From 92f4e30f458a2a9d0e2aec27da36aa84cdb9fa2f Mon Sep 17 00:00:00 2001
From: ramkrishna <ramkrishna.s.vasudevan@gmail.com>
Date: Wed, 24 Jun 2015 09:12:29 +0530
Subject: [PATCH] HBASE-13945 - Prefix_Tree seekBefore() does not work
 correctly (Ram)

---
 .../java/org/apache/hadoop/hbase/KeyValueUtil.java   | 12 ++++++++++--
 .../hbase/io/encoding/BufferedDataBlockEncoder.java  |  2 ++
 .../hadoop/hbase/io/encoding/DataBlockEncoder.java   |  5 +++--
 .../org/apache/hadoop/hbase/io/hfile/TestSeekTo.java |  5 +----
 4 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValueUtil.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValueUtil.java
index 77a39fff0e2..38b9470fb0e 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValueUtil.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValueUtil.java
@@ -105,11 +105,15 @@ public class KeyValueUtil {
     return kvCell;
   }
 
+  /**
+   * The position will be set to the beginning of the new ByteBuffer
+   * @param cell
+   * @return the Bytebuffer containing the key part of the cell
+   */
   public static ByteBuffer copyKeyToNewByteBuffer(final Cell cell) {
     byte[] bytes = new byte[keyLength(cell)];
     appendKeyTo(cell, bytes, 0);
     ByteBuffer buffer = ByteBuffer.wrap(bytes);
-    buffer.position(buffer.limit());//make it look as if each field were appended
     return buffer;
   }
 
@@ -151,11 +155,15 @@ public class KeyValueUtil {
     return pos;
   }
 
+  /**
+   * The position will be set to the beginning of the new ByteBuffer
+   * @param cell
+   * @return the ByteBuffer containing the cell
+   */
   public static ByteBuffer copyToNewByteBuffer(final Cell cell) {
     byte[] bytes = new byte[length(cell)];
     appendToByteArray(cell, bytes, 0);
     ByteBuffer buffer = ByteBuffer.wrap(bytes);
-    buffer.position(buffer.limit());//make it look as if each field were appended
     return buffer;
   }
 
diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/BufferedDataBlockEncoder.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/BufferedDataBlockEncoder.java
index 93fd3a42921..e872856387b 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/BufferedDataBlockEncoder.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/BufferedDataBlockEncoder.java
@@ -582,6 +582,7 @@ abstract class BufferedDataBlockEncoder implements DataBlockEncoder {
     public ByteBuffer getKeyDeepCopy() {
       ByteBuffer keyBuffer = ByteBuffer.allocate(current.keyLength);
       keyBuffer.put(current.keyBuffer, 0, current.keyLength);
+      keyBuffer.rewind();
       return keyBuffer;
     }
 
@@ -616,6 +617,7 @@ abstract class BufferedDataBlockEncoder implements DataBlockEncoder {
           kvBuffer.put(current.tagsBuffer, 0, current.tagsLength);
         }
       }
+      kvBuffer.rewind();
       return kvBuffer;
     }
 
diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/DataBlockEncoder.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/DataBlockEncoder.java
index 0e85380fd11..7218ad5b0c6 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/DataBlockEncoder.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/DataBlockEncoder.java
@@ -153,8 +153,9 @@ public interface DataBlockEncoder {
      * @return value at current position
      */
     ByteBuffer getValueShallowCopy();
-
-    /** @return key value at current position with position set to limit */
+    
+    //TODO : to be removed - currently used in testcases only
+    /** @return a key value buffer with the position set at the beginning of the buffer */
     ByteBuffer getKeyValueBuffer();
 
     /**
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestSeekTo.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestSeekTo.java
index a7712b271cf..1a190fdddd3 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestSeekTo.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestSeekTo.java
@@ -64,10 +64,7 @@ public class TestSeekTo {
   public static Collection<Object[]> parameters() {
     List<Object[]> paramList = new ArrayList<Object[]>();
     for (DataBlockEncoding encoding : DataBlockEncoding.values()) {
-      // Remove after HBASE-13939
-      if (encoding != DataBlockEncoding.PREFIX_TREE) {
-        paramList.add(new Object[] { encoding });
-      }
+      paramList.add(new Object[] { encoding });
     }
     return paramList;
   }