HDFS-17544. [ARR] The router client rpc protocol PB supports asynchrony. (apache#6870). Contributed by Jian Zhang.

Signed-off-by: He Xiaoqiao <hexiaoqiao@apache.org>

Author: KeeProMise

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java

@@ -274,47 +274,47 @@ public class ClientNamenodeProtocolTranslatorPB implements
     ProtocolMetaInterface, ClientProtocol, Closeable, ProtocolTranslator {
   final private ClientNamenodeProtocolPB rpcProxy;
 
-  static final GetServerDefaultsRequestProto VOID_GET_SERVER_DEFAULT_REQUEST =
+  protected static final GetServerDefaultsRequestProto VOID_GET_SERVER_DEFAULT_REQUEST =
       GetServerDefaultsRequestProto.newBuilder().build();
 
-  private final static GetFsStatusRequestProto VOID_GET_FSSTATUS_REQUEST =
+  protected final static GetFsStatusRequestProto VOID_GET_FSSTATUS_REQUEST =
       GetFsStatusRequestProto.newBuilder().build();
 
-  private final static GetFsReplicatedBlockStatsRequestProto
+  protected final static GetFsReplicatedBlockStatsRequestProto
       VOID_GET_FS_REPLICATED_BLOCK_STATS_REQUEST =
       GetFsReplicatedBlockStatsRequestProto.newBuilder().build();
 
-  private final static GetFsECBlockGroupStatsRequestProto
+  protected final static GetFsECBlockGroupStatsRequestProto
       VOID_GET_FS_ECBLOCKGROUP_STATS_REQUEST =
       GetFsECBlockGroupStatsRequestProto.newBuilder().build();
 
-  private final static RollEditsRequestProto VOID_ROLLEDITS_REQUEST =
+  protected final static RollEditsRequestProto VOID_ROLLEDITS_REQUEST =
       RollEditsRequestProto.getDefaultInstance();
 
-  private final static RefreshNodesRequestProto VOID_REFRESH_NODES_REQUEST =
+  protected final static RefreshNodesRequestProto VOID_REFRESH_NODES_REQUEST =
       RefreshNodesRequestProto.newBuilder().build();
 
-  private final static FinalizeUpgradeRequestProto
+  protected final static FinalizeUpgradeRequestProto
       VOID_FINALIZE_UPGRADE_REQUEST =
       FinalizeUpgradeRequestProto.newBuilder().build();
 
-  private final static UpgradeStatusRequestProto
+  protected final static UpgradeStatusRequestProto
       VOID_UPGRADE_STATUS_REQUEST =
       UpgradeStatusRequestProto.newBuilder().build();
 
-  private final static GetDataEncryptionKeyRequestProto
+  protected final static GetDataEncryptionKeyRequestProto
       VOID_GET_DATA_ENCRYPTIONKEY_REQUEST =
       GetDataEncryptionKeyRequestProto.newBuilder().build();
 
-  private final static GetStoragePoliciesRequestProto
+  protected final static GetStoragePoliciesRequestProto
       VOID_GET_STORAGE_POLICIES_REQUEST =
       GetStoragePoliciesRequestProto.newBuilder().build();
 
-  private final static GetErasureCodingPoliciesRequestProto
+  protected final static GetErasureCodingPoliciesRequestProto
       VOID_GET_EC_POLICIES_REQUEST = GetErasureCodingPoliciesRequestProto
       .newBuilder().build();
 
-  private final static GetErasureCodingCodecsRequestProto
+  protected final static GetErasureCodingCodecsRequestProto
       VOID_GET_EC_CODEC_REQUEST = GetErasureCodingCodecsRequestProto
       .newBuilder().build();
 
@@ -1137,7 +1137,7 @@ public void removeCacheDirective(long id)
             setId(id).build()));
   }
 
-  private static class BatchedCacheEntries
+  protected static class BatchedCacheEntries
       implements BatchedEntries<CacheDirectiveEntry> {
     private final ListCacheDirectivesResponseProto response;
 
@@ -1200,7 +1200,7 @@ public void removeCachePool(String cachePoolName) throws IOException {
             setPoolName(cachePoolName).build()));
   }
 
-  private static class BatchedCachePoolEntries
+  protected static class BatchedCachePoolEntries
       implements BatchedEntries<CachePoolEntry> {
     private final ListCachePoolsResponseProto proto;
 

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/protocolPB/AsyncRpcProtocolPBUtil.java

@@ -0,0 +1,69 @@
+/**
+ * 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.hdfs.protocolPB;
+
+import org.apache.hadoop.hdfs.server.federation.router.async.ApplyFunction;
+import org.apache.hadoop.io.Writable;
+import org.apache.hadoop.ipc.CallerContext;
+import org.apache.hadoop.ipc.Client;
+import org.apache.hadoop.ipc.ProtobufRpcEngine2;
+import org.apache.hadoop.ipc.Server;
+import org.apache.hadoop.ipc.internal.ShadedProtobufHelper;
+import org.apache.hadoop.util.concurrent.AsyncGet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+
+import static org.apache.hadoop.hdfs.server.federation.router.async.Async.warpCompletionException;
+import static org.apache.hadoop.hdfs.server.federation.router.async.AsyncUtil.asyncApply;
+import static org.apache.hadoop.hdfs.server.federation.router.async.AsyncUtil.asyncCompleteWith;
+import static org.apache.hadoop.hdfs.server.federation.router.async.AsyncUtil.asyncReturn;
+import static org.apache.hadoop.ipc.internal.ShadedProtobufHelper.ipc;
+
+public final class AsyncRpcProtocolPBUtil {
+  public static final Logger LOG = LoggerFactory.getLogger(AsyncRpcProtocolPBUtil.class);
+
+  private AsyncRpcProtocolPBUtil() {}
+
+  public static <T, R> R asyncIpcClient(
+      ShadedProtobufHelper.IpcCall<T> call, ApplyFunction<T, R> response,
+      Class<R> clazz) throws IOException {
+    ipc(call);
+    AsyncGet<T, Exception> asyncReqMessage =
+        (AsyncGet<T, Exception>) ProtobufRpcEngine2.getAsyncReturnMessage();
+    CompletableFuture<Writable> responseFuture = Client.getResponseFuture();
+    // transfer originCall & callerContext to worker threads of executor.
+    final Server.Call originCall = Server.getCurCall().get();
+    final CallerContext originContext = CallerContext.getCurrent();
+    asyncCompleteWith(responseFuture);
+    asyncApply(o -> {
+      try {
+        Server.getCurCall().set(originCall);
+        CallerContext.setCurrent(originContext);
+        T res = asyncReqMessage.get(-1, null);
+        return response.apply(res);
+      } catch (Exception e) {
+        throw warpCompletionException(e);
+      }
+    });
+    return asyncReturn(clazz);
+  }
+}