gistfile1.txt

From 891c3126dc9e62c09cfcd7204f68f3c9e848102e Mon Sep 17 00:00:00 2001
From: Marcus Eriksson <marcuse@spotify.com>
Date: Tue, 26 Mar 2013 21:14:33 +0100
Subject: [PATCH] use Java7 apis for moving files and creating symlinks

---
 .../cassandra/db/compaction/LeveledManifest.java   |    2 +-
 .../org/apache/cassandra/io/util/FileUtils.java    |   58 ++++++++++++++++-
 src/java/org/apache/cassandra/utils/CLibrary.java  |   67 --------------------
 test/unit/org/apache/cassandra/db/ScrubTest.java   |    2 +-
 .../cassandra/io/sstable/SSTableReaderTest.java    |    2 +-
 5 files changed, 57 insertions(+), 74 deletions(-)

diff --git a/src/java/org/apache/cassandra/db/compaction/LeveledManifest.java b/src/java/org/apache/cassandra/db/compaction/LeveledManifest.java
index 71356f0..83d3a70 100644
--- a/src/java/org/apache/cassandra/db/compaction/LeveledManifest.java
+++ b/src/java/org/apache/cassandra/db/compaction/LeveledManifest.java
@@ -572,6 +572,6 @@ public class LeveledManifest
         SSTableMetadata.serializer.legacySerialize(metadata, descriptor, dos);
         dos.flush();
         dos.close();
-        FileUtils.renameWithConfirm(filename + "-tmp", filename);
+        FileUtils.replaceWithOutConfirm(filename + "-tmp", filename);
     }
 }
diff --git a/src/java/org/apache/cassandra/io/util/FileUtils.java b/src/java/org/apache/cassandra/io/util/FileUtils.java
index 69038fa..2b2ae03 100644
--- a/src/java/org/apache/cassandra/io/util/FileUtils.java
+++ b/src/java/org/apache/cassandra/io/util/FileUtils.java
@@ -21,6 +21,10 @@ import java.io.*;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.nio.MappedByteBuffer;
+import java.nio.file.AtomicMoveNotSupportedException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
 import java.text.DecimalFormat;
 import java.util.Arrays;
 
@@ -34,7 +38,6 @@ import org.apache.cassandra.io.FSError;
 import org.apache.cassandra.io.FSReadError;
 import org.apache.cassandra.io.FSWriteError;
 import org.apache.cassandra.service.StorageService;
-import org.apache.cassandra.utils.CLibrary;
 
 public class FileUtils
 {
@@ -73,7 +76,7 @@ public class FileUtils
 
         try
         {
-            CLibrary.createHardLink(from, to);
+            Files.createLink(to.toPath(), from.toPath());
         }
         catch (IOException e)
         {
@@ -114,7 +117,46 @@ public class FileUtils
 
     public static void renameWithOutConfirm(String from, String to)
     {
-        new File(from).renameTo(new File(to));
+        Path fromPath = new File(from).toPath();
+        Path toPath = new File(to).toPath();
+        try
+        {
+            try
+            {
+                Files.move(fromPath, toPath, StandardCopyOption.ATOMIC_MOVE);
+            }
+            catch (AtomicMoveNotSupportedException e)
+            {
+                Files.move(fromPath, toPath);
+            }
+        }
+        catch (IOException e)
+        {
+            if (logger.isTraceEnabled())
+                logger.trace("Could not move file "+from+" to "+to, e);
+        }
+    }
+
+    public static void replaceWithOutConfirm(String from, String to)
+    {
+        Path fromPath = new File(from).toPath();
+        Path toPath = new File(to).toPath();
+        try
+        {
+            try
+            {
+                Files.move(fromPath, toPath, StandardCopyOption.ATOMIC_MOVE, StandardCopyOption.REPLACE_EXISTING);
+            }
+            catch (AtomicMoveNotSupportedException e)
+            {
+                logger.debug("Atomic replace not supported", e);
+                Files.move(fromPath, toPath, StandardCopyOption.REPLACE_EXISTING);
+            }
+        }
+        catch (IOException e)
+        {
+            logger.error("Could not replace file "+to+" with "+from, e);
+        }
     }
 
     public static void renameWithConfirm(String from, String to)
@@ -125,12 +167,20 @@ public class FileUtils
     public static void renameWithConfirm(File from, File to)
     {
         assert from.exists();
+        Path fromPath = from.toPath();
+        Path toPath = to.toPath();
         if (logger.isDebugEnabled())
             logger.debug((String.format("Renaming %s to %s", from.getPath(), to.getPath())));
         // this is not FSWE because usually when we see it it's because we didn't close the file before renaming it,
         // and Windows is picky about that.
-        if (!from.renameTo(to))
+        try
+        {
+            Files.move(fromPath, toPath);
+        }
+        catch (IOException e)
+        {
             throw new RuntimeException(String.format("Failed to rename %s to %s", from.getPath(), to.getPath()));
+        }
     }
 
     public static void truncate(String path, long size)
diff --git a/src/java/org/apache/cassandra/utils/CLibrary.java b/src/java/org/apache/cassandra/utils/CLibrary.java
index 2f6e088..b57c8bf 100644
--- a/src/java/org/apache/cassandra/utils/CLibrary.java
+++ b/src/java/org/apache/cassandra/utils/CLibrary.java
@@ -74,8 +74,6 @@ public final class CLibrary
     private static native int mlockall(int flags) throws LastErrorException;
     private static native int munlockall() throws LastErrorException;
 
-    private static native int link(String from, String to) throws LastErrorException;
-
     // fcntl - manipulate file descriptor, `man 2 fcntl`
     public static native int fcntl(int fd, int command, long flags) throws LastErrorException;
 
@@ -131,71 +129,6 @@ public final class CLibrary
         }
     }
 
-    /**
-     * Create a hard link for a given file.
-     *
-     * @param sourceFile      The name of the source file.
-     * @param destinationFile The name of the destination file.
-     *
-     * @throws java.io.IOException if an error has occurred while creating the link.
-     */
-    public static void createHardLink(File sourceFile, File destinationFile) throws IOException
-    {
-        try
-        {
-            link(sourceFile.getAbsolutePath(), destinationFile.getAbsolutePath());
-        }
-        catch (UnsatisfiedLinkError e)
-        {
-            createHardLinkWithExec(sourceFile, destinationFile);
-        }
-        catch (RuntimeException e)
-        {
-            logger.error("Unable to create hard link", e);
-            if (!(e instanceof LastErrorException))
-                throw e;
-            // there are 17 different error codes listed on the man page.  punt until/unless we find which
-            // ones actually turn up in practice.
-            throw new IOException(String.format("Unable to create hard link from %s to %s (errno %d)",
-                                                sourceFile, destinationFile, errno(e)));
-        }
-    }
-
-    public static void createHardLinkWithExec(File sourceFile, File destinationFile) throws IOException
-    {
-        String osname = System.getProperty("os.name");
-        ProcessBuilder pb;
-        if (osname.startsWith("Windows"))
-        {
-            float osversion = Float.parseFloat(System.getProperty("os.version"));
-            if (osversion >= 6.0f)
-            {
-                pb = new ProcessBuilder("cmd", "/c", "mklink", "/H", destinationFile.getAbsolutePath(), sourceFile.getAbsolutePath());
-            }
-            else
-            {
-                pb = new ProcessBuilder("fsutil", "hardlink", "create", destinationFile.getAbsolutePath(), sourceFile.getAbsolutePath());
-            }
-        }
-        else
-        {
-            pb = new ProcessBuilder("ln", sourceFile.getAbsolutePath(), destinationFile.getAbsolutePath());
-            pb.redirectErrorStream(true);
-        }
-        try
-        {
-            FBUtilities.exec(pb);
-        }
-        catch (IOException ex)
-        {
-            String st = osname.startsWith("Windows")
-                      ? "Unable to create hard link.  This probably means your data directory path is too long.  Exception follows:"
-                      : "Unable to create hard link with exec.  Suggest installing JNA to avoid the need to exec entirely.  Exception follows: ";
-            logger.error(st, ex);
-            throw ex;
-        }
-    }
-
     public static void trySkipCache(int fd, long offset, int len)
     {
         if (fd < 0)
diff --git a/test/unit/org/apache/cassandra/db/ScrubTest.java b/test/unit/org/apache/cassandra/db/ScrubTest.java
index e800bbb..16a263b 100644
--- a/test/unit/org/apache/cassandra/db/ScrubTest.java
+++ b/test/unit/org/apache/cassandra/db/ScrubTest.java
@@ -72,7 +72,7 @@ public class ScrubTest extends SchemaLoader
             if (!srcFile.getName().contains(cf))
                 continue;
             File destFile = new File(destDir, srcFile.getName());
-            CLibrary.createHardLink(srcFile, destFile);
+            FileUtils.createHardLink(srcFile, destFile);
 
             assert destFile.exists() : destFile.getAbsoluteFile();
 
diff --git a/test/unit/org/apache/cassandra/io/sstable/SSTableReaderTest.java b/test/unit/org/apache/cassandra/io/sstable/SSTableReaderTest.java
index a8b6d64..7f4bad2 100644
--- a/test/unit/org/apache/cassandra/io/sstable/SSTableReaderTest.java
+++ b/test/unit/org/apache/cassandra/io/sstable/SSTableReaderTest.java
@@ -238,7 +238,7 @@ public class SSTableReaderTest extends SchemaLoader
             if (!srcFile.getName().startsWith("Indexed1"))
                 continue;
             File destFile = new File(destDir, srcFile.getName());
-            CLibrary.createHardLink(srcFile, destFile);
+            FileUtils.createHardLink(srcFile, destFile);
 
             assert destFile.exists() : destFile.getAbsoluteFile();
         }
-- 
1.7.2.5