com.amazon.ionhiveserde.objectinspectors.IonStructToStructInspector Maven / Gradle / Ivy

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An Apache Hive SerDe (short for serializer/deserializer) for the Ion file format.

There is a newer version: 1.2.0

/*
 * Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * or in the "license" file accompanying this file. This file 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 com.amazon.ionhiveserde.objectinspectors;

import static com.amazon.ionhiveserde.objectinspectors.IonUtil.isIonNull;

import com.amazon.ion.IonStruct;
import com.amazon.ion.IonValue;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector;
import org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils;
import org.apache.hadoop.hive.serde2.objectinspector.StructField;
import org.apache.hadoop.hive.serde2.objectinspector.StructObjectInspector;
import org.apache.hadoop.hive.serde2.typeinfo.StructTypeInfo;

/**
 * Adapts an {@link IonStruct} for the struct Hive type.
 */
public class IonStructToStructInspector extends StructObjectInspector {

    private final Map fieldsByName;
    private final List fields;

    /**
     * Creates a Ion struct to Hive struct object inspector.
     *
     * @param structTypeInfo TypeInfo for all fields
     * @param fieldObjectInspectors list of field ObjectInspectors in order
     */
    public IonStructToStructInspector(final StructTypeInfo structTypeInfo,
                                      final List fieldObjectInspectors) {
        fieldsByName = new HashMap<>();
        fields = new ArrayList<>();

        final ArrayList structFieldNames = structTypeInfo.getAllStructFieldNames();
        for (int i = 0; i < structFieldNames.size(); i++) {
            final String fieldName = structFieldNames.get(i);
            final ObjectInspector objectInspector = fieldObjectInspectors.get(i);

            final IonStructField field = new IonStructField(fieldName, objectInspector, i);
            fields.add(field);
            fieldsByName.put(fieldName, field);
        }
    }

    @Override
    public List getAllStructFieldRefs() {
        return fields;
    }

    @Override
    public StructField getStructFieldRef(final String fieldName) {
        if (fieldName == null) {
            throw new IllegalArgumentException("field name cannot be null");
        }

        return fieldsByName.get(fieldName);
    }

    @Override
    public Object getStructFieldData(final Object data, final StructField fieldRef) {
        if (isIonNull((IonValue) data)) {
            return null;
        }
        if (fieldRef == null) {
            throw new IllegalArgumentException("fieldRef name cannot be null");
        }

        final IonStruct struct = (IonStruct) data;

        return struct.get(fieldRef.getFieldName());
    }

    @Override
    public List