Message.cs :  » Network-Clients » GROF » grof » C# / CSharp Open Source

using System;
using System.Net;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;


namespace grof{
  /// <summary>
  /// <c>Message</c> objects are sent between group
    /// members in order to exchange information. There
    /// are different kinds of messages:
    /// <para>
    /// <list type="bullet">
    /// <item>
    /// JOIN = Indicates that a group member wants to join a group.
    /// </item>
    /// <item>
    /// LEAVE = Indicates that a group member wants to leave a group.
    /// </item>
    /// <item>
    /// APP = Represents an application message which is used by the
    /// framework user.
    /// </item>
    /// <item>
    /// ALIVE = Group members sent this message to other group members
    /// in order to signal that their alive.
    /// </item>
    /// </list>
    /// </para>
    /// <para>
    /// <c>Message</c> objects have to be serializable (=stripped into
    /// bytes) for sending over the network.
    /// </para>
  /// </summary>
  [Serializable]
  public class Message
  {
        /// <summary>
        /// The type of the message.
        /// </summary>
    public enum MessageType { JOIN, LEAVE, JOINED, LEFT, APP, ALIVE };
    
        /// <summary>
        /// Messages sent by a specific group member are numbered 
        /// sequentially (0,1,2,3...)
        /// </summary>
    private long messageCounter;

        /// <summary>
        /// Encapsulates important data about the group member
        /// like member name, host address etc.
        /// </summary>
    private GroupMemberInfo gmInfo;

        /// <summary>
        /// The user data which ought to be transmitted to 
        /// other group members.
        /// </summary>
    private Object data;

        /// <summary>
        /// The variable holding the message type.
        /// </summary>
    private MessageType type;

        /// <summary>
        /// The timestamp when the message was sent.
        /// </summary>
    private long timeStamp;
    
        /// <summary>
        /// Creates instances of class
        /// <c>Message</c>.
        /// </summary>
        /// <param name="type">The message type (JOIN, LEAVE etc.).</param>
        /// <param name="messageCounter">The message counter.</param>
        /// <param name="timeStamp">Indicates when message was sent.</param>
        /// <param name="data">The user data which is sent.</param>
        /// <param name="gmInfo">Encapsulates important group member infos.</param>
    public Message( MessageType type, long messageCounter, long timeStamp, Object data, GroupMemberInfo gmInfo )
    {
      this.type = type;
      this.data = data;
      this.gmInfo = gmInfo;
      this.messageCounter = messageCounter;
      this.timeStamp = timeStamp;
    }
    
        /// <summary>
        /// Serializes the message object into a
        /// byte array.
        /// </summary>
        /// <returns>The byte array containing the
        /// serialized object.</returns>
    public byte[] ToBytes()
    {
      MemoryStream ms = new MemoryStream();
            BinaryFormatter bf = new BinaryFormatter();
            bf.Serialize(ms, this);
            return ms.ToArray();
    }
    
        /// <summary>
        /// Deserializes the byte stream into a
        /// message object.
        /// </summary>
        /// <param name="bytes">The byte array which is 
        /// deserialized.</param>
        /// <returns>The deserialized message object.</returns>
    public static Message FromBytes( byte[] bytes )
    {
      MemoryStream ms = new MemoryStream( bytes );
            BinaryFormatter bf = new BinaryFormatter();
            ms.Position = 0;
            return ( Message ) bf.Deserialize( ms );
    }
    
        /// <summary>
        /// Prints a user friendly representation of the
        /// message object.
        /// </summary>
        /// <returns>The message object as string.</returns>
    public override String ToString()
    {
      return type + "-" + this.messageCounter + "-" + 
        DateTime.FromBinary( this.timeStamp ).ToString() + "-" + 
        gmInfo.ToString() + "-" + this.data;
    }
    
        /// <summary>
        /// Returns the user data.
        /// </summary>
        /// <returns>The user data.</returns>
    public object GetData()
    {
      return this.data;
    }
    
        /// <summary>
        /// Returns the message type.
        /// </summary>
        /// <returns>The message type.</returns>
    public MessageType GetType()
    {
      return this.type;      
    }
    
        /// <summary>
        /// Returns the group member info object.
        /// </summary>
        /// <returns>The group member info.</returns>
    public GroupMemberInfo GetGroupMemberInfo()
    {
      return this.gmInfo;
    }
    
        /// <summary>
        /// Returns the timestamp.
        /// </summary>
        /// <returns>The timestamp of the message
        /// object.</returns>
    public long GetTimeStamp()
    {
      return this.timeStamp;
    }
    
        /// <summary>
        /// Returns the message counter.
        /// </summary>
        /// <returns>The message counter.</returns>
    public long GetMessageCounter()
    {
      return this.messageCounter;
    }
  }
}