Removed Cache and SoftReferenceCache since they are no longer used.

core/src/main/scala/spark/Cache.scala

-/*
- * 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 spark
-
-import java.util.concurrent.atomic.AtomicInteger
-
-private[spark] sealed trait CachePutResponse
-private[spark] case class CachePutSuccess(size: Long) extends CachePutResponse
-private[spark] case class CachePutFailure() extends CachePutResponse
-
-/**
- * An interface for caches in Spark, to allow for multiple implementations. Caches are used to store
- * both partitions of cached RDDs and broadcast variables on Spark executors. Caches are also aware
- * of which entries are part of the same dataset (for example, partitions in the same RDD). The key
- * for each value in a cache is a (datasetID, partition) pair.
- *
- * A single Cache instance gets created on each machine and is shared by all caches (i.e. both the 
- * RDD split cache and the broadcast variable cache), to enable global replacement policies. 
- * However, because these several independent modules all perform caching, it is important to give
- * them separate key namespaces, so that an RDD and a broadcast variable (for example) do not use
- * the same key. For this purpose, Cache has the notion of KeySpaces. Each client module must first
- * ask for a KeySpace, and then call get() and put() on that space using its own keys.
- * 
- * This abstract class handles the creation of key spaces, so that subclasses need only deal with
- * keys that are unique across modules.
- */
-private[spark] abstract class Cache {
-  private val nextKeySpaceId = new AtomicInteger(0)
-  private def newKeySpaceId() = nextKeySpaceId.getAndIncrement()
-
-  def newKeySpace() = new KeySpace(this, newKeySpaceId())
-
-  /**
-   * Get the value for a given (datasetId, partition), or null if it is not
-   * found.
-   */
-  def get(datasetId: Any, partition: Int): Any
-
-  /**
-   * Attempt to put a value in the cache; returns CachePutFailure if this was
-   * not successful (e.g. because the cache replacement policy forbids it), and
-   * CachePutSuccess if successful. If size estimation is available, the cache
-   * implementation should set the size field in CachePutSuccess.
-   */
-  def put(datasetId: Any, partition: Int, value: Any): CachePutResponse
-
-  /**
-   * Report the capacity of the cache partition. By default this just reports
-   * zero. Specific implementations can choose to provide the capacity number.
-   */
-  def getCapacity: Long = 0L
-}
-
-/**
- * A key namespace in a Cache.
- */
-private[spark] class KeySpace(cache: Cache, val keySpaceId: Int) {
-  def get(datasetId: Any, partition: Int): Any =
-    cache.get((keySpaceId, datasetId), partition)
-
-  def put(datasetId: Any, partition: Int, value: Any): CachePutResponse =
-    cache.put((keySpaceId, datasetId), partition, value)
-
-  def getCapacity: Long = cache.getCapacity
-}

core/src/main/scala/spark/SoftReferenceCache.scala

-/*
- * 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 spark
-
-import com.google.common.collect.MapMaker
-
-/**
- * An implementation of Cache that uses soft references.
- */
-private[spark] class SoftReferenceCache extends Cache {
-  val map = new MapMaker().softValues().makeMap[Any, Any]()
-
-  override def get(datasetId: Any, partition: Int): Any =
-    map.get((datasetId, partition))
-
-  override def put(datasetId: Any, partition: Int, value: Any): CachePutResponse = {
-    map.put((datasetId, partition), value)
-    return CachePutSuccess(0)
-  }
-}