| /* |
| * 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.tsfile.file.metadata.enums.TSDataType; |
| |
| import java.io.IOException; |
| |
| /** |
| * this is a special transformer which outputs data just as input without any modification. |
| * |
| * <p>i.e. it's just the function f(x) = x. |
| * |
| * <p>It's mainly used for a UDF with aggregation query as its parameters. |
| */ |
| public class TransparentTransformer extends UnaryTransformer { |
| |
| public TransparentTransformer(LayerPointReader layerPointReader) { |
| super(layerPointReader); |
| } |
| |
| @Override |
| public TSDataType getDataType() { |
| return layerPointReaderDataType; |
| } |
| |
| @Override |
| protected void transformAndCache() throws QueryProcessException, IOException { |
| switch (layerPointReaderDataType) { |
| case BOOLEAN: |
| cachedBoolean = layerPointReader.currentBoolean(); |
| break; |
| case DOUBLE: |
| cachedDouble = layerPointReader.currentDouble(); |
| break; |
| case FLOAT: |
| cachedFloat = layerPointReader.currentFloat(); |
| break; |
| case INT32: |
| cachedInt = layerPointReader.currentInt(); |
| break; |
| case INT64: |
| cachedLong = layerPointReader.currentLong(); |
| break; |
| case TEXT: |
| cachedBinary = layerPointReader.currentBinary(); |
| break; |
| default: |
| throw new QueryProcessException("unsupported data type: " + layerPointReader.getDataType()); |
| } |
| } |
| } |