de.esoco.coroutine.step.nio

Class AsynchronousSocketStep

java.lang.Object

org.obrel.core.RelatedObject

de.esoco.coroutine.CoroutineStep<I,O>

de.esoco.coroutine.step.nio.AsynchronousChannelStep<java.nio.ByteBuffer,java.nio.ByteBuffer>

de.esoco.coroutine.step.nio.AsynchronousSocketStep

All Implemented Interfaces:

de.esoco.lib.property.Fluent<CoroutineStep<java.nio.ByteBuffer,java.nio.ByteBuffer>>, org.obrel.core.FluentRelatable<CoroutineStep<java.nio.ByteBuffer,java.nio.ByteBuffer>>, org.obrel.core.Relatable

Direct Known Subclasses:

SocketReceive, SocketSend

public abstract class AsynchronousSocketStep
extends AsynchronousChannelStep<java.nio.ByteBuffer,java.nio.ByteBuffer>

The base class for coroutine steps that perform communication on instances of AsynchronousSocketChannel. The channel will be opened and connected as necessary. It may also be provided before the step is invoked in a state relation with the type SOCKET_CHANNEL. If the channel is opened by this step it will have the MetaTypes.MANAGED flag so that it will be automatically closed when the CoroutineScope finishes.

Nested Class Summary

Nested classes/interfaces inherited from class de.esoco.coroutine.step.nio.AsynchronousChannelStep

AsynchronousChannelStep.ChannelCallback<V,C extends java.nio.channels.AsynchronousChannel>, AsynchronousChannelStep.ChannelOperation<C extends java.nio.channels.AsynchronousChannel>

Field Summary

Fields

Modifier and Type	Field and Description
static org.obrel.core.RelationType<java.nio.channels.AsynchronousSocketChannel>	SOCKET_CHANNEL State: the AsynchronousSocketChannel that the steps in a coroutine operate on.

Fields inherited from class de.esoco.coroutine.step.nio.AsynchronousChannelStep

CHANNEL_GROUP

Constructor Summary

Constructors

Constructor and Description
AsynchronousSocketStep(java.util.function.Function<Continuation<?>,java.net.SocketAddress> fGetSocketAddress) Creates a new instance that connects to the socket with the address provided by the given factory.

Method Summary

Modifier and Type	Method and Description
protected java.nio.ByteBuffer	execute(java.nio.ByteBuffer rData, Continuation<?> rContinuation) This method must be implemented by subclasses to provide the actual functionality of this step.
protected java.net.SocketAddress	getSocketAddress(Continuation<?> rContinuation) Returns the address of the socket to connect to.
protected java.util.function.Function<Continuation<?>,java.net.SocketAddress>	getSocketAddressFactory() Returns the socket address factory of this step.
protected java.nio.channels.AsynchronousSocketChannel	getSocketChannel(Continuation<?> rContinuation) Returns the channel to be used by this step.
protected abstract boolean	performAsyncOperation(int nBytesProcessed, java.nio.channels.AsynchronousSocketChannel rChannel, java.nio.ByteBuffer rData, AsynchronousChannelStep.ChannelCallback<java.lang.Integer,java.nio.channels.AsynchronousSocketChannel> rCallback) Implementation of the ChannelOperation functional interface method signature.
protected abstract void	performBlockingOperation(java.nio.channels.AsynchronousSocketChannel aChannel, java.nio.ByteBuffer rData) Must be implemented for the blocking execution of a step.
void	runAsync(java.util.concurrent.CompletableFuture<java.nio.ByteBuffer> fPreviousExecution, CoroutineStep<java.nio.ByteBuffer,?> rNextStep, Continuation<?> rContinuation) Runs this execution step asynchronously as a continuation of a previous code execution in a CompletableFuture and proceeds to the next step afterwards.

Methods inherited from class de.esoco.coroutine.step.nio.AsynchronousChannelStep

getChannelGroup

Methods inherited from class de.esoco.coroutine.CoroutineStep

fail, runBlocking, terminateCoroutine, toString

Methods inherited from class org.obrel.core.RelatedObject

deleteRelation, get, getRelation, getRelations, notifyRelationListeners, readRelations, relationsEqual, relationsHashCode, relationsString, set, set, transform, writeRelations

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.obrel.core.FluentRelatable

with, with, with

Methods inherited from interface org.obrel.core.Relatable

deleteRelation, deleteRelation, deleteRelations, get, get, get, getAll, getRelation, getRelationCount, getRelations, getRelations, hasFlag, hasRelation, hasRelations, init, set, set, set, set, set, streamRelations, transform

Methods inherited from interface de.esoco.lib.property.Fluent

_with

Field Detail

SOCKET_CHANNEL

public static final org.obrel.core.RelationType<java.nio.channels.AsynchronousSocketChannel> SOCKET_CHANNEL

State: the AsynchronousSocketChannel that the steps in a coroutine operate on.

Constructor Detail

AsynchronousSocketStep

public AsynchronousSocketStep(java.util.function.Function<Continuation<?>,java.net.SocketAddress> fGetSocketAddress)

Creates a new instance that connects to the socket with the address provided by the given factory. The factory may return NULL if the step should connect to a channel that is stored in a state relation with the type SOCKET_CHANNEL.

Parameters:

fGetSocketAddress - A function that provides the socket address to connect to from the current continuation

Method Detail

runAsync

public void runAsync(java.util.concurrent.CompletableFuture<java.nio.ByteBuffer> fPreviousExecution,
                     CoroutineStep<java.nio.ByteBuffer,?> rNextStep,
                     Continuation<?> rContinuation)

Runs this execution step asynchronously as a continuation of a previous code execution in a CompletableFuture and proceeds to the next step afterwards.

Subclasses that need to suspend the invocation of the next step until some condition is met (e.g. sending or receiving data has finished) need to override this method and create a Suspension by invoking Continuation.suspend(CoroutineStep, CoroutineStep) on the next step. If the condition that caused the suspension resolves the coroutine execution can be resumed by calling Suspension.resume(Object).

Subclasses that override this method also need to handle errors by terminating any further execution (i.e. not resuming a suspension if such exists) and forwarding the causing exception to Continuation.fail(Throwable).

Overrides:

runAsync in class CoroutineStep<java.nio.ByteBuffer,java.nio.ByteBuffer>

Parameters:

fPreviousExecution - The future of the previous code execution

rNextStep - The next step to execute or NULL for none

rContinuation - The continuation of the execution

performAsyncOperation

protected abstract boolean performAsyncOperation(int nBytesProcessed,
                                                 java.nio.channels.AsynchronousSocketChannel rChannel,
                                                 java.nio.ByteBuffer rData,
                                                 AsynchronousChannelStep.ChannelCallback<java.lang.Integer,java.nio.channels.AsynchronousSocketChannel> rCallback)
                                          throws java.lang.Exception

Implementation of the ChannelOperation functional interface method signature.

Throws:

java.lang.Exception

See Also:

AsynchronousChannelStep.ChannelOperation.execute(int,java.nio.channels.AsynchronousChannel, ByteBuffer, AsynchronousChannelStep.ChannelCallback)

performBlockingOperation

protected abstract void performBlockingOperation(java.nio.channels.AsynchronousSocketChannel aChannel,
                                                 java.nio.ByteBuffer rData)
                                          throws java.lang.Exception

Must be implemented for the blocking execution of a step. It receives an AsynchronousSocketChannel which must be accessed through the blocking API (like Future.get()).

Parameters:

aChannel - The channel to perform the operation on

rData - The byte buffer for the operation data

Throws:

java.lang.Exception - Any kind of exception may be thrown

execute

protected java.nio.ByteBuffer execute(java.nio.ByteBuffer rData,
                                      Continuation<?> rContinuation)

This method must be implemented by subclasses to provide the actual functionality of this step.

Specified by:

execute in class CoroutineStep<java.nio.ByteBuffer,java.nio.ByteBuffer>

Parameters:

rData - The input value

rContinuation - The continuation of the execution

Returns:

The result of the execution

getSocketAddress

protected java.net.SocketAddress getSocketAddress(Continuation<?> rContinuation)

Returns the address of the socket to connect to.

Parameters:

rContinuation - The current continuation

Returns:

The socket address

getSocketAddressFactory

protected java.util.function.Function<Continuation<?>,java.net.SocketAddress> getSocketAddressFactory()

Returns the socket address factory of this step.

Returns:

The socket address factory function

getSocketChannel

protected java.nio.channels.AsynchronousSocketChannel getSocketChannel(Continuation<?> rContinuation)
                                                                throws java.io.IOException

Returns the channel to be used by this step. This first checks the currently exexcuting coroutine in the continuation parameter for an existing SOCKET_CHANNEL relation. If that doesn't exists or the channel is closed a new AsynchronousSocketChannel will be opened and stored in the coroutine relation. Using the coroutine to store the channel allows coroutines to be structured so that multiple subroutines perform communication on different channels.

Parameters:

rContinuation - The continuation to query for an existing channel

Returns:

The socket channel

Throws:

java.io.IOException - If opening the channel fails