From cb1f10b468e7771af75cb2288d375a87ab66d316 Mon Sep 17 00:00:00 2001
From: Reynold Xin <rxin@databricks.com>
Date: Tue, 6 Dec 2016 11:48:11 -0800
Subject: [PATCH] [SPARK-18714][SQL] Add a simple time function to SparkSession
## What changes were proposed in this pull request?
Many Spark developers often want to test the runtime of some function in interactive debugging and testing. This patch adds a simple time function to SparkSession:
```
scala> spark.time { spark.range(1000).count() }
Time taken: 77 ms
res1: Long = 1000
```
## How was this patch tested?
I tested this interactively in spark-shell.
Author: Reynold Xin <rxin@databricks.com>
Closes #16140 from rxin/SPARK-18714.
---
.../org/apache/spark/sql/SparkSession.scala | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/SparkSession.scala b/sql/core/src/main/scala/org/apache/spark/sql/SparkSession.scala
index 08d74ac018..f3dde480ea 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/SparkSession.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/SparkSession.scala
@@ -618,6 +618,22 @@ class SparkSession private(
@InterfaceStability.Evolving
def readStream: DataStreamReader = new DataStreamReader(self)
+ /**
+ * Executes some code block and prints to stdout the time taken to execute the block. This is
+ * available in Scala only and is used primarily for interactive testing and debugging.
+ *
+ * @since 2.1.0
+ */
+ @InterfaceStability.Stable
+ def time[T](f: => T): T = {
+ val start = System.nanoTime()
+ val ret = f
+ val end = System.nanoTime()
+ // scalastyle:off println
+ println(s"Time taken: ${(end - start) / 1000 / 1000} ms")
+ // scalastyle:on println
+ ret
+ }
// scalastyle:off
// Disable style checker so "implicits" object can start with lowercase i
--
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