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com.blazebit.persistence.parser.expression.LazyCopyingResultVisitorAdapter Maven / Gradle / Ivy
/*
* Copyright 2014 - 2021 Blazebit.
*
* 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 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 com.blazebit.persistence.parser.expression;
import com.blazebit.persistence.parser.predicate.BetweenPredicate;
import com.blazebit.persistence.parser.predicate.BooleanLiteral;
import com.blazebit.persistence.parser.predicate.CompoundPredicate;
import com.blazebit.persistence.parser.predicate.EqPredicate;
import com.blazebit.persistence.parser.predicate.ExistsPredicate;
import com.blazebit.persistence.parser.predicate.GePredicate;
import com.blazebit.persistence.parser.predicate.GtPredicate;
import com.blazebit.persistence.parser.predicate.InPredicate;
import com.blazebit.persistence.parser.predicate.IsEmptyPredicate;
import com.blazebit.persistence.parser.predicate.IsNullPredicate;
import com.blazebit.persistence.parser.predicate.LePredicate;
import com.blazebit.persistence.parser.predicate.LikePredicate;
import com.blazebit.persistence.parser.predicate.LtPredicate;
import com.blazebit.persistence.parser.predicate.MemberOfPredicate;
import com.blazebit.persistence.parser.predicate.Predicate;
import java.util.ArrayList;
import java.util.List;
/**
* This is a visitor that can be used to copy an expression tree by returning a different expression than the original one.
*
* @author Christian Beikov
* @since 1.3.0
*/
public abstract class LazyCopyingResultVisitorAdapter implements Expression.ResultVisitor {
protected void onPathExpressionCopy(PathExpression expression) {
// No-op
}
protected List visitExpressionList(List expressions) {
List newExpressions = null;
int size = expressions.size();
for (int i = 0; i < size; i++) {
T originalExpr = expressions.get(i);
T newExpr = (T) originalExpr.accept(this);
if (newExpressions == null) {
if (originalExpr != newExpr) {
newExpressions = new ArrayList<>(expressions.size());
for (int j = 0; j < i; j++) {
newExpressions.add(expressions.get(j));
}
newExpressions.add(newExpr);
}
} else {
newExpressions.add(newExpr);
}
}
return newExpressions;
}
@Override
public Expression visit(ArrayExpression expression) {
Expression newBase = expression.getBase().accept(this);
Expression newIndex = expression.getIndex().accept(this);
if (expression.getBase() != newBase || expression.getIndex() != newIndex) {
return new ArrayExpression((PropertyExpression) newBase, newIndex);
}
return expression;
}
@Override
public Expression visit(TreatExpression expression) {
Expression newExpression = expression.getExpression().accept(this);
if (newExpression != expression.getExpression()) {
return new TreatExpression(newExpression, expression.getType());
}
return expression;
}
@Override
public Expression visit(PropertyExpression expression) {
return expression;
}
@Override
public Expression visit(ParameterExpression expression) {
return expression;
}
@Override
public Expression visit(ListIndexExpression expression) {
Expression newExpression = expression.getPath().accept(this);
if (newExpression != expression.getPath()) {
return new ListIndexExpression((PathExpression) newExpression);
}
return expression;
}
@Override
public Expression visit(MapEntryExpression expression) {
Expression newExpression = expression.getPath().accept(this);
if (newExpression != expression.getPath()) {
return new MapEntryExpression((PathExpression) newExpression);
}
return expression;
}
@Override
public Expression visit(MapKeyExpression expression) {
Expression newExpression = expression.getPath().accept(this);
if (newExpression != expression.getPath()) {
return new MapKeyExpression((PathExpression) newExpression);
}
return expression;
}
@Override
public Expression visit(MapValueExpression expression) {
Expression newExpression = expression.getPath().accept(this);
if (newExpression != expression.getPath()) {
return new MapValueExpression((PathExpression) newExpression);
}
return expression;
}
@Override
public Expression visit(NullExpression expression) {
return expression;
}
@Override
public Expression visit(SubqueryExpression expression) {
throw new UnsupportedOperationException("Not yet implemented!");
}
@Override
public Expression visit(FunctionExpression expression) {
List newExpressions = visitExpressionList(expression.getExpressions());
boolean copy = false;
if (newExpressions == null) {
newExpressions = expression.getExpressions();
} else {
copy = true;
}
WindowDefinition newWindowDefinition = expression.getWindowDefinition();
if (newWindowDefinition != null) {
Predicate newFilterPredicate = newWindowDefinition.getFilterPredicate() == null ? null : (Predicate) newWindowDefinition.getFilterPredicate().accept(this);
if (newFilterPredicate != newWindowDefinition.getFilterPredicate()) {
copy = true;
}
List newPartitionExpressions = visitExpressionList(newWindowDefinition.getPartitionExpressions());
if (newPartitionExpressions == null) {
newPartitionExpressions = newWindowDefinition.getPartitionExpressions();
} else {
copy = true;
}
List newOrderByExpressions = visitOrderByList(newWindowDefinition.getOrderByExpressions());
if (newOrderByExpressions == null) {
newOrderByExpressions = newWindowDefinition.getOrderByExpressions();
} else {
copy = true;
}
Expression newFrameStartExpression = newWindowDefinition.getFrameStartExpression() == null ? null : newWindowDefinition.getFrameStartExpression().accept(this);
if (newFrameStartExpression != newWindowDefinition.getFrameStartExpression()) {
copy = true;
}
Expression newFrameEndExpression = newWindowDefinition.getFrameEndExpression() == null ? null : newWindowDefinition.getFrameEndExpression().accept(this);
if (newFrameEndExpression != newWindowDefinition.getFrameEndExpression()) {
copy = true;
}
if (copy) {
newWindowDefinition = new WindowDefinition(
newWindowDefinition.getWindowName(),
newPartitionExpressions,
newOrderByExpressions,
newFilterPredicate,
newWindowDefinition.getFrameMode(),
newWindowDefinition.getFrameStartType(),
newFrameStartExpression,
newWindowDefinition.getFrameEndType(),
newFrameEndExpression,
newWindowDefinition.getFrameExclusionType()
);
}
}
if (copy) {
return new FunctionExpression(expression.getFunctionName(), newExpressions, newWindowDefinition);
}
return expression;
}
private List visitOrderByList(List expressions) {
List newExpressions = null;
int size = expressions.size();
for (int i = 0; i < size; i++) {
OrderByItem orderByItem = expressions.get(i);
Expression originalExpr = orderByItem.getExpression();
Expression newExpr = originalExpr.accept(this);
if (newExpressions == null) {
if (originalExpr != newExpr) {
newExpressions = new ArrayList<>(expressions.size());
for (int j = 0; j < i; j++) {
newExpressions.add(expressions.get(j));
}
newExpressions.add(new OrderByItem(orderByItem.isAscending(), orderByItem.isNullFirst(), newExpr));
}
} else {
newExpressions.add(new OrderByItem(orderByItem.isAscending(), orderByItem.isNullFirst(), newExpr));
}
}
return newExpressions;
}
@Override
public Expression visit(TypeFunctionExpression expression) {
Expression originalExpr = expression.getExpressions().get(0);
Expression newExpr = originalExpr.accept(this);
if (originalExpr != newExpr) {
return new TypeFunctionExpression(newExpr);
}
return expression;
}
@Override
public Expression visit(TrimExpression expression) {
Expression newTrimSource = expression.getTrimSource().accept(this);
Expression newTrimCharacter = expression.getTrimCharacter() == null ? null : expression.getTrimCharacter().accept(this);
if (expression.getTrimSource() != newTrimSource || expression.getTrimCharacter() != newTrimCharacter) {
return new TrimExpression(expression.getTrimspec(), newTrimSource, newTrimCharacter);
}
return expression;
}
@Override
public Expression visit(WhenClauseExpression expression) {
Expression newCondition = expression.getCondition().accept(this);
Expression newResult = expression.getResult().accept(this);
if (expression.getCondition() != newCondition || expression.getResult() != newResult) {
return new WhenClauseExpression(newCondition, newResult);
}
return expression;
}
@Override
public Expression visit(GeneralCaseExpression expression) {
List newExpressions = visitExpressionList(expression.getWhenClauses());
Expression newDefaultExpr = null;
if (expression.getDefaultExpr() != null) {
newDefaultExpr = expression.getDefaultExpr().accept(this);
}
if (newExpressions != null) {
return new GeneralCaseExpression(newExpressions, newDefaultExpr);
} else if (expression.getDefaultExpr() != newDefaultExpr) {
return new GeneralCaseExpression(expression.getWhenClauses(), newDefaultExpr);
}
return expression;
}
@Override
public Expression visit(SimpleCaseExpression expression) {
Expression newCaseOperandExpr = expression.getCaseOperand().accept(this);
List newExpressions = visitExpressionList(expression.getWhenClauses());
Expression newDefaultExpr = null;
if (expression.getDefaultExpr() != null) {
newDefaultExpr = expression.getDefaultExpr().accept(this);
}
if (newExpressions != null) {
return new SimpleCaseExpression(newCaseOperandExpr, newExpressions, newDefaultExpr);
} else if (expression.getCaseOperand() != newCaseOperandExpr || expression.getDefaultExpr() != newDefaultExpr) {
return new SimpleCaseExpression(newCaseOperandExpr, expression.getWhenClauses(), newDefaultExpr);
}
return expression;
}
@Override
public Expression visit(PathExpression expression) {
List newExpressions = visitExpressionList(expression.getExpressions());
if (newExpressions != null) {
PathExpression pathExpression = new PathExpression(newExpressions);
onPathExpressionCopy(pathExpression);
return pathExpression;
}
return expression;
}
@Override
public Expression visit(ArithmeticExpression expression) {
Expression newLeft = expression.getLeft().accept(this);
Expression newRight = expression.getRight().accept(this);
if (newLeft != expression.getLeft() || newRight != expression.getRight()) {
return new ArithmeticExpression(newLeft, newRight, expression.getOp());
}
return expression;
}
@Override
public Expression visit(ArithmeticFactor expression) {
Expression newExpr = expression.getExpression().accept(this);
if (newExpr != expression.getExpression()) {
return new ArithmeticFactor(newExpr, expression.isInvertSignum());
}
return expression;
}
@Override
public Expression visit(NumericLiteral expression) {
return expression;
}
@Override
public Expression visit(BooleanLiteral expression) {
return expression;
}
@Override
public Expression visit(StringLiteral expression) {
return expression;
}
@Override
public Expression visit(DateLiteral expression) {
return expression;
}
@Override
public Expression visit(TimeLiteral expression) {
return expression;
}
@Override
public Expression visit(TimestampLiteral expression) {
return expression;
}
@Override
public Expression visit(EnumLiteral expression) {
return expression;
}
@Override
public Expression visit(EntityLiteral expression) {
return expression;
}
@Override
public Expression visit(CompoundPredicate predicate) {
List newPredicates = visitExpressionList(predicate.getChildren());
if (newPredicates != null) {
return new CompoundPredicate(predicate.getOperator(), newPredicates, predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(EqPredicate predicate) {
Expression leftExpr = predicate.getLeft().accept(this);
Expression rightExpr = predicate.getRight().accept(this);
if (leftExpr != predicate.getLeft() || rightExpr != predicate.getRight()) {
return new EqPredicate(leftExpr, rightExpr, predicate.getQuantifier(), predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(IsNullPredicate predicate) {
Expression newExpr = predicate.getExpression().accept(this);
if (newExpr != predicate.getExpression()) {
return new IsNullPredicate(newExpr, predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(IsEmptyPredicate predicate) {
Expression newExpr = predicate.getExpression().accept(this);
if (newExpr != predicate.getExpression()) {
return new IsEmptyPredicate(newExpr, predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(MemberOfPredicate predicate) {
Expression leftExpr = predicate.getLeft().accept(this);
Expression rightExpr = predicate.getRight().accept(this);
if (leftExpr != predicate.getLeft() || rightExpr != predicate.getRight()) {
return new MemberOfPredicate(leftExpr, rightExpr, predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(LikePredicate predicate) {
Expression leftExpr = predicate.getLeft().accept(this);
Expression rightExpr = predicate.getRight().accept(this);
if (leftExpr != predicate.getLeft() || rightExpr != predicate.getRight()) {
return new LikePredicate(leftExpr, rightExpr, predicate.isCaseSensitive(), predicate.getEscapeCharacter(), predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(BetweenPredicate predicate) {
Expression newLeftExpr = predicate.getLeft().accept(this);
Expression newStartExpr = predicate.getStart().accept(this);
Expression newEndExpr = predicate.getEnd().accept(this);
if (newLeftExpr != predicate.getLeft() || newStartExpr != predicate.getStart() || newEndExpr != predicate.getEnd()) {
return new BetweenPredicate(newLeftExpr, newStartExpr, newEndExpr, predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(InPredicate predicate) {
Expression newLeftExpr = predicate.getLeft().accept(this);
List newExpressions = visitExpressionList(predicate.getRight());
if (newExpressions == null) {
if (newLeftExpr != predicate.getLeft()) {
return new InPredicate(predicate.isNegated(), newLeftExpr, predicate.getRight());
}
} else {
return new InPredicate(predicate.isNegated(), newLeftExpr, newExpressions);
}
return predicate;
}
@Override
public Expression visit(GtPredicate predicate) {
Expression leftExpr = predicate.getLeft().accept(this);
Expression rightExpr = predicate.getRight().accept(this);
if (leftExpr != predicate.getLeft() || rightExpr != predicate.getRight()) {
return new GtPredicate(leftExpr, rightExpr, predicate.getQuantifier(), predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(GePredicate predicate) {
Expression leftExpr = predicate.getLeft().accept(this);
Expression rightExpr = predicate.getRight().accept(this);
if (leftExpr != predicate.getLeft() || rightExpr != predicate.getRight()) {
return new GePredicate(leftExpr, rightExpr, predicate.getQuantifier(), predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(LtPredicate predicate) {
Expression leftExpr = predicate.getLeft().accept(this);
Expression rightExpr = predicate.getRight().accept(this);
if (leftExpr != predicate.getLeft() || rightExpr != predicate.getRight()) {
return new LtPredicate(leftExpr, rightExpr, predicate.getQuantifier(), predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(LePredicate predicate) {
Expression leftExpr = predicate.getLeft().accept(this);
Expression rightExpr = predicate.getRight().accept(this);
if (leftExpr != predicate.getLeft() || rightExpr != predicate.getRight()) {
return new LePredicate(leftExpr, rightExpr, predicate.getQuantifier(), predicate.isNegated());
}
return predicate;
}
@Override
public Expression visit(ExistsPredicate predicate) {
Expression newExpr = predicate.getExpression().accept(this);
if (newExpr != predicate.getExpression()) {
return new ExistsPredicate(newExpr, predicate.isNegated());
}
return predicate;
}
}
