Class PLZFOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

com.ning.compress.lzf.parallel.PLZFOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable, Channel, WritableByteChannel

public class PLZFOutputStream
extends FilterOutputStream
implements WritableByteChannel

Decorator OutputStream implementation that will compress output using LZF compression algorithm, given uncompressed input to write. Its counterpart is LZFInputStream; although in some ways LZFCompressingInputStream can be seen as the opposite.

This class uses a parallel implementation to make use of all available cores, modulo system load.

See Also:

• LZFInputStream
• LZFCompressingInputStream
• LZFOutputStream

Field Summary

Fields

Modifier and Type	Field	Description
protected byte[]	_outputBuffer
protected boolean	_outputStreamClosed	Flag that indicates if we have already called '_outputStream.close()' (to avoid calling it multiple times)
protected int	_position
private BlockManager	blockManager
private final ExecutorService	compressExecutor
private static final int	DEFAULT_OUTPUT_BUFFER_SIZE
(package private) Exception	writeException
private final ExecutorService	writeExecutor

Fields inherited from class FilterOutputStream

out

Constructor Summary

Constructors

Modifier	Constructor	Description
	PLZFOutputStream(OutputStream outputStream)
protected	PLZFOutputStream(OutputStream outputStream, int nThreads)
protected	PLZFOutputStream(OutputStream outputStream, int bufferSize, int nThreads)

Method Summary

Modifier and Type	Method	Description
protected void	checkNotClosed()
protected void	checkWriteException()
void	close()
void	flush()	This flush method does nothing.
protected static int	getNThreads()
OutputStream	getUnderlyingOutputStream()	Method that can be used to find underlying OutputStream that we write encoded LZF encoded data into, after compressing it.
boolean	isOpen()
void	write(byte[] buffer, int offset, int length)
void	write(int singleByte)	WARNING: using this method will lead to very poor performance!
void	write(InputStream in)
int	write(ByteBuffer src)
void	write(FileChannel in)
protected void	writeCompressedBlock()	Compress and write the current block to the OutputStream

Methods inherited from class FilterOutputStream

write

Methods inherited from class OutputStream

nullOutputStream

Methods inherited from class Object

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

Field Details

DEFAULT_OUTPUT_BUFFER_SIZE

private static final int DEFAULT_OUTPUT_BUFFER_SIZE

See Also:

• Constant Field Values

_outputBuffer

protected byte[] _outputBuffer

_position

protected int _position

_outputStreamClosed

protected boolean _outputStreamClosed

Flag that indicates if we have already called '_outputStream.close()' (to avoid calling it multiple times)

blockManager

private BlockManager blockManager

compressExecutor

private final ExecutorService compressExecutor

writeExecutor

private final ExecutorService writeExecutor

writeException

volatile Exception writeException

Constructor Details

PLZFOutputStream

public PLZFOutputStream(OutputStream outputStream)

PLZFOutputStream

protected PLZFOutputStream(OutputStream outputStream,
 int nThreads)

PLZFOutputStream

protected PLZFOutputStream(OutputStream outputStream,
 int bufferSize,
 int nThreads)

Method Details

getNThreads

protected static int getNThreads()

write

public void write(int singleByte)
           throws IOException

WARNING: using this method will lead to very poor performance!

Overrides:

write in class FilterOutputStream

Throws:

IOException

write

public void write(byte[] buffer,
 int offset,
 int length)
           throws IOException

Overrides:

write in class FilterOutputStream

Throws:

IOException

write

public void write(InputStream in)
           throws IOException

Throws:

IOException

write

public void write(FileChannel in)
           throws IOException

Throws:

IOException

write

public int write(ByteBuffer src)
          throws IOException

Specified by:

write in interface WritableByteChannel

Throws:

IOException

flush

public void flush()
           throws IOException

This flush method does nothing.

Specified by:

flush in interface Flushable

Overrides:

flush in class FilterOutputStream

Throws:

IOException

isOpen

public boolean isOpen()

Specified by:

isOpen in interface Channel

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Specified by:

close in interface Closeable

Overrides:

close in class FilterOutputStream

Throws:

IOException

getUnderlyingOutputStream

public OutputStream getUnderlyingOutputStream()

Method that can be used to find underlying OutputStream that we write encoded LZF encoded data into, after compressing it. Will never return null; although underlying stream may be closed (if this stream has been closed).

writeCompressedBlock

protected void writeCompressedBlock()
                             throws IOException

Compress and write the current block to the OutputStream

Throws:

IOException

checkWriteException

protected void checkWriteException()
                            throws IOException

Throws:

IOException

checkNotClosed

protected void checkNotClosed()
                       throws IOException

Throws:

IOException