From 8b16d8b61abfaac13aa5df3ef9894ca857b6623a Mon Sep 17 00:00:00 2001
From: Markus KARG <markus@headcrashing.eu>
Date: Tue, 24 May 2016 23:59:55 +0200
Subject: [PATCH] offloading file copy work to operating system allows
 potential speedup

Since Plexus Utils enforces Java 7 it is safe to invoke NIO operations
introduced by JRE 7. Among those operations are methods for potentially
offloading work to the operating system. Theoretically this should be
(much) faster on modern JREs than pumping bytes up and down the JVM just
to get them from one file into another. Even without any actual
performance gain it makes sense to get rid of custom code in favor of
JRE code, as it improves class loading speed and reduces memory and
on-disk footprint, while cutting down number of potential bugs at the
same time.
---
 .../java/org/codehaus/plexus/util/FileUtils.java | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/main/java/org/codehaus/plexus/util/FileUtils.java b/src/main/java/org/codehaus/plexus/util/FileUtils.java
index 40c063a9..a038d0b0 100644
--- a/src/main/java/org/codehaus/plexus/util/FileUtils.java
+++ b/src/main/java/org/codehaus/plexus/util/FileUtils.java
@@ -1104,6 +1104,16 @@ public static void copyFile( final File source, final File destination )
 
     private static void doCopyFile( File source, File destination )
         throws IOException
+    {
+        // offload to operating system if supported
+        if ( Java7Detector.isJava7() )
+            doCopyFileUsingNewIO( source, destination );
+        else
+            doCopyFileUsingLegacyIO( source, destination );
+    }
+
+    private static void doCopyFileUsingLegacyIO( File source, File destination )
+        throws IOException
     {
         FileInputStream fis = null;
         FileOutputStream fos = null;
@@ -1141,6 +1151,12 @@ private static void doCopyFile( File source, File destination )
         }
     }
 
+    private static void doCopyFileUsingNewIO( File source, File destination )
+        throws IOException
+    {
+        NioFiles.copy( source, destination );
+    }
+
     /**
      * Copy file from source to destination only if source timestamp is later than the destination timestamp.
      * The directories up to <code>destination</code> will be created if they don't already exist.