/*

  * 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.giraph.utils;

 import java.io.IOException;

 import org.apache.hadoop.mapreduce.TaskAttemptContext;

 import org.apache.log4j.Level;

 import org.apache.log4j.Logger;

 /**

  * Logger utils for log4j

  */

 public class LoggerUtils {

   /**

    * Don't construct this.

    */

   private LoggerUtils() { }

   /**

    * Helper method to set the status and log message together if condition

    * has been been met.

    *

    * @param condition Must be true to write status and log

    * @param context Context to set the status with

    * @param logger Logger to write to

    * @param level Level of logging

    * @param message Message to set status with

    */

   public static void conditionalSetStatusAndLog(

       boolean condition,

       TaskAttemptContext context, Logger logger, Level level,

       String message) {

     if (condition) {

       setStatusAndLog(context, logger, level, message);

     }

   }

   /**

    * Helper method to set the status and log message together.

    *

    * @param context Context to set the status with

    * @param logger Logger to write to

    * @param level Level of logging

    * @param message Message to set status with

    */

   public static void setStatusAndLog(

       TaskAttemptContext context, Logger logger, Level level,

       String message) {

     try {

       setStatus(context, message);

     } catch (IOException e) {

       throw new IllegalStateException("setStatusAndLog: Got IOException", e);

     }

     if (logger.isEnabledFor(level)) {

       logger.log(level, message);

     }

   }

   /**

    * Set Hadoop status message.

    *

    * NOTE: In theory this function could get folded in to the callsites, but

    * the issue is that some Hadoop jars, e.g. 0.23 and 2.0.0, don't actually

    * throw IOException on setStatus while others do. This makes wrapping it in a

    * try/catch cause a compile error on those Hadoops. With this function every

    * caller sees a method that throws IOException. In case it doesn't actually,

    * there is no more compiler error because not throwing a decalred exception

    * is at best a warning.

    *

    * @param context Context to set the status with

    * @param message Message to set status with

    * @throws IOException If something goes wrong with setting status message

    */

   private static void setStatus(TaskAttemptContext context, String message)

     throws IOException {

     context.setStatus(message);

   }

 }