| /* |
| * 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.transformation.dag.transformer.unary; |
| |
| import org.apache.iotdb.db.exception.query.QueryProcessException; |
| import org.apache.iotdb.db.queryengine.transformation.api.LayerPointReader; |
| import org.apache.iotdb.db.queryengine.transformation.api.YieldableState; |
| import org.apache.iotdb.db.queryengine.transformation.dag.transformer.Transformer; |
| |
| import org.apache.tsfile.enums.TSDataType; |
| |
| import java.io.IOException; |
| |
| public abstract class UnaryTransformer extends Transformer { |
| |
| protected final LayerPointReader layerPointReader; |
| protected final TSDataType layerPointReaderDataType; |
| protected final boolean isLayerPointReaderConstant; |
| |
| protected UnaryTransformer(LayerPointReader layerPointReader) { |
| this.layerPointReader = layerPointReader; |
| layerPointReaderDataType = layerPointReader.getDataType(); |
| isLayerPointReaderConstant = layerPointReader.isConstantPointReader(); |
| } |
| |
| @Override |
| public final boolean isConstantPointReader() { |
| return isLayerPointReaderConstant; |
| } |
| |
| @Override |
| public YieldableState yieldValue() throws Exception { |
| final YieldableState yieldableState = layerPointReader.yield(); |
| if (!YieldableState.YIELDABLE.equals(yieldableState)) { |
| return yieldableState; |
| } |
| |
| if (!isLayerPointReaderConstant) { |
| cachedTime = layerPointReader.currentTime(); |
| } |
| |
| if (layerPointReader.isCurrentNull()) { |
| currentNull = true; |
| } else { |
| transformAndCache(); |
| } |
| |
| layerPointReader.readyForNext(); |
| return YieldableState.YIELDABLE; |
| } |
| |
| @Override |
| protected final boolean cacheValue() throws QueryProcessException, IOException { |
| if (!layerPointReader.next()) { |
| return false; |
| } |
| |
| if (!isLayerPointReaderConstant) { |
| cachedTime = layerPointReader.currentTime(); |
| } |
| |
| if (layerPointReader.isCurrentNull()) { |
| currentNull = true; |
| } else { |
| transformAndCache(); |
| } |
| |
| layerPointReader.readyForNext(); |
| return true; |
| } |
| |
| protected abstract void transformAndCache() throws QueryProcessException, IOException; |
| } |