com.amazon.ionhiveserde.configuration.PathExtractionConfig 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.configuration;

import com.amazon.ion.IonReader;
import com.amazon.ion.IonStruct;
import com.amazon.ion.IonValue;
import com.amazon.ionhiveserde.configuration.source.RawConfiguration;
import com.amazon.ionpathextraction.PathExtractor;
import com.amazon.ionpathextraction.PathExtractorBuilder;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.function.BiFunction;

/**
 * Encapsulates the path_extractor configuration.
 */
class PathExtractionConfig {

    private static final String PATH_EXTRACTOR_KEY_FORMAT = "ion.%s.path_extractor";
    private static final String PATH_EXTRACTOR_DEFAULT_FORMAT = "( %s )";
    private static final String CASE_SENSITIVITY_KEY = "ion.path_extractor.case_sensitive";

    private final PathExtractor pathExtractor;
    private final Boolean caseSensitivity;

    /**
     * Constructor.
     *
     * @param configuration raw configuration.
     * @param columnNames table column names.
     */
    PathExtractionConfig(final RawConfiguration configuration, final List columnNames) {
        final Map searchPathByColumnName = new HashMap<>();
        for (final String columnName : columnNames) {
            final String searchPathExpression = configuration.getOrDefault(
                String.format(PATH_EXTRACTOR_KEY_FORMAT, columnName),
                String.format(PATH_EXTRACTOR_DEFAULT_FORMAT, columnName));

            searchPathByColumnName.put(columnName, searchPathExpression);
        }

        final boolean caseSensitivity = Boolean.parseBoolean(configuration.getOrDefault(CASE_SENSITIVITY_KEY, "false"));
        this.caseSensitivity = caseSensitivity;
        // Note: Serde property specifies case sensitivity, but path extractor APIs accept case insensitivity
        final PathExtractorBuilder builder = PathExtractorBuilder.standard()
                .withMatchRelativePaths(false)
                .withMatchCaseInsensitive(!caseSensitivity);

        for (final Entry entry : searchPathByColumnName.entrySet()) {
            final String columnName = entry.getKey();
            final String searchPathExpression = entry.getValue();

            final BiFunction callback = (ionReader, struct) -> {
                final IonValue ionValue = struct.getSystem().newValue(ionReader);

                if (ionValue.isNullValue()) {
                    struct.put(columnName, null); // Hive can't handle IonNull
                } else {
                    struct.put(columnName, ionValue);
                }

                return 0;
            };

            builder.withSearchPath(searchPathExpression, callback);
        }

        pathExtractor = builder.build();
    }

    /**
     * Returns the configured path extractor will accumulated matched paths to a given {@link IonStruct}.

     * @return PathExtractor configured for matching.
     */
    PathExtractor pathExtractor() {
        return pathExtractor;
    }

    /**
     * Returns a boolean that indicates if the pathExtractor is configured case sensitive.

     * @return true if the pathExtractor is configured case sensitive, false otherwise.
     */
    public Boolean getCaseSensitivity() {
        return caseSensitivity;
    }
}