From febd79c1282c7e73e3f9aae1f7143474b1dde76c Mon Sep 17 00:00:00 2001
From: Zhihong Yu <tedyu@apache.org>
Date: Tue, 15 Oct 2013 17:03:07 +0000
Subject: [PATCH] HBASE-9753 Excessive readpoint checks in MemstoreScanner

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1532432 13f79535-47bb-0310-9956-ffa450edef68
---
 .../apache/hadoop/hbase/regionserver/MemStore.java    | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java
index ea1fc20b4a2..2e10e05badd 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MemStore.java
@@ -678,7 +678,7 @@ public class MemStore implements HeapSize {
     this.lock.readLock().lock();
     try {
       return Collections.<KeyValueScanner>singletonList(
-          new MemStoreScanner());
+          new MemStoreScanner(MultiVersionConsistencyControl.getThreadReadPoint()));
     } finally {
       this.lock.readLock().unlock();
     }
@@ -730,6 +730,8 @@ public class MemStore implements HeapSize {
     // The allocator and snapshot allocator at the time of creating this scanner
     volatile MemStoreLAB allocatorAtCreation;
     volatile MemStoreLAB snapshotAllocatorAtCreation;
+    
+    private long readPoint;
 
     /*
     Some notes...
@@ -752,9 +754,10 @@ public class MemStore implements HeapSize {
       the adds to kvset in the MemStoreScanner.
     */
 
-    MemStoreScanner() {
+    MemStoreScanner(long readPoint) {
       super();
 
+      this.readPoint = readPoint;
       kvsetAtCreation = kvset;
       snapshotAtCreation = snapshot;
       if (allocator != null) {
@@ -768,13 +771,11 @@ public class MemStore implements HeapSize {
     }
 
     private KeyValue getNext(Iterator<KeyValue> it) {
-      long readPoint = MultiVersionConsistencyControl.getThreadReadPoint();
-
       KeyValue v = null;
       try {
         while (it.hasNext()) {
           v = it.next();
-          if (v.getMvccVersion() <= readPoint) {
+          if (v.getMvccVersion() <= this.readPoint) {
             return v;
           }
         }