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

Class FramedSnappyCompressorInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.compress.compressors.CompressorInputStream

org.apache.commons.compress.compressors.snappy.FramedSnappyCompressorInputStream

All Implemented Interfaces:

Closeable, AutoCloseable, InputStreamStatistics

public class FramedSnappyCompressorInputStream
extends CompressorInputStream
implements InputStreamStatistics

CompressorInputStream for the framing Snappy format.

Based on the "spec" in the version "Last revised: 2013-10-25"

Since:

1.7

See Also:

• Snappy framing format description

Field Summary

Fields

Modifier and Type	Field	Description
private final int	blockSize
private final PureJavaCrc32C	checksum
(package private) static final int	COMPRESSED_CHUNK_TYPE
private final CountingInputStream	countingStream
private SnappyCompressorInputStream	currentCompressedChunk
private final FramedSnappyDialect	dialect	The dialect to expect
private boolean	endReached
private long	expectedChecksum
private final PushbackInputStream	inputStream	The underlying stream to read compressed data from
private boolean	inUncompressedChunk
(package private) static final long	MASK_OFFSET	package private for tests only.
private static final int	MAX_SKIPPABLE_TYPE
private static final int	MAX_UNSKIPPABLE_TYPE
private static final int	MIN_UNSKIPPABLE_TYPE
private final byte[]	oneByte
private static final int	PADDING_CHUNK_TYPE
private static final int	STREAM_IDENTIFIER_TYPE
private final ByteUtils.ByteSupplier	supplier
(package private) static final byte[]	SZ_SIGNATURE
private static final int	UNCOMPRESSED_CHUNK_TYPE
private int	uncompressedBytesRemaining
private long	unreadBytes

Constructor Summary

Constructors

Constructor	Description
FramedSnappyCompressorInputStream(InputStream in)	Constructs a new input stream that decompresses snappy-framed-compressed data from the specified input stream using the FramedSnappyDialect.STANDARD dialect.
FramedSnappyCompressorInputStream(InputStream in, int blockSize, FramedSnappyDialect dialect)	Constructs a new input stream that decompresses snappy-framed-compressed data from the specified input stream.
FramedSnappyCompressorInputStream(InputStream in, FramedSnappyDialect dialect)	Constructs a new input stream that decompresses snappy-framed-compressed data from the specified input stream.

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()
long	getCompressedCount()
static boolean	matches(byte[] signature, int length)	Checks if the signature matches what is expected for a .sz file.
int	read()
int	read(byte[] b, int off, int len)
private long	readCrc()
private void	readNextBlock()
private int	readOnce(byte[] b, int off, int len)	Read from the current chunk into the given array.
private int	readOneByte()
private int	readSize()
private void	readStreamIdentifier()
private void	skipBlock()
(package private) static long	unmask(long x)
private void	verifyLastChecksumAndReset()

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

count, count, getBytesRead, getCount, getUncompressedCount, pushedBackBytes

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

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

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

getUncompressedCount

Field Details

MASK_OFFSET

static final long MASK_OFFSET

package private for tests only.

See Also:

• Constant Field Values

STREAM_IDENTIFIER_TYPE

private static final int STREAM_IDENTIFIER_TYPE

See Also:

• Constant Field Values

COMPRESSED_CHUNK_TYPE

static final int COMPRESSED_CHUNK_TYPE

See Also:

• Constant Field Values

UNCOMPRESSED_CHUNK_TYPE

private static final int UNCOMPRESSED_CHUNK_TYPE

See Also:

• Constant Field Values

PADDING_CHUNK_TYPE

private static final int PADDING_CHUNK_TYPE

See Also:

• Constant Field Values

MIN_UNSKIPPABLE_TYPE

private static final int MIN_UNSKIPPABLE_TYPE

See Also:

• Constant Field Values

MAX_UNSKIPPABLE_TYPE

private static final int MAX_UNSKIPPABLE_TYPE

See Also:

• Constant Field Values

MAX_SKIPPABLE_TYPE

private static final int MAX_SKIPPABLE_TYPE

See Also:

• Constant Field Values

SZ_SIGNATURE

static final byte[] SZ_SIGNATURE

unreadBytes

private long unreadBytes

countingStream

private final CountingInputStream countingStream

inputStream

private final PushbackInputStream inputStream

The underlying stream to read compressed data from

dialect

private final FramedSnappyDialect dialect

The dialect to expect

currentCompressedChunk

private SnappyCompressorInputStream currentCompressedChunk

oneByte

private final byte[] oneByte

endReached

private boolean endReached

inUncompressedChunk

private boolean inUncompressedChunk

uncompressedBytesRemaining

private int uncompressedBytesRemaining

expectedChecksum

private long expectedChecksum

blockSize

private final int blockSize

checksum

private final PureJavaCrc32C checksum

supplier

private final ByteUtils.ByteSupplier supplier

Constructor Details

FramedSnappyCompressorInputStream

public FramedSnappyCompressorInputStream(InputStream in)
                                  throws IOException

Constructs a new input stream that decompresses snappy-framed-compressed data from the specified input stream using the FramedSnappyDialect.STANDARD dialect.

Parameters:

in - the InputStream from which to read the compressed data

Throws:

IOException - if reading fails

FramedSnappyCompressorInputStream

public FramedSnappyCompressorInputStream(InputStream in,
 FramedSnappyDialect dialect)
                                  throws IOException

Constructs a new input stream that decompresses snappy-framed-compressed data from the specified input stream.

Parameters:

in - the InputStream from which to read the compressed data

dialect - the dialect used by the compressed stream

Throws:

IOException - if reading fails

FramedSnappyCompressorInputStream

public FramedSnappyCompressorInputStream(InputStream in,
 int blockSize,
 FramedSnappyDialect dialect)
                                  throws IOException

Constructs a new input stream that decompresses snappy-framed-compressed data from the specified input stream.

Parameters:

in - the InputStream from which to read the compressed data

blockSize - the block size to use for the compressed stream

dialect - the dialect used by the compressed stream

Throws:

IOException - if reading fails

IllegalArgumentException - if blockSize is not bigger than 0

Since:

1.14

Method Details

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

read

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

Overrides:

read in class InputStream

Throws:

IOException

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

getCompressedCount

public long getCompressedCount()

Specified by:

getCompressedCount in interface InputStreamStatistics

Returns:

the amount of raw or compressed bytes read by the stream

Since:

1.17

readOnce

private int readOnce(byte[] b,
 int off,
 int len)
              throws IOException

Read from the current chunk into the given array.

Returns:

-1 if there is no current chunk or the number of bytes read from the current chunk (which may be -1 if the end of the chunk is reached).

Throws:

IOException

readNextBlock

private void readNextBlock()
                    throws IOException

Throws:

IOException

readCrc

private long readCrc()
              throws IOException

Throws:

IOException

unmask

static long unmask(long x)

readSize

private int readSize()
              throws IOException

Throws:

IOException

skipBlock

private void skipBlock()
                throws IOException

Throws:

IOException

readStreamIdentifier

private void readStreamIdentifier()
                           throws IOException

Throws:

IOException

readOneByte

private int readOneByte()
                 throws IOException

Throws:

IOException

verifyLastChecksumAndReset

private void verifyLastChecksumAndReset()
                                 throws IOException

Throws:

IOException

matches

public static boolean matches(byte[] signature,
 int length)

Checks if the signature matches what is expected for a .sz file.

.sz files start with a chunk with tag 0xff and content sNaPpY.

Parameters:

signature - the bytes to check

length - the number of bytes to check

Returns:

true if this is a .sz stream, false otherwise