/*

  * 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.jython.wrappers;

 import org.apache.hadoop.io.WritableComparable;

 import org.apache.hadoop.io.WritableUtils;

 import org.apache.log4j.Logger;

 import org.python.core.PyException;

 import org.python.core.PyObject;

 import org.python.core.PyString;

 import org.python.modules.cPickle;

 import com.google.common.base.Preconditions;

 import java.io.DataInput;

 import java.io.DataOutput;

 import java.io.IOException;

 /**

  * Wraps a Jython object, adding {@link WritableComparable} interface.

  * Used for graph types (IVEMM) that are in pure Jython.

  */

 public class JythonWritableWrapper extends JythonWrapperBase

     implements WritableComparable {

   /** Logger */

   private static final Logger LOG =

       Logger.getLogger(JythonWritableWrapper.class);

   /**

    * Constructor

    *

    * @param pyObject jython object to wrap

    */

   public JythonWritableWrapper(PyObject pyObject) {

     super(pyObject);

   }

   @Override

   public void readFields(DataInput in) throws IOException {

     String str = WritableUtils.readString(in);

     PyString pyString = new PyString(str);

     Object object;

     try {

       object = cPickle.loads(pyString);

     } catch (PyException e) {

       LOG.fatal("Could not deserialize Jython value from string " + str);

       throw e;

     }

     Preconditions.checkArgument(object instanceof PyObject);

     setPyObject((PyObject) object);

   }

   @Override

   public void write(DataOutput out) throws IOException {

     PyString pyString;

     try {

       pyString = cPickle.dumps(getPyObject());

     } catch (PyException e) {

       LOG.fatal("Could not serialize wrapped Jython value: " +

           getPyObject().__str__());

       throw e;

     }

     WritableUtils.writeString(out, pyString.getString());

   }

   @Override

   public int compareTo(Object other) {

     int result = -1;

     if (other instanceof PyObject) {

       PyObject pyOther = (PyObject) other;

       result = getPyObject().__cmp__(pyOther);

     } else if (JythonWritableWrapper.class.equals(other.getClass())) {

       JythonWritableWrapper wrapperOther = (JythonWritableWrapper) other;

       result = getPyObject().__cmp__(wrapperOther.getPyObject());

     }

     return result;

   }

   @Override

   public boolean equals(Object obj) {

     if (obj == null) {

       return false;

     }

     if (this == obj) {

       return true;

     }

     if (obj instanceof JythonWritableWrapper) {

       return compareTo(obj) == 0;

     }

     return false;

   }

   @Override

   public int hashCode() {

     return getPyObject().__hash__().asInt();

   }

 }