From 1e3d8c822608482b9dc34040fd19333979d1a607 Mon Sep 17 00:00:00 2001
From: Ramkrishna <ramkrishna.s.vasudevan@intel.com>
Date: Mon, 17 Oct 2016 12:26:36 +0530
Subject: [PATCH] HBASE-16792 Reuse KeyValue.KeyOnlyKeyValue in
 BufferedDataBlockEncoder.SeekerState (Binlijin)

---
 .../java/org/apache/hadoop/hbase/KeyValue.java    | 15 +++++++++++++++
 .../io/encoding/BufferedDataBlockEncoder.java     |  4 ++--
 .../apache/hadoop/hbase/regionserver/HRegion.java |  4 ++--
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValue.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValue.java
index 8f8554cf2aa..f9a621a538d 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValue.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValue.java
@@ -43,6 +43,7 @@ import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.ClassSize;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.io.RawComparator;
+
 import com.google.common.annotations.VisibleForTesting;
 
 /**
@@ -2641,6 +2642,20 @@ public class KeyValue implements ExtendedCell {
       this.rowLen = Bytes.toShort(this.bytes, this.offset);
     }
 
+    public void set(KeyOnlyKeyValue keyOnlyKeyValue) {
+      this.bytes = keyOnlyKeyValue.bytes;
+      this.length = keyOnlyKeyValue.length;
+      this.offset = keyOnlyKeyValue.offset;
+      this.rowLen = keyOnlyKeyValue.rowLen;
+    }
+
+    public void clear() {
+      rowLen = -1;
+      bytes = null;
+      offset = 0;
+      length = 0;
+    }
+
     @Override
     public int getKeyOffset() {
       return this.offset;
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 4d3a26c9d15..edecd9ad0bc 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
@@ -139,7 +139,7 @@ abstract class BufferedDataBlockEncoder extends AbstractDataBlockEncoder {
     protected void invalidate() {
       valueOffset = -1;
       tagsCompressedLength = 0;
-      currentKey = new KeyValue.KeyOnlyKeyValue();
+      currentKey.clear();
       uncompressTags = true;
       currentBuffer = null;
     }
@@ -188,7 +188,7 @@ abstract class BufferedDataBlockEncoder extends AbstractDataBlockEncoder {
             keyBuffer, nextState.lastCommonPrefix, nextState.keyLength
                 - nextState.lastCommonPrefix);
       }
-      currentKey = nextState.currentKey;
+      currentKey.set(nextState.currentKey);
 
       valueOffset = nextState.valueOffset;
       keyLength = nextState.keyLength;
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java
index f61eb4be938..ca92f066fe7 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java
@@ -356,9 +356,9 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
     // We need to ensure that while we are calculating the smallestReadPoint
     // no new RegionScanners can grab a readPoint that we are unaware of.
     // We achieve this by synchronizing on the scannerReadPoints object.
-    synchronized(scannerReadPoints) {
+    synchronized (scannerReadPoints) {
       minimumReadPoint = mvcc.getReadPoint();
-      for (Long readPoint: this.scannerReadPoints.values()) {
+      for (Long readPoint : this.scannerReadPoints.values()) {
         if (readPoint < minimumReadPoint) {
           minimumReadPoint = readPoint;
         }