net.smacke.jaydio.align

Class ByteChannelAligner<T extends JaydioByteBuffer>

java.lang.Object

net.smacke.jaydio.align.ByteChannelAligner<T>

All Implemented Interfaces:

Closeable, AutoCloseable, ByteChannel, Channel, ReadableByteChannel, SeekableByteChannel, WritableByteChannel

Direct Known Subclasses:

DirectIoByteChannelAligner, MockByteChannelAligner

public abstract class ByteChannelAligner<T extends JaydioByteBuffer>
extends Object
implements SeekableByteChannel

Abstract class which handles reading and writing from/to an underlying byte channel in appropriate increments and and at appropriate boundaries of the channel. The motivation for this class is that direct I/O in Linux (and in Windows too, I believe) requires all reads and writes to obey these strange alignment rules. It may seem like overkill to segment out the alignment logic necessary for this into its own abstract class, separate from any actual channel, but this allows for highly flexible testing with mock objects, to avoid doing actual heavy-weight I/O when possible.

Author:

smacke

Constructor Summary

Constructors

Constructor and Description
ByteChannelAligner(DirectIoLib lib, BufferedChannel<T> channel, T buffer)

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
void	flush()
boolean	isOpen()
long	position()
ByteChannelAligner<T>	position(long pos)
int	read()
int	read(ByteBuffer dst)
int	readBytes(byte[] dst, int offset, int length)
long	size()
ByteChannelAligner<T>	truncate(long size)
int	write(ByteBuffer src)
void	write(int b)
int	writeBytes(byte[] src, int offset, int length)

Methods inherited from class java.lang.Object

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

Constructor Detail

ByteChannelAligner

public ByteChannelAligner(DirectIoLib lib,
                  BufferedChannel<T> channel,
                  T buffer)

Method Detail

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Throws:

IOException

position

public long position()

Specified by:

position in interface SeekableByteChannel

position

public ByteChannelAligner<T> position(long pos)
                                                        throws IOException

Specified by:

position in interface SeekableByteChannel

Throws:

IOException

size

public long size()

Specified by:

size in interface SeekableByteChannel

readBytes

public int readBytes(byte[] dst,
            int offset,
            int length)
              throws IOException

Throws:

IOException

read

public int read(ByteBuffer dst)
         throws IOException

Specified by:

read in interface ReadableByteChannel

Specified by:

read in interface SeekableByteChannel

Throws:

IOException

writeBytes

public int writeBytes(byte[] src,
             int offset,
             int length)
               throws IOException

Throws:

IOException

write

public int write(ByteBuffer src)
          throws IOException

Specified by:

write in interface SeekableByteChannel

Specified by:

write in interface WritableByteChannel

Throws:

IOException

write

public void write(int b)
           throws IOException

Throws:

IOException

read

public int read()
         throws IOException

Throws:

IOException

isOpen

public boolean isOpen()

Specified by:

isOpen in interface Channel

truncate

public ByteChannelAligner<T> truncate(long size)
                                                        throws IOException

Specified by:

truncate in interface SeekableByteChannel

Throws:

IOException

flush

public void flush()
           throws IOException

Throws:

IOException