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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.spark.api.java
import org.apache.spark._
import org.apache.spark.rdd.RDD
import org.apache.spark.api.java.function.{Function => JFunction}
import org.apache.spark.storage.StorageLevel
class JavaRDD[T](val rdd: RDD[T])(implicit val classManifest: ClassManifest[T]) extends
JavaRDDLike[T, JavaRDD[T]] {
override def wrapRDD(rdd: RDD[T]): JavaRDD[T] = JavaRDD.fromRDD(rdd)
// Common RDD functions
/** Persist this RDD with the default storage level (`MEMORY_ONLY`). */
def cache(): JavaRDD[T] = wrapRDD(rdd.cache())
/**
* Set this RDD's storage level to persist its values across operations after the first time
* it is computed. This can only be used to assign a new storage level if the RDD does not
* have a storage level set yet..
*/
def persist(newLevel: StorageLevel): JavaRDD[T] = wrapRDD(rdd.persist(newLevel))
/**
* Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
* This method blocks until all blocks are deleted.
*/
def unpersist(): JavaRDD[T] = wrapRDD(rdd.unpersist())
/**
* Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
*
* @param blocking Whether to block until all blocks are deleted.
*/
def unpersist(blocking: Boolean): JavaRDD[T] = wrapRDD(rdd.unpersist(blocking))
// Transformations (return a new RDD)
/**
* Return a new RDD containing the distinct elements in this RDD.
*/
def distinct(): JavaRDD[T] = wrapRDD(rdd.distinct())
/**
* Return a new RDD containing the distinct elements in this RDD.
*/
def distinct(numPartitions: Int): JavaRDD[T] = wrapRDD(rdd.distinct(numPartitions))
/**
* Return a new RDD containing only the elements that satisfy a predicate.
*/
def filter(f: JFunction[T, java.lang.Boolean]): JavaRDD[T] =
wrapRDD(rdd.filter((x => f(x).booleanValue())))
/**
* Return a new RDD that is reduced into `numPartitions` partitions.
*/
def coalesce(numPartitions: Int): JavaRDD[T] = rdd.coalesce(numPartitions)
/**
* Return a new RDD that is reduced into `numPartitions` partitions.
*/
def coalesce(numPartitions: Int, shuffle: Boolean): JavaRDD[T] =
rdd.coalesce(numPartitions, shuffle)
/**
* Return a new RDD that has exactly numPartitions partitions.
*
* Can increase or decrease the level of parallelism in this RDD. Internally, this uses
* a shuffle to redistribute data.
*
* If you are decreasing the number of partitions in this RDD, consider using `coalesce`,
* which can avoid performing a shuffle.
*/
def repartition(numPartitions: Int): JavaRDD[T] = rdd.repartition(numPartitions)
/**
* Return a sampled subset of this RDD.
*/
def sample(withReplacement: Boolean, fraction: Double, seed: Int): JavaRDD[T] =
wrapRDD(rdd.sample(withReplacement, fraction, seed))
/**
* Return the union of this RDD and another one. Any identical elements will appear multiple
* times (use `.distinct()` to eliminate them).
*/
def union(other: JavaRDD[T]): JavaRDD[T] = wrapRDD(rdd.union(other.rdd))
/**
* Return an RDD with the elements from `this` that are not in `other`.
*
* Uses `this` partitioner/partition size, because even if `other` is huge, the resulting
* RDD will be <= us.
*/
def subtract(other: JavaRDD[T]): JavaRDD[T] = wrapRDD(rdd.subtract(other))
/**
* Return an RDD with the elements from `this` that are not in `other`.
*/
def subtract(other: JavaRDD[T], numPartitions: Int): JavaRDD[T] =
wrapRDD(rdd.subtract(other, numPartitions))
/**
* Return an RDD with the elements from `this` that are not in `other`.
*/
def subtract(other: JavaRDD[T], p: Partitioner): JavaRDD[T] =
wrapRDD(rdd.subtract(other, p))
}
object JavaRDD {
implicit def fromRDD[T: ClassManifest](rdd: RDD[T]): JavaRDD[T] = new JavaRDD[T](rdd)
implicit def toRDD[T](rdd: JavaRDD[T]): RDD[T] = rdd.rdd
}
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