de.esoco.coroutine.step.nio

Class FileRead

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.AsynchronousFileStep

de.esoco.coroutine.step.nio.FileRead

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

public class FileRead
extends AsynchronousFileStep

Implements asynchronous reading from a AsynchronousFileChannel.

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 inherited from class de.esoco.coroutine.step.nio.AsynchronousFileStep

FILE_CHANNEL, FILE_POSITION

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

CHANNEL_GROUP

Constructor Summary

Constructors

Constructor and Description
FileRead(java.util.function.Function<Continuation<?>,java.nio.channels.AsynchronousFileChannel> fGetFileChannel, java.util.function.BiPredicate<java.lang.Integer,java.nio.ByteBuffer> pCheckFinished) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
protected boolean	performAsyncOperation(int nBytesRead, java.nio.channels.AsynchronousFileChannel rChannel, java.nio.ByteBuffer rData, AsynchronousChannelStep.ChannelCallback<java.lang.Integer,java.nio.channels.AsynchronousFileChannel> rCallback) Implementation of the ChannelOperation functional interface method signature.
protected void	performBlockingOperation(java.nio.channels.AsynchronousFileChannel aChannel, java.nio.ByteBuffer rData) Must be implemented for the blocking execution of a step.
static AsynchronousFileStep	readFrom(java.util.function.Function<Continuation<?>,java.nio.channels.AsynchronousFileChannel> fGetFileChannel) Suspends until a file has been read completely.
static AsynchronousFileStep	readFrom(java.lang.String sFileName, java.nio.file.OpenOption... rExtraOptions) Invokes readFrom(Function) with a function that opens a file channel with the given file name and options.
AsynchronousFileStep	until(java.util.function.BiPredicate<java.lang.Integer,java.nio.ByteBuffer> pCheckFinished) Returns a new read step instance the suspends until data has been read from a file and a certain condition on that data is met or an end-of-stream signal is received.

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

execute, getFileChannel, getFileChannelFactory, openFileChannel, runAsync

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

Constructor Detail

FileRead

public FileRead(java.util.function.Function<Continuation<?>,java.nio.channels.AsynchronousFileChannel> fGetFileChannel,
                java.util.function.BiPredicate<java.lang.Integer,java.nio.ByteBuffer> pCheckFinished)

Creates a new instance.

Parameters:

fGetFileChannel - A function that provides the file channel from the current continuation

pCheckFinished - A predicate that checks whether the operation is complete by evaluating the byte buffer after reading

Method Detail

readFrom

public static AsynchronousFileStep readFrom(java.util.function.Function<Continuation<?>,java.nio.channels.AsynchronousFileChannel> fGetFileChannel)

Suspends until a file has been read completely. The data will be stored in the input ByteBuffer of the step. If the capacity of the buffer is reached before the EOF signal is received the coroutine will be terminated with a CoroutineException. To stop reading when a certain condition is met a derived step can be created with #until(Predicate).

After the data has been fully received Buffer.flip() will be invoked on the buffer so that it can be used directly for subsequent reading from it.

Parameters:

fGetFileChannel - A function that provides the file channel from the current continuation

Returns:

A new step instance

readFrom

public static AsynchronousFileStep readFrom(java.lang.String sFileName,
                                            java.nio.file.OpenOption... rExtraOptions)

Invokes readFrom(Function) with a function that opens a file channel with the given file name and options. The option StandardOpenOption.READ will always be used and should therefore not occur in the extra options.

Parameters:

sFileName - The name of the file to read from

rExtraOptions - Additional options to use besides StandardOpenOption.READ

Returns:

A new step instance

until

public AsynchronousFileStep until(java.util.function.BiPredicate<java.lang.Integer,java.nio.ByteBuffer> pCheckFinished)

Returns a new read step instance the suspends until data has been read from a file and a certain condition on that data is met or an end-of-stream signal is received. If the capacity of the buffer is reached before the receiving is finished the coroutine will fail with an exception.

Parameters:

pCheckFinished - A predicate that checks whether the data has been read completely

Returns:

A new step instance

performAsyncOperation

protected boolean performAsyncOperation(int nBytesRead,
                                        java.nio.channels.AsynchronousFileChannel rChannel,
                                        java.nio.ByteBuffer rData,
                                        AsynchronousChannelStep.ChannelCallback<java.lang.Integer,java.nio.channels.AsynchronousFileChannel> rCallback)
                                 throws java.io.IOException

Implementation of the ChannelOperation functional interface method signature.

Specified by:

performAsyncOperation in class AsynchronousFileStep

Throws:

java.io.IOException

See Also:

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

performBlockingOperation

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

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

Specified by:

performBlockingOperation in class AsynchronousFileStep

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