feat: remoove NonblockingConcurrentHashMap (#1176)

Author: fengjiachun

README.md

@@ -43,7 +43,6 @@ SOFAJRaft was ported from Baidu's [braft](https://github.com/brpc/braft) with so
 ## License
 SOFAJRaft is licensed under the [Apache License 2.0](./LICENSE). SOFAJRaft relies on some third-party components, and their open source protocol is also Apache License 2.0.
 In addition, SOFAJRaft also directly references some code (possibly with minor changes), which open source protocol is Apache License 2.0, including
-- NonBlockingHashMap/NonBlockingHashMapLong in [JCTools](https://github.com/JCTools/JCTools)
 - HashedWheelTimer in [Netty](https://github.com/netty/netty), also referenced Netty's Pipeline design
 - Efficient encoding/decoding of UTF8 String in [Protobuf](https://github.com/protocolbuffers/protobuf)
 

README_zh_CN.md

@@ -41,7 +41,6 @@ SOFAJRaft 是从百度的 [braft](https://github.com/brpc/braft) 移植而来，
 ## 开源许可
 SOFAJRaft 基于 [Apache License 2.0](./LICENSE) 协议，SOFAJRaft 依赖了一些第三方组件，它们的开源协议也为 Apache License 2.0，
 另外 SOFAJRaft 也直接引用了一些开源协议为 Apache License 2.0 的代码（可能有一些小小的改动）包括：
-- [JCTools](https://github.com/JCTools/JCTools) 中的 NonBlockingHashMap/NonBlockingHashMapLong
 - [Netty](https://github.com/netty/netty) 中的 HashedWheelTimer，另外还参考了 Netty 的 Pipeline 设计
 - [Protobuf](https://github.com/protocolbuffers/protobuf) 中对 UTF8 String 高效的编码/解码
 

jraft-rheakv/rheakv-core/src/main/java/com/alipay/sofa/jraft/rhea/util/Maps.java

@@ -24,12 +24,8 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
-import com.alipay.sofa.jraft.rhea.util.concurrent.collection.NonBlockingHashMap;
-import com.alipay.sofa.jraft.rhea.util.concurrent.collection.NonBlockingHashMapLong;
 import com.alipay.sofa.jraft.util.Ints;
 import com.alipay.sofa.jraft.util.Requires;
-import com.alipay.sofa.jraft.util.SystemPropertyUtil;
-import com.alipay.sofa.jraft.util.internal.UnsafeUtil;
 
 /**
  * Static utility methods pertaining to {@link Map} instances.
@@ -38,9 +34,6 @@
  */
 public final class Maps {
 
-    private static final boolean USE_NON_BLOCKING_HASH = SystemPropertyUtil.getBoolean("rhea.use.non_blocking_hash",
-                                                           true);
-
     /**
      * Creates a mutable, empty {@code HashMap} instance.
      */
@@ -89,9 +82,6 @@ public static <K extends Comparable, V> TreeMap<K, V> newTreeMap() {
      * Creates a mutable, empty {@code ConcurrentMap} instance.
      */
     public static <K, V> ConcurrentMap<K, V> newConcurrentMap() {
-        if (USE_NON_BLOCKING_HASH && UnsafeUtil.hasUnsafe()) {
-            return new NonBlockingHashMap<>();
-        }
         return new ConcurrentHashMap<>();
     }
 
@@ -100,30 +90,21 @@ public static <K, V> ConcurrentMap<K, V> newConcurrentMap() {
      * that it should hold {@code expectedSize} elements without growth.
      */
     public static <K, V> ConcurrentMap<K, V> newConcurrentMap(int initialCapacity) {
-        if (USE_NON_BLOCKING_HASH && UnsafeUtil.hasUnsafe()) {
-            return new NonBlockingHashMap<>(initialCapacity);
-        }
         return new ConcurrentHashMap<>(initialCapacity);
     }
 
     /**
-     * Creates a mutable, empty {@code NonBlockingHashMapLong} instance.
+     * Creates a mutable, empty {@code ConcurrentHashMap} instance.
      */
     public static <V> ConcurrentMap<Long, V> newConcurrentMapLong() {
-        if (USE_NON_BLOCKING_HASH && UnsafeUtil.hasUnsafe()) {
-            return new NonBlockingHashMapLong<>();
-        }
         return new ConcurrentHashMap<>();
     }
 
     /**
-     * Creates a {@code NonBlockingHashMapLong} instance, with a high enough "initial capacity"
+     * Creates a {@code ConcurrentHashMap} instance, with a high enough "initial capacity"
      * that it should hold {@code expectedSize} elements without growth.
      */
     public static <V> ConcurrentMap<Long, V> newConcurrentMapLong(int initialCapacity) {
-        if (USE_NON_BLOCKING_HASH) {
-            return new NonBlockingHashMapLong<>(initialCapacity);
-        }
         return new ConcurrentHashMap<>(initialCapacity);
     }