rohityadav1993 commented on code in PR #16727: URL: https://github.com/apache/pinot/pull/16727#discussion_r2431176573
########## pinot-spi/src/main/java/org/apache/pinot/spi/data/readers/ColumnReaderFactory.java: ########## @@ -0,0 +1,92 @@ +/** + * 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.pinot.spi.data.readers; + +import java.io.Closeable; +import java.io.IOException; +import java.io.Serializable; +import java.util.Map; +import java.util.Set; +import org.apache.pinot.spi.data.FieldSpec; +import org.apache.pinot.spi.data.Schema; + + +/** + * Factory interface for creating ColumnReader instances for different data sources. + * + * <p>This factory provides a generic way to create column readers for various data sources + * such as Pinot segments, Parquet files, etc. The factory handles: + * <ul> + * <li>Creating column readers for existing columns</li> + * <li>Creating default value readers for new columns</li> + * <li>Data type conversions between source and target schemas</li> + * <li>Resource management</li> + * </ul> + */ +public interface ColumnReaderFactory extends Closeable, Serializable { + + /** + * Initialize the factory with the data source and target schema. + * + * @param targetSchema Target schema for the output segment + * @throws IOException If initialization fails + */ + void init(Schema targetSchema) throws IOException; + + /** + * Get the set of column names available in the source data. + * + * @return Set of available column names in the source + */ + Set<String> getAvailableColumns(); + + /** + * Get the total number of documents/rows in the data source. + * + * @return Total number of documents + */ + int getNumDocs(); + + /** + * Create a column reader for the specified column. + * + * @param columnName Name of the column to read + * @param targetFieldSpec Target field specification from the output schema + * @return ColumnReader instance for the specified column + * @throws IOException If the column reader cannot be created + */ + ColumnReader createColumnReader(String columnName, FieldSpec targetFieldSpec) throws IOException; + + /** + * Get all column readers for the target schema. + * This is a convenience method that creates readers for all columns in the target schema. + * + * @return Map of column name to ColumnReader + * @throws IOException If any column reader cannot be created + */ + Map<String, ColumnReader> getAllColumnReaders() throws IOException; + + /** + * Check if the specified column exists in the source data. + * + * @param columnName Column name to check + * @return true if the column exists in source, false otherwise + */ + boolean hasColumn(String columnName); Review Comment: Removing these from the ColumnReaderFactory interface. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
