rdblue commented on a change in pull request #1854: URL: https://github.com/apache/iceberg/pull/1854#discussion_r539540686
########## File path: mr/src/main/java/org/apache/iceberg/mr/hive/Deserializer.java ########## @@ -0,0 +1,271 @@ +/* + * 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.HashMap; +import java.util.List; +import java.util.Map; +import java.util.UUID; +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.PrimitiveObjectInspector; +import org.apache.hadoop.hive.serde2.objectinspector.StructField; +import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector; +import org.apache.hadoop.hive.serde2.objectinspector.primitive.StringObjectInspector; +import org.apache.iceberg.Schema; +import org.apache.iceberg.data.GenericRecord; +import org.apache.iceberg.data.Record; +import org.apache.iceberg.mr.hive.serde.objectinspector.WriteObjectInspector; +import org.apache.iceberg.schema.SchemaWithPartnerVisitor; +import org.apache.iceberg.types.Type.PrimitiveType; +import org.apache.iceberg.types.Types.ListType; +import org.apache.iceberg.types.Types.MapType; +import org.apache.iceberg.types.Types.NestedField; +import org.apache.iceberg.types.Types.StructType; + + +class Deserializer { + private FieldDeserializer fieldDeserializer; + + /** + * Builder to create a Deserializer instance. + * Requires an Iceberg Schema and the Hive ObjectInspector for converting the data. + */ + static class Builder { + private Schema schema; + private ObjectInspector inspector; + + Builder schema(Schema mainSchema) { + this.schema = mainSchema; + return this; + } + + Builder inspector(ObjectInspector mainInspector) { + this.inspector = mainInspector; + return this; + } + + Deserializer build() { + return new Deserializer(schema, inspector); + } + } + + /** + * Deserializes the Hive result object to an Iceberg record using the provided ObjectInspectors. + * @param data The Hive data to deserialize + * @return The resulting Iceberg Record + */ + Record deserialize(Object data) { + return (Record) fieldDeserializer.value(data); + } + + private Deserializer(Schema schema, ObjectInspector fieldInspector) { + this.fieldDeserializer = DeserializerVisitor.visit(schema, fieldInspector); + } + + private static class DeserializerVisitor extends SchemaWithPartnerVisitor<ObjectInspector, FieldDeserializer> { + + public static FieldDeserializer visit(Schema schema, ObjectInspector objectInspector) { + return visit(schema, new FixNameMappingObjectInspector(schema, objectInspector), new DeserializerVisitor(), + new PartnerObjectInspectorByNameAccessors()); + } + + @Override + public FieldDeserializer schema(Schema schema, ObjectInspector inspector, FieldDeserializer deserializer) { + return deserializer; + } + + @Override + public FieldDeserializer field(NestedField field, ObjectInspector inspector, FieldDeserializer deserializer) { + return deserializer; + } + + @Override + public FieldDeserializer primitive(PrimitiveType type, ObjectInspector inspector) { + switch (type.typeId()) { + case BOOLEAN: + case INTEGER: + case LONG: + case FLOAT: + case DOUBLE: + case STRING: + // Generic conversions where Iceberg and Hive are using the same java object + return o -> ((PrimitiveObjectInspector) inspector).getPrimitiveJavaObject(o); + case UUID: + // TODO: This will not work with Parquet. Parquet UUID expect byte[], others are expecting UUID + return o -> UUID.fromString(((StringObjectInspector) inspector).getPrimitiveJavaObject(o)); + case DATE: + case TIMESTAMP: + case FIXED: + case BINARY: + case DECIMAL: + // Iceberg specific conversions + return o -> ((WriteObjectInspector) inspector).convert(o); + case TIME: + default: + throw new IllegalArgumentException("Unsupported column type: " + type); + } + } + + @Override + public FieldDeserializer struct(StructType type, ObjectInspector inspector, List<FieldDeserializer> deserializers) { + return o -> { + if (o == null) { + return null; + } + + List<Object> data = ((StructObjectInspector) inspector).getStructFieldsDataAsList(o); + Record result = GenericRecord.create(type); + + for (int i = 0; i < deserializers.size(); i++) { + Object fieldValue = data.get(i); + if (fieldValue != null) { + result.set(i, deserializers.get(i).value(fieldValue)); + } else { + result.set(i, null); + } + } + + return result; + }; + } + + @Override + public FieldDeserializer list(ListType listTypeInfo, ObjectInspector inspector, FieldDeserializer deserializer) { + return o -> { + if (o == null) { + return null; + } + + List<Object> result = new ArrayList<>(); Review comment: We don't want to bring in any additional Guava classes if possible, but using the ones that are already there is a good thing. For this case, we can easily replace map class implementations with an import change later. ---------------------------------------------------------------- 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]
