context: //
  // System.Runtime.Remoting.Channels.SoapServerFormatterSink.cs
  //
  // Authors: 	Duncan Mak (duncan@ximian.com)
  // 		Jean-Marc Andre (jean-marc.andre@polymtl.ca)
  //
  // 2002 (C) Copyright, Ximian, Inc.
  //
  
  //
  // Permission is hereby granted, free of charge, to any person obtaining
  // a copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to
  // permit persons to whom the Software is furnished to do so, subject to
  // the following conditions:
  // 
  // The above copyright notice and this permission notice shall be
  // included in all copies or substantial portions of the Software.
  // 
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  //
  
  using System.Collections;
  using System.IO;
  using System.Reflection;
  using System.Runtime.Remoting.Messaging;
  using System.Runtime.Serialization;
  using System.Runtime.Serialization.Formatters;
  using System.Runtime.Serialization.Formatters.Soap;
  using System.Runtime.InteropServices;
  
  
  namespace System.Runtime.Remoting.Channels {
  
  	/// <summary>
  	//	The formatter sink that uses SoapFormatter
  	/// </summary>
  	// <remarks>
  	// 	The formatter sink deserializes the message from the channel sink
  	// 	and passes the result to the remoting infrastructure
  	// </remark>
  	// 	
  	public class SoapServerFormatterSink : IServerChannelSink, IChannelSinkBase
  	{
  		IServerChannelSink next_sink;
  		IChannelReceiver _receiver;
  		private SoapCore _soapCore = SoapCore.DefaultInstance;
  		
  		public SoapServerFormatterSink (SoapServerFormatterSink.Protocol protocol,
  						IServerChannelSink nextSink,
  						IChannelReceiver receiver)
  		{
  			this.next_sink = nextSink;
  			_receiver = receiver;
  		}
  
  		internal SoapCore SoapCore
  		{
  			get { return _soapCore; }
  			set { _soapCore = value; }
  		}
  		
  		/// <summary>
  		//	Gets the next channel sink in the channel sink chain
  		//  </summary>
  		/// <value>
  		//	The next channel sink in the sink chain
  		//  </value>
  		public IServerChannelSink NextChannelSink {
  			get {
  				return next_sink;
  			}
  		}
  
  		public IDictionary Properties {
  			get {
  				return null;
  			}
  		}
  
  		[ComVisible(false)]
  		public TypeFilterLevel TypeFilterLevel
  		{
  			get { return _soapCore.TypeFilterLevel; }
  			set 
  			{
  				IDictionary props = (IDictionary) ((ICloneable)_soapCore.Properties).Clone ();
  				props ["typeFilterLevel"] = value;
  				_soapCore = new SoapCore (this, props, SoapServerFormatterSinkProvider.AllowedProperties);
  			}
  		}
  
  		public void AsyncProcessResponse (IServerResponseChannelSinkStack sinkStack, object state,
  						  IMessage msg, ITransportHeaders headers, Stream stream)
  						  
  		{
  			ITransportHeaders responseHeaders = new TransportHeaders();
  
  			if(sinkStack != null) stream = sinkStack.GetResponseStream(msg, responseHeaders);
  			if(stream == null) stream = new MemoryStream();
  
  			SoapMessageFormatter soapMsgFormatter = (SoapMessageFormatter)state;
  
  			SoapMessage soapMessage = (SoapMessage) soapMsgFormatter.BuildSoapMessageFromMethodResponse((IMethodReturnMessage)msg, out responseHeaders);
  
  			_soapCore.Serializer.Serialize(stream, soapMessage, null);
  
  			if(stream is MemoryStream) stream.Position = 0;
  			sinkStack.AsyncProcessResponse (msg, responseHeaders, stream);
  		}
  
  		public Stream GetResponseStream (IServerResponseChannelSinkStack sinkStack, object state,
  						IMessage msg, ITransportHeaders headers)
  		{
  			// this method shouldn't be called
  			throw new NotSupportedException ();
  		}
  		
  		public ServerProcessing ProcessMessage (IServerChannelSinkStack sinkStack,
  							IMessage requestMsg, ITransportHeaders requestHeaders, Stream requestStream,
  							out IMessage responseMsg, out ITransportHeaders responseHeaders, out Stream responseStream)
  		{
  			// Check whether the request was already processed by another
  			// formatter sink and pass the request to the next sink if so.
  			if (requestMsg != null)
  				return next_sink.ProcessMessage (sinkStack,
  								 requestMsg,
  								 requestHeaders,
  								 requestStream,
  								 out responseMsg,
  								 out responseHeaders,
  								 out responseStream);
  
  			// Check whether the request is suitable for this formatter
  			// and pass the request to the next sink if not.
  			// Note that a null content-type is handled as suitable,
  			// otherwise no other sink will be able to handle the request.
  			string contentType = requestHeaders["Content-Type"] as string;
  			if (contentType == null || !contentType.StartsWith ("text/xml") || requestHeaders["SOAPAction"] == null) {
  				return next_sink.ProcessMessage (sinkStack,
  					requestMsg,
  					requestHeaders,
  					requestStream,
  					out responseMsg,
  					out responseHeaders,
  					out responseStream);
  			}
  
  			responseMsg = null;
  			responseHeaders = null;
  			responseStream = null;
  
  			ServerProcessing sp;
  			SoapMessageFormatter soapMsgFormatter = new SoapMessageFormatter();
  			sinkStack.Push(this, soapMsgFormatter);
  
  			try {
  				string url = (string)requestHeaders[CommonTransportKeys.RequestUri];
  				string uri;
  				_receiver.Parse(url, out uri);
  				if(uri == null)	uri = url;
  				Type serverType = RemotingServices.GetServerTypeForUri(uri);
  				if (serverType == null) throw new RemotingException ("No receiver for uri " + uri);
  			
  				SoapFormatter fm = _soapCore.GetSafeDeserializer ();
  				SoapMessage soapMessage = soapMsgFormatter.CreateSoapMessage (true);
  				fm.TopObject = soapMessage;
  				fm.Deserialize(requestStream);
  
  				requestMsg = soapMsgFormatter.BuildMethodCallFromSoapMessage(soapMessage, uri);
  				
  				sp = next_sink.ProcessMessage(sinkStack, requestMsg, requestHeaders, null, out responseMsg, out responseHeaders, out responseStream);
  				
  				if(sp == ServerProcessing.Complete) {
  					if(responseMsg != null && responseStream == null) {
  
  						object rtnMessageObject = soapMsgFormatter.BuildSoapMessageFromMethodResponse((IMethodReturnMessage) responseMsg, out responseHeaders);
  						responseStream = new MemoryStream();
  						_soapCore.Serializer.Serialize(responseStream, rtnMessageObject);
  						responseStream.Position = 0;
  					}
  				}
  			}
  			catch(Exception e)
  			{
  				responseMsg = (IMethodReturnMessage)new ReturnMessage(e, (IMethodCallMessage)requestMsg);
  				object rtnMessageObject = soapMsgFormatter.BuildSoapMessageFromMethodResponse((IMethodReturnMessage) responseMsg, out responseHeaders);
  				responseStream = new MemoryStream();
  				_soapCore.Serializer.Serialize(responseStream, rtnMessageObject);
  				responseStream.Position = 0;
  				sp = ServerProcessing.Complete;
  			}
  
  
gt: 			if (sp == ServerProcessing.Complete)