org.apache.hadoop.hdfs.server.common.CountingLogger.java Source code

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Here is the source code for org.apache.hadoop.hdfs.server.common.CountingLogger.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.hdfs.server.common;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.impl.Log4JLogger;
import org.apache.log4j.Logger;

/**
 * This class wraps any class implementing Log interface so that on each error()
 * and warn() call a corresponding function in subscribing ErrorCounter object
 * is invoked.
 */
public class CountingLogger implements Log {
    private final Log log;
    private ErrorCounter counter;

    public CountingLogger(Log log) {
        if (log == null) {
            throw new NullPointerException();
        }
        this.log = log;
    }

    @Override
    public void debug(Object arg0) {
        log.debug(arg0);
    }

    @Override
    public void debug(Object arg0, Throwable arg1) {
        log.debug(arg0, arg1);
    }

    @Override
    public synchronized void error(Object arg0) {
        if (counter != null) {
            counter.errorInc();
        }
        log.error(arg0);
    }

    @Override
    public synchronized void error(Object arg0, Throwable arg1) {
        if (counter != null) {
            counter.errorInc();
        }
        log.error(arg0, arg1);
    }

    @Override
    public void fatal(Object arg0) {
        log.fatal(arg0);
    }

    @Override
    public void fatal(Object arg0, Throwable arg1) {
        log.fatal(arg0, arg1);
    }

    @Override
    public void info(Object arg0) {
        log.info(arg0);
    }

    @Override
    public void info(Object arg0, Throwable arg1) {
        log.info(arg0, arg1);
    }

    @Override
    public boolean isDebugEnabled() {
        return log.isDebugEnabled();
    }

    @Override
    public boolean isErrorEnabled() {
        return log.isErrorEnabled();
    }

    @Override
    public boolean isFatalEnabled() {
        return log.isFatalEnabled();
    }

    @Override
    public boolean isInfoEnabled() {
        return log.isInfoEnabled();
    }

    @Override
    public boolean isTraceEnabled() {
        return log.isTraceEnabled();
    }

    @Override
    public boolean isWarnEnabled() {
        return log.isWarnEnabled();
    }

    @Override
    public void trace(Object arg0) {
        log.trace(arg0);
    }

    @Override
    public void trace(Object arg0, Throwable arg1) {
        log.trace(arg0, arg1);
    }

    @Override
    public synchronized void warn(Object arg0) {
        if (counter != null) {
            counter.warnInc();
        }
        log.warn(arg0);
    }

    @Override
    public synchronized void warn(Object arg0, Throwable arg1) {
        if (counter != null) {
            counter.warnInc();
        }
        log.warn(arg0, arg1);
    }

    public synchronized void setCounter(ErrorCounter counter) {
        this.counter = counter;
    }

    public Logger getLogger() {
        return ((Log4JLogger) log).getLogger();
    }

    /**
     * Interface for counting failures of different types. An object implementing it is responsible
     * for maintaining counters for events of each type.
     */
    public interface ErrorCounter {
        /** Invoked each time a error() of corresponding logger is called */
        public void errorInc();

        /** Invoked each time a warn() of corresponding logger is called */
        public void warnInc();
    }
}