| /** |
| * 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.oncrpc; |
| |
| import java.nio.ByteBuffer; |
| |
| import org.jboss.netty.buffer.ChannelBuffer; |
| import org.jboss.netty.buffer.ChannelBuffers; |
| import org.jboss.netty.channel.Channel; |
| import org.jboss.netty.channel.ChannelHandlerContext; |
| import org.jboss.netty.channel.Channels; |
| import org.jboss.netty.channel.MessageEvent; |
| import org.jboss.netty.channel.SimpleChannelUpstreamHandler; |
| import org.jboss.netty.handler.codec.frame.FrameDecoder; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public final class RpcUtil { |
| /** |
| * The XID in RPC call. It is used for starting with new seed after each |
| * reboot. |
| */ |
| private static int xid = (int) (System.currentTimeMillis() / 1000) << 12; |
| |
| public static int getNewXid(String caller) { |
| return xid = ++xid + caller.hashCode(); |
| } |
| |
| public static void sendRpcResponse(ChannelHandlerContext ctx, |
| RpcResponse response) { |
| Channels.fireMessageReceived(ctx, response); |
| } |
| |
| public static FrameDecoder constructRpcFrameDecoder() { |
| return new RpcFrameDecoder(); |
| } |
| |
| public static final SimpleChannelUpstreamHandler STAGE_RPC_MESSAGE_PARSER = new RpcMessageParserStage(); |
| public static final SimpleChannelUpstreamHandler STAGE_RPC_TCP_RESPONSE = new RpcTcpResponseStage(); |
| public static final SimpleChannelUpstreamHandler STAGE_RPC_UDP_RESPONSE = new RpcUdpResponseStage(); |
| |
| /** |
| * An RPC client can separate a RPC message into several frames (i.e., |
| * fragments) when transferring it across the wire. RpcFrameDecoder |
| * reconstructs a full RPC message from these fragments. |
| * |
| * RpcFrameDecoder is a stateful pipeline stage. It has to be constructed for |
| * each RPC client. |
| */ |
| static class RpcFrameDecoder extends FrameDecoder { |
| public static final Logger LOG = |
| LoggerFactory.getLogger(RpcFrameDecoder.class); |
| private ChannelBuffer currentFrame; |
| |
| @Override |
| protected Object decode(ChannelHandlerContext ctx, Channel channel, |
| ChannelBuffer buf) { |
| |
| if (buf.readableBytes() < 4) |
| return null; |
| |
| buf.markReaderIndex(); |
| |
| byte[] fragmentHeader = new byte[4]; |
| buf.readBytes(fragmentHeader); |
| int length = XDR.fragmentSize(fragmentHeader); |
| boolean isLast = XDR.isLastFragment(fragmentHeader); |
| |
| if (buf.readableBytes() < length) { |
| buf.resetReaderIndex(); |
| return null; |
| } |
| |
| ChannelBuffer newFragment = buf.readSlice(length); |
| if (currentFrame == null) { |
| currentFrame = newFragment; |
| } else { |
| currentFrame = ChannelBuffers.wrappedBuffer(currentFrame, newFragment); |
| } |
| |
| if (isLast) { |
| ChannelBuffer completeFrame = currentFrame; |
| currentFrame = null; |
| return completeFrame; |
| } else { |
| return null; |
| } |
| } |
| } |
| |
| /** |
| * RpcMessageParserStage parses the network bytes and encapsulates the RPC |
| * request into a RpcInfo instance. |
| */ |
| static final class RpcMessageParserStage extends SimpleChannelUpstreamHandler { |
| private static final Logger LOG = LoggerFactory |
| .getLogger(RpcMessageParserStage.class); |
| |
| @Override |
| public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) |
| throws Exception { |
| ChannelBuffer buf = (ChannelBuffer) e.getMessage(); |
| ByteBuffer b = buf.toByteBuffer().asReadOnlyBuffer(); |
| XDR in = new XDR(b, XDR.State.READING); |
| |
| RpcInfo info = null; |
| try { |
| RpcCall callHeader = RpcCall.read(in); |
| ChannelBuffer dataBuffer = ChannelBuffers.wrappedBuffer(in.buffer() |
| .slice()); |
| info = new RpcInfo(callHeader, dataBuffer, ctx, e.getChannel(), |
| e.getRemoteAddress()); |
| } catch (Exception exc) { |
| LOG.info("Malformed RPC request from " + e.getRemoteAddress()); |
| } |
| |
| if (info != null) { |
| Channels.fireMessageReceived(ctx, info); |
| } |
| } |
| } |
| |
| /** |
| * RpcTcpResponseStage sends an RpcResponse across the wire with the |
| * appropriate fragment header. |
| */ |
| private static class RpcTcpResponseStage extends SimpleChannelUpstreamHandler { |
| |
| @Override |
| public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) |
| throws Exception { |
| RpcResponse r = (RpcResponse) e.getMessage(); |
| byte[] fragmentHeader = XDR.recordMark(r.data().readableBytes(), true); |
| ChannelBuffer header = ChannelBuffers.wrappedBuffer(fragmentHeader); |
| ChannelBuffer d = ChannelBuffers.wrappedBuffer(header, r.data()); |
| e.getChannel().write(d); |
| } |
| } |
| |
| /** |
| * RpcUdpResponseStage sends an RpcResponse as a UDP packet, which does not |
| * require a fragment header. |
| */ |
| private static final class RpcUdpResponseStage extends |
| SimpleChannelUpstreamHandler { |
| |
| @Override |
| public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) |
| throws Exception { |
| RpcResponse r = (RpcResponse) e.getMessage(); |
| e.getChannel().write(r.data(), r.remoteAddress()); |
| } |
| } |
| } |