org.apache.carbondata.core.dictionary.server.DictionaryServerHandler.java Source code

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Here is the source code for org.apache.carbondata.core.dictionary.server.DictionaryServerHandler.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.carbondata.core.dictionary.server;

import org.apache.carbondata.common.logging.LogService;
import org.apache.carbondata.common.logging.LogServiceFactory;
import org.apache.carbondata.core.dictionary.generator.ServerDictionaryGenerator;
import org.apache.carbondata.core.dictionary.generator.key.DictionaryMessage;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

/**
 * Handler for Dictionary server.
 */
@ChannelHandler.Sharable
public class DictionaryServerHandler extends ChannelInboundHandlerAdapter {

    private static final LogService LOGGER = LogServiceFactory
            .getLogService(DictionaryServerHandler.class.getName());

    /**
     * dictionary generator
     */
    private ServerDictionaryGenerator generatorForServer = new ServerDictionaryGenerator();

    /**
     * channel registered
     *
     * @param ctx
     * @throws Exception
     */
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        LOGGER.audit("Connected " + ctx);
        super.channelActive(ctx);
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        try {
            ByteBuf data = (ByteBuf) msg;
            DictionaryMessage key = new DictionaryMessage();
            key.readData(data);
            data.release();
            int outPut = processMessage(key);
            key.setDictionaryValue(outPut);
            // Send back the response
            ByteBuf buffer = ctx.alloc().buffer();
            key.writeData(buffer);
            ctx.writeAndFlush(buffer);
        } catch (Exception e) {
            LOGGER.error(e);
            throw e;
        }
    }

    /**
     * handle exceptions
     *
     * @param ctx
     * @param cause
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        LOGGER.error(cause, "exceptionCaught");
        ctx.close();
    }

    /**
     * process message by message type
     *
     * @param key
     * @return
     * @throws Exception
     */
    public int processMessage(DictionaryMessage key) throws Exception {
        switch (key.getType()) {
        case DICT_GENERATION:
            return generatorForServer.generateKey(key);
        case TABLE_INTIALIZATION:
            generatorForServer.initializeGeneratorForTable(key);
            return 0;
        case SIZE:
            return generatorForServer.size(key);
        case WRITE_DICTIONARY:
            generatorForServer.writeDictionaryData();
            return 0;
        default:
            return -1;
        }
    }

}