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//
//   http://www.apache.org/licenses/LICENSE-2.0
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using System.Collections.Generic;
using Org.Apache.REEF.Network.Group.Pipelining.Impl;
using Org.Apache.REEF.Tang.Annotations;
using Org.Apache.REEF.Tang.Interface;

namespace Org.Apache.REEF.Network.Group.Pipelining
{
    /// <summary>
    /// User specified class to convert the message to be communicated in to pipelining 
    /// amenable data and vice-versa 
    /// </summary>
    /// <typeparam name="T">The message type</typeparam>
    //// [DefaultImplementation(typeof(DefaultPipelineDataConverter<>))]
    public interface IPipelineDataConverter<T>
    {
        /// <summary>
        /// Converts the original message to be communicated in to a vector of pipelined messages.
        /// Each element of vector is communicated as a single logical unit.
        /// </summary>
        /// <param name="message">The original message</param>
        /// <returns>The list of pipelined messages</returns>
        List<PipelineMessage<T>> PipelineMessage(T message);

        /// <summary>
        /// Constructs the full final message from the vector of communicated pipelined messages
        /// </summary>
        /// <param name="pipelineMessage">The enumerator over received pipelined messages</param>
        /// <returns>The full constructed message</returns>
        T FullMessage(List<PipelineMessage<T>> pipelineMessage);
    }
}