co.mitro.core.server.data.RPCLogger.java Source code

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Here is the source code for co.mitro.core.server.data.RPCLogger.java

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/*******************************************************************************
 * Copyright (c) 2013, 2014 Lectorius, Inc.
 * Authors:
 * Vijay Pandurangan (vijayp@mitro.co)
 * Evan Jones (ej@mitro.co)
 * Adam Hilss (ahilss@mitro.co)
 *
 *
 *     This program is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *     
 *     You can contact the authors at inbound@mitro.co.
 *******************************************************************************/
package co.mitro.core.server.data;

import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Preconditions;

import co.mitro.recordio.JsonRecordWriter;

public class RPCLogger {
    private static final Logger logger = LoggerFactory.getLogger(RPCLogger.class);
    private static final int LOG_TIME_HOURS = 12;

    private static JsonRecordWriter rpcLogger = null;
    private static String prefix = null;
    private static Timer rotator;

    /** Not constructible: All members are static (should we change that?). */
    private RPCLogger() {
    }

    public static synchronized void stopLogging() throws IOException {
        try {
            if (rotator != null) {
                rotator.cancel();
            }
        } finally {
            if (rpcLogger != null) {
                rpcLogger.close();
            }
            rpcLogger = null;
            rotator = null;
            prefix = null;
        }
    }

    public static synchronized void startLoggingWithPrefix(String prefix) throws IOException {
        Preconditions.checkNotNull(prefix);
        Preconditions.checkState(RPCLogger.prefix == null, "RPCLogger already started");

        RPCLogger.prefix = prefix;
        // this thread runs as a daemon, so it doesn't stop the JVM from exiting
        rotator = new Timer(true);

        // run the log cycler immediately so that it can create the 1st log file. 
        rotator.schedule(new LogRotator(), 0, TimeUnit.HOURS.toMillis(LOG_TIME_HOURS));
    }

    private static synchronized void closeAndSetNewJsonLogger() throws IOException {
        if (rpcLogger != null) {
            rpcLogger.close();
            rpcLogger = null;
        }
        // prefix can be null if we do start/stop very quickly (e.g. unit tests)
        if (prefix != null) {
            rpcLogger = JsonRecordWriter.MakeFromFilePrefix(prefix);
        }
    }

    public static synchronized void log(Object rpc, Object logMetadata) {
        if (null != rpcLogger) {
            rpcLogger.writeJson(rpc, logMetadata);
        }
    }

    public final static class LogRotator extends TimerTask {
        @Override
        public void run() {
            try {
                logger.info("Cycling log file");
                RPCLogger.closeAndSetNewJsonLogger();
            } catch (IOException e) {
                logger.error("Unknown error cycling log file: ", e);
            }
        }
    }
}