/* * 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.vector.accessor; import org.apache.drill.exec.record.metadata.ColumnMetadata; /** * Base interface for all column readers, defining a generic set of methods * that all readers provide. In particular, given the metadata and the object * type, one can determine what to do with each reader when working with readers * generically. The getObject() and getAsString() methods provide * generic data access for tests and debugging. */ public interface ColumnReader { ColumnMetadata schema(); /** * The type of this reader. * * @return type of reader */ ObjectType type(); /** * Determine if this value is null. *