/*

  * 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.types;

 import org.apache.hadoop.io.Writable;

 import com.google.common.collect.Maps;

 import java.util.Map;

 import static org.apache.giraph.types.JavaWritablePair.BOOLEAN_BOOLEAN_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.BYTE_BYTE_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.DOUBLE_DOUBLE_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.DOUBLE_FLOAT_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.FLOAT_FLOAT_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.INT_BYTE_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.INT_INT_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.LONG_BYTE_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.LONG_INT_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.LONG_LONG_WRITABLE;

 import static org.apache.giraph.types.JavaWritablePair.SHORT_BYTE_WRITABLE;

 /**

  * Mapping of all the known Writable wrappers.

  */

 public class WritableUnwrappers {

   /** Map of (Writable,Java)-type pair to wrapper for those types */

   private static final Map<JavaWritablePair, WritableUnwrapper> MAP;

   static {

     MAP = Maps.newHashMap();

     MAP.put(BOOLEAN_BOOLEAN_WRITABLE, new BooleanWritableToBooleanUnwrapper());

     MAP.put(BYTE_BYTE_WRITABLE, new ByteWritableToByteUnwrapper());

     MAP.put(DOUBLE_DOUBLE_WRITABLE, new DoubleWritableToDoubleUnwrapper());

     MAP.put(DOUBLE_FLOAT_WRITABLE, new FloatWritableToDoubleUnwrapper());

     MAP.put(FLOAT_FLOAT_WRITABLE, new FloatWritableToFloatUnwrapper());

     MAP.put(INT_BYTE_WRITABLE, new ByteWritableToIntUnwrapper());

     MAP.put(INT_INT_WRITABLE, new IntWritableToIntUnwrapper());

     MAP.put(SHORT_BYTE_WRITABLE, new ByteWritableToShortUnwrapper());

     MAP.put(LONG_BYTE_WRITABLE, new ByteWritableToLongUnwrapper());

     MAP.put(LONG_INT_WRITABLE, new IntWritableToLongUnwrapper());

     MAP.put(LONG_LONG_WRITABLE, new LongWritableToLongUnwrapper());

   }

   /** Don't construct */

   private WritableUnwrappers() { }

   /**

    * Lookup type converter

    *

    * @param writableClass class of Writable

    * @param javaClass class of Java type

    * @param <W> Writable type

    * @param <J> Java type

    * @return {@link WritableUnwrapper}

    */

   public static <W extends Writable, J> WritableUnwrapper<W, J> lookup(

       Class<W> writableClass, Class<J> javaClass) {

     return lookup(JavaWritablePair.create(writableClass, javaClass));

   }

   /**

    * Lookup type converter

    *

    * @param classes JavaAndWritableClasses

    * @param <W> Writable type

    * @param <J> Java type

    * @return {@link WritableUnwrapper}

    */

   public static <W extends Writable, J> WritableUnwrapper<W, J> lookup(

       JavaWritablePair<W, J> classes) {

     return MAP.get(classes);

   }

 }