/*

  * 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.comm;

 import org.apache.giraph.graph.Vertex;

 import org.apache.giraph.graph.Edge;

 import org.apache.giraph.graph.WorkerInfo;

 import org.apache.giraph.graph.partition.Partition;

 import org.apache.hadoop.io.Writable;

 import org.apache.hadoop.io.WritableComparable;

 import java.io.IOException;

 /**

  * Public interface for workers to do message communication

  *

  * @param <I> Vertex id

  * @param <V> Vertex value

  * @param <E> Edge value

  * @param <M> Message data

  */

 @SuppressWarnings("rawtypes")

 public interface WorkerClient<I extends WritableComparable,

     V extends Writable, E extends Writable, M extends Writable> {

   /**

    *  Setup the client.

    */

   void setup();

   /**

    * Fix changes to the workers and the mapping between partitions and

    * workers.

    */

   void fixPartitionIdToSocketAddrMap();

   /**

    * Sends a message to destination vertex.

    *

    * @param destVertexId Destination vertex id.

    * @param message Message to send.

    */

   void sendMessageRequest(I destVertexId, M message);

   /**

    * Sends a partition to the appropriate partition owner

    *

    * @param workerInfo Owner the vertices belong to

    * @param partition Partition to send

    */

   void sendPartitionRequest(WorkerInfo workerInfo,

                             Partition<I, V, E, M> partition);

   /**

    * Sends a request to the appropriate vertex range owner to add an edge

    *

    * @param vertexIndex Index of the vertex to get the request

    * @param edge Edge to be added

    * @throws IOException

    */

   void addEdgeRequest(I vertexIndex, Edge<I, E> edge) throws IOException;

   /**

    * Sends a request to the appropriate vertex range owner to remove an edge

    *

    * @param vertexIndex Index of the vertex to get the request

    * @param destinationVertexIndex Index of the edge to be removed

    * @throws IOException

    */

   void removeEdgeRequest(I vertexIndex, I destinationVertexIndex)

     throws IOException;

   /**

    * Sends a request to the appropriate vertex range owner to add a vertex

    *

    * @param vertex Vertex to be added

    * @throws IOException

    */

   void addVertexRequest(Vertex<I, V, E, M> vertex) throws IOException;

   /**

    * Sends a request to the appropriate vertex range owner to remove a vertex

    *

    * @param vertexIndex Index of the vertex to be removed

    * @throws IOException

    */

   void removeVertexRequest(I vertexIndex) throws IOException;

   /**

    * Flush all outgoing messages.  This will synchronously ensure that all

    * messages have been send and delivered prior to returning.

    *

    * @throws IOException

    */

   void flush() throws IOException;

   /**

    * Get the messages sent during this superstep and clear them.

    *

    * @return Number of messages sent before the reset.

    */

   long resetMessageCount();

   /**

    * Closes all connections.

    *

    * @throws IOException

    */

   void closeConnections() throws IOException;

 }