| /* |
| * 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.lang.sqlpp.util; |
| |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.apache.asterix.common.exceptions.AsterixException; |
| import org.apache.asterix.lang.common.base.ILangExpression; |
| import org.apache.asterix.lang.common.clause.GroupbyClause; |
| import org.apache.asterix.lang.common.clause.LetClause; |
| import org.apache.asterix.lang.common.context.Scope; |
| import org.apache.asterix.lang.common.expression.GbyVariableExpressionPair; |
| import org.apache.asterix.lang.common.expression.VariableExpr; |
| import org.apache.asterix.lang.common.struct.VarIdentifier; |
| 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.visitor.FreeVariableVisitor; |
| |
| public class SqlppVariableUtil { |
| |
| private static final String USER_VAR_PREFIX = "$"; |
| |
| private SqlppVariableUtil() { |
| } |
| |
| public static VarIdentifier toUserDefinedVariableName(VarIdentifier var) { |
| String varName = var.getValue(); |
| return toUserDefinedVariableName(varName); |
| } |
| |
| public static VarIdentifier toUserDefinedVariableName(String varName) { |
| if (varName.startsWith(USER_VAR_PREFIX)) { |
| return new VarIdentifier(varName.substring(1)); |
| } |
| return new VarIdentifier(varName); |
| } |
| |
| public static String variableNameToDisplayedFieldName(String varName) { |
| if (varName.startsWith(USER_VAR_PREFIX)) { |
| return varName.substring(1); |
| } else { |
| // We use prefix "$" for user-defined variables and "#" for system-generated variables. |
| // However, in displayed query results, "$" is the prefix for |
| // system-generated variables/alias. Therefore we need to replace the prefix |
| // "#" with "$" if the system-generated alias needs to present in the final result. |
| return USER_VAR_PREFIX + varName.substring(1); |
| } |
| } |
| |
| public static String toUserDefinedName(String varName) { |
| if (varName.startsWith(USER_VAR_PREFIX)) { |
| return varName.substring(1); |
| } |
| return varName; |
| } |
| |
| public static Set<VariableExpr> getLiveUserDefinedVariables(Scope scope) { |
| Set<VariableExpr> results = new HashSet<>(); |
| Set<VariableExpr> liveVars = scope.getLiveVariables(); |
| Iterator<VariableExpr> liveVarIter = liveVars.iterator(); |
| while (liveVarIter.hasNext()) { |
| VariableExpr var = liveVarIter.next(); |
| if (SqlppVariableUtil.isUserDefinedVariable(var)) { |
| results.add(var); |
| } |
| } |
| return results; |
| } |
| |
| private static boolean isUserDefinedVariable(VariableExpr varExpr) { |
| return varExpr.getVar().getValue().startsWith(USER_VAR_PREFIX); |
| } |
| |
| public static String toInternalVariableName(String varName) { |
| return USER_VAR_PREFIX + varName; |
| } |
| |
| public static VarIdentifier toInternalVariableIdentifier(String idName) { |
| return new VarIdentifier(USER_VAR_PREFIX + idName); |
| } |
| |
| public static Collection<VariableExpr> getFreeVariables(ILangExpression langExpr) throws AsterixException { |
| Collection<VariableExpr> freeVars = new HashSet<>(); |
| FreeVariableVisitor visitor = new FreeVariableVisitor(); |
| langExpr.accept(visitor, freeVars); |
| return freeVars; |
| } |
| |
| public static Collection<VariableExpr> getBindingVariables(FromClause fromClause) { |
| Set<VariableExpr> bindingVars = new HashSet<>(); |
| if (fromClause == null) { |
| return bindingVars; |
| } |
| for (FromTerm fromTerm : fromClause.getFromTerms()) { |
| bindingVars.addAll(getBindingVariables(fromTerm)); |
| } |
| return bindingVars; |
| } |
| |
| public static Collection<VariableExpr> getBindingVariables(FromTerm fromTerm) { |
| Set<VariableExpr> bindingVars = new HashSet<>(); |
| if (fromTerm == null) { |
| return bindingVars; |
| } |
| bindingVars.add(fromTerm.getLeftVariable()); |
| if (fromTerm.hasPositionalVariable()) { |
| bindingVars.add(fromTerm.getPositionalVariable()); |
| } |
| for (AbstractBinaryCorrelateClause correlateClause : fromTerm.getCorrelateClauses()) { |
| bindingVars.add(correlateClause.getRightVariable()); |
| if (correlateClause.hasPositionalVariable()) { |
| bindingVars.add(correlateClause.getPositionalVariable()); |
| } |
| } |
| return bindingVars; |
| } |
| |
| public static Collection<VariableExpr> getBindingVariables(GroupbyClause gbyClause) { |
| Set<VariableExpr> bindingVars = new HashSet<>(); |
| if (gbyClause == null) { |
| return bindingVars; |
| } |
| for (GbyVariableExpressionPair gbyKey : gbyClause.getGbyPairList()) { |
| VariableExpr var = gbyKey.getVar(); |
| if (var != null) { |
| bindingVars.add(var); |
| } |
| } |
| for (GbyVariableExpressionPair gbyKey : gbyClause.getDecorPairList()) { |
| VariableExpr var = gbyKey.getVar(); |
| if (var != null) { |
| bindingVars.add(var); |
| } |
| } |
| bindingVars.addAll(gbyClause.getWithVarList()); |
| bindingVars.add(gbyClause.getGroupVar()); |
| return bindingVars; |
| } |
| |
| public static Collection<VariableExpr> getBindingVariables(List<LetClause> letClauses) { |
| Set<VariableExpr> bindingVars = new HashSet<>(); |
| if (letClauses == null || letClauses.isEmpty()) { |
| return bindingVars; |
| } |
| for (LetClause letClause : letClauses) { |
| bindingVars.add(letClause.getVarExpr()); |
| } |
| return bindingVars; |
| } |
| |
| } |