| /* |
| * 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.iotdb.db.queryengine.plan.expression.unary; |
| |
| import org.apache.iotdb.db.queryengine.plan.expression.Expression; |
| import org.apache.iotdb.db.queryengine.plan.expression.ExpressionType; |
| import org.apache.iotdb.db.queryengine.plan.expression.visitor.ExpressionVisitor; |
| import org.apache.iotdb.tsfile.utils.ReadWriteIOUtils; |
| |
| import java.io.DataOutputStream; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| |
| public class IsNullExpression extends UnaryExpression { |
| private final boolean isNot; |
| |
| public IsNullExpression(Expression expression, boolean isNot) { |
| super(expression); |
| this.isNot = isNot; |
| } |
| |
| public IsNullExpression(ByteBuffer byteBuffer) { |
| super(Expression.deserialize(byteBuffer)); |
| isNot = ReadWriteIOUtils.readBool(byteBuffer); |
| } |
| |
| public boolean isNot() { |
| return isNot; |
| } |
| |
| @Override |
| protected String getExpressionStringInternal() { |
| return expression.getExpressionString() + " IS " + (isNot ? "NOT " : "") + "NULL"; |
| } |
| |
| @Override |
| public ExpressionType getExpressionType() { |
| return ExpressionType.IS_NULL; |
| } |
| |
| @Override |
| protected void serialize(ByteBuffer byteBuffer) { |
| super.serialize(byteBuffer); |
| ReadWriteIOUtils.write(isNot, byteBuffer); |
| } |
| |
| @Override |
| protected void serialize(DataOutputStream stream) throws IOException { |
| super.serialize(stream); |
| ReadWriteIOUtils.write(isNot, stream); |
| } |
| |
| @Override |
| public String getOutputSymbolInternal() { |
| return expression.getOutputSymbol() + " IS " + (isNot ? "NOT " : "") + "NULL"; |
| } |
| |
| @Override |
| public <R, C> R accept(ExpressionVisitor<R, C> visitor, C context) { |
| return visitor.visitIsNullExpression(this, context); |
| } |
| } |