sparksoniq.spark.closures.ForClauseFlatMapClosure Maven / Gradle / Ivy

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/*
 * 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.
 *
 * Author: Stefan Irimescu
 *
 */

package sparksoniq.spark.closures;

import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.types.StructType;
import org.rumbledb.api.Item;

import com.esotericsoftware.kryo.Kryo;
import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;

import sparksoniq.jsoniq.runtime.iterator.RuntimeIterator;
import sparksoniq.semantics.DynamicContext;
import sparksoniq.spark.DataFrameUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class ForClauseFlatMapClosure implements FlatMapFunction {

	private static final long serialVersionUID = 1L;
	private RuntimeIterator _expression;
    private StructType _inputSchema;
    private int _duplicateColumnIndex;

    private List> _rowColumns;
    private DynamicContext _context;
    private List _results;
    private List _newColumn;


    private transient Kryo _kryo;
    private transient Output _output;
    private transient Input _input;

    public ForClauseFlatMapClosure(
            RuntimeIterator expression,
            StructType inputSchema,
            int duplicateVariableIndex) {
        _expression = expression;
        _inputSchema = inputSchema;
        _duplicateColumnIndex = duplicateVariableIndex;

        _rowColumns = new ArrayList<>();
        _context = new DynamicContext();
        _results = new ArrayList<>();
        _newColumn = new ArrayList<>();

        _kryo = new Kryo();
        _kryo.setReferences(false);
        DataFrameUtils.registerKryoClassesKryo(_kryo);
        _output = new Output(128, -1);
        _input = new Input();
    }

    @Override
    public Iterator call(Row row) {
        _rowColumns.clear();
        _context.removeAllVariables();
        _results.clear();

        String[] columnNames = _inputSchema.fieldNames();

        // Deserialize row
        List