From 64a83756350d9d0f07b72c84f2719e82cf78ee49 Mon Sep 17 00:00:00 2001
From: yliu <yliu@apache.org>
Date: Thu, 19 Feb 2015 08:26:42 +0800
Subject: [PATCH] HADOOP-11595. Add default implementation for
 AbstractFileSystem#truncate. (yliu)

---
 hadoop-common-project/hadoop-common/CHANGES.txt            | 3 +++
 .../main/java/org/apache/hadoop/fs/AbstractFileSystem.java | 7 +++++--
 .../test/java/org/apache/hadoop/fs/TestAfsCheckPath.java   | 6 ------
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index e6d560a3579..c01e3d64e77 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -970,6 +970,9 @@ Release 2.7.0 - UNRELEASED
     HADOOP-11545. ArrayIndexOutOfBoundsException is thrown with "hadoop
     credential list -provider". (Brahma Reddy Battula via aajisaka)
 
+    HADOOP-11595. Add default implementation for AbstractFileSystem#truncate.
+    (yliu)
+
 Release 2.6.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java
index 975cc3cc87a..959d9d57e4d 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java
@@ -642,9 +642,12 @@ public abstract FSDataInputStream open(final Path f, int bufferSize)
    * {@link FileContext#truncate(Path, long)} except that Path f must be for
    * this file system.
    */
-  public abstract boolean truncate(Path f, long newLength)
+  public boolean truncate(Path f, long newLength)
       throws AccessControlException, FileNotFoundException,
-      UnresolvedLinkException, IOException;
+      UnresolvedLinkException, IOException {
+    throw new UnsupportedOperationException(getClass().getSimpleName()
+        + " doesn't support truncate");
+  }
 
   /**
    * The specification of this method matches that of
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestAfsCheckPath.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestAfsCheckPath.java
index 6b9378d90aa..3bd14f1495a 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestAfsCheckPath.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestAfsCheckPath.java
@@ -140,12 +140,6 @@ public FSDataInputStream open(Path f, int bufferSize) throws IOException {
       return null;
     }
 
-    @Override
-    public boolean truncate(Path f, long newLength) throws IOException {
-      // deliberately empty
-      return false;
-    }
-
     @Override
     public void renameInternal(Path src, Path dst) throws IOException {
       // deliberately empty