org.apache.hadoop.hbase.ipc.NettyRpcDuplexHandler.java Source code

Java tutorial

Introduction

Here is the source code for org.apache.hadoop.hbase.ipc.NettyRpcDuplexHandler.java

Source

/**
 * 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.ipc;

import org.apache.hadoop.hbase.shaded.com.google.protobuf.Message;
import org.apache.hadoop.hbase.shaded.com.google.protobuf.Message.Builder;
import org.apache.hadoop.hbase.shaded.com.google.protobuf.TextFormat;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufInputStream;
import io.netty.buffer.ByteBufOutputStream;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.handler.timeout.IdleStateEvent;
import io.netty.util.concurrent.PromiseCombiner;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.CellScanner;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.codec.Codec;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RPCProtos.CellBlockMeta;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RPCProtos.ExceptionResponse;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RPCProtos.RequestHeader;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RPCProtos.ResponseHeader;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.ipc.RemoteException;

/**
 * The netty rpc handler.
 */
@InterfaceAudience.Private
class NettyRpcDuplexHandler extends ChannelDuplexHandler {

    private static final Log LOG = LogFactory.getLog(NettyRpcDuplexHandler.class);

    private final NettyRpcConnection conn;

    private final CellBlockBuilder cellBlockBuilder;

    private final Codec codec;

    private final CompressionCodec compressor;

    private final Map<Integer, Call> id2Call = new HashMap<>();

    public NettyRpcDuplexHandler(NettyRpcConnection conn, CellBlockBuilder cellBlockBuilder, Codec codec,
            CompressionCodec compressor) {
        this.conn = conn;
        this.cellBlockBuilder = cellBlockBuilder;
        this.codec = codec;
        this.compressor = compressor;

    }

    private void writeRequest(ChannelHandlerContext ctx, Call call, ChannelPromise promise) throws IOException {
        id2Call.put(call.id, call);
        ByteBuf cellBlock = cellBlockBuilder.buildCellBlock(codec, compressor, call.cells, ctx.alloc());
        CellBlockMeta cellBlockMeta;
        if (cellBlock != null) {
            CellBlockMeta.Builder cellBlockMetaBuilder = CellBlockMeta.newBuilder();
            cellBlockMetaBuilder.setLength(cellBlock.writerIndex());
            cellBlockMeta = cellBlockMetaBuilder.build();
        } else {
            cellBlockMeta = null;
        }
        RequestHeader requestHeader = IPCUtil.buildRequestHeader(call, cellBlockMeta);
        int sizeWithoutCellBlock = IPCUtil.getTotalSizeWhenWrittenDelimited(requestHeader, call.param);
        int totalSize = cellBlock != null ? sizeWithoutCellBlock + cellBlock.writerIndex() : sizeWithoutCellBlock;
        ByteBuf buf = ctx.alloc().buffer(sizeWithoutCellBlock + 4);
        buf.writeInt(totalSize);
        ByteBufOutputStream bbos = new ByteBufOutputStream(buf);
        requestHeader.writeDelimitedTo(bbos);
        if (call.param != null) {
            call.param.writeDelimitedTo(bbos);
        }
        if (cellBlock != null) {
            ChannelPromise withoutCellBlockPromise = ctx.newPromise();
            ctx.write(buf, withoutCellBlockPromise);
            ChannelPromise cellBlockPromise = ctx.newPromise();
            ctx.write(cellBlock, cellBlockPromise);
            PromiseCombiner combiner = new PromiseCombiner();
            combiner.addAll(withoutCellBlockPromise, cellBlockPromise);
            combiner.finish(promise);
        } else {
            ctx.write(buf, promise);
        }
    }

    @Override
    public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
        if (msg instanceof Call) {
            writeRequest(ctx, (Call) msg, promise);
        } else {
            ctx.write(msg, promise);
        }
    }

    private void readResponse(ChannelHandlerContext ctx, ByteBuf buf) throws IOException {
        int totalSize = buf.readInt();
        ByteBufInputStream in = new ByteBufInputStream(buf);
        ResponseHeader responseHeader = ResponseHeader.parseDelimitedFrom(in);
        int id = responseHeader.getCallId();
        if (LOG.isTraceEnabled()) {
            LOG.trace("got response header " + TextFormat.shortDebugString(responseHeader) + ", totalSize: "
                    + totalSize + " bytes");
        }
        RemoteException remoteExc;
        if (responseHeader.hasException()) {
            ExceptionResponse exceptionResponse = responseHeader.getException();
            remoteExc = IPCUtil.createRemoteException(exceptionResponse);
            if (IPCUtil.isFatalConnectionException(exceptionResponse)) {
                // Here we will cleanup all calls so do not need to fall back, just return.
                exceptionCaught(ctx, remoteExc);
                return;
            }
        } else {
            remoteExc = null;
        }
        Call call = id2Call.remove(id);
        if (call == null) {
            // So we got a response for which we have no corresponding 'call' here on the client-side.
            // We probably timed out waiting, cleaned up all references, and now the server decides
            // to return a response. There is nothing we can do w/ the response at this stage. Clean
            // out the wire of the response so its out of the way and we can get other responses on
            // this connection.
            int readSoFar = IPCUtil.getTotalSizeWhenWrittenDelimited(responseHeader);
            int whatIsLeftToRead = totalSize - readSoFar;
            if (LOG.isDebugEnabled()) {
                LOG.debug("Unknown callId: " + id + ", skipping over this response of " + whatIsLeftToRead
                        + " bytes");
            }
            return;
        }
        if (remoteExc != null) {
            call.setException(remoteExc);
            return;
        }
        Message value;
        if (call.responseDefaultType != null) {
            Builder builder = call.responseDefaultType.newBuilderForType();
            builder.mergeDelimitedFrom(in);
            value = builder.build();
        } else {
            value = null;
        }
        CellScanner cellBlockScanner;
        if (responseHeader.hasCellBlockMeta()) {
            int size = responseHeader.getCellBlockMeta().getLength();
            // Maybe we could read directly from the ByteBuf.
            // The problem here is that we do not know when to release it.
            byte[] cellBlock = new byte[size];
            buf.readBytes(cellBlock);
            cellBlockScanner = cellBlockBuilder.createCellScanner(this.codec, this.compressor, cellBlock);
        } else {
            cellBlockScanner = null;
        }
        call.setResponse(value, cellBlockScanner);
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        if (msg instanceof ByteBuf) {
            ByteBuf buf = (ByteBuf) msg;
            try {
                readResponse(ctx, buf);
            } finally {
                buf.release();
            }
        } else {
            super.channelRead(ctx, msg);
        }
    }

    private void cleanupCalls(ChannelHandlerContext ctx, IOException error) {
        for (Call call : id2Call.values()) {
            call.setException(error);
        }
        id2Call.clear();
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        if (!id2Call.isEmpty()) {
            cleanupCalls(ctx, new IOException("Connection closed"));
        }
        conn.shutdown();
        ctx.fireChannelInactive();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        if (!id2Call.isEmpty()) {
            cleanupCalls(ctx, IPCUtil.toIOE(cause));
        }
        conn.shutdown();
    }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
        if (evt instanceof IdleStateEvent) {
            IdleStateEvent idleEvt = (IdleStateEvent) evt;
            switch (idleEvt.state()) {
            case WRITER_IDLE:
                if (id2Call.isEmpty()) {
                    if (LOG.isDebugEnabled()) {
                        LOG.debug("shutdown connection to " + conn.remoteId().address
                                + " because idle for a long time");
                    }
                    // It may happen that there are still some pending calls in the event loop queue and
                    // they will get a closed channel exception. But this is not a big deal as it rarely
                    // rarely happens and the upper layer could retry immediately.
                    conn.shutdown();
                }
                break;
            default:
                LOG.warn("Unrecognized idle state " + idleEvt.state());
                break;
            }
        } else if (evt instanceof CallEvent) {
            // just remove the call for now until we add other call event other than timeout and cancel.
            id2Call.remove(((CallEvent) evt).call.id);
        } else {
            ctx.fireUserEventTriggered(evt);
        }
    }
}