net.jpountz.lz4

Class LZ4BlockOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

net.jpountz.lz4.LZ4BlockOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

public class LZ4BlockOutputStream
extends java.io.FilterOutputStream

Streaming LZ4 (not compatible with the LZ4 Frame format). This class compresses data into fixed-size blocks of compressed data. This class uses its own format and is not compatible with the LZ4 Frame format. For interoperability with other LZ4 tools, use LZ4FrameOutputStream, which is compatible with the LZ4 Frame format. This class remains for backward compatibility.

See Also:

LZ4BlockInputStream, LZ4FrameOutputStream

Field Summary

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

Constructors

Constructor and Description
LZ4BlockOutputStream(java.io.OutputStream out) Creates a new instance which compresses into blocks of 64 KB.
LZ4BlockOutputStream(java.io.OutputStream out, int blockSize) Creates a new instance which compresses with the standard LZ4 compression algorithm.
LZ4BlockOutputStream(java.io.OutputStream out, int blockSize, LZ4Compressor compressor) Creates a new instance which checks stream integrity using StreamingXXHash32 and doesn't sync flush.
LZ4BlockOutputStream(java.io.OutputStream out, int blockSize, LZ4Compressor compressor, java.util.zip.Checksum checksum, boolean syncFlush) Creates a new OutputStream with configurable block size.

Method Summary

Modifier and Type	Method and Description
void	close()
void	finish() Same as close() except that it doesn't close the underlying stream.
void	flush() Flushes this compressed OutputStream.
java.lang.String	toString()
void	write(byte[] b)
void	write(byte[] b, int off, int len)
void	write(int b)

Methods inherited from class java.lang.Object

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

Constructor Detail

LZ4BlockOutputStream

public LZ4BlockOutputStream(java.io.OutputStream out,
                            int blockSize,
                            LZ4Compressor compressor,
                            java.util.zip.Checksum checksum,
                            boolean syncFlush)

Creates a new OutputStream with configurable block size. Large blocks require more memory at compression and decompression time but should improve the compression ratio.

Parameters:

out - the OutputStream to feed

blockSize - the maximum number of bytes to try to compress at once, must be >= 64 and <= 32 M

compressor - the LZ4Compressor instance to use to compress data

checksum - the Checksum instance to use to check data for integrity.

syncFlush - true if pending data should also be flushed on flush()

LZ4BlockOutputStream

public LZ4BlockOutputStream(java.io.OutputStream out,
                            int blockSize,
                            LZ4Compressor compressor)

Creates a new instance which checks stream integrity using StreamingXXHash32 and doesn't sync flush.

Parameters:

out - the OutputStream to feed

blockSize - the maximum number of bytes to try to compress at once, must be >= 64 and <= 32 M

compressor - the LZ4Compressor instance to use to compress data

See Also:

LZ4BlockOutputStream(OutputStream, int, LZ4Compressor, Checksum, boolean), StreamingXXHash32.asChecksum()

LZ4BlockOutputStream

public LZ4BlockOutputStream(java.io.OutputStream out,
                            int blockSize)

Creates a new instance which compresses with the standard LZ4 compression algorithm.

Parameters:

out - the OutputStream to feed

blockSize - the maximum number of bytes to try to compress at once, must be >= 64 and <= 32 M

See Also:

LZ4BlockOutputStream(OutputStream, int, LZ4Compressor), LZ4Factory.fastCompressor()

LZ4BlockOutputStream

public LZ4BlockOutputStream(java.io.OutputStream out)

Creates a new instance which compresses into blocks of 64 KB.

Parameters:

out - the OutputStream to feed

See Also:

LZ4BlockOutputStream(OutputStream, int)

Method Detail

write

public void write(int b)
           throws java.io.IOException

Overrides:

write in class java.io.FilterOutputStream

Throws:

java.io.IOException

write

public void write(byte[] b,
                  int off,
                  int len)
           throws java.io.IOException

Overrides:

write in class java.io.FilterOutputStream

Throws:

java.io.IOException

write

public void write(byte[] b)
           throws java.io.IOException

Overrides:

write in class java.io.FilterOutputStream

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.FilterOutputStream

Throws:

java.io.IOException

flush

public void flush()
           throws java.io.IOException

Flushes this compressed OutputStream. If the stream has been created with syncFlush=true, pending data will be compressed and appended to the underlying OutputStream before calling OutputStream.flush() on the underlying stream. Otherwise, this method just flushes the underlying stream, so pending data might not be available for reading until finish() or close() is called.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.FilterOutputStream

Throws:

java.io.IOException

finish

public void finish()
            throws java.io.IOException

Same as close() except that it doesn't close the underlying stream. This can be useful if you want to keep on using the underlying stream.

Throws:

java.io.IOException - if an I/O error occurs.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object