com.linkedin.bowser.tool.REPLServer.java Source code

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Here is the source code for com.linkedin.bowser.tool.REPLServer.java

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/*
 * Copyright 2010-2011 LinkedIn Corporation
 * 
 * Licensed 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 com.linkedin.bowser.tool;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.net.InetSocketAddress;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.mina.common.IdleStatus;
import org.apache.mina.common.IoAcceptor;
import org.apache.mina.common.IoHandler;
import org.apache.mina.common.IoSession;
import org.apache.mina.filter.LoggingFilter;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.textline.TextLineCodecFactory;
import org.apache.mina.transport.socket.nio.SocketAcceptor;

import com.linkedin.bowser.core.exceptions.QueryFormatException;
import com.linkedin.bowser.core.exceptions.QueryRuntimeException;
import com.linkedin.bowser.core.objects.NQLObject;

/**
 * @author ruslan
 * 
 */
public class REPLServer implements IoHandler {
    private final Log log = LogFactory.getLog(REPLServer.class.getName());

    private final boolean _verbose;
    private final Integer _parallelism;
    private final Map<String, NQLObject> _symbols;

    private final InetSocketAddress _socketAddress;
    private final IoAcceptor _acceptor;

    public REPLServer(Config cfg) {
        _verbose = cfg.getVerbose();
        _parallelism = cfg.getParallelism();
        _symbols = cfg.getSymbols();
        _socketAddress = new InetSocketAddress(cfg.getPort());

        _acceptor = new SocketAcceptor();
        _acceptor.getFilterChain().addLast("logger", new LoggingFilter());
        _acceptor.getFilterChain().addLast("codec",
                new ProtocolCodecFilter(new TextLineCodecFactory(Charset.forName("UTF-8"))));
    }

    public void start() throws IOException {
        log.info("Starting REPLServer: " + _socketAddress.getAddress().toString());
        _acceptor.bind(_socketAddress, this);
    }

    public void stop() {
        log.info("Stopping REPLServer");
        _acceptor.unbind(_socketAddress);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.apache.mina.core.service.IoHandler#exceptionCaught(org.apache.mina.core.session
     * .IoSession, java.lang.Throwable)
     */
    @Override
    public void exceptionCaught(IoSession session, Throwable ex) throws Exception {
        log.error(ex);
        session.close();
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.apache.mina.core.service.IoHandler#messageReceived(org.apache.mina.core.session
     * .IoSession, java.lang.Object)
     */
    @Override
    public void messageReceived(IoSession session, Object message) throws Exception {
        final String line = message.toString();
        if (line.trim().equalsIgnoreCase("quit")) {
            session.close();
            return;
        }

        REPL repl = (REPL) session.getAttribute(REPL.class.getName());
        if (repl != null) {
            ByteArrayOutputStream ous = new ByteArrayOutputStream();
            PrintStream out = new PrintStream(ous);

            try {
                repl.execute(line, new PrintStream(ous));
            } catch (QueryRuntimeException e) {
                out.println(e.getMessage());
            } catch (QueryFormatException e) {
                out.println(e.getMessage());
            }

            out.flush();
            session.write(ous.toString());
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.apache.mina.core.service.IoHandler#messageSent(org.apache.mina.core.session.IoSession
     * , java.lang.Object)
     */
    @Override
    public void messageSent(IoSession session, Object obj) throws Exception {
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.apache.mina.core.service.IoHandler#sessionClosed(org.apache.mina.core.session
     * .IoSession)
     */
    @Override
    public void sessionClosed(IoSession session) throws Exception {
        session.removeAttribute(REPL.class.getName());
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.apache.mina.core.service.IoHandler#sessionCreated(org.apache.mina.core.session
     * .IoSession)
     */
    @Override
    public void sessionCreated(IoSession session) throws Exception {
        session.setAttribute(REPL.class.getName(),
                new REPL(_verbose, _parallelism, new HashMap<String, NQLObject>(_symbols)));
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.apache.mina.core.service.IoHandler#sessionIdle(org.apache.mina.core.session.IoSession
     * , org.apache.mina.core.session.IdleStatus)
     */
    @Override
    public void sessionIdle(IoSession arg0, IdleStatus session) throws Exception {
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * org.apache.mina.core.service.IoHandler#sessionOpened(org.apache.mina.core.session
     * .IoSession)
     */
    @Override
    public void sessionOpened(IoSession session) throws Exception {
    }

    public static class Config {
        private boolean _verbose;
        private Integer _parallelism;
        private int _port = 9298;
        private Map<String, NQLObject> _symbols;

        public int getPort() {
            return _port;
        }

        public void setPort(int port) {
            _port = port;
        }

        public boolean getVerbose() {
            return _verbose;
        }

        public void setVerbose(boolean verbose) {
            _verbose = verbose;
        }

        public Integer getParallelism() {
            return _parallelism;
        }

        public void setParallelism(Integer parallelism) {
            _parallelism = parallelism;
        }

        public Map<String, NQLObject> getSymbols() {
            return _symbols;
        }

        public void setSymbols(Map<String, NQLObject> symbols) {
            _symbols = symbols;
        }
    }/* Config */
}