Merge pull request #720 from ooyala/2013-07/persistent-rdds-api

Add a public method getCachedRdds to SparkContext

3 files changed, 70 insertions, 1 deletions

diff --git a/core/src/main/scala/spark/SparkContext.scala b/core/src/main/scala/spark/SparkContext.scala
index c01e315e35..24ba605646 100644
--- a/core/src/main/scala/spark/SparkContext.scala
+++ b/core/src/main/scala/spark/SparkContext.scala
@@ -546,6 +546,12 @@ class SparkContext(
     StorageUtils.rddInfoFromStorageStatus(getExecutorStorageStatus, this)
   }
 
+  /**
+   * Returns an immutable map of RDDs that have marked themselves as persistent via cache() call.
+   * Note that this does not necessarily mean the caching or computation was successful.
+   */
+  def getPersistentRDDs: Map[Int, RDD[_]] = persistentRdds.toMap
+
   def getStageInfo: Map[Stage,StageInfo] = {
     dagScheduler.stageToInfos
   }
@@ -580,7 +586,7 @@ class SparkContext(
         case null | "file" =>
           if (SparkHadoopUtil.isYarnMode()) {
             logWarning("local jar specified as parameter to addJar under Yarn mode")
-            return 
+            return
           }
           env.httpFileServer.addJar(new File(uri.getPath))
         case _ => path
diff --git a/core/src/main/scala/spark/util/TimeStampedHashMap.scala b/core/src/main/scala/spark/util/TimeStampedHashMap.scala
index cc7909194a..07772a0afb 100644
--- a/core/src/main/scala/spark/util/TimeStampedHashMap.scala
+++ b/core/src/main/scala/spark/util/TimeStampedHashMap.scala
@@ -20,6 +20,7 @@ package spark.util
 import java.util.concurrent.ConcurrentHashMap
 import scala.collection.JavaConversions
 import scala.collection.mutable.Map
+import scala.collection.immutable
 import spark.scheduler.MapStatus
 
 /**
@@ -99,6 +100,8 @@ class TimeStampedHashMap[A, B] extends Map[A, B]() with spark.Logging {
     }
   }
 
+  def toMap: immutable.Map[A, B] = iterator.toMap
+
   /**
    * Removes old key-value pairs that have timestamp earlier than `threshTime`
    */
diff --git a/core/src/test/scala/spark/SparkContextInfoSuite.scala b/core/src/test/scala/spark/SparkContextInfoSuite.scala
new file mode 100644
index 0000000000..6d50bf5e1b
--- /dev/null
+++ b/core/src/test/scala/spark/SparkContextInfoSuite.scala
@@ -0,0 +1,60 @@
+/*
+ * 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 org.scalatest.FunSuite
+import spark.SparkContext._
+
+class SparkContextInfoSuite extends FunSuite with LocalSparkContext {
+  test("getPersistentRDDs only returns RDDs that are marked as cached") {
+    sc = new SparkContext("local", "test")
+    assert(sc.getPersistentRDDs.isEmpty === true)
+
+    val rdd = sc.makeRDD(Array(1, 2, 3, 4), 2)
+    assert(sc.getPersistentRDDs.isEmpty === true)
+
+    rdd.cache()
+    assert(sc.getPersistentRDDs.size === 1)
+    assert(sc.getPersistentRDDs.values.head === rdd)
+  }
+
+  test("getPersistentRDDs returns an immutable map") {
+    sc = new SparkContext("local", "test")
+    val rdd1 = sc.makeRDD(Array(1, 2, 3, 4), 2).cache()
+
+    val myRdds = sc.getPersistentRDDs
+    assert(myRdds.size === 1)
+    assert(myRdds.values.head === rdd1)
+
+    val rdd2 = sc.makeRDD(Array(5, 6, 7, 8), 1).cache()
+
+    // getPersistentRDDs should have 2 RDDs, but myRdds should not change
+    assert(sc.getPersistentRDDs.size === 2)
+    assert(myRdds.size === 1)
+  }
+
+  test("getRDDStorageInfo only reports on RDDs that actually persist data") {
+    sc = new SparkContext("local", "test")
+    val rdd = sc.makeRDD(Array(1, 2, 3, 4), 2).cache()
+
+    assert(sc.getRDDStorageInfo.size === 0)
+
+    rdd.collect()
+    assert(sc.getRDDStorageInfo.size === 1)
+  }
+}
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