WCF (Indigo): Under the Hood of the Channel Layer

1. WCF (Indigo): Under the Hood of the Channel Layer Steve Swartz COM416 Architect Microsoft Corporation

2. C C C B B B A A A From the Outside Client Service Bv Bv Message Bv Bv Address Binding Contract (Where) (How) (What)

3. C C B B A A From the Inside Service Bv Bv

4. Positioning This Talk • This Talk • How Does the Channel Layer Work? • Why Do You Care? • Other Talks • How Does the ServiceModel Work? • COM417: Thursday, 10:00am • How Do You Build XML Messaging Apps? • COM326: Thursday, 5:15pm • How Do You Build Channels? • COM424: Thursday, 3:45pm • How Do You Hook Channels Into WebHost? • COM413: Friday, 1:00pm

5. Big Ideas • Bindings: How You Use The Channel Layer • Bindings Are Easy & Extensible • Channels: How Messages Are Exchanged • Channels have Shape, Capabilities, Stacks • Factories: How Channels Are Created

6. Factory Factory Factory Listener Listener Listener Channel Channel Channel Channel Channel Channel The Talk-In-A-Slide Binding Binding Factory Listener CreateChannel<T>() AcceptChannel() Channel Channel Send() Receive() Message

7. Factory Factory Factory Listener Listener Listener Channel Channel Channel Channel Channel Channel Agenda: Message Binding Binding Factory Listener CreateChannel<T>() AcceptChannel() Channel Channel Send() Receive() Message

8. Message: The Basics • CLR Representation of SOAP Infoset • Supports SOAP 1.1 / SOAP 1.2 • Encoding-Agnostic • Stream-Oriented public abstract class Message : IDisposable { public abstract MessageHeaders Headers { get; } public abstract MessageProperties Properties { get; } public abstract MessageVersion Version { get; } public T GetBody<T>() { } static public Message CreateMessage(...) { } public void WriteMessage(XmlWriter writer) { } }

9. Message: Constructors • Select Action • Select Message Version • Select Formatter • Body as Object, XMLReader • Special Support for Faults, Replies

10. Factory Factory Factory Listener Listener Listener Channel Channel Channel Channel Channel Channel Agenda: Bindings Binding Binding Factory Listener CreateChannel<T>() AcceptChannel() Channel Channel Send() Receive() Message

11. C C C B B B A A A Bindings: What Are They? Client Service Message Address Binding Contract (Where) (How) (What)

12. Bindings: Out of the Box T = Transport Security | S = WS-Security | O = One-Way Only

13. Bindings: Scenarios • Shipping Channels • Change defaults • Change options • Change set of channels used • Future Channels • Change versions, functionality • Preserve app code • Custom Channels • Binding benefits for any channel

14. Binding: Object Model public abstract class Binding : IDefaultCommunicationTimeouts { protected Binding() { } public abstract string Scheme { get; set{} } public TimeSpan OpenTimeout { get; set{} } public TimeSpan SendTimeout { get; set{} } public TimeSpan ReceiveTimeout { get; set{} } public TimeSpan CloseTimeout { get; set{} } public virtual IChannelFactory<TChannel> BuildChannelFactory<TChannel>(BindingParameterCollection p) {} public virtual IChannelListener<TChannel> BuildChannelListener<TChannel>(BindingParameterCollection p) {} }

15. Bindings: Build Your Own • Subclass Binding • An (Internal) Binding Element Collection • Completely Defines Binding, Channel Stack • A Constructor • Loads and Initializes B.E. Collection • A Public API • Simplifies Working With B.E. Collection

16. Binding: Binding Elements public abstract class BindingElement { protected BindingElement() { } public virtual IChannelFactory<TChannel> BuildChannelFactory<TChannel>(ChannelBuildContext context) {} public virtual IChannelListener<TChannel> BuildChannelListener<TChannel>(ChannelBuildContext context) {} } public class ChannelBuildContext { public ChannelBuildContext() {} public BindingElementCollection UnhandledBindingElements { get; } public BindingParameterCollection BindingParameters { get; } public IChannelFactory<TChan> BuildInnerChannelFactory<TChan>() {} public IChannelListener<TChan> BuildInnerChannelListener<TChan>(){} BindingElement RemoveNextElement(){} }

17. Bindings: Building Factories • Call “Build()” on First Binding Element • It Builds Its Factory • It Optionally Consumes Binding Elements • It Optionally Consumes Binding Parameters • It Calls “BuildInner()” on BuildContext • It Wires Inner Factory to Itself • It Returns

18. Factory Factory Factory Listener Listener Listener Channel Channel Channel Channel Channel Channel Agenda: Factories Binding Binding Factory Listener CreateChannel<T>() AcceptChannel() Channel Channel Send() Receive() Message

19. Factories: In Perspective • Apps use Channels • Factories Create Channels • Factories Share Resources • Per Process • Per Machine Channel Factory Process Manager MachineManager

20. ICommunicationObject • Implemented by all channels, factories public interface ICommunicationObject : IDisposable { // Created, Opening, Opened, Closing, Closed, Faulted CommunicationState State { get; } event EventHandler Closed; event EventHandler Closing; event EventHandler Faulted; event EventHandler Opened; event EventHandler Opening; // Async Calls Available, Too void Open(); void Close(); void Abort(); }

21. IChannelManager • Implemented by all channels, factories public interface IChannelManager : ICommunicationObject { MessageVersion MessageVersion { get; } string Scheme { get; } ReadOnlyCollection<IChannel> GetChannels(); T GetProperty<T>() where T : class; }

22. Factories: The Client • Clients Initiate Connections • One contract, one binding, many addresses • Async methods available public interface IChannelFactory<TChannel> : IChannelFactory { TChannel CreateChannel(string address); TChannel CreateChannel(Uri address); TChannel CreateChannel(EndpointAddress to); } public interface IChannelFactory : IChannelManager { }

23. Factories: The Service • Services Passively Wait For Connectinons • One address, one binding, many contracts • Async methods available public interface IChannelListener<TChannel> : IChannelListener { void SetUri( /* … */ ); bool WaitForChannel(TimeSpan timeout); TChannel AcceptChannel(); TChannel AcceptChannel(TimeSpan timeout); } public interface IChannelListener : IChannelManager { }

24. Factory Factory Factory Listener Listener Listener Channel Channel Channel Channel Channel Channel Agenda: Channels Binding Binding Factory Listener CreateChannel<T>() AcceptChannel() Channel Channel Send() Receive() Message

25. Channels: Three Shapes public interface IOutputChannel : IChannel { void Send(Message message); } public interface IInputChannel : IChannel { Message Receive(); } public interface IDuplexChannel : IInputChannel, IOutputChannel { } public interface IRequestChannel : IChannel { Message Request(Message message); } public interface IReplyChannel : IChannel { IRequestContext ReceiveRequest(); } public interface IRequestContext : IDisposable { Message RequestMessage { get; } void Reply(Message message); }

26. Channels: Sessions public interface ISession { string Id { get; } } public interface ISessionChannel<SessionType> where SessionType : ISession { SessionType Session { get; } } public interface IInputSession : ISession { } public interface IInputSessionChannel : IInputChannel, ISessionChannel<IInputSession> { }

27. Channel Families: Transports Channel Channel Channel Transport

28. Channel Families: Encoders Channel Channel Channel Channel Encoder

29. Channel Channel Channel Families: Dual Channel DualChannel

30. Channel Families: Protocols ProtocolChannel EP EP ProtocolChannel TransportChannel TransportChannel M M Message M M

31. In Summary • Bindings: How You Use The Channel Layer • Bindings Are Easy & Also Extensible • Channels: How Messages Are Exchanged • Channels have Shape, Capabilities, Stacks • Factories: How Channels Are Created

32. Community Resources • At PDC • For more information, go see • Service Model Internals: COM417, Thursday, 10:00am • XML Messaging: COM326, Thursday, 5:15pm • Building Channels: COM424, Thursday, 3:45pm • WebHost Integration: COM413, Friday, 1:00pm • Ask The Experts table: WCF Internals • I’ll be at COM Track lounge: Thu 3:30-6:30pm, Fri 8:30-11am • After PDC • If you miss some of these sessions, watch the DVD! • MSDN dev center • The WCF newsgroup • Channel 9 tag

33. © 2005 Microsoft Corporation. All rights reserved. This presentation is for informational purposes only. Microsoft makes no warranties, express or implied, in this summary.