org.xnio.channels

Class NullStreamSinkChannel

java.lang.Object

org.xnio.channels.NullStreamSinkChannel

All Implemented Interfaces:

Closeable, AutoCloseable, Channel, GatheringByteChannel, InterruptibleChannel, WritableByteChannel, CloseableChannel, CloseListenerSettable<NullStreamSinkChannel>, Configurable, StreamSinkChannel, SuspendableWriteChannel, WriteListenerSettable<NullStreamSinkChannel>

public final class NullStreamSinkChannel
extends Object
implements StreamSinkChannel, WriteListenerSettable<NullStreamSinkChannel>, CloseListenerSettable<NullStreamSinkChannel>

A bit-bucket stream sink channel. This channel type is always writable.

Author:

David M. Lloyd

Nested Class Summary

Nested classes/interfaces inherited from interface org.xnio.channels.WriteListenerSettable

WriteListenerSettable.Setter<C extends Channel>

Nested classes/interfaces inherited from interface org.xnio.channels.CloseListenerSettable

CloseListenerSettable.Setter<C extends Channel>

Field Summary

Fields inherited from interface org.xnio.channels.Configurable

EMPTY

Constructor Summary

Constructors

Constructor and Description
NullStreamSinkChannel(XnioIoThread thread) Construct a new instance.

Method Summary

Methods

Modifier and Type	Method and Description
void	awaitWritable() Block until this channel becomes writable again.
void	awaitWritable(long time, TimeUnit timeUnit) Block until this channel becomes writable again, or until the timeout expires.
void	close() Close this channel.
boolean	flush() Flush any waiting partial send or write.
ChannelListener<? super NullStreamSinkChannel>	getCloseListener() Get the close listener.
ChannelListener.Setter<NullStreamSinkChannel>	getCloseSetter() Get the setter which can be used to change the close listener for this channel.
XnioIoThread	getIoThread() Get the I/O thread associated with this channel.
<T> T	getOption(Option<T> option) Get the value of a channel option.
XnioWorker	getWorker() Get the worker for this channel.
ChannelListener<? super NullStreamSinkChannel>	getWriteListener() Get the write listener.
ChannelListener.Setter<NullStreamSinkChannel>	getWriteSetter() Get the setter which can be used to change the write listener for this channel.
XnioExecutor	getWriteThread() Deprecated.
boolean	isOpen() Determine whether this channel is open.
boolean	isWriteResumed() Determine whether writes are resumed.
void	resumeWrites() Resume writes on this channel.
void	setCloseListener(ChannelListener<? super NullStreamSinkChannel> closeListener) Set the close listener.
<T> T	setOption(Option<T> option, T value) Set an option for this channel.
void	setWriteListener(ChannelListener<? super NullStreamSinkChannel> writeListener) Set the write listener.
void	shutdownWrites() Indicate that writing is complete for this channel.
boolean	supportsOption(Option<?> option) Determine whether an option is supported on this channel.
void	suspendWrites() Suspend further write notifications on this channel.
long	transferFrom(FileChannel src, long position, long count) Transfer bytes into this channel from the given file.
long	transferFrom(StreamSourceChannel source, long count, ByteBuffer throughBuffer) Transfers bytes from the given channel source.
void	wakeupWrites() Resume writes on this channel, and force the write listener to be triggered even if the channel isn't actually writable.
int	write(ByteBuffer src)
long	write(ByteBuffer[] srcs)
long	write(ByteBuffer[] srcs, int offset, int length)
int	writeFinal(ByteBuffer src) Writes some data to the channel, with the same semantics as WritableByteChannel.write(java.nio.ByteBuffer).
long	writeFinal(ByteBuffer[] srcs) Writes some data to the channel, with the same semantics as GatheringByteChannel.write(java.nio.ByteBuffer[]).
long	writeFinal(ByteBuffer[] srcs, int offset, int length) Writes some data to the channel, with the same semantics as GatheringByteChannel.write(java.nio.ByteBuffer[], int, int).

Methods inherited from class java.lang.Object

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

Constructor Detail

NullStreamSinkChannel

public NullStreamSinkChannel(XnioIoThread thread)

Construct a new instance.

Parameters:

thread - the write thread for this channel

Method Detail

getWorker

public XnioWorker getWorker()

Description copied from interface: CloseableChannel

Get the worker for this channel.

Specified by:

getWorker in interface CloseableChannel

Returns:

the worker

getIoThread

public XnioIoThread getIoThread()

Description copied from interface: CloseableChannel

Get the I/O thread associated with this channel.

Specified by:

getIoThread in interface CloseableChannel

Returns:

the I/O thread associated with this channel

getWriteThread

@Deprecated
public XnioExecutor getWriteThread()

Deprecated.

Description copied from interface: SuspendableWriteChannel

Get the write thread for this channel.

Specified by:

getWriteThread in interface SuspendableWriteChannel

Returns:

the thread, or null if none is configured or available

transferFrom

public long transferFrom(FileChannel src,
                long position,
                long count)
                  throws IOException

Description copied from interface: StreamSinkChannel

Transfer bytes into this channel from the given file. Using this method in preference to FileChannel.transferTo(long, long, WritableByteChannel) may provide a performance advantage on some platforms.

If the current thread is interrupted when this method is called, it may throw a InterruptedIOException; however, if this exception is thrown, the InterruptedIOException.bytesTransferred field is guaranteed to be 0.

Specified by:

transferFrom in interface StreamSinkChannel

Parameters:

src - the file to read from

position - the position within the file from which the transfer is to begin

count - the number of bytes to be transferred

Returns:

the number of bytes (possibly 0) that were actually transferred

Throws:

IOException - if an I/O error occurs

transferFrom

public long transferFrom(StreamSourceChannel source,
                long count,
                ByteBuffer throughBuffer)
                  throws IOException

Description copied from interface: StreamSinkChannel

Transfers bytes from the given channel source. On some platforms, this may avoid copying bytes between user and kernel space. On other platforms, bytes are passed through the throughBuffer parameter's buffer space. On entry, throughBuffer will be cleared. On exit, the buffer will be flipped for emptying, and may be empty or may contain data. If this method returns a value less than count, then the remaining data in throughBuffer may contain data read from source which must be written to this channel to complete the operation. Note that using a direct buffer may provide an intermediate performance gain on platforms without zero-copy facilities.

If the current thread is interrupted when this method is called, it may throw a InterruptedIOException; however, if this exception is thrown, the InterruptedIOException.bytesTransferred field is guaranteed to be 0.

Specified by:

transferFrom in interface StreamSinkChannel

Parameters:

source - the source to read from

count - the number of bytes to be transferred

throughBuffer - the buffer to copy through.

Returns:

the number of bytes (possibly 0) that were actually transferred, or -1 if the end of input was reached

Throws:

IOException - if an I/O error occurs

setWriteListener

public void setWriteListener(ChannelListener<? super NullStreamSinkChannel> writeListener)

Description copied from interface: WriteListenerSettable

Set the write listener.

Specified by:

setWriteListener in interface WriteListenerSettable<NullStreamSinkChannel>

Parameters:

writeListener - the write listener

getWriteListener

public ChannelListener<? super NullStreamSinkChannel> getWriteListener()

Description copied from interface: WriteListenerSettable

Get the write listener.

Specified by:

getWriteListener in interface WriteListenerSettable<NullStreamSinkChannel>

Returns:

the write listener

setCloseListener

public void setCloseListener(ChannelListener<? super NullStreamSinkChannel> closeListener)

Description copied from interface: CloseListenerSettable

Set the close listener.

Specified by:

setCloseListener in interface CloseListenerSettable<NullStreamSinkChannel>

Parameters:

closeListener - the close listener

getCloseListener

public ChannelListener<? super NullStreamSinkChannel> getCloseListener()

Description copied from interface: CloseListenerSettable

Get the close listener.

Specified by:

getCloseListener in interface CloseListenerSettable<NullStreamSinkChannel>

Returns:

the close listener

getWriteSetter

public ChannelListener.Setter<NullStreamSinkChannel> getWriteSetter()

Description copied from interface: StreamSinkChannel

Get the setter which can be used to change the write listener for this channel.

Specified by:

getWriteSetter in interface StreamSinkChannel

Specified by:

getWriteSetter in interface SuspendableWriteChannel

Returns:

the setter

getCloseSetter

public ChannelListener.Setter<NullStreamSinkChannel> getCloseSetter()

Description copied from interface: StreamSinkChannel

Get the setter which can be used to change the close listener for this channel. If the channel is already closed, then the listener will not be called.

Specified by:

getCloseSetter in interface CloseableChannel

Specified by:

getCloseSetter in interface StreamSinkChannel

Specified by:

getCloseSetter in interface SuspendableWriteChannel

Returns:

the setter

writeFinal

public int writeFinal(ByteBuffer src)
               throws IOException

Description copied from interface: StreamSinkChannel

Writes some data to the channel, with the same semantics as WritableByteChannel.write(java.nio.ByteBuffer). If all the data is written out then the channel will have its writes shutdown. Semantically this method is equivalent to: int rem = src.remaining(); int written = channel.write(src); if(written == rem) { channel.shutdownWrites() } If an exception is thrown the caller is still responsible for closing the channel.

Specified by:

writeFinal in interface StreamSinkChannel

Parameters:

src - The data to write

Returns:

The amount of data that was actually written.

Throws:

IOException

See Also:

WritableByteChannel.write(java.nio.ByteBuffer), SuspendableWriteChannel.shutdownWrites()

writeFinal

public long writeFinal(ByteBuffer[] srcs,
              int offset,
              int length)
                throws IOException

Description copied from interface: StreamSinkChannel

Writes some data to the channel, with the same semantics as GatheringByteChannel.write(java.nio.ByteBuffer[], int, int). If all the data is written out then the channel will have its writes shutdown. If an exception is thrown the caller is still responsible for closing the channel.

Specified by:

writeFinal in interface StreamSinkChannel

Parameters:

srcs - The buffers from which bytes are to be retrieved

offset - The offset within the buffer array of the first buffer from which bytes are to be retrieved; must be non-negative and no larger than srcs.length

length - The maximum number of buffers to be accessed; must be non-negative and no larger than srcs.length - offset

Returns:

The amount of data that was actually written

Throws:

IOException

See Also:

GatheringByteChannel.write(java.nio.ByteBuffer[], int, int), SuspendableWriteChannel.shutdownWrites()

writeFinal

public long writeFinal(ByteBuffer[] srcs)
                throws IOException

Description copied from interface: StreamSinkChannel

Writes some data to the channel, with the same semantics as GatheringByteChannel.write(java.nio.ByteBuffer[]). If all the data is written out then the channel will have its writes shutdown. If an exception is thrown the caller is still responsible for closing the channel.

Specified by:

writeFinal in interface StreamSinkChannel

Parameters:

srcs - The buffers from which bytes are to be retrieved

Returns:

The amount of data that was actually written

Throws:

IOException

See Also:

GatheringByteChannel.write(java.nio.ByteBuffer[]), SuspendableWriteChannel.shutdownWrites()

write

public int write(ByteBuffer src)
          throws IOException

Specified by:

write in interface WritableByteChannel

Throws:

IOException

write

public long write(ByteBuffer[] srcs)
           throws IOException

Specified by:

write in interface GatheringByteChannel

Throws:

IOException

write

public long write(ByteBuffer[] srcs,
         int offset,
         int length)
           throws IOException

Specified by:

write in interface GatheringByteChannel

Throws:

IOException

suspendWrites

public void suspendWrites()

Description copied from interface: SuspendableWriteChannel

Suspend further write notifications on this channel.

Specified by:

suspendWrites in interface SuspendableWriteChannel

resumeWrites

public void resumeWrites()

Description copied from interface: SuspendableWriteChannel

Resume writes on this channel. The write listener will be called as soon as the channel becomes writable.

Specified by:

resumeWrites in interface SuspendableWriteChannel

wakeupWrites

public void wakeupWrites()

Description copied from interface: SuspendableWriteChannel

Resume writes on this channel, and force the write listener to be triggered even if the channel isn't actually writable.

Specified by:

wakeupWrites in interface SuspendableWriteChannel

isWriteResumed

public boolean isWriteResumed()

Description copied from interface: SuspendableWriteChannel

Determine whether writes are resumed.

Specified by:

isWriteResumed in interface SuspendableWriteChannel

Returns:

true if writes are resumed, false if writes are suspended

shutdownWrites

public void shutdownWrites()
                    throws IOException

Description copied from interface: SuspendableWriteChannel

Indicate that writing is complete for this channel. Further attempts to write data to this channel after this method is invoked will result in an exception. If this method was already called, calling this method again will have no additional effect. After this method is called, any remaining data still must be flushed out via the SuspendableWriteChannel.flush() method; once this is done, if the read side of the channel was shut down, the channel will automatically close.

Specified by:

shutdownWrites in interface SuspendableWriteChannel

Throws:

IOException - if an I/O error occurs

awaitWritable

public void awaitWritable()
                   throws IOException

Description copied from interface: SuspendableWriteChannel

Block until this channel becomes writable again. This method may return spuriously before the channel becomes writable.

Specified by:

awaitWritable in interface SuspendableWriteChannel

Throws:

InterruptedIOException - if the operation is interrupted; the thread's interrupt flag will be set as well

IOException - if an I/O error occurs

awaitWritable

public void awaitWritable(long time,
                 TimeUnit timeUnit)
                   throws IOException

Description copied from interface: SuspendableWriteChannel

Block until this channel becomes writable again, or until the timeout expires. This method may return spuriously before the channel becomes writable or the timeout expires.

Specified by:

awaitWritable in interface SuspendableWriteChannel

Parameters:

time - the time to wait

timeUnit - the time unit

Throws:

InterruptedIOException - if the operation is interrupted; the thread's interrupt flag will be set as well

IOException - if an I/O error occurs

flush

public boolean flush()
              throws IOException

Description copied from interface: SuspendableWriteChannel

Flush any waiting partial send or write. If there is no data to flush, or if the flush completed successfully, this method will return true. If there is data to flush which cannot be immediately written, this method will return false. If this method returns true after SuspendableWriteChannel.shutdownWrites() was called on this channel, the write listener will no longer be invoked on this channel. If this is case and additionally this is a write-only channel or the read side was previously shut down, then the channel will automatically be closed.

Specified by:

flush in interface SuspendableWriteChannel

Returns:

true if the message was flushed, or false if the result would block

Throws:

IOException - if an I/O error occurs

isOpen

public boolean isOpen()

Description copied from interface: SuspendableWriteChannel

Determine whether this channel is open. This method will return false if all directions are shut down, even if there is unflushed write data pending.

Specified by:

isOpen in interface Channel

Specified by:

isOpen in interface SuspendableWriteChannel

Returns:

true if the channel is open, false otherwise

close

public void close()
           throws IOException

Description copied from interface: SuspendableWriteChannel

Close this channel. If data has been written but not flushed, that data may be discarded, depending on the channel implementation. When a channel is closed, its close listener is invoked. Invoking this method more than once has no additional effect.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Specified by:

close in interface InterruptibleChannel

Specified by:

close in interface CloseableChannel

Specified by:

close in interface SuspendableWriteChannel

Throws:

IOException - if the close failed

supportsOption

public boolean supportsOption(Option<?> option)

Description copied from interface: Configurable

Determine whether an option is supported on this channel.

Specified by:

supportsOption in interface Configurable

Parameters:

option - the option

Returns:

true if it is supported

getOption

public <T> T getOption(Option<T> option)
            throws IOException

Description copied from interface: Configurable

Get the value of a channel option.

Specified by:

getOption in interface Configurable

Type Parameters:

T - the type of the option value

Parameters:

option - the option to get

Returns:

the value of the option, or null if it is not set

Throws:

IOException - if an I/O error occurred when reading the option

setOption

public <T> T setOption(Option<T> option,
              T value)
            throws IllegalArgumentException,
                   IOException

Description copied from interface: Configurable

Set an option for this channel. Unsupported options are ignored.

Specified by:

setOption in interface Configurable

Type Parameters:

T - the type of the option value

Parameters:

option - the option to set

value - the value of the option to set

Returns:

the previous option value, if any

Throws:

IllegalArgumentException - if the value is not acceptable for this option

IOException - if an I/O error occurred when modifying the option