org.xerial.snappy

Class SnappyFramedOutputStream

java.lang.Object

java.io.OutputStream

org.xerial.snappy.SnappyFramedOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable, Channel, WritableByteChannel

public final class SnappyFramedOutputStream
extends OutputStream
implements WritableByteChannel

Implements the x-snappy-framed as an OutputStream and WritableByteChannel.

Since:

1.1.0

Author:

Brett Okken

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_BLOCK_SIZE The default block size to use.
static double	DEFAULT_MIN_COMPRESSION_RATIO The default min compression ratio to use.
static int	MAX_BLOCK_SIZE The x-snappy-framed specification allows for a chunk size up to 16,777,211 bytes in length.

Constructor Summary

Constructors

Constructor and Description
SnappyFramedOutputStream(OutputStream out) Creates a new SnappyFramedOutputStream using the DEFAULT_BLOCK_SIZE and DEFAULT_MIN_COMPRESSION_RATIO.
SnappyFramedOutputStream(OutputStream out, BufferPool bufferPool) Creates a new SnappyFramedOutputStream using the DEFAULT_BLOCK_SIZE and DEFAULT_MIN_COMPRESSION_RATIO.
SnappyFramedOutputStream(OutputStream out, int blockSize, double minCompressionRatio) Creates a new SnappyFramedOutputStream instance.
SnappyFramedOutputStream(OutputStream out, int blockSize, double minCompressionRatio, BufferPool bufferPool) Creates a new SnappyFramedOutputStream instance.
SnappyFramedOutputStream(WritableByteChannel out) Creates a new SnappyFramedOutputStream using the DEFAULT_BLOCK_SIZE and DEFAULT_MIN_COMPRESSION_RATIO.
SnappyFramedOutputStream(WritableByteChannel out, BufferPool bufferPool) Creates a new SnappyFramedOutputStream using the DEFAULT_BLOCK_SIZE and DEFAULT_MIN_COMPRESSION_RATIO.
SnappyFramedOutputStream(WritableByteChannel out, int blockSize, double minCompressionRatio) Creates a new SnappyFramedOutputStream instance.
SnappyFramedOutputStream(WritableByteChannel out, int blockSize, double minCompressionRatio, BufferPool bufferPool) Creates a new SnappyFramedOutputStream instance.

Method Summary

Modifier and Type	Method and Description
void	close()
void	flush()
boolean	isOpen()
long	transferFrom(InputStream is) Transfers all the content from is to this OutputStream.
long	transferFrom(ReadableByteChannel rbc) Transfers all the content from rbc to this WritableByteChannel.
void	write(byte[] input, int offset, int length)
int	write(ByteBuffer src)
void	write(int b)

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

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

Field Detail

MAX_BLOCK_SIZE

public static final int MAX_BLOCK_SIZE

The x-snappy-framed specification allows for a chunk size up to 16,777,211 bytes in length. However, it also goes on to state:

We place an additional restriction that the uncompressed data in a chunk must be no longer than 65536 bytes. This allows consumers to easily use small fixed-size buffers.

See Also:

Constant Field Values

DEFAULT_BLOCK_SIZE

public static final int DEFAULT_BLOCK_SIZE

The default block size to use.

See Also:

Constant Field Values

DEFAULT_MIN_COMPRESSION_RATIO

public static final double DEFAULT_MIN_COMPRESSION_RATIO

The default min compression ratio to use.

See Also:

Constant Field Values

Constructor Detail

SnappyFramedOutputStream

public SnappyFramedOutputStream(OutputStream out)
                         throws IOException

Creates a new SnappyFramedOutputStream using the DEFAULT_BLOCK_SIZE and DEFAULT_MIN_COMPRESSION_RATIO.

Uses DefaultPoolFactory to obtain BufferPool for buffers.

Parameters:

out - The underlying OutputStream to write to. Must not be null.

Throws:

IOException

SnappyFramedOutputStream

public SnappyFramedOutputStream(OutputStream out,
                                BufferPool bufferPool)
                         throws IOException

Creates a new SnappyFramedOutputStream using the DEFAULT_BLOCK_SIZE and DEFAULT_MIN_COMPRESSION_RATIO.

Parameters:

out - The underlying OutputStream to write to. Must not be null.

bufferPool - Used to obtain buffer instances. Must not be null.

Throws:

IOException

SnappyFramedOutputStream

public SnappyFramedOutputStream(OutputStream out,
                                int blockSize,
                                double minCompressionRatio)
                         throws IOException

Creates a new SnappyFramedOutputStream instance.

Uses DefaultPoolFactory to obtain BufferPool for buffers.

Parameters:

out - The underlying OutputStream to write to. Must not be null.

blockSize - The block size (of raw data) to compress before writing frames to out. Must be in (0, 65536].

minCompressionRatio - Defines the minimum compression ratio ( compressedLength / rawLength) that must be achieved to write the compressed data. This must be in (0, 1.0].

Throws:

IOException

SnappyFramedOutputStream

public SnappyFramedOutputStream(OutputStream out,
                                int blockSize,
                                double minCompressionRatio,
                                BufferPool bufferPool)
                         throws IOException

Creates a new SnappyFramedOutputStream instance.

Parameters:

out - The underlying OutputStream to write to. Must not be null.

blockSize - The block size (of raw data) to compress before writing frames to out. Must be in (0, 65536].

minCompressionRatio - Defines the minimum compression ratio ( compressedLength / rawLength) that must be achieved to write the compressed data. This must be in (0, 1.0].

bufferPool - Used to obtain buffer instances. Must not be null.

Throws:

IOException

SnappyFramedOutputStream

public SnappyFramedOutputStream(WritableByteChannel out)
                         throws IOException

Creates a new SnappyFramedOutputStream using the DEFAULT_BLOCK_SIZE and DEFAULT_MIN_COMPRESSION_RATIO.

Uses DefaultPoolFactory to obtain BufferPool for buffers.

Parameters:

out - The underlying WritableByteChannel to write to. Must not be null.

Throws:

IOException

Since:

1.1.1

SnappyFramedOutputStream

public SnappyFramedOutputStream(WritableByteChannel out,
                                BufferPool bufferPool)
                         throws IOException

Creates a new SnappyFramedOutputStream using the DEFAULT_BLOCK_SIZE and DEFAULT_MIN_COMPRESSION_RATIO.

Uses DefaultPoolFactory to obtain BufferPool for buffers.

Parameters:

out - The underlying WritableByteChannel to write to. Must not be null.

bufferPool - Used to obtain buffer instances. Must not be null.

Throws:

IOException

SnappyFramedOutputStream

public SnappyFramedOutputStream(WritableByteChannel out,
                                int blockSize,
                                double minCompressionRatio)
                         throws IOException

Creates a new SnappyFramedOutputStream instance.

Parameters:

out - The underlying WritableByteChannel to write to. Must not be null.

blockSize - The block size (of raw data) to compress before writing frames to out. Must be in (0, 65536].

minCompressionRatio - Defines the minimum compression ratio ( compressedLength / rawLength) that must be achieved to write the compressed data. This must be in (0, 1.0].

Throws:

IOException

Since:

1.1.1

SnappyFramedOutputStream

public SnappyFramedOutputStream(WritableByteChannel out,
                                int blockSize,
                                double minCompressionRatio,
                                BufferPool bufferPool)
                         throws IOException

Creates a new SnappyFramedOutputStream instance.

Parameters:

out - The underlying WritableByteChannel to write to. Must not be null.

blockSize - The block size (of raw data) to compress before writing frames to out. Must be in (0, 65536].

minCompressionRatio - Defines the minimum compression ratio ( compressedLength / rawLength) that must be achieved to write the compressed data. This must be in (0, 1.0].

bufferPool - Used to obtain buffer instances. Must not be null.

Throws:

IOException

Since:

1.1.1

Method Detail

isOpen

public boolean isOpen()

Specified by:

isOpen in interface Channel

write

public void write(int b)
           throws IOException

Specified by:

write in class OutputStream

Throws:

IOException

write

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

Overrides:

write in class OutputStream

Throws:

IOException

write

public int write(ByteBuffer src)
          throws IOException

Specified by:

write in interface WritableByteChannel

Throws:

IOException

transferFrom

public long transferFrom(InputStream is)
                  throws IOException

Transfers all the content from is to this OutputStream. This potentially limits the amount of buffering required to compress content.

Parameters:

is - The source of data to compress.

Returns:

The number of bytes read from is.

Throws:

IOException

Since:

1.1.1

transferFrom

public long transferFrom(ReadableByteChannel rbc)
                  throws IOException

Transfers all the content from rbc to this WritableByteChannel. This potentially limits the amount of buffering required to compress content.

Parameters:

rbc - The source of data to compress.

Returns:

The number of bytes read from rbc.

Throws:

IOException

Since:

1.1.1

flush

public final void flush()
                 throws IOException

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException

close

public final void close()
                 throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Overrides:

close in class OutputStream

Throws:

IOException