(BuiltinFunctions.DATASET)) { |
| LiteralExpr dataverseNameExpr = (LiteralExpr) callExpr.getExprList().get(0); |
| LiteralExpr datasetNameExpr = (LiteralExpr) callExpr.getExprList().get(1); |
| String dataverseName = ((StringLiteral) dataverseNameExpr.getValue()).getValue(); |
| String datasetName = ((StringLiteral) datasetNameExpr.getValue()).getValue(); |
| elementBodyAnalysisContext.datasetCallExpression = callExpr; |
| elementBodyAnalysisContext.dataverseName = DataverseName.createBuiltinDataverseName(dataverseName); |
| elementBodyAnalysisContext.datasetName = datasetName; |
| return callExpr; |
| |
| } else if (FunctionMapUtil.isSql92AggregateFunction(functionSignature) |
| || FunctionMapUtil.isCoreAggregateFunction(functionSignature) |
| || BuiltinFunctions.getWindowFunction(functionIdentifier) != null) { |
| elementBodyAnalysisContext.isExpressionInline = false; |
| return callExpr; |
| } |
| return callExpr; |
| } |
| |
| @Override |
| public Expression visit(SelectExpression selectExpression, ILangExpression arg) throws CompilationException { |
| if (arg != null) { |
| // We are not in a top-level SELECT-EXPR. Do not proceed. |
| return selectExpression; |
| } |
| if (selectExpression.hasOrderby() || selectExpression.hasLimit() || selectExpression.hasLetClauses()) { |
| elementBodyAnalysisContext.isExpressionInline = false; |
| return selectExpression; |
| } |
| selectExpression.getSelectSetOperation().accept(this, selectExpression); |
| return selectExpression; |
| } |
| |
| @Override |
| public Expression visit(SelectSetOperation selectSetOperation, ILangExpression arg) throws CompilationException { |
| if (selectSetOperation.hasRightInputs()) { |
| elementBodyAnalysisContext.isExpressionInline = false; |
| return null; |
| } |
| SetOperationInput leftInput = selectSetOperation.getLeftInput(); |
| if (leftInput.subquery()) { |
| elementBodyAnalysisContext.isExpressionInline = false; |
| return null; |
| } |
| leftInput.getSelectBlock().accept(this, arg); |
| return null; |
| } |
| |
| @Override |
| public Expression visit(SelectBlock selectBlock, ILangExpression arg) throws CompilationException { |
| if (selectBlock.hasGroupbyClause() || selectBlock.hasLetHavingClausesAfterGroupby()) { |
| elementBodyAnalysisContext.isExpressionInline = false; |
| return null; |
| } |
| if (selectBlock.hasFromClause()) { |
| selectBlock.getFromClause().accept(this, arg); |
| } |
| if (selectBlock.hasLetWhereClauses()) { |
| selectBlock.getLetWhereList().forEach(c -> { |
| if (c.getClauseType() == Clause.ClauseType.LET_CLAUSE) { |
| if (elementBodyAnalysisContext.letClauses == null) { |
| elementBodyAnalysisContext.letClauses = new ArrayList<>(); |
| } |
| elementBodyAnalysisContext.letClauses.add((LetClause) c); |
| |
| } else { //c.getClauseType() == Clause.ClauseType.WHERE_CLAUSE |
| if (elementBodyAnalysisContext.whereClauses == null) { |
| elementBodyAnalysisContext.whereClauses = new ArrayList<>(); |
| } |
| elementBodyAnalysisContext.whereClauses.add((WhereClause) c); |
| } |
| }); |
| } |
| selectBlock.getSelectClause().accept(this, arg); |
| return null; |
| } |
| |
| @Override |
| public Expression visit(FromClause fromClause, ILangExpression arg) throws CompilationException { |
| if (fromClause.getFromTerms().size() > 1) { |
| elementBodyAnalysisContext.isExpressionInline = false; |
| return null; |
| } |
| fromClause.getFromTerms().get(0).accept(this, arg); |
| return null; |
| } |
| |
| @Override |
| public Expression visit(FromTerm fromTerm, ILangExpression arg) throws CompilationException { |
| List<AbstractBinaryCorrelateClause> correlateClauses = fromTerm.getCorrelateClauses(); |
| List<AbstractBinaryCorrelateClause> unnestClauses = |
| correlateClauses.stream().filter(c -> c.getClauseType().equals(Clause.ClauseType.UNNEST_CLAUSE)) |
| .map(c -> (UnnestClause) c).collect(Collectors.toList()); |
| if (correlateClauses.size() != unnestClauses.size()) { |
| elementBodyAnalysisContext.isExpressionInline = false; |
| return null; |
| |
| } else if (fromTerm.hasPositionalVariable()) { |
| // TODO (GLENN): Add support for positional variables. |
| elementBodyAnalysisContext.isExpressionInline = false; |
| return null; |
| } |
| |
| if (!unnestClauses.isEmpty()) { |
| elementBodyAnalysisContext.unnestClauses = unnestClauses; |
| } |
| fromTerm.getLeftExpression().accept(this, arg); |
| elementBodyAnalysisContext.fromTermVariable = fromTerm.getLeftVariable(); |
| return null; |
| } |
| |
| @Override |
| public Expression visit(SelectClause selectClause, ILangExpression arg) throws CompilationException { |
| if (selectClause.selectElement()) { |
| elementBodyAnalysisContext.selectElement = selectClause.getSelectElement().getExpression(); |
| |
| } else if (selectClause.selectRegular()) { |
| SelectRegular selectRegular = selectClause.getSelectRegular(); |
| List<Projection> projectionList = selectRegular.getProjections(); |
| if (projectionList.stream().anyMatch(p -> p.getKind() != Projection.Kind.NAMED_EXPR)) { |
| elementBodyAnalysisContext.isExpressionInline = false; |
| |
| } else { |
| elementBodyAnalysisContext.selectClauseProjections = projectionList; |
| for (Projection projection : projectionList) { |
| projection.getExpression().accept(this, arg); |
| } |
| } |
| } |
| return null; |
| } |
| |
| public ElementBodyAnalysisContext getElementBodyAnalysisContext() throws CompilationException { |
| if (elementBodyAnalysisContext.isExpressionInline |
| && (elementBodyAnalysisContext.datasetName == null || elementBodyAnalysisContext.dataverseName == null |
| || elementBodyAnalysisContext.datasetCallExpression == null)) { |
| throw new CompilationException(ErrorCode.COMPILATION_ILLEGAL_STATE, |
| "Analysis of inline element body yielded no dataset!"); |
| } |
| return elementBodyAnalysisContext; |
| } |
| } |
