/*

  * 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;

 import java.util.List;

 import org.apache.giraph.comm.messages.MessageEncodeAndStoreType;

 import org.apache.giraph.conf.BulkConfigurator;

 import org.apache.giraph.conf.GiraphConfiguration;

 import org.apache.giraph.conf.GiraphConstants;

 import org.apache.giraph.conf.StrConfOption;

 import org.apache.giraph.edge.IdAndNullArrayEdges;

 import org.apache.giraph.edge.IdAndValueArrayEdges;

 import org.apache.giraph.edge.LongDiffNullArrayEdges;

 import org.apache.giraph.types.ops.PrimitiveIdTypeOps;

 import org.apache.giraph.types.ops.TypeOps;

 import org.apache.giraph.types.ops.TypeOpsUtils;

 import org.apache.giraph.utils.ReflectionUtils;

 import org.apache.hadoop.conf.Configuration;

 import org.apache.hadoop.io.LongWritable;

 import org.apache.hadoop.io.NullWritable;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.io.WritableComparable;

 /**

  * Default block factory abstract class, providing default methods that need

  * to be/can be overridden for specifying required/most common parameters,

  * to simplify setting properties.

  *

  * @param <S> Execution stage type

  */

 public abstract class AbstractBlockFactory<S> implements BlockFactory<S> {

   /**

    * Comma separated list of BulkConfigurators, that are going to be called

    * to simplify specifying of large number of properties.

    */

   public static final StrConfOption CONFIGURATORS = new StrConfOption(

       "digraph.block_factory_configurators", null, "");

   @Override

   public List<String> getGcJavaOpts(Configuration conf) {

     return null;

   }

   @Override

   public final void initConfig(GiraphConfiguration conf) {

     initConfigurators(conf);

     GiraphConstants.VERTEX_ID_CLASS.setIfUnset(conf, getVertexIDClass(conf));

     GiraphConstants.VERTEX_VALUE_CLASS.setIfUnset(

         conf, getVertexValueClass(conf));

     GiraphConstants.EDGE_VALUE_CLASS.setIfUnset(conf, getEdgeValueClass(conf));

     GiraphConstants.RESOLVER_CREATE_VERTEX_ON_MSGS.setIfUnset(

         conf, shouldCreateVertexOnMsgs(conf));

     if (shouldSendOneMessageToAll(conf)) {

       GiraphConstants.MESSAGE_ENCODE_AND_STORE_TYPE.setIfUnset(

           conf, MessageEncodeAndStoreType.EXTRACT_BYTEARRAY_PER_PARTITION);

     }

     BlockUtils.BLOCK_WORKER_CONTEXT_VALUE_CLASS.setIfUnset(

         conf, getWorkerContextValueClass(conf));

     // optimize edge structure, if available and not set already

     if (!GiraphConstants.VERTEX_EDGES_CLASS.contains(conf)) {

       @SuppressWarnings("rawtypes")

       Class<? extends WritableComparable> vertexIDClass =

           GiraphConstants.VERTEX_ID_CLASS.get(conf);

       Class<? extends Writable> edgeValueClass =

           GiraphConstants.EDGE_VALUE_CLASS.get(conf);

       @SuppressWarnings("rawtypes")

       PrimitiveIdTypeOps<? extends WritableComparable> idTypeOps =

           TypeOpsUtils.getPrimitiveIdTypeOpsOrNull(vertexIDClass);

       if (edgeValueClass.equals(NullWritable.class)) {

         if (vertexIDClass.equals(LongWritable.class)) {

           GiraphConstants.VERTEX_EDGES_CLASS.set(

               conf, LongDiffNullArrayEdges.class);

         } else if (idTypeOps != null) {

           GiraphConstants.VERTEX_EDGES_CLASS.set(

               conf, IdAndNullArrayEdges.class);

         }

       } else {

         TypeOps<?> edgeValueTypeOps =

             TypeOpsUtils.getTypeOpsOrNull(edgeValueClass);

         if (edgeValueTypeOps != null && idTypeOps != null) {

           GiraphConstants.VERTEX_EDGES_CLASS.set(

               conf, IdAndValueArrayEdges.class);

         }

       }

     }

     additionalInitConfig(conf);

   }

   @Override

   public void registerOutputs(GiraphConfiguration conf) {

   }

   private void initConfigurators(GiraphConfiguration conf) {

     String configurators = CONFIGURATORS.get(conf);

     if (configurators != null) {

       String[] split = configurators.split(",");

       for (String configurator : split) {

         runConfigurator(conf, configurator);

       }

     }

   }

   private void runConfigurator(GiraphConfiguration conf, String configurator) {

     String[] packages = getConvenienceConfiguratorPackages();

     String[] prefixes = new String[packages.length + 1];

     prefixes[0] = "";

     for (int i = 0; i < packages.length; i++) {

       prefixes[i + 1] = packages[i] + ".";

     }

     for (String prefix : prefixes) {

       try {

         @SuppressWarnings({ "unchecked", "rawtypes" })

         Class<BulkConfigurator> confClass =

             (Class) Class.forName(prefix + configurator);

         BulkConfigurator c = ReflectionUtils.newInstance(confClass);

         c.configure(conf);

         return;

       // CHECKSTYLE: stop EmptyBlock

       // ignore ClassNotFoundException, and continue the loop

       } catch (ClassNotFoundException e) {

       }

       // CHECKSTYLE: resume EmptyBlock

     }

     throw new IllegalStateException(

         "Configurator " + configurator + " not found");

   }

   /**

    * Additional configuration initialization, other then overriding

    * class specification.

    */

   protected void additionalInitConfig(GiraphConfiguration conf) {

   }

   /**

    * Concrete vertex id class application will use.

    */

   @SuppressWarnings("rawtypes")

   protected abstract Class<? extends WritableComparable> getVertexIDClass(

       GiraphConfiguration conf);

   /**

    * Concrete vertex value class application will use.

    */

   protected abstract Class<? extends Writable> getVertexValueClass(

       GiraphConfiguration conf);

   /**

    * Concrete edge value class application will use.

    */

   protected abstract Class<? extends Writable> getEdgeValueClass(

       GiraphConfiguration conf);

   /**

    * Concrete worker context value class application will use, if overridden.

    */

   protected Class<?> getWorkerContextValueClass(GiraphConfiguration conf) {

     return Object.class;

   }

   /**

    * Override if vertices shouldn't be created by default, if message is sent

    * to a vertex that doesn't exist.

    */

   protected boolean shouldCreateVertexOnMsgs(GiraphConfiguration conf) {

     return true;

   }

   // TODO - see if it should be deprecated

   protected boolean shouldSendOneMessageToAll(GiraphConfiguration conf) {

     return false;

   }

   /**

    * Provide list of strings representing packages where configurators will

    * be searched for, allowing that full path is not required for

    * CONFIGURATORS option.

    */

   protected String[] getConvenienceConfiguratorPackages() {

     return new String[] { };

   }

 }