org.apache.crunch.impl.spark.fn.PairFlatMapPairDoFn.java Source code

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Here is the source code for org.apache.crunch.impl.spark.fn.PairFlatMapPairDoFn.java

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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.
 */
package org.apache.crunch.impl.spark.fn;

import com.google.common.collect.Iterables;
import com.google.common.collect.Iterators;
import org.apache.crunch.DoFn;
import org.apache.crunch.Pair;
import org.apache.crunch.impl.spark.GuavaUtils;
import org.apache.crunch.impl.spark.SparkRuntimeContext;
import org.apache.spark.api.java.function.PairFlatMapFunction;
import scala.Tuple2;

import java.util.Iterator;

public class PairFlatMapPairDoFn<K, V, K2, V2> extends PairFlatMapFunction<Iterator<Tuple2<K, V>>, K2, V2> {
    private final DoFn<Pair<K, V>, Pair<K2, V2>> fn;
    private final SparkRuntimeContext ctxt;

    public PairFlatMapPairDoFn(DoFn<Pair<K, V>, Pair<K2, V2>> fn, SparkRuntimeContext ctxt) {
        this.fn = fn;
        this.ctxt = ctxt;
    }

    @Override
    public Iterable<Tuple2<K2, V2>> call(Iterator<Tuple2<K, V>> input) throws Exception {
        ctxt.initialize(fn);
        return Iterables.transform(
                new CrunchIterable<Pair<K, V>, Pair<K2, V2>>(fn,
                        Iterators.transform(input, GuavaUtils.<K, V>tuple2PairFunc())),
                GuavaUtils.<K2, V2>pair2tupleFunc());
    }
}