/*

  * 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.block_app.framework.output;

 import java.io.IOException;

 import java.util.HashMap;

 import java.util.Map;

 import org.apache.giraph.bsp.BspOutputFormat;

 import org.apache.giraph.conf.GiraphConfiguration;

 import org.apache.giraph.conf.GiraphConstants;

 import org.apache.giraph.conf.StrConfOption;

 import org.apache.giraph.utils.ConfigurationObjectUtils;

 import org.apache.giraph.utils.DefaultOutputCommitter;

 import org.apache.hadoop.conf.Configuration;

 import org.apache.hadoop.mapreduce.JobContext;

 import org.apache.hadoop.mapreduce.OutputCommitter;

 import org.apache.hadoop.mapreduce.TaskAttemptContext;

 /**

  * Hadoop output format to use with block output.

  * It keeps track of all registered outputs, and knows how to create them.

  */

 public class BlockOutputFormat extends BspOutputFormat {

   private static final StrConfOption OUTPUT_CONF_OPTIONS = new StrConfOption(

       "giraph.outputConfOptions", "",

       "List of conf options for outputs used");

   public static <OD> void addOutputDesc(OD outputDesc, String confOption,

       GiraphConfiguration conf) {

     GiraphConstants.HADOOP_OUTPUT_FORMAT_CLASS.set(conf,

         BlockOutputFormat.class);

     String currentOutputs = OUTPUT_CONF_OPTIONS.get(conf);

     if (!currentOutputs.isEmpty()) {

       currentOutputs = currentOutputs + ",";

     }

     OUTPUT_CONF_OPTIONS.set(conf, currentOutputs + confOption);

     ConfigurationObjectUtils.setObjectKryo(outputDesc, confOption, conf);

   }

   /**

    * Returns an array of output configuration options set in the input

    * configuration.

    *

    * @param conf Configuration

    * @return Array of options

    */

   public static String[] getOutputConfOptions(Configuration conf) {

     String outputConfOptions = OUTPUT_CONF_OPTIONS.get(conf);

     return outputConfOptions.isEmpty() ?

         new String[0] : outputConfOptions.split(",");

   }

   public static <OW extends BlockOutputWriter, OD extends BlockOutputDesc<OW>>

   OD createInitAndCheckOutputDesc(String confOption, Configuration conf,

       String jobIdentifier) {

     OD outputDesc = ConfigurationObjectUtils.getObjectKryo(confOption, conf);

     outputDesc.initializeAndCheck(jobIdentifier, conf);

     return outputDesc;

   }

   public static Map<String, BlockOutputDesc>

   createInitAndCheckOutputDescsMap(Configuration conf, String jobIdentifier) {

     String[] outputConfOptions = getOutputConfOptions(conf);

     Map<String, BlockOutputDesc> ret = new HashMap<>(outputConfOptions.length);

     for (String outputConfOption : outputConfOptions) {

       ret.put(outputConfOption,

           createInitAndCheckOutputDesc(outputConfOption, conf, jobIdentifier));

     }

     return ret;

   }

   public static Map<String, BlockOutputDesc> createInitAndCheckOutputDescsMap(

       JobContext jobContext) {

     return createInitAndCheckOutputDescsMap(jobContext.getConfiguration(),

         jobContext.getJobID().toString());

   }

   @Override

   public void checkOutputSpecs(JobContext jobContext)

       throws IOException, InterruptedException {

     createInitAndCheckOutputDescsMap(jobContext);

   }

   @Override

   public OutputCommitter getOutputCommitter(

       TaskAttemptContext context) throws IOException, InterruptedException {

     return new DefaultOutputCommitter() {

       @Override

       public void commit(JobContext jobContext) throws IOException {

         Map<String, BlockOutputDesc> map =

             createInitAndCheckOutputDescsMap(jobContext);

         for (BlockOutputDesc outputDesc : map.values()) {

           outputDesc.commit();

         }

       }

     };

   }

 }