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

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

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/**
 * 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 io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufInputStream;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

import java.io.IOException;

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.protobuf.generated.RPCProtos;
import org.apache.hadoop.ipc.RemoteException;

import com.google.protobuf.Message;

/**
 * Handles Hbase responses
 */
@InterfaceAudience.Private
public class AsyncServerResponseHandler extends ChannelInboundHandlerAdapter {
    public static final Log LOG = LogFactory.getLog(AsyncServerResponseHandler.class.getName());

    private final AsyncRpcChannel channel;

    /**
     * Constructor
     *
     * @param channel on which this response handler operates
     */
    public AsyncServerResponseHandler(AsyncRpcChannel channel) {
        this.channel = channel;
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf inBuffer = (ByteBuf) msg;
        ByteBufInputStream in = new ByteBufInputStream(inBuffer);
        int totalSize = inBuffer.readableBytes();
        try {
            // Read the header
            RPCProtos.ResponseHeader responseHeader = RPCProtos.ResponseHeader.parseDelimitedFrom(in);
            int id = responseHeader.getCallId();
            AsyncCall call = channel.removePendingCall(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;

                // This is done through a Netty ByteBuf which has different behavior than InputStream.
                // It does not return number of bytes read but will update pointer internally and throws an
                // exception when too many bytes are to be skipped.
                inBuffer.skipBytes(whatIsLeftToRead);
                return;
            }

            if (responseHeader.hasException()) {
                RPCProtos.ExceptionResponse exceptionResponse = responseHeader.getException();
                RemoteException re = createRemoteException(exceptionResponse);
                if (exceptionResponse.getExceptionClassName().equals(FatalConnectionException.class.getName())) {
                    channel.close(re);
                } else {
                    call.setFailed(re);
                }
            } else {
                Message value = null;
                // Call may be null because it may have timedout and been cleaned up on this side already
                if (call.responseDefaultType != null) {
                    Message.Builder builder = call.responseDefaultType.newBuilderForType();
                    builder.mergeDelimitedFrom(in);
                    value = builder.build();
                }
                CellScanner cellBlockScanner = null;
                if (responseHeader.hasCellBlockMeta()) {
                    int size = responseHeader.getCellBlockMeta().getLength();
                    byte[] cellBlock = new byte[size];
                    inBuffer.readBytes(cellBlock, 0, cellBlock.length);
                    cellBlockScanner = channel.client.createCellScanner(cellBlock);
                }
                call.setSuccess(value, cellBlockScanner);
            }
        } catch (IOException e) {
            // Treat this as a fatal condition and close this connection
            channel.close(e);
        } finally {
            inBuffer.release();
        }
    }

    /**
     * @param e Proto exception
     * @return RemoteException made from passed <code>e</code>
     */
    private RemoteException createRemoteException(final RPCProtos.ExceptionResponse e) {
        String innerExceptionClassName = e.getExceptionClassName();
        boolean doNotRetry = e.getDoNotRetry();
        return e.hasHostname() ?
        // If a hostname then add it to the RemoteWithExtrasException
                new RemoteWithExtrasException(innerExceptionClassName, e.getStackTrace(), e.getHostname(),
                        e.getPort(), doNotRetry)
                : new RemoteWithExtrasException(innerExceptionClassName, e.getStackTrace(), doNotRetry);
    }
}