Package org.eclipse.jetty.websocket.core.internal.messages

Class DispatchedMessageSink

java.lang.Object
org.eclipse.jetty.websocket.core.internal.messages.AbstractMessageSink
org.eclipse.jetty.websocket.core.internal.messages.DispatchedMessageSink
All Implemented Interfaces:
MessageSink
Direct Known Subclasses:
InputStreamMessageSink, ReaderMessageSink
public abstract class DispatchedMessageSink extends AbstractMessageSink
Centralized logic for Dispatched Message Handling.

A Dispatched MessageSink can consist of 1 or more accept(Frame, Callback) calls.

The first accept(Frame, Callback) in a message will trigger a dispatch to the function specified in the constructor.

The completion of the dispatched function call is the sign that the next message is suitable for processing from the network. (The connection fillAndParse should remain idle for the NEXT message until such time as the dispatched function call has completed)

There are a few use cases we need to handle.

1. Normal Processing 

     Connection Thread | DispatchedMessageSink | Thread 2
     TEXT                accept()
                          - dispatch -           function.read(stream)
     CONT                accept()                stream.read()
     CONT                accept()                stream.read()
     CONT=fin            accept()                stream.read()
                           EOF                   stream.read EOF
     IDLE
                                                 exit method
     RESUME(NEXT MSG)

2. Early Exit (with no activity) 

     Connection Thread | DispatchedMessageSink | Thread 2
     TEXT                accept()
                          - dispatch -           function.read(stream)
     CONT                accept()                exit method (normal return)
     IDLE
     TIMEOUT

3. Early Exit (due to exception) 

     Connection Thread | DispatchedMessageSink | Thread 2
     TEXT                accept()
                          - dispatch -           function.read(stream)
     CONT                accept()                exit method (throwable)
     callback.fail()
     endpoint.onError()
     close(error)

4. Early Exit (with Custom Threading) 

     Connection Thread | DispatchedMessageSink | Thread 2              | Thread 3
     TEXT                accept()
                          - dispatch -           function.read(stream)
                                                 thread.new(stream)      stream.read()
                                                 exit method
     CONT                accept()                                        stream.read()
     CONT                accept()                                        stream.read()
     CONT=fin            accept()                                        stream.read()
                           EOF                                           stream.read EOF
     RESUME(NEXT MSG)