org.apache.commons.compress.compressors.bzip2

Class BZip2CompressorInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.compress.compressors.CompressorInputStream

org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, BZip2Constants, InputStreamStatistics

public class BZip2CompressorInputStream
extends CompressorInputStream
implements BZip2Constants, InputStreamStatistics

An input stream that decompresses from the BZip2 format to be read as any other stream.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	BZip2CompressorInputStream.Data

Field Summary

Fields

Modifier and Type	Field and Description
private BitInputStream	bin
private boolean	blockRandomised
private int	blockSize100k always: in the range 0 ..
private int	computedBlockCRC
private int	computedCombinedCRC
private CRC	crc
private int	currentState
private BZip2CompressorInputStream.Data	data All memory intensive stuff.
private boolean	decompressConcatenated
private static int	EOF
private int	last Index of the last char in the block, so the block size == last + 1.
private int	nInUse
private static int	NO_RAND_PART_A_STATE
private static int	NO_RAND_PART_B_STATE
private static int	NO_RAND_PART_C_STATE
private int	origPtr Index in zptr[] of original string after sorting.
private static int	RAND_PART_A_STATE
private static int	RAND_PART_B_STATE
private static int	RAND_PART_C_STATE
private static int	START_BLOCK_STATE
private int	storedBlockCRC
private int	storedCombinedCRC
private int	su_ch2
private int	su_chPrev
private int	su_count
private int	su_i2
private int	su_j2
private int	su_rNToGo
private int	su_rTPos
private int	su_tPos
private char	su_z

Fields inherited from interface org.apache.commons.compress.compressors.bzip2.BZip2Constants

BASEBLOCKSIZE, G_SIZE, MAX_ALPHA_SIZE, MAX_CODE_LEN, MAX_SELECTORS, N_GROUPS, N_ITERS, NUM_OVERSHOOT_BYTES, RUNA, RUNB

Constructor Summary

Constructors

Constructor and Description
BZip2CompressorInputStream(java.io.InputStream in) Constructs a new BZip2CompressorInputStream which decompresses bytes read from the specified stream.
BZip2CompressorInputStream(java.io.InputStream in, boolean decompressConcatenated) Constructs a new BZip2CompressorInputStream which decompresses bytes read from the specified stream.

Method Summary

Modifier and Type	Method and Description
private static boolean	bsGetBit(BitInputStream bin)
private static int	bsGetInt(BitInputStream bin)
private static char	bsGetUByte(BitInputStream bin)
private static int	bsR(BitInputStream bin, int n) read bits from the input stream
private static void	checkBounds(int checkVal, int limitExclusive, java.lang.String name)
void	close()
private boolean	complete()
private void	createHuffmanDecodingTables(int alphaSize, int nGroups) Called by recvDecodingTables() exclusively.
private void	endBlock()
private void	getAndMoveToFrontDecode()
private int	getAndMoveToFrontDecode0()
long	getCompressedCount()
private static void	hbCreateDecodeTables(int[] limit, int[] base, int[] perm, char[] length, int minLen, int maxLen, int alphaSize) Called by createHuffmanDecodingTables() exclusively.
private boolean	init(boolean isFirstStream)
private void	initBlock()
private void	makeMaps()
static boolean	matches(byte[] signature, int length) Checks if the signature matches what is expected for a bzip2 file.
int	read()
int	read(byte[] dest, int offs, int len)
private int	read0()
private int	readNextByte(BitInputStream in)
private void	recvDecodingTables()
private int	setupBlock()
private int	setupNoRandPartA()
private int	setupNoRandPartB()
private int	setupNoRandPartC()
private int	setupRandPartA()
private int	setupRandPartB()
private int	setupRandPartC()

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

count, count, getBytesRead, getCount, getUncompressedCount, pushedBackBytes

Methods inherited from class java.io.InputStream

available, mark, markSupported, read, reset, skip

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 Detail

last

private int last

Index of the last char in the block, so the block size == last + 1.

origPtr

private int origPtr

Index in zptr[] of original string after sorting.

blockSize100k

private int blockSize100k

always: in the range 0 .. 9. The current block size is 100000 * this number.

blockRandomised

private boolean blockRandomised

crc

private final CRC crc

nInUse

private int nInUse

bin

private BitInputStream bin

decompressConcatenated

private final boolean decompressConcatenated

EOF

private static final int EOF

See Also:

Constant Field Values

START_BLOCK_STATE

private static final int START_BLOCK_STATE

See Also:

Constant Field Values

RAND_PART_A_STATE

private static final int RAND_PART_A_STATE

See Also:

Constant Field Values

RAND_PART_B_STATE

private static final int RAND_PART_B_STATE

See Also:

Constant Field Values

RAND_PART_C_STATE

private static final int RAND_PART_C_STATE

See Also:

Constant Field Values

NO_RAND_PART_A_STATE

private static final int NO_RAND_PART_A_STATE

See Also:

Constant Field Values

NO_RAND_PART_B_STATE

private static final int NO_RAND_PART_B_STATE

See Also:

Constant Field Values

NO_RAND_PART_C_STATE

private static final int NO_RAND_PART_C_STATE

See Also:

Constant Field Values

currentState

private int currentState

storedBlockCRC

private int storedBlockCRC

storedCombinedCRC

private int storedCombinedCRC

computedBlockCRC

private int computedBlockCRC

computedCombinedCRC

private int computedCombinedCRC

su_count

private int su_count

su_ch2

private int su_ch2

su_chPrev

private int su_chPrev

su_i2

private int su_i2

su_j2

private int su_j2

su_rNToGo

private int su_rNToGo

su_rTPos

private int su_rTPos

su_tPos

private int su_tPos

su_z

private char su_z

data

private BZip2CompressorInputStream.Data data

All memory intensive stuff. This field is initialized by initBlock().

Constructor Detail

BZip2CompressorInputStream

public BZip2CompressorInputStream(java.io.InputStream in)
                           throws java.io.IOException

Constructs a new BZip2CompressorInputStream which decompresses bytes read from the specified stream. This doesn't suppprt decompressing concatenated .bz2 files.

Parameters:

in - the InputStream from which this object should be created

Throws:

java.io.IOException - if the stream content is malformed or an I/O error occurs.

java.lang.NullPointerException - if in == null

BZip2CompressorInputStream

public BZip2CompressorInputStream(java.io.InputStream in,
                                  boolean decompressConcatenated)
                           throws java.io.IOException

Constructs a new BZip2CompressorInputStream which decompresses bytes read from the specified stream.

Parameters:

in - the InputStream from which this object should be created

decompressConcatenated - if true, decompress until the end of the input; if false, stop after the first .bz2 stream and leave the input position to point to the next byte after the .bz2 stream

Throws:

java.io.IOException - if in == null, the stream content is malformed, or an I/O error occurs.

Method Detail

read

public int read()
         throws java.io.IOException

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

read

public int read(byte[] dest,
                int offs,
                int len)
         throws java.io.IOException

Overrides:

read in class java.io.InputStream

Throws:

java.io.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

makeMaps

private void makeMaps()

read0

private int read0()
           throws java.io.IOException

Throws:

java.io.IOException

readNextByte

private int readNextByte(BitInputStream in)
                  throws java.io.IOException

Throws:

java.io.IOException

init

private boolean init(boolean isFirstStream)
              throws java.io.IOException

Throws:

java.io.IOException

initBlock

private void initBlock()
                throws java.io.IOException

Throws:

java.io.IOException

endBlock

private void endBlock()
               throws java.io.IOException

Throws:

java.io.IOException

complete

private boolean complete()
                  throws java.io.IOException

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.InputStream

Throws:

java.io.IOException

bsR

private static int bsR(BitInputStream bin,
                       int n)
                throws java.io.IOException

read bits from the input stream

Parameters:

n - the number of bits to read, must not exceed 32?

Returns:

the requested bits combined into an int

Throws:

java.io.IOException

bsGetBit

private static boolean bsGetBit(BitInputStream bin)
                         throws java.io.IOException

Throws:

java.io.IOException

bsGetUByte

private static char bsGetUByte(BitInputStream bin)
                        throws java.io.IOException

Throws:

java.io.IOException

bsGetInt

private static int bsGetInt(BitInputStream bin)
                     throws java.io.IOException

Throws:

java.io.IOException

checkBounds

private static void checkBounds(int checkVal,
                                int limitExclusive,
                                java.lang.String name)
                         throws java.io.IOException

Throws:

java.io.IOException

hbCreateDecodeTables

private static void hbCreateDecodeTables(int[] limit,
                                         int[] base,
                                         int[] perm,
                                         char[] length,
                                         int minLen,
                                         int maxLen,
                                         int alphaSize)
                                  throws java.io.IOException

Called by createHuffmanDecodingTables() exclusively.

Throws:

java.io.IOException

recvDecodingTables

private void recvDecodingTables()
                         throws java.io.IOException

Throws:

java.io.IOException

createHuffmanDecodingTables

private void createHuffmanDecodingTables(int alphaSize,
                                         int nGroups)
                                  throws java.io.IOException

Called by recvDecodingTables() exclusively.

Throws:

java.io.IOException

getAndMoveToFrontDecode

private void getAndMoveToFrontDecode()
                              throws java.io.IOException

Throws:

java.io.IOException

getAndMoveToFrontDecode0

private int getAndMoveToFrontDecode0()
                              throws java.io.IOException

Throws:

java.io.IOException

setupBlock

private int setupBlock()
                throws java.io.IOException

Throws:

java.io.IOException

setupRandPartA

private int setupRandPartA()
                    throws java.io.IOException

Throws:

java.io.IOException

setupNoRandPartA

private int setupNoRandPartA()
                      throws java.io.IOException

Throws:

java.io.IOException

setupRandPartB

private int setupRandPartB()
                    throws java.io.IOException

Throws:

java.io.IOException

setupRandPartC

private int setupRandPartC()
                    throws java.io.IOException

Throws:

java.io.IOException

setupNoRandPartB

private int setupNoRandPartB()
                      throws java.io.IOException

Throws:

java.io.IOException

setupNoRandPartC

private int setupNoRandPartC()
                      throws java.io.IOException

Throws:

java.io.IOException

matches

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

Checks if the signature matches what is expected for a bzip2 file.

Parameters:

signature - the bytes to check

length - the number of bytes to check

Returns:

true, if this stream is a bzip2 compressed stream, false otherwise

Since:

1.1