using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using Taobao.Top.Link.Channel;
using Top.Api;
namespace Taobao.Top.Link.Endpoints
{
/// deal with protocol/callback/send
///
public class EndpointHandler
{
private ITopLogger _log;
private int _flag;
//all connect in/out endpoints
private IDictionary _idByToken;
private IDictionary _callbacks;
private EventHandler _onMessage;
public Action MessageHandler { get; set; }
public OnAckMessage AckMessageHandler { get; set; }
public EndpointHandler(ITopLogger logger)
{
this._log = logger;
this._idByToken = new Dictionary();
this._callbacks = new Dictionary();
this._onMessage = new EventHandler(this.OnMessage);
}
public void Send(Message message, IChannelSender sender)
{
this.Send(message, sender, null);
}
public void Send(Message message, IChannelSender sender, SendCallback callback)
{
if (callback != null)
{
message.Flag = System.Threading.Interlocked.Increment(ref this._flag);
this._callbacks.Add(message.Flag, callback);
}
using (var s = new MemoryStream())
{
MessageIO.WriteMessage(s, message);
this.GetChannel(sender).Send(s.ToArray());
}
}
internal IDictionary SendAndWait(EndpointProxy e
, IChannelSender sender
, Message message
, int timeout)
{
SendCallback callback = new SendCallback(e);
this.Send(message, sender, callback);
callback.WaitReturn(timeout);
if (callback.Error != null)
throw callback.Error;
return callback.Return;
}
private IClientChannel GetChannel(IChannelSender sender)
{
var channel = sender as IClientChannel;
if (channel.OnMessage == null)
channel.OnMessage = this._onMessage;
return channel;
}
private void OnMessage(object sender, ChannelContext ctx)
{
Message msg = MessageIO.ReadMessage(new MemoryStream((byte[])ctx.Message));
SendCallback callback = this._callbacks.ContainsKey(msg.Flag)
? this._callbacks[msg.Flag]
: null;
if (msg.MessageType == MessageType.CONNECTACK)
{
this.HandleConnectAck(callback, msg);
return;
}
Identity msgFrom = msg.Token != null && this._idByToken.ContainsKey(msg.Token)
? this._idByToken[msg.Token]
: null;
// must CONNECT/CONNECTACK for got token before SEND
if (msgFrom == null)
{
var error = new LinkException(Text.E_UNKNOWN_MSG_FROM);
if (callback == null)
throw error;
callback.Error = error;
return;
}
#region raise callback of client
if (callback != null)
{
this.HandleCallback(callback, msg, msgFrom);
return;
}
else if (this.IsError(msg))
{
this._log.Error(Text.E_GOT_ERROR, msg.StatusCode, msg.StatusPhase);
return;
}
#endregion
#region raise event
if (msg.MessageType == MessageType.SENDACK)
{
if (this.AckMessageHandler != null)
this.AckMessageHandler(msg.Content, msgFrom);
return;
}
if (this.MessageHandler == null)
return;
EndpointContext endpointContext = new EndpointContext(ctx, this, msgFrom, msg.Flag, msg.Token);
endpointContext.Message = msg.Content;
try
{
this.MessageHandler(endpointContext);
}
catch (Exception e)
{
// onMessage error should be reply to client
if (e is LinkException)
endpointContext.Error(
((LinkException)e).ErrorCode,
((LinkException)e).Message);
else
endpointContext.Error(0, e.Message);
}
#endregion
}
private void HandleConnectAck(SendCallback callback, Message msg)
{
if (callback == null)
throw new LinkException(Text.E_NO_CALLBACK);
if (this.IsError(msg))
callback.Error = new LinkException(msg.StatusCode, msg.StatusPhase);
else
{
callback.Return = null;
// set token for proxy for sending message next time
callback.Target.Token = msg.Token;
// store token from target endpoint for receiving it's message
// next time
if (this._idByToken.ContainsKey(msg.Token))
this._idByToken[msg.Token] = callback.Target.Identity;
else
this._idByToken.Add(msg.Token, callback.Target.Identity);
this._log.Info(Text.E_CONNECT_SUCCESS, callback.Target.Identity, msg.Token);
}
}
private void HandleCallback(SendCallback callback, Message msg, Identity msgFrom)
{
if (!callback.Target.Identity.Equals(msgFrom))
{
this._log.Warn(Text.E_IDENTITY_NOT_MATCH_WITH_CALLBACK, msgFrom, callback.Target.Identity);
return;
}
if (this.IsError(msg))
callback.Error = new LinkException(msg.StatusCode, msg.StatusPhase);
else
callback.Return = msg.Content;
}
private bool IsError(Message msg)
{
return msg.StatusCode > 0 || !string.IsNullOrEmpty(msg.StatusPhase);
}
public delegate void OnAckMessage(IDictionary message, Identity messageFrom);
}
}