From 1b354e2bd5ad93512a0cbb4d89a24a579a3d5595 Mon Sep 17 00:00:00 2001
From: Mahadev Konar <mahadev@apache.org>
Date: Fri, 16 Jul 2010 18:37:50 +0000
Subject: [PATCH] HADOOP-6834. TFile.append compares initial key against null
 lastKey (hong tang via mahadev)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@964897 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                   |   3 +
 .../apache/hadoop/io/file/tfile/TFile.java    |   2 +-
 .../io/file/tfile/TestTFileComparator2.java   | 106 ++++++++++++++++++
 3 files changed, 110 insertions(+), 1 deletion(-)
 create mode 100644 src/test/core/org/apache/hadoop/io/file/tfile/TestTFileComparator2.java

diff --git a/CHANGES.txt b/CHANGES.txt
index 1720df98ea..75b82178b3 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -127,6 +127,9 @@ Trunk (unreleased changes)
     HADOOP-6647. balancer fails with "is not authorized for protocol 
     interface NamenodeProtocol" in secure environment (boryas)
 
+    HADOOP-6834. TFile.append compares initial key against null lastKey
+    (hong tang via mahadev)
+
 Release 0.21.0 - Unreleased
 
   INCOMPATIBLE CHANGES
diff --git a/src/java/org/apache/hadoop/io/file/tfile/TFile.java b/src/java/org/apache/hadoop/io/file/tfile/TFile.java
index 5ad4db89eb..0b9ed9d2b3 100644
--- a/src/java/org/apache/hadoop/io/file/tfile/TFile.java
+++ b/src/java/org/apache/hadoop/io/file/tfile/TFile.java
@@ -452,7 +452,7 @@ public class TFile {
             tfileIndex.setFirstKey(key, 0, len);
           }
 
-          if (tfileMeta.isSorted()) {
+          if (tfileMeta.isSorted() && tfileMeta.getRecordCount()>0) {
             byte[] lastKey = lastKeyBufferOS.getBuffer();
             int lastLen = lastKeyBufferOS.size();
             if (tfileMeta.getComparator().compare(key, 0, len, lastKey, 0,
diff --git a/src/test/core/org/apache/hadoop/io/file/tfile/TestTFileComparator2.java b/src/test/core/org/apache/hadoop/io/file/tfile/TestTFileComparator2.java
new file mode 100644
index 0000000000..9e13c71403
--- /dev/null
+++ b/src/test/core/org/apache/hadoop/io/file/tfile/TestTFileComparator2.java
@@ -0,0 +1,106 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership. The ASF
+ * licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package org.apache.hadoop.io.file.tfile;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.io.BytesWritable;
+import org.apache.hadoop.io.LongWritable;
+import org.apache.hadoop.io.file.tfile.TFile.Writer;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class TestTFileComparator2 {
+  private static final String ROOT = System.getProperty("test.build.data",
+      "/tmp/tfile-test");
+  private static final String name = "test-tfile-comparator2";
+  private final static int BLOCK_SIZE = 512;
+  private static final String VALUE = "value";
+  private static final String jClassLongWritableComparator = "jclass:"
+      + LongWritable.Comparator.class.getName();
+  private static final long NENTRY = 10000;
+
+  private static long cube(long n) {
+    return n*n*n;
+  }
+  
+  private static String buildValue(long i) {
+    return String.format("%s-%d", VALUE, i);
+  }
+  
+  @Test
+  public void testSortedLongWritable() throws IOException {
+    Configuration conf = new Configuration();
+    Path path = new Path(ROOT, name);
+    FileSystem fs = path.getFileSystem(conf);
+    FSDataOutputStream out = fs.create(path);
+    try {
+    TFile.Writer writer = new Writer(out, BLOCK_SIZE, "gz",
+        jClassLongWritableComparator, conf);
+      try {
+        LongWritable key = new LongWritable(0);
+        for (long i=0; i<NENTRY; ++i) {
+          key.set(cube(i-NENTRY/2));
+          DataOutputStream dos = writer.prepareAppendKey(-1);
+          try {
+            key.write(dos);
+          } finally {
+            dos.close();
+          }
+          dos = writer.prepareAppendValue(-1);
+          try {
+            dos.write(buildValue(i).getBytes());
+          } finally {
+            dos.close();
+          }
+        }
+      } finally {
+        writer.close();
+      } 
+    } finally {
+      out.close();
+    }
+    
+    FSDataInputStream in = fs.open(path);
+    try {
+      TFile.Reader reader = new TFile.Reader(in, fs.getFileStatus(path)
+          .getLen(), conf);
+      try {
+        TFile.Reader.Scanner scanner = reader.createScanner();
+        long i=0;
+        BytesWritable value = new BytesWritable();
+        for (; !scanner.atEnd(); scanner.advance()) {
+          scanner.entry().getValue(value);
+          assertEquals(buildValue(i), new String(value.getBytes(), 0, value
+              .getLength()));
+          ++i;
+        }
+      } finally {
+        reader.close();
+      }
+    } finally {
+      in.close();
+    }
+  }
+}