Package org.apache.commons.compress.utils

Class SeekableInMemoryByteChannel

java.lang.Object

org.apache.commons.compress.utils.SeekableInMemoryByteChannel

All Implemented Interfaces:

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

public class SeekableInMemoryByteChannel
extends Object
implements SeekableByteChannel

A SeekableByteChannel implementation that wraps a byte[].

When this channel is used for writing an internal buffer grows to accommodate incoming data. The natural size limit is the value of Integer.MAX_VALUE and it is not possible to set the position or truncate to a value bigger than that. Internal buffer can be accessed via array().

Since:

1.13

Field Summary

Fields

Modifier and Type	Field	Description
private final AtomicBoolean	closed
private byte[]	data
private static final int	NAIVE_RESIZE_LIMIT
private int	position
private int	size

Constructor Summary

Constructors

Constructor	Description
SeekableInMemoryByteChannel()	Constructs a new instance using a default empty buffer.
SeekableInMemoryByteChannel(byte[] data)	Constructs a new instance from a byte array.
SeekableInMemoryByteChannel(int size)	Constructs a new instance from a size of storage to be allocated.

Method Summary

Modifier and Type	Method	Description
byte[]	array()	Obtains the array backing this channel.
void	close()
private void	ensureOpen()
boolean	isOpen()
long	position()	Returns this channel's position.
SeekableByteChannel	position(long newPosition)
int	read(ByteBuffer buf)
private void	resize(int newLength)
long	size()	Returns the current size of entity to which this channel is connected.
SeekableByteChannel	truncate(long newSize)	Truncates the entity, to which this channel is connected, to the given size.
int	write(ByteBuffer b)

Methods inherited from class java.lang.Object

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

Field Details

NAIVE_RESIZE_LIMIT

private static final int NAIVE_RESIZE_LIMIT

See Also:

• Constant Field Values

data

private byte[] data

closed

private final AtomicBoolean closed

position

private int position

size

private int size

Constructor Details

SeekableInMemoryByteChannel

public SeekableInMemoryByteChannel()

Constructs a new instance using a default empty buffer.

SeekableInMemoryByteChannel

public SeekableInMemoryByteChannel(byte[] data)

Constructs a new instance from a byte array.

This constructor is intended to be used with pre-allocated buffer or when reading from a given byte array.

Parameters:

data - input data or pre-allocated array.

SeekableInMemoryByteChannel

public SeekableInMemoryByteChannel(int size)

Constructs a new instance from a size of storage to be allocated.

Creates a channel and allocates internal storage of a given size.

Parameters:

size - size of internal buffer to allocate, in bytes.

Method Details

array

public byte[] array()

Obtains the array backing this channel.

NOTE: The returned buffer is not aligned with containing data, use size() to obtain the size of data stored in the buffer.

Returns:

internal byte array.

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Specified by:

close in interface Closeable

ensureOpen

private void ensureOpen()
                 throws ClosedChannelException

Throws:

ClosedChannelException

isOpen

public boolean isOpen()

Specified by:

isOpen in interface Channel

position

public long position()

Returns this channel's position.

This method violates the contract of SeekableByteChannel.position() as it will not throw any exception when invoked on a closed channel. Instead it will return the position the channel had when close has been called.

Specified by:

position in interface SeekableByteChannel

position

public SeekableByteChannel position(long newPosition)
                             throws IOException

Specified by:

position in interface SeekableByteChannel

Throws:

IOException

read

public int read(ByteBuffer buf)
         throws IOException

Specified by:

read in interface ReadableByteChannel

Specified by:

read in interface SeekableByteChannel

Throws:

IOException

resize

private void resize(int newLength)

size

public long size()

Returns the current size of entity to which this channel is connected.

This method violates the contract of SeekableByteChannel.size() as it will not throw any exception when invoked on a closed channel. Instead it will return the size the channel had when close has been called.

Specified by:

size in interface SeekableByteChannel

truncate

public SeekableByteChannel truncate(long newSize)

Truncates the entity, to which this channel is connected, to the given size.

This method violates the contract of SeekableByteChannel.truncate(long) as it will not throw any exception when invoked on a closed channel.

Specified by:

truncate in interface SeekableByteChannel

Throws:

IllegalArgumentException - if size is negative or bigger than the maximum of a Java integer

write

public int write(ByteBuffer b)
          throws IOException

Specified by:

write in interface SeekableByteChannel

Specified by:

write in interface WritableByteChannel

Throws:

IOException