BackPort HBASE-11554 Remove Reusable poolmap Rpc client type. (#2208)

Co-authored-by: niuyulin <niuyulin@xiaomi.com>
Signed-off-by: stack <stack@apache.org>

hbase-client/src/main/java/org/apache/hadoop/hbase/util/PoolMap.java

@@ -228,7 +228,7 @@ public class PoolMap<K, V> implements Map<K, V> {
   }
 
   public enum PoolType {
-    Reusable, ThreadLocal, RoundRobin;
+    ThreadLocal, RoundRobin;
 
     public static PoolType valueOf(String poolTypeName,
         PoolType defaultPoolType, PoolType... allowedPoolTypes) {
@@ -270,8 +270,6 @@ public class PoolMap<K, V> implements Map<K, V> {
 
   protected Pool<V> createPool() {
     switch (poolType) {
-    case Reusable:
-      return new ReusablePool<>(poolMaxSize);
     case RoundRobin:
       return new RoundRobinPool<>(poolMaxSize);
     case ThreadLocal:
@@ -280,51 +278,6 @@ public class PoolMap<K, V> implements Map<K, V> {
     return null;
   }
 
-  /**
-   * The <code>ReusablePool</code> represents a {@link PoolMap.Pool} that builds
-   * on the {@link java.util.LinkedList} class. It essentially allows resources to be
-   * checked out, at which point it is removed from this pool. When the resource
-   * is no longer required, it should be returned to the pool in order to be
-   * reused.
-   *
-   * <p>
-   * If {@link #maxSize} is set to {@link Integer#MAX_VALUE}, then the size of
-   * the pool is unbounded. Otherwise, it caps the number of consumers that can
-   * check out a resource from this pool to the (non-zero positive) value
-   * specified in {@link #maxSize}.
-   * </p>
-   *
-   * @param <R>
-   *          the type of the resource
-   */
-  @SuppressWarnings("serial")
-  public static class ReusablePool<R> extends ConcurrentLinkedQueue<R> implements Pool<R> {
-    private int maxSize;
-
-    public ReusablePool(int maxSize) {
-      this.maxSize = maxSize;
-
-    }
-
-    @Override
-    public R get() {
-      return poll();
-    }
-
-    @Override
-    public R put(R resource) {
-      if (super.size() < maxSize) {
-        add(resource);
-      }
-      return null;
-    }
-
-    @Override
-    public Collection<R> values() {
-      return this;
-    }
-  }
-
   /**
    * The <code>RoundRobinPool</code> represents a {@link PoolMap.Pool}, which
    * stores its resources in an {@link ArrayList}. It load-balances access to

hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestReusablePoolMap.java

@@ -1,90 +0,0 @@
-/**
- * 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.hbase.util;
-
-import static org.junit.Assert.assertEquals;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ThreadLocalRandom;
-import org.apache.hadoop.hbase.HBaseClassTestRule;
-import org.apache.hadoop.hbase.testclassification.MiscTests;
-import org.apache.hadoop.hbase.testclassification.SmallTests;
-import org.apache.hadoop.hbase.util.PoolMap.PoolType;
-import org.junit.ClassRule;
-import org.junit.Test;
-import org.junit.experimental.categories.Category;
-
-@Category({ MiscTests.class, SmallTests.class })
-public class TestReusablePoolMap extends PoolMapTestBase {
-
-  @ClassRule
-  public static final HBaseClassTestRule CLASS_RULE =
-      HBaseClassTestRule.forClass(TestReusablePoolMap.class);
-
-  @Override
-  protected PoolType getPoolType() {
-    return PoolType.Reusable;
-  }
-
-  @Test
-  public void testSingleThreadedClient() throws InterruptedException, ExecutionException {
-    Random rand = ThreadLocalRandom.current();
-    String randomKey = String.valueOf(rand.nextInt());
-    String randomValue = String.valueOf(rand.nextInt());
-    // As long as we poll values we put, the pool size should remain zero
-    runThread(randomKey, randomValue, randomValue);
-    assertEquals(0, poolMap.size(randomKey));
-  }
-
-  @Test
-  public void testMultiThreadedClients() throws InterruptedException, ExecutionException {
-    Random rand = ThreadLocalRandom.current();
-    // As long as we poll values we put, the pool size should remain zero
-    for (int i = 0; i < POOL_SIZE; i++) {
-      String randomKey = String.valueOf(rand.nextInt());
-      String randomValue = String.valueOf(rand.nextInt());
-      runThread(randomKey, randomValue, randomValue);
-      assertEquals(0, poolMap.size(randomKey));
-    }
-    poolMap.clear();
-    String randomKey = String.valueOf(rand.nextInt());
-    for (int i = 0; i < POOL_SIZE - 1; i++) {
-      String randomValue = String.valueOf(rand.nextInt());
-      runThread(randomKey, randomValue, randomValue);
-      assertEquals(0, poolMap.size(randomKey));
-    }
-    assertEquals(0, poolMap.size(randomKey));
-  }
-
-  @Test
-  public void testPoolCap() throws InterruptedException, ExecutionException {
-    Random rand = ThreadLocalRandom.current();
-    // As long as we poll values we put, the pool size should remain zero
-    String randomKey = String.valueOf(rand.nextInt());
-    List<String> randomValues = new ArrayList<>();
-    for (int i = 0; i < POOL_SIZE * 2; i++) {
-      String randomValue = String.valueOf(rand.nextInt());
-      randomValues.add(randomValue);
-      runThread(randomKey, randomValue, randomValue);
-    }
-    assertEquals(0, poolMap.size(randomKey));
-  }
-}