From 5898b95329ecc042b0798123d656013426f48d14 Mon Sep 17 00:00:00 2001
From: stack <stack@apache.org>
Date: Tue, 24 Nov 2015 17:06:46 -0800
Subject: [PATCH] HBASE-14860 Improve BoundedByteBufferPool; make lockless

---
 .../hadoop/hbase/io/BoundedByteBufferPool.java | 14 +++++++++-----
 .../hbase/io/TestBoundedByteBufferPool.java    | 18 ++++++++++++++++++
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/io/BoundedByteBufferPool.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/io/BoundedByteBufferPool.java
index dfbdc5bbfd9..deddb5192d1 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/io/BoundedByteBufferPool.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/io/BoundedByteBufferPool.java
@@ -76,19 +76,23 @@ public class BoundedByteBufferPool {
   // queued buffers in any transition.
   private final AtomicLong stateRef = new AtomicLong();
 
-  private static int toCountOfBuffers(long state) {
+  @VisibleForTesting
+  static int toCountOfBuffers(long state) {
     return (int)state;
   }
 
-  private static int toTotalCapacity(long state) {
+  @VisibleForTesting
+  static int toTotalCapacity(long state) {
     return (int)(state >>> 32);
   }
 
-  private static long toState(int countOfBuffers, int totalCapacity) {
-    return ((long)totalCapacity << 32) | totalCapacity;
+  @VisibleForTesting
+  static long toState(int countOfBuffers, int totalCapacity) {
+    return ((long)totalCapacity << 32) | countOfBuffers;
   }
 
-  private static long subtractOneBufferFromState(long state, int capacity) {
+  @VisibleForTesting
+  static long subtractOneBufferFromState(long state, int capacity) {
     return state - ((long)capacity << 32) - 1;
   }
 
diff --git a/hbase-common/src/test/java/org/apache/hadoop/hbase/io/TestBoundedByteBufferPool.java b/hbase-common/src/test/java/org/apache/hadoop/hbase/io/TestBoundedByteBufferPool.java
index bf4f0a5ec88..8775d7f7bab 100644
--- a/hbase-common/src/test/java/org/apache/hadoop/hbase/io/TestBoundedByteBufferPool.java
+++ b/hbase-common/src/test/java/org/apache/hadoop/hbase/io/TestBoundedByteBufferPool.java
@@ -17,6 +17,10 @@
  */
 package org.apache.hadoop.hbase.io;
 
+import static org.apache.hadoop.hbase.io.BoundedByteBufferPool.subtractOneBufferFromState;
+import static org.apache.hadoop.hbase.io.BoundedByteBufferPool.toCountOfBuffers;
+import static org.apache.hadoop.hbase.io.BoundedByteBufferPool.toState;
+import static org.apache.hadoop.hbase.io.BoundedByteBufferPool.toTotalCapacity;
 import static org.junit.Assert.assertEquals;
 
 import java.nio.ByteBuffer;
@@ -146,4 +150,18 @@ public class TestBoundedByteBufferPool {
     // runningAverage in pool
     assertEquals(initialByteBufferSize, this.reservoir.getRunningAverage());
   }
+
+  @Test
+  public void testStateConversionMethods() {
+    int countOfBuffers = 123;
+    int totalCapacity = 456;
+
+    long state = toState(countOfBuffers, totalCapacity);
+    assertEquals(countOfBuffers, toCountOfBuffers(state));
+    assertEquals(totalCapacity, toTotalCapacity(state));
+
+    long state2 = subtractOneBufferFromState(state, 7);
+    assertEquals(countOfBuffers - 1, toCountOfBuffers(state2));
+    assertEquals(totalCapacity - 7, toTotalCapacity(state2));
+  }
 }