InputRDD.java

/*
 * 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
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package org.apache.tinkerpop.gremlin.spark.process.computer.io;

import org.apache.commons.configuration.Configuration;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.tinkerpop.gremlin.hadoop.structure.io.VertexWritable;

/**
 * An InputRDD is used to read data from the underlying graph system and yield the respective adjacency list.
 * Note that {@link InputFormatRDD} is a type of InputRDD that simply uses the specified {@link org.apache.hadoop.mapreduce.InputFormat} to generate the respective graphRDD.
 *
 * @author Marko A. Rodriguez (http://markorodriguez.com)
 */
public interface InputRDD {

    /**
     * Read the graphRDD from the underlying graph system.
     * @param configuration the configuration for the {@link org.apache.tinkerpop.gremlin.spark.process.computer.SparkGraphComputer}.
     * @param sparkContext the Spark context with the requisite methods for generating a {@link JavaPairRDD}.
     * @return an adjacency list representation of the underlying graph system.
     */
    public JavaPairRDD<Object, VertexWritable> readGraphRDD(final Configuration configuration, final JavaSparkContext sparkContext);
}