Package org.apache.qpid.protonj2.engine

Interface Engine

All Superinterfaces:
Consumer<ProtonBuffer>
All Known Implementing Classes:
ProtonEngine
public interface Engine extends Consumer<ProtonBuffer>
AMQP Engine interface.

  • Method Details

    • isWritable

      boolean isWritable()
      Returns true if the engine is accepting input from the ingestion entry points.

      When false any attempts to write more data into the engine will result in an error being returned from the write operation. An engine that has not been started or that has been failed or shutdown will report as not writable.

      Returns:
      true if the engine is current accepting more input.

    • isRunning

      boolean isRunning()
      Returns:
      true if the Engine has entered the running state and is not failed or shutdown.

    • isShutdown

      boolean isShutdown()
      Returns:
      true if the Engine has been shutdown and is no longer usable.

    • isFailed

      boolean isFailed()
      Returns:
      true if the Engine has encountered a critical error and cannot produce new data.

    • failureCause

      Throwable failureCause()
      Returns:
      the error that caused the Engine fail and shutdown (or null if not failed).

    • state

      EngineState state()
      Returns:
      the current state of the engine.

    • connection

      Connection connection()
      Gets the Connection instance that is associated with this Engine instance. It is valid for an engine implementation to not return a Connection instance prior to the engine having been started.
      Returns:
      the Connection that is linked to this engine instance.

    • start

      Connection start() throws EngineStateException
      Starts the engine and returns the Connection instance that is bound to this Engine. A non-started Engine will not allow ingestion of any inbound data and a Connection linked to the engine that was obtained from the connection() method cannot produce any outbound data.
      Returns:
      the Connection instance that is linked to this Engine
      Throws:
      EngineStateException - if the Engine state has already transition to shutdown or failed.

    • shutdown

      Engine shutdown()
      Shutdown the engine preventing any future outbound or inbound processing. When the engine is shut down any resources, Connection, Session or Link instances that have an engine shutdown event handler registered will be notified and should react by locally closing that resource if they wish to ensure that the resource's local close event handler gets signaled if that resource is not already locally closed.
      Returns:
      this Engine

    • engineFailed

      EngineStateException engineFailed(Throwable cause)
      Transition the Engine to a failed state if not already closed or closing. If called when the engine has not failed the engine will be transitioned to the failed state and the method will return an appropriate EngineFailedException that wraps the given cause. If called after the engine was shutdown the method returns an EngineShutdownException indicating that the engine was already shutdown. Repeated calls to this method while the engine is in the failed state must not alter the original failure error or elicit new engine failed event notifications.
      Parameters:
      cause - The exception that caused the engine to be forcibly transitioned to the failed state.
      Returns:
      an EngineStateException that can be thrown indicating the failure and engine state.

    • ingest

      Engine ingest(ProtonBuffer input) throws EngineStateException
      Provide data input for this Engine from some external source. If the engine is not writable when this method is called an EngineNotWritableException will be thrown if unless the reason for the not writable state is due to engine failure or the engine already having been shut down in which case the appropriate EngineStateException will be thrown to indicate the reason.
      Parameters:
      input - The data to feed into to Engine.
      Returns:
      this Engine
      Throws:
      EngineStateException - if the Engine state precludes accepting new input.

    • accept

      default void accept(ProtonBuffer input) throws EngineStateException
      Provide data input for this Engine from some external source. If the engine is not writable when this method is called an EngineNotWritableException will be thrown if unless the reason for the not writable state is due to engine failure or the engine already having been shut down in which case the appropriate EngineStateException will be thrown to indicate the reason.
      Specified by:
      accept in interface Consumer<ProtonBuffer>
      Parameters:
      input - The data to feed into to Engine.
      Throws:
      EngineStateException - if the Engine state precludes accepting new input.

    • tick

      long tick(long currentTime) throws IllegalStateException, EngineStateException
      Prompt the engine to perform idle-timeout/heartbeat handling, and return an absolute deadline in milliseconds that tick must again be called by/at, based on the provided current time in milliseconds, to ensure the periodic work is carried out as necessary. It is an error to call this method if the connection has not been opened. A returned deadline of 0 indicates there is no periodic work necessitating tick be called, e.g. because neither peer has defined an idle-timeout value. The provided milliseconds time values should be derived from a monotonic source such as System.nanoTime() to prevent wall clock changes leading to erroneous behaviour. Note that for System.nanoTime() derived values in particular that the returned deadline could be a different sign than the originally given value, and so (if non-zero) the returned deadline should have the current time originally provided subtracted from it in order to establish a relative time delay to the next deadline. Supplying System.currentTimeMillis() derived values can lead to erroneous behaviour during wall clock changes and so is not recommended. It is an error to call this method if tickAuto(ScheduledExecutorService) was called.
      Parameters:
      currentTime - the current time of this tick call.
      Returns:
      the absolute deadline in milliseconds to next call tick by/at, or 0 if there is none.
      Throws:
      IllegalStateException - if the Engine is already performing auto tick handling.
      EngineStateException - if the Engine state precludes accepting new input.

    • tickAuto

      Engine tickAuto(ScheduledExecutorService executor) throws IllegalStateException, EngineStateException
      Allows the engine to manage idle timeout processing by providing it the single threaded executor context where all transport work is done which ensures singled threaded access while removing the need for the client library or server application to manage calls to the tick(long) methods.
      Parameters:
      executor - The single threaded execution context where all engine work takes place.
      Returns:
      this Engine
      Throws:
      IllegalStateException - if the Engine is already performing auto tick handling.
      EngineStateException - if the Engine state precludes accepting new input.

    • tickAuto

      Engine tickAuto(Scheduler scheduler) throws IllegalStateException, EngineStateException
      Allows the engine to manage idle timeout processing by providing it the single threaded executor context where all transport work is done which ensures singled threaded access while removing the need for the client library or server application to manage calls to the tick(long) methods.
      Parameters:
      scheduler - The single threaded execution context where all engine work takes place.
      Returns:
      this Engine
      Throws:
      IllegalStateException - if the Engine is already performing auto tick handling.
      EngineStateException - if the Engine state precludes accepting new input.

    • pipeline

      EnginePipeline pipeline()
      Gets the EnginePipeline for this Engine.
      Returns:
      the EnginePipeline for this Engine.

    • configuration

      EngineConfiguration configuration()
      Gets the Configuration for this engine.
      Returns:
      the configuration object for this engine.

    • saslDriver

      EngineSaslDriver saslDriver()
      Gets the SASL driver for this engine, if no SASL layer is configured then a default no-op driver must be returned that indicates this. The SASL driver provides the engine with client and server side SASL handshaking support. An Engine implementation can support pluggable SASL drivers or exert tight control over the driver as it sees fit.
      Returns:
      the SASL driver for the engine.

    • outputHandler

      default Engine outputHandler(EventHandler<ProtonBuffer> output)
      Sets a handler instance that will be notified when data from the engine is ready to be written to some output sink (socket etc).
      Parameters:
      output - The ProtonBuffer handler instance that performs IO for the engine output.
      Returns:
      this Engine

    • outputConsumer

      default Engine outputConsumer(Consumer<ProtonBuffer> consumer)
      Sets a Consumer instance that will be notified when data from the engine is ready to be written to some output sink (socket etc).
      Parameters:
      consumer - The ProtonBuffer consumer instance that performs IO for the engine output.
      Returns:
      this Engine

    • outputHandler

      Engine outputHandler(BiConsumer<ProtonBuffer,Runnable> output)
      Sets a BiConsumer instance that will be notified when data from the engine is ready to be written to some output sink (socket etc). The Runnable value provided (if non-null) should be invoked once the I/O operation has completely successfully. If the event of an error writing the data the handler should throw an error or if performed asynchronously the Engine should be marked failed via a call to engineFailed(Throwable).
      Parameters:
      output - The ProtonBuffer handler instance that performs IO for the engine output.
      Returns:
      this Engine

    • errorHandler

      Engine errorHandler(EventHandler<Engine> engineFailure)
      Sets a handler instance that will be notified when the engine encounters a fatal error.
      Parameters:
      engineFailure - The ProtonException handler instance that will be notified if the engine fails.
      Returns:
      this Engine

    • shutdownHandler

      Engine shutdownHandler(EventHandler<Engine> engineShutdownEventHandler)
      Sets a handler instance that will be notified when the engine is shut down via a call to the shutdown() method is called.
      Parameters:
      engineShutdownEventHandler - The Engine instance that was was explicitly shut down.
      Returns:
      this Engine