From bc474f4842b53f196d4092df82ef2946f7d259af Mon Sep 17 00:00:00 2001
From: Sun Rui <rui.sun@intel.com>
Date: Thu, 31 Mar 2016 23:03:27 +0800
Subject: [PATCH] [SPARK-14037][SPARKR][investigation-only] Buffer the output
 to evalute the performance.

---
 R/pkg/R/serialize.R | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/R/pkg/R/serialize.R b/R/pkg/R/serialize.R
index 3bbf60d9b668c..ceddc2e831540 100644
--- a/R/pkg/R/serialize.R
+++ b/R/pkg/R/serialize.R
@@ -122,10 +122,14 @@ writeRawSerialize <- function(outputCon, batch) {
 }
 
 writeRowSerialize <- function(outputCon, rows) {
-  invisible(lapply(rows, function(r) {
+  buf <- rawConnection(raw(0), "wb")
+  on.exit(close(buf))
+  lapply(rows, function(r) {
     bytes <- serializeRow(r)
-    writeRaw(outputCon, bytes)
-  }))
+    writeRaw(buf, bytes)
+  })
+  bytes <- rawConnectionValue(buf)
+  writeBin(bytes, outputCon, endian = "big") 
 }
 
 serializeRow <- function(row) {