Merge pull request #4285 from vespa-engine/hmusum/use-FileChannel-for-file-copying

Copy files correctly

2 files changed, 28 insertions, 20 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/io/IOUtils.java b/vespajlib/src/main/java/com/yahoo/io/IOUtils.java
index 2572842b213..febe02cb33e 100644
--- a/vespajlib/src/main/java/com/yahoo/io/IOUtils.java
+++ b/vespajlib/src/main/java/com/yahoo/io/IOUtils.java
@@ -3,6 +3,7 @@ package com.yahoo.io;
 
 
 import java.io.*;
+import java.nio.channels.FileChannel;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.util.List;
@@ -155,33 +156,22 @@ public abstract class IOUtils {
     /**
      * Copies a file to another file.
      * If the out file exists it will be overwritten.
-     * NOTE: Not an optimal implementation currently.
      *
      * @throws IOException if copying fails
      */
     public static void copy(String inFile, String outFile) throws IOException {
-        BufferedReader reader=null;
-        BufferedWriter writer=null;
-
-        try {
-            reader = createReader(inFile);
-            writer = createWriter(outFile, false);
-            int c;
-            while (-1 != (c = reader.read()) )
-                writer.write(c);
-        } finally {
-            closeReader(reader);
-            closeWriter(writer);
-        }
+        copy(new File(inFile), new File(outFile));
     }
 
     /**
      * Copies a file to another file.
      * If the out file exists it will be overwritten.
-     * NOTE: Not an optimal implementation currently.
      */
     public static void copy(File inFile, File outFile) throws IOException {
-        copy(inFile.toString(),outFile.toString());
+        try (FileChannel sourceChannel = new FileInputStream(inFile).getChannel();
+             FileChannel destChannel = new FileOutputStream(outFile).getChannel()) {
+            destChannel.transferFrom(sourceChannel, 0, sourceChannel.size());
+        }
     }
 
     /**
@@ -275,8 +265,8 @@ public abstract class IOUtils {
     }
 
     /**
-     * Returns the number of line in a file.
-     * If the files does not exists, 0 is returned
+     * Returns the number of lines in a file.
+     * If the file does not exists, 0 is returned
      */
     public static int countLines(String file) {
         BufferedReader reader = null;
@@ -292,7 +282,6 @@ public abstract class IOUtils {
         } finally {
             closeReader(reader);
         }
-
     }
 
     /**
diff --git a/vespajlib/src/test/java/com/yahoo/io/IOUtilsTestCase.java b/vespajlib/src/test/java/com/yahoo/io/IOUtilsTestCase.java
index 3a8b0dde1c1..8955bd9ea05 100644
--- a/vespajlib/src/test/java/com/yahoo/io/IOUtilsTestCase.java
+++ b/vespajlib/src/test/java/com/yahoo/io/IOUtilsTestCase.java
@@ -1,15 +1,23 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.io;
 
+import org.junit.Test;
+
 import java.io.*;
 import java.util.Arrays;
 import java.util.List;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
 /**
  * @author bratseth
  */
-public class IOUtilsTestCase extends junit.framework.TestCase {
+public class IOUtilsTestCase {
 
+    @Test
     public void testCloseNUllDoesNotFail() {
         IOUtils.closeWriter(null);
         IOUtils.closeReader(null);
@@ -17,12 +25,14 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         IOUtils.closeOutputStream(null);
     }
 
+    @Test
     public void testFileWriter() throws IOException {
         IOUtils.writeFile("temp1.txt", "hello",false);
         assertEquals("hello", IOUtils.readFile(new File("temp1.txt")));
         new File("temp1.txt").delete();
     }
 
+    @Test
     public void testFileWriterWithoutEncoding() throws IOException {
         BufferedWriter writer=null;
         try {
@@ -36,6 +46,7 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         new File("temp2.txt").delete();
     }
 
+    @Test
     public void testFileWriterWithoutEncodingFromFileName() throws IOException {
         BufferedWriter writer=null;
         try {
@@ -49,12 +60,14 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         new File("temp3.txt").delete();
     }
 
+    @Test
     public void testFileCounting() throws IOException {
         IOUtils.writeFile("temp4.txt","hello\nworld",false);
         assertEquals(2,IOUtils.countLines("temp4.txt"));
         new File("temp4.txt").delete();
     }
 
+    @Test
     public void testFileCopy() throws IOException {
         IOUtils.writeFile("temp5.txt","hello",false);
         IOUtils.copy(new File("temp5.txt"), new File("temp5copy.txt"));
@@ -63,6 +76,7 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         new File("temp5copy.txt").delete();
     }
 
+    @Test
     public void testFileCopyWithLineCap() throws IOException {
         IOUtils.writeFile("temp6.txt","hello\nyou\nworld",false);
         IOUtils.copy("temp6.txt","temp6copy.txt",2);
@@ -71,6 +85,7 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         new File("temp6copy.txt").delete();
     }
 
+    @Test
     public void testGetLines() throws IOException {
         IOUtils.writeFile("temp7.txt","hello\nworld",false);
         List<String> lines=IOUtils.getLines("temp7.txt");
@@ -80,6 +95,7 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         new File("temp7.txt").delete();
     }
 
+    @Test
     public void testFileWriterAppend() throws IOException {
         boolean append=true;
         IOUtils.writeFile("temp8.txt", "hello",!append);
@@ -95,6 +111,7 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         new File("temp8.txt").delete();
     }
 
+    @Test
     public void testCloseAllReaders() throws IOException {
         StringReader reader1=new StringReader("hello");
         StringReader reader2=new StringReader("world");
@@ -115,6 +132,7 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         }
     }
 
+    @Test
     public void testDirCopying() throws IOException {
         IOUtils.writeFile("temp1/temp1.txt","hello",false);
         IOUtils.writeFile("temp1/temp2.txt","world",false);
@@ -127,6 +145,7 @@ public class IOUtilsTestCase extends junit.framework.TestCase {
         assertTrue(!new File("temp2").exists());
     }
 
+    @Test
     public void testDirCopyingWithFilter() throws IOException {
         IOUtils.writeFile("temp1/temp1.txt","hello",false);
         IOUtils.writeFile("temp1/temp2.txt","world",false);