HADOOP-9163 The rpc msg in ProtobufRpcEngine.proto should be moved out to avoid an extra copy (Sanjay Radia)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1452581 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -153,6 +153,9 @@ Trunk (Unreleased)
     HADOOP-9112. test-patch should -1 for @Tests without a timeout 
     (Surenkumar Nihalani via bobby)
 
+    HADOOP-9163 The rpc msg in ProtobufRpcEngine.proto should be moved out to
+    avoid an extra copy (Sanjay Radia)
+
   BUG FIXES
 
     HADOOP-8419. Fixed GzipCode NPE reset for IBM JDK. (Yu Li via eyang)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/ProtobufRpcEngine.java

@@ -21,6 +21,7 @@ package org.apache.hadoop.ipc;
 import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
 import java.net.InetSocketAddress;
@@ -39,7 +40,7 @@ import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.retry.RetryPolicy;
 import org.apache.hadoop.ipc.Client.ConnectionId;
 import org.apache.hadoop.ipc.RPC.RpcInvoker;
-import org.apache.hadoop.ipc.protobuf.ProtobufRpcEngineProtos.RequestProto;
+import org.apache.hadoop.ipc.protobuf.ProtobufRpcEngineProtos.RequestHeaderProto;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.token.SecretManager;
 import org.apache.hadoop.security.token.TokenIdentifier;
@@ -128,25 +129,12 @@ public class ProtobufRpcEngine implements RpcEngine {
           .getProtocolVersion(protocol);
     }
 
-    private RequestProto constructRpcRequest(Method method,
-        Object[] params) throws ServiceException {
-      RequestProto rpcRequest;
-      RequestProto.Builder builder = RequestProto
+    private RequestHeaderProto constructRpcRequestHeader(Method method) {
+      RequestHeaderProto.Builder builder = RequestHeaderProto
           .newBuilder();
       builder.setMethodName(method.getName());
+     
 
-      if (params.length != 2) { // RpcController + Message
-        throw new ServiceException("Too many parameters for request. Method: ["
-            + method.getName() + "]" + ", Expected: 2, Actual: "
-            + params.length);
-      }
-      if (params[1] == null) {
-        throw new ServiceException("null param while calling Method: ["
-            + method.getName() + "]");
-      }
-
-      Message param = (Message) params[1];
-      builder.setRequest(param.toByteString());
       // For protobuf, {@code protocol} used when creating client side proxy is
       // the interface extending BlockingInterface, which has the annotations 
       // such as ProtocolName etc.
@@ -160,8 +148,7 @@ public class ProtobufRpcEngine implements RpcEngine {
       // For PB this may limit the use of mixins on client side.
       builder.setDeclaringClassProtocolName(protocolName);
       builder.setClientProtocolVersion(clientProtocolVersion);
-      rpcRequest = builder.build();
-      return rpcRequest;
+      return builder.build();
     }
 
     /**
@@ -189,8 +176,18 @@ public class ProtobufRpcEngine implements RpcEngine {
       if (LOG.isDebugEnabled()) {
         startTime = Time.now();
       }
+      
+      if (args.length != 2) { // RpcController + Message
+        throw new ServiceException("Too many parameters for request. Method: ["
+            + method.getName() + "]" + ", Expected: 2, Actual: "
+            + args.length);
+      }
+      if (args[1] == null) {
+        throw new ServiceException("null param while calling Method: ["
+            + method.getName() + "]");
+      }
 
-      RequestProto rpcRequest = constructRpcRequest(method, args);
+      RequestHeaderProto rpcRequestHeader = constructRpcRequestHeader(method);
       RpcResponseWrapper val = null;
       
       if (LOG.isTraceEnabled()) {
@@ -198,9 +195,12 @@ public class ProtobufRpcEngine implements RpcEngine {
             remoteId + ": " + method.getName() +
             " {" + TextFormat.shortDebugString((Message) args[1]) + "}");
       }
+
+
+      Message theRequest = (Message) args[1];
       try {
         val = (RpcResponseWrapper) client.call(RPC.RpcKind.RPC_PROTOCOL_BUFFER,
-            new RpcRequestWrapper(rpcRequest), remoteId);
+            new RpcRequestWrapper(rpcRequestHeader, theRequest), remoteId);
 
       } catch (Throwable e) {
         if (LOG.isTraceEnabled()) {
@@ -275,20 +275,25 @@ public class ProtobufRpcEngine implements RpcEngine {
    * use type Writable as a wrapper to work across multiple RpcEngine kinds.
    */
   private static class RpcRequestWrapper implements Writable {
-    RequestProto message;
+    RequestHeaderProto requestHeader;
+    Message theRequest; // for clientSide, the request is here
+    byte[] theRequestRead; // for server side, the request is here
 
     @SuppressWarnings("unused")
     public RpcRequestWrapper() {
     }
 
-    RpcRequestWrapper(RequestProto message) {
-      this.message = message;
+    RpcRequestWrapper(RequestHeaderProto requestHeader, Message theRequest) {
+      this.requestHeader = requestHeader;
+      this.theRequest = theRequest;
     }
 
     @Override
     public void write(DataOutput out) throws IOException {
-      ((Message)message).writeDelimitedTo(
-          DataOutputOutputStream.constructOutputStream(out));
+      OutputStream os = DataOutputOutputStream.constructOutputStream(out);
+      
+      ((Message)requestHeader).writeDelimitedTo(os);
+      theRequest.writeDelimitedTo(os);
     }
 
     @Override
@@ -296,13 +301,16 @@ public class ProtobufRpcEngine implements RpcEngine {
       int length = ProtoUtil.readRawVarint32(in);
       byte[] bytes = new byte[length];
       in.readFully(bytes);
-      message = RequestProto.parseFrom(bytes);
+      requestHeader = RequestHeaderProto.parseFrom(bytes);
+      length = ProtoUtil.readRawVarint32(in);
+      theRequestRead = new byte[length];
+      in.readFully(theRequestRead);
     }
     
     @Override
     public String toString() {
-      return message.getDeclaringClassProtocolName() + "." +
-          message.getMethodName();
+      return requestHeader.getDeclaringClassProtocolName() + "." +
+          requestHeader.getMethodName();
     }
   }
 
@@ -434,7 +442,7 @@ public class ProtobufRpcEngine implements RpcEngine {
       public Writable call(RPC.Server server, String connectionProtocolName,
           Writable writableRequest, long receiveTime) throws Exception {
         RpcRequestWrapper request = (RpcRequestWrapper) writableRequest;
-        RequestProto rpcRequest = request.message;
+        RequestHeaderProto rpcRequest = request.requestHeader;
         String methodName = rpcRequest.getMethodName();
         
         
@@ -474,7 +482,8 @@ public class ProtobufRpcEngine implements RpcEngine {
         }
         Message prototype = service.getRequestPrototype(methodDescriptor);
         Message param = prototype.newBuilderForType()
-            .mergeFrom(rpcRequest.getRequest()).build();
+            .mergeFrom(request.theRequestRead).build();
+        
         Message result;
         try {
           long startTime = Time.now();

hadoop-common-project/hadoop-common/src/main/proto/ProtobufRpcEngine.proto

@@ -1,4 +1,4 @@
-/**
+/**DER
  * 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
@@ -28,20 +28,17 @@ option java_generate_equals_and_hash = true;
 package hadoop.common;
 
 /**
- * This message is used for Protobuf Rpc Engine.
- * The message is used to marshal a Rpc-request
- * from RPC client to the RPC server.
+ * This message is the header for the Protobuf Rpc Engine
+ * when sending a RPC request from  RPC client to the RPC server.
+ * The actual request (serialized as protobuf) follows this request.
  *
  * No special header is needed for the Rpc Response for Protobuf Rpc Engine.
  * The normal RPC response header (see RpcHeader.proto) are sufficient. 
  */
-message RequestProto {
+message RequestHeaderProto {
   /** Name of the RPC method */
   required string methodName = 1;
 
-  /** Bytes corresponding to the client protobuf request */
-  optional bytes request = 2;
-  
   /** 
    * RPCs for a particular interface (ie protocol) are done using a
    * IPC connection that is setup using rpcProxy.