Package org.apache.commons.compress.compressors.snappy

Class SnappyCompressorInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.compress.compressors.CompressorInputStream

org.apache.commons.compress.compressors.lz77support.AbstractLZ77CompressorInputStream

org.apache.commons.compress.compressors.snappy.SnappyCompressorInputStream

All Implemented Interfaces:

Closeable, AutoCloseable, InputStreamStatistics

public class SnappyCompressorInputStream
extends AbstractLZ77CompressorInputStream

CompressorInputStream for the raw Snappy format.

This implementation uses an internal buffer in order to handle the back-references that are at the heart of the LZ77 algorithm. The size of the buffer must be at least as big as the biggest offset used in the compressed stream. The current version of the Snappy algorithm as defined by Google works on 32k blocks and doesn't contain offsets bigger than 32k which is the default block size used by this class.

Since:

1.7

See Also:

• Snappy compressed format description

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_BLOCK_SIZE	Default block size

Constructor Summary

Constructors

Constructor	Description
SnappyCompressorInputStream(InputStream is)	Constructor using the default buffer size of 32k.
SnappyCompressorInputStream(InputStream is, int blockSize)	Constructor using a configurable buffer size.

Method Summary

Modifier and Type	Method	Description
int	getSize()	Get the uncompressed size of the stream
int	read(byte[] b, int off, int len)

Methods inherited from class org.apache.commons.compress.compressors.lz77support.AbstractLZ77CompressorInputStream

available, close, getCompressedCount, prefill, read

Methods inherited from class org.apache.commons.compress.compressors.CompressorInputStream

getBytesRead, getCount, getUncompressedCount

Methods inherited from class java.io.InputStream

mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.compress.utils.InputStreamStatistics

getUncompressedCount

Field Details

DEFAULT_BLOCK_SIZE

public static final int DEFAULT_BLOCK_SIZE

Default block size

See Also:

• Constant Field Values

Constructor Details

SnappyCompressorInputStream

public SnappyCompressorInputStream(InputStream is)
                            throws IOException

Constructor using the default buffer size of 32k.

Parameters:

is - An InputStream to read compressed data from

Throws:

IOException - if reading fails

SnappyCompressorInputStream

public SnappyCompressorInputStream(InputStream is,
 int blockSize)
                            throws IOException

Constructor using a configurable buffer size.

Parameters:

is - An InputStream to read compressed data from

blockSize - The block size used in compression

Throws:

IOException - if reading fails

IllegalArgumentException - if blockSize is not bigger than 0

Method Details

getSize

public int getSize()

Get the uncompressed size of the stream

Overrides:

getSize in class AbstractLZ77CompressorInputStream

Returns:

the uncompressed size

read

public int read(byte[] b,
 int off,
 int len)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException