pvary commented on a change in pull request #1612: URL: https://github.com/apache/iceberg/pull/1612#discussion_r526698367
########## File path: mr/src/main/java/org/apache/iceberg/mr/hive/HiveSchemaUtil.java ########## @@ -0,0 +1,167 @@ +/* + * 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.iceberg.mr.hive; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import org.apache.hadoop.hive.metastore.api.FieldSchema; +import org.apache.hadoop.hive.serde2.objectinspector.ListObjectInspector; +import org.apache.hadoop.hive.serde2.objectinspector.MapObjectInspector; +import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector; +import org.apache.hadoop.hive.serde2.objectinspector.StructField; +import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector; +import org.apache.hadoop.hive.serde2.objectinspector.primitive.TimestampObjectInspector; +import org.apache.hadoop.hive.serde2.typeinfo.TypeInfo; +import org.apache.hadoop.hive.serde2.typeinfo.TypeInfoUtils; +import org.apache.iceberg.Schema; +import org.apache.iceberg.mr.hive.serde.objectinspector.IcebergObjectInspector; +import org.apache.iceberg.mr.hive.serde.objectinspector.IcebergRecordObjectInspector; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class HiveSchemaUtil { + private static final Logger LOG = LoggerFactory.getLogger(HiveSchemaUtil.class); + + private HiveSchemaUtil() { + } + + /** + * Converts the list of Hive FieldSchemas to an Iceberg schema. + * <p> + * The list should contain the columns and the partition columns as well. + * @param fieldSchemas The list of the columns + * @return An equivalent Iceberg Schema + */ + public static Schema schema(List<FieldSchema> fieldSchemas) { + List<String> names = new ArrayList<>(fieldSchemas.size()); + List<TypeInfo> typeInfos = new ArrayList<>(fieldSchemas.size()); + + for (FieldSchema col : fieldSchemas) { + names.add(col.getName()); + typeInfos.add(TypeInfoUtils.getTypeInfoFromTypeString(col.getType())); + } + + return convert(names, typeInfos); + } + + /** + * Converts the Hive properties defining the columns to an Iceberg schema. + * @param columnNames The property containing the column names + * @param columnTypes The property containing the column types + * @param columnNameDelimiter The name delimiter + * @return The Iceberg schema + */ + public static Schema schema(String columnNames, String columnTypes, String columnNameDelimiter) { + // Parse the configuration parameters + List<String> names = new ArrayList<>(); + Collections.addAll(names, columnNames.split(columnNameDelimiter)); + + return HiveSchemaUtil.convert(names, TypeInfoUtils.getTypeInfosFromTypeString(columnTypes)); + } + + /** + * Checks if the ObjectInspectors generated by the two schema definitions are compatible. + * <p> + * Currently only allows the same column names and column types. Later we might want allow compatible column types as + * well. + * TODO: We might want to allow compatible conversions + * @param schema First schema + * @param other Second schema + * @return True if the two schema is compatible + */ + public static boolean compatible(Schema schema, Schema other) { + ObjectInspector inspector = IcebergObjectInspector.create(schema); + ObjectInspector otherInspector = IcebergObjectInspector.create(other); + + if (!(inspector instanceof IcebergRecordObjectInspector) || + !(otherInspector instanceof IcebergRecordObjectInspector)) { + return false; + } + + return compatible(inspector, otherInspector); + } + + private static boolean compatible(ObjectInspector inspector, ObjectInspector other) { + if (inspector == null && other == null) { + // We do not expect this type of calls, but for completeness shake Review comment: Fixed! Thanks for pointing out! ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
