From 6760505a7e7874654925fbfc3bac8c7f634b7f8e Mon Sep 17 00:00:00 2001
From: Himanshu <g.himanshu@gmail.com>
Date: Thu, 4 Jul 2019 08:41:17 -0700
Subject: [PATCH] fix FileUtils performance regression due to
 FilterOutputStream (#8024)

---
 .../java/org/apache/druid/java/util/common/FileUtils.java | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/core/src/main/java/org/apache/druid/java/util/common/FileUtils.java b/core/src/main/java/org/apache/druid/java/util/common/FileUtils.java
index 17f0ed01c33..6025ad6cf73 100644
--- a/core/src/main/java/org/apache/druid/java/util/common/FileUtils.java
+++ b/core/src/main/java/org/apache/druid/java/util/common/FileUtils.java
@@ -242,6 +242,14 @@ public class FileUtils
   {
     return new FilterOutputStream(out)
     {
+      // Default implementation of this method in FilterOutputStream converts single write operation to
+      // multiple write operations of 1 byte each, which is terribly inefficient.
+      @Override
+      public void write(byte b[], int off, int len) throws IOException
+      {
+        out.write(b, off, len);
+      }
+
       @Override
       public void close()
       {