Use this Global Class Application For Developing Chat Engine
using System;
using System.Threading ;
using System.Web;
using System.Collections;
using System.Collections.Specialized;
using System.Text;
namespace ASPNETChat
{
/// <summary>
/// The business logic of the chat application
/// </summary>
public class ChatEngine
{
private static Hashtable Rooms = new Hashtable(40);
public ChatEngine()
{
}
/// <summary>
/// Deletes the empty chat rooms
/// </summary>
/// <param name="state"></param>
public static void CleanChatRooms(object state)
{
Monitor.Enter(Rooms);
foreach(object key in Rooms.Keys)
{
ChatRoom room=(ChatRoom)Rooms[key.ToString()];
room.ExpireUsers(100);
if (room.IsEmpty())
{
room.Dispose();
Rooms.Remove(key.ToString());
}
}
Monitor.Exit(Rooms);
}
/// <summary>
/// Returns the chat room for this two users or create a new one if nothing exists
/// </summary>
/// <param name="user1ID"></param>
/// <param name="user2ID"></param>
/// <returns></returns>
public static ChatRoom GetRoom(string user1ID,string user2ID)
{
return GetRoom(user1ID,"",user2ID,"");
}
/// <summary>
/// Returns or creats a chat room for these two users or create a new one if nothing exists
/// </summary>
/// <param name="user1ID"></param>
/// <param name="user1Name"></param>
/// <param name="user2ID"></param>
/// <param name="user2Name"></param>
/// <returns></returns>
private static ChatRoom GetRoom(string user1ID,string user1Name,string user2ID,string user2Name)
{
ChatRoom room=null;
string rid1=CreateRoomID(user1ID,user2ID);
string rid2=CreateRoomID(user2ID,user1ID);
Monitor.Enter(Rooms);
if (Rooms.Contains(rid1))
room=(ChatRoom)Rooms[rid1];
else
{
if (Rooms.Contains(rid2))
room=(ChatRoom)Rooms[rid2];
else
{
//if (user1Name=="" && user2Name=="")
// return null;
//else
room=new ChatRoom(user1ID,user1Name,user2ID,user2Name);
Rooms.Add(rid1,room);
}
}
Monitor.Exit(Rooms);
return room;
}
#region Room ID,User IDs Manipulation
/// <summary>
/// Creates the room id using the ids of the two users
/// </summary>
/// <param name="user1"></param>
/// <param name="user2"></param>
/// <returns></returns>
public static string CreateRoomID(string user1,string user2)
{
user1=user1.ToUpper();
user2=user2.ToUpper();
return user1+";"+user2;
}
#endregion
#region Delete Room
/// <summary>
/// Deletes the specified room
/// </summary>
/// <param name="roomID"></param>
public static void DeleteRoom(string roomID)
{
Monitor.Enter(Rooms);
ChatRoom room=(ChatRoom)Rooms[roomID];
room.Dispose();
Rooms.Remove(roomID);
Monitor.Exit(Rooms);
}
public static void DeleteRoom(string user1id,string user2id)
{
DeleteRoom(CreateRoomID(user1id,user2id));
}
#endregion
}
public class ChatRoom : IDisposable
{
//public Hashtable activeUsers = null;
public ArrayList messages = null;
public string RoomID;
private ChatUser FirstUser;
private ChatUser SecondUser;
public void Dispose()
{
this.messages.Clear();
this.RoomID="";
this.FirstUser.Dispose();
this.SecondUser.Dispose();
}
/// <summary>
/// Returns the user with the specified id
/// </summary>
/// <param name="userID"></param>
/// <returns></returns>
public ChatUser GetUser(string userID)
{
userID=userID.ToUpper();
if (FirstUser.UserID.ToUpper()==userID)
return FirstUser;
else
return SecondUser;
}
#region constructors
public ChatRoom(string user1ID,string user1Name,string user2ID,string user2Name)
{
this.messages = new ArrayList();
this.RoomID=ChatEngine.CreateRoomID(user1ID,user2ID);
this.FirstUser=new ChatUser(user1ID,user1Name);
this.SecondUser=new ChatUser(user2ID,user2Name);
}
#endregion
/// <summary>
/// Determines if the users of the room are active or not
/// </summary>
/// <returns></returns>
public bool IsEmpty()
{
lock(this)
{
if (this.FirstUser.IsActive==false&& this.SecondUser.IsActive==false)
return true;
else
return false;
}
}
#region Operations Join,Send,Leave
//
/// <summary>
/// Marks the user as inactive
/// </summary>
/// <param name="userID"></param>
/// <returns></returns>
public string LeaveRoom(string userID)
{
//deactivate user
ChatUser user=this.GetUser(userID);
user.IsActive=false;
user.LastSeen=DateTime.Now;
//Add leaving message
Message msg = new Message(user.UserName ,"",MsgType.Left);
this.AddMsg(msg);
//Get all the messages to the user
int lastMsgID;
ArrayList previousMsgs= this.GetMessagesSince( user.LastMessageReceived,out lastMsgID);
user.LastMessageReceived=lastMsgID;
//return the messages to the user
string str=GenerateMessagesString(previousMsgs);
if (IsEmpty())
ChatEngine.DeleteRoom(this.RoomID);
return "";
}
/// <summary>
/// Activates the user and adds a join message to the room
/// </summary>
/// <param name="userID"></param>
/// <param name="userName"></param>
/// <returns>All the messages sent in the room</returns>
public string JoinRoom(string userID,string userName)
{
//activate user
ChatUser user=this.GetUser(userID);
user.IsActive=true;
user.UserName=userName;
user.LastSeen=DateTime.Now;
//Add join message
Message msg=new Message(user.UserName ,"",MsgType.Join);
this.AddMsg(msg);
//Get all the messages to the user
int lastMsgID;
ArrayList previousMessages=this.GetMessagesSince(-1,out lastMsgID);
user.LastMessageReceived=lastMsgID;
//return the messages to the user
string str=GenerateMessagesString(previousMessages);
return str;
}
/// <summary>
/// Adds a message in the room
/// </summary>
/// <param name="strMsg"></param>
/// <param name="senderID"></param>
/// <param name="toUserID"></param>
/// <returns>All the messages sent from the other user from the last time the user sent a message</returns>
public string SendMessage(string strMsg,string senderID,string toUserID)
{
ChatUser user=this.GetUser(senderID);
Message msg=new Message(user.UserName ,strMsg,MsgType.Msg);
user.LastSeen=DateTime.Now;
this.ExpireUsers(100);
this.AddMsg(msg);
int lastMsgID;
ArrayList previousMsgs= this.GetMessagesSince( user.LastMessageReceived,out lastMsgID);
if (lastMsgID!=-1)
user.LastMessageReceived=lastMsgID;
string res=this.GenerateMessagesString(previousMsgs);
return res;
}
#endregion
/// <summary>
/// Removes the users that hasn't sent any message during the last window secondes
/// </summary>
/// <param name="window">time in secondes</param>
public void ExpireUsers(int window)
{
lock(this)
{
if (this.FirstUser.LastSeen != System.DateTime.MinValue )
{
TimeSpan span = DateTime.Now - this.FirstUser.LastSeen;
if (span.TotalSeconds > window && this.FirstUser.IsActive!=false)
{
this.LeaveRoom(this.FirstUser.UserID);
}
}
if (this.SecondUser.LastSeen != System.DateTime.MinValue )
{
TimeSpan span = DateTime.Now - this.SecondUser.LastSeen;
if (span.TotalSeconds > window && this.SecondUser.IsActive!=false)
{
this.LeaveRoom(this.SecondUser.UserID);
}
}
}
}
/// <summary>
/// Adds a message to the room
/// <param name="msg"></param>
/// <returns> the id of the new message</returns>
public int AddMsg(Message msg)
{
int count;
lock(messages)
{
count = messages.Count;
messages.Add(msg);
}
return count;
}
/// <summary>
/// Iterates over the messages array calling ToString() for each message
/// </summary>
/// <param name="msgs"></param>
/// <returns></returns>
private string GenerateMessagesString(ArrayList msgs)
{
string res="";
for (int i=0;i<msgs.Count;i++)
{
res+=((Message)msgs[i]).ToString()+"\n";
}
return res;
}
/// <summary>
/// Returns an array that contains all messages sent after the message with id=msgid
/// </summary>
/// <param name="msgid">The id of the message after which all the message will be retuned </param>
/// <param name="lastMsgID">the id of the last message returned</param>
/// <returns></returns>
public ArrayList GetMessagesSince(int msgid,out int lastMsgID)
{
lock(messages)
{
if ((messages.Count) <= (msgid+1))
lastMsgID=-1;
else
lastMsgID=messages.Count-1;
return messages.GetRange(msgid+1 , messages.Count - (msgid+1));
}
}
/// <summary>
/// Returns all the messages sent since the last message the user received
/// </summary>
/// <param name="userID"></param>
/// <returns></returns>
public string UpdateUser(string userID)
{
ChatUser user=this.GetUser(userID);
user.LastSeen=DateTime.Now;
this.ExpireUsers(100);
int lastMsgID;
ArrayList previousMsgs= this.GetMessagesSince( user.LastMessageReceived,out lastMsgID);
if (lastMsgID!=-1)
user.LastMessageReceived=lastMsgID;
string res=this.GenerateMessagesString(previousMsgs);
return res;
}
}
#region the ChatUser Class
public class ChatUser : IDisposable
{
public string UserID;
public string UserName;
public bool IsActive;
public DateTime LastSeen;
public int LastMessageReceived;
public ChatUser(string id,string userName)
{
this.UserID=id;
this.IsActive=false;
this.LastSeen=DateTime.MinValue ;
this.UserName=userName;
this.LastMessageReceived=0;
}
public void Dispose()
{
this.UserID="";
this.IsActive=false;
this.LastSeen=DateTime.MinValue ;
this.UserName="";
this.LastMessageReceived=0;
}
}
#endregion
#region the Message Class
public class Message
{
public string user;
public string msg;
public MsgType type;
public Message(string _user, string _msg, MsgType _type)
{
user = _user;
msg = _msg;
type = _type;
}
public override string ToString()
{
switch(this.type)
{
case MsgType.Msg:
return this.user+" says: "+this.msg;
case MsgType.Join :
return this.user + " has joined the room";
case MsgType.Left :
return this.user + " has left the room";
}
return "";
}
public Message(string _user, MsgType _type) : this(_user, "", _type) { }
public Message(MsgType _type) : this("", "", _type) { }
}
public enum MsgType { Msg, Start, Join, Left, Action }
#endregion
}
using System.Threading ;
using System.Web;
using System.Collections;
using System.Collections.Specialized;
using System.Text;
namespace ASPNETChat
{
/// <summary>
/// The business logic of the chat application
/// </summary>
public class ChatEngine
{
private static Hashtable Rooms = new Hashtable(40);
public ChatEngine()
{
}
/// <summary>
/// Deletes the empty chat rooms
/// </summary>
/// <param name="state"></param>
public static void CleanChatRooms(object state)
{
Monitor.Enter(Rooms);
foreach(object key in Rooms.Keys)
{
ChatRoom room=(ChatRoom)Rooms[key.ToString()];
room.ExpireUsers(100);
if (room.IsEmpty())
{
room.Dispose();
Rooms.Remove(key.ToString());
}
}
Monitor.Exit(Rooms);
}
/// <summary>
/// Returns the chat room for this two users or create a new one if nothing exists
/// </summary>
/// <param name="user1ID"></param>
/// <param name="user2ID"></param>
/// <returns></returns>
public static ChatRoom GetRoom(string user1ID,string user2ID)
{
return GetRoom(user1ID,"",user2ID,"");
}
/// <summary>
/// Returns or creats a chat room for these two users or create a new one if nothing exists
/// </summary>
/// <param name="user1ID"></param>
/// <param name="user1Name"></param>
/// <param name="user2ID"></param>
/// <param name="user2Name"></param>
/// <returns></returns>
private static ChatRoom GetRoom(string user1ID,string user1Name,string user2ID,string user2Name)
{
ChatRoom room=null;
string rid1=CreateRoomID(user1ID,user2ID);
string rid2=CreateRoomID(user2ID,user1ID);
Monitor.Enter(Rooms);
if (Rooms.Contains(rid1))
room=(ChatRoom)Rooms[rid1];
else
{
if (Rooms.Contains(rid2))
room=(ChatRoom)Rooms[rid2];
else
{
//if (user1Name=="" && user2Name=="")
// return null;
//else
room=new ChatRoom(user1ID,user1Name,user2ID,user2Name);
Rooms.Add(rid1,room);
}
}
Monitor.Exit(Rooms);
return room;
}
#region Room ID,User IDs Manipulation
/// <summary>
/// Creates the room id using the ids of the two users
/// </summary>
/// <param name="user1"></param>
/// <param name="user2"></param>
/// <returns></returns>
public static string CreateRoomID(string user1,string user2)
{
user1=user1.ToUpper();
user2=user2.ToUpper();
return user1+";"+user2;
}
#endregion
#region Delete Room
/// <summary>
/// Deletes the specified room
/// </summary>
/// <param name="roomID"></param>
public static void DeleteRoom(string roomID)
{
Monitor.Enter(Rooms);
ChatRoom room=(ChatRoom)Rooms[roomID];
room.Dispose();
Rooms.Remove(roomID);
Monitor.Exit(Rooms);
}
public static void DeleteRoom(string user1id,string user2id)
{
DeleteRoom(CreateRoomID(user1id,user2id));
}
#endregion
}
public class ChatRoom : IDisposable
{
//public Hashtable activeUsers = null;
public ArrayList messages = null;
public string RoomID;
private ChatUser FirstUser;
private ChatUser SecondUser;
public void Dispose()
{
this.messages.Clear();
this.RoomID="";
this.FirstUser.Dispose();
this.SecondUser.Dispose();
}
/// <summary>
/// Returns the user with the specified id
/// </summary>
/// <param name="userID"></param>
/// <returns></returns>
public ChatUser GetUser(string userID)
{
userID=userID.ToUpper();
if (FirstUser.UserID.ToUpper()==userID)
return FirstUser;
else
return SecondUser;
}
#region constructors
public ChatRoom(string user1ID,string user1Name,string user2ID,string user2Name)
{
this.messages = new ArrayList();
this.RoomID=ChatEngine.CreateRoomID(user1ID,user2ID);
this.FirstUser=new ChatUser(user1ID,user1Name);
this.SecondUser=new ChatUser(user2ID,user2Name);
}
#endregion
/// <summary>
/// Determines if the users of the room are active or not
/// </summary>
/// <returns></returns>
public bool IsEmpty()
{
lock(this)
{
if (this.FirstUser.IsActive==false&& this.SecondUser.IsActive==false)
return true;
else
return false;
}
}
#region Operations Join,Send,Leave
//
/// <summary>
/// Marks the user as inactive
/// </summary>
/// <param name="userID"></param>
/// <returns></returns>
public string LeaveRoom(string userID)
{
//deactivate user
ChatUser user=this.GetUser(userID);
user.IsActive=false;
user.LastSeen=DateTime.Now;
//Add leaving message
Message msg = new Message(user.UserName ,"",MsgType.Left);
this.AddMsg(msg);
//Get all the messages to the user
int lastMsgID;
ArrayList previousMsgs= this.GetMessagesSince( user.LastMessageReceived,out lastMsgID);
user.LastMessageReceived=lastMsgID;
//return the messages to the user
string str=GenerateMessagesString(previousMsgs);
if (IsEmpty())
ChatEngine.DeleteRoom(this.RoomID);
return "";
}
/// <summary>
/// Activates the user and adds a join message to the room
/// </summary>
/// <param name="userID"></param>
/// <param name="userName"></param>
/// <returns>All the messages sent in the room</returns>
public string JoinRoom(string userID,string userName)
{
//activate user
ChatUser user=this.GetUser(userID);
user.IsActive=true;
user.UserName=userName;
user.LastSeen=DateTime.Now;
//Add join message
Message msg=new Message(user.UserName ,"",MsgType.Join);
this.AddMsg(msg);
//Get all the messages to the user
int lastMsgID;
ArrayList previousMessages=this.GetMessagesSince(-1,out lastMsgID);
user.LastMessageReceived=lastMsgID;
//return the messages to the user
string str=GenerateMessagesString(previousMessages);
return str;
}
/// <summary>
/// Adds a message in the room
/// </summary>
/// <param name="strMsg"></param>
/// <param name="senderID"></param>
/// <param name="toUserID"></param>
/// <returns>All the messages sent from the other user from the last time the user sent a message</returns>
public string SendMessage(string strMsg,string senderID,string toUserID)
{
ChatUser user=this.GetUser(senderID);
Message msg=new Message(user.UserName ,strMsg,MsgType.Msg);
user.LastSeen=DateTime.Now;
this.ExpireUsers(100);
this.AddMsg(msg);
int lastMsgID;
ArrayList previousMsgs= this.GetMessagesSince( user.LastMessageReceived,out lastMsgID);
if (lastMsgID!=-1)
user.LastMessageReceived=lastMsgID;
string res=this.GenerateMessagesString(previousMsgs);
return res;
}
#endregion
/// <summary>
/// Removes the users that hasn't sent any message during the last window secondes
/// </summary>
/// <param name="window">time in secondes</param>
public void ExpireUsers(int window)
{
lock(this)
{
if (this.FirstUser.LastSeen != System.DateTime.MinValue )
{
TimeSpan span = DateTime.Now - this.FirstUser.LastSeen;
if (span.TotalSeconds > window && this.FirstUser.IsActive!=false)
{
this.LeaveRoom(this.FirstUser.UserID);
}
}
if (this.SecondUser.LastSeen != System.DateTime.MinValue )
{
TimeSpan span = DateTime.Now - this.SecondUser.LastSeen;
if (span.TotalSeconds > window && this.SecondUser.IsActive!=false)
{
this.LeaveRoom(this.SecondUser.UserID);
}
}
}
}
/// <summary>
/// Adds a message to the room
/// <param name="msg"></param>
/// <returns> the id of the new message</returns>
public int AddMsg(Message msg)
{
int count;
lock(messages)
{
count = messages.Count;
messages.Add(msg);
}
return count;
}
/// <summary>
/// Iterates over the messages array calling ToString() for each message
/// </summary>
/// <param name="msgs"></param>
/// <returns></returns>
private string GenerateMessagesString(ArrayList msgs)
{
string res="";
for (int i=0;i<msgs.Count;i++)
{
res+=((Message)msgs[i]).ToString()+"\n";
}
return res;
}
/// <summary>
/// Returns an array that contains all messages sent after the message with id=msgid
/// </summary>
/// <param name="msgid">The id of the message after which all the message will be retuned </param>
/// <param name="lastMsgID">the id of the last message returned</param>
/// <returns></returns>
public ArrayList GetMessagesSince(int msgid,out int lastMsgID)
{
lock(messages)
{
if ((messages.Count) <= (msgid+1))
lastMsgID=-1;
else
lastMsgID=messages.Count-1;
return messages.GetRange(msgid+1 , messages.Count - (msgid+1));
}
}
/// <summary>
/// Returns all the messages sent since the last message the user received
/// </summary>
/// <param name="userID"></param>
/// <returns></returns>
public string UpdateUser(string userID)
{
ChatUser user=this.GetUser(userID);
user.LastSeen=DateTime.Now;
this.ExpireUsers(100);
int lastMsgID;
ArrayList previousMsgs= this.GetMessagesSince( user.LastMessageReceived,out lastMsgID);
if (lastMsgID!=-1)
user.LastMessageReceived=lastMsgID;
string res=this.GenerateMessagesString(previousMsgs);
return res;
}
}
#region the ChatUser Class
public class ChatUser : IDisposable
{
public string UserID;
public string UserName;
public bool IsActive;
public DateTime LastSeen;
public int LastMessageReceived;
public ChatUser(string id,string userName)
{
this.UserID=id;
this.IsActive=false;
this.LastSeen=DateTime.MinValue ;
this.UserName=userName;
this.LastMessageReceived=0;
}
public void Dispose()
{
this.UserID="";
this.IsActive=false;
this.LastSeen=DateTime.MinValue ;
this.UserName="";
this.LastMessageReceived=0;
}
}
#endregion
#region the Message Class
public class Message
{
public string user;
public string msg;
public MsgType type;
public Message(string _user, string _msg, MsgType _type)
{
user = _user;
msg = _msg;
type = _type;
}
public override string ToString()
{
switch(this.type)
{
case MsgType.Msg:
return this.user+" says: "+this.msg;
case MsgType.Join :
return this.user + " has joined the room";
case MsgType.Left :
return this.user + " has left the room";
}
return "";
}
public Message(string _user, MsgType _type) : this(_user, "", _type) { }
public Message(MsgType _type) : this("", "", _type) { }
}
public enum MsgType { Msg, Start, Join, Left, Action }
#endregion
}
