compiler/frontend/spark/src/main/java/org/apache/nemo/compiler/frontend/spark/core/JavaSparkContext.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
 * "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.nemo.compiler.frontend.spark.core;

import org.apache.nemo.compiler.frontend.spark.core.rdd.SparkJavaRDD;
import org.apache.spark.SparkContext;

import java.util.List;

/**
 * Spark context wrapper for Java.
 */
public final class JavaSparkContext {
  private final SparkContext sparkContext;

  /**
   * Constructor.
   *
   * @param sparkContext spark context to wrap.
   */
  public JavaSparkContext(final SparkContext sparkContext) {
    this.sparkContext = sparkContext;
  }

  /**
   * Create a String {@link SparkJavaRDD} from a text file path.
   *
   * @param path the path to read.
   * @return the RDD.
   */
  public SparkJavaRDD<String> textFile(final String path) {
    return this.textFile(path, 1);
  }

  /**
   * Create a String {@link SparkJavaRDD} from a text file path with specific minimum parallelism.
   *
   * @param path          the path to read.
   * @param minPartitions the minimum parallelism.
   * @return the RDD.
   */
  public SparkJavaRDD<String> textFile(final String path, final int minPartitions) {
    return SparkJavaRDD.of(sparkContext, minPartitions, path);
  }

  /**
   * Initiate a SparkJavaRDD with the number of parallelism.
   *
   * @param list input data as list.
   * @param <T>  type of the initial element.
   * @return the newly initiated SparkJavaRDD.
   */
  public <T> SparkJavaRDD<T> parallelize(final List<T> list) {
    return this.parallelize(list, 1);
  }

  /**
   * Initiate a SparkJavaRDD with the number of parallelism.
   *
   * @param l      input data as list.
   * @param slices number of slices (parallelism).
   * @param <T>    type of the initial element.
   * @return the newly initiated SparkJavaRDD.
   */
  public <T> SparkJavaRDD<T> parallelize(final List<T> l, final int slices) {
    return SparkJavaRDD.of(this.sparkContext, l, slices);
  }
}