| /* |
| * 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.drill.exec.physical.impl.scan.project; |
| |
| import org.apache.drill.exec.physical.impl.scan.project.ScanLevelProjection.ScanProjectionParser; |
| import org.apache.drill.exec.physical.impl.scan.project.ReaderLevelProjection.ReaderProjectionResolver; |
| import org.apache.drill.exec.physical.resultSet.ResultVectorCache; |
| |
| /** |
| * Do-nothing implementation of the metadata manager. Allows the |
| * metadata manager to be optional without needing an if-statement |
| * on every access. |
| */ |
| |
| public class NoOpMetadataManager implements MetadataManager { |
| |
| @Override |
| public void bind(ResultVectorCache vectorCache) { } |
| |
| @Override |
| public ScanProjectionParser projectionParser() { return null; } |
| |
| @Override |
| public ReaderProjectionResolver resolver() { |
| // The resolver is requested only for user-defined metadata |
| // managers, not for this default, no-op version. If this |
| // method is called, something is amiss with the default |
| // setup. |
| throw new UnsupportedOperationException("Not supported"); |
| } |
| |
| @Override |
| public void define() { } |
| |
| @Override |
| public void load(int rowCount) { } |
| |
| @Override |
| public void endFile() { } |
| |
| @Override |
| public void close() { } |
| } |