Package org.apache.commons.compress.compressors.deflate64

Class HuffmanDecoder

java.lang.Object

org.apache.commons.compress.compressors.deflate64.HuffmanDecoder

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

class HuffmanDecoder
extends java.lang.Object
implements java.io.Closeable

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	HuffmanDecoder.BinaryTreeNode
private static class	HuffmanDecoder.DecoderState
private static class	HuffmanDecoder.DecodingMemory
private class	HuffmanDecoder.HuffmanCodes
private static class	HuffmanDecoder.InitialState
private class	HuffmanDecoder.UncompressedState

Field Summary

Fields

Modifier and Type	Field	Description
private static int[]	CODE_LENGTHS_ORDER	When using dynamic huffman codes the order in which the values are stored follows the positioning below
private static int[]	DISTANCE_TABLE	-------------------------------------------------------------------- idx xtra dist idx xtra dist idx xtra dist -------------------------------------------------------------------- 0 0 1 10 4 33-48 20 9 1025-1536 1 0 2 11 4 49-64 21 9 1537-2048 2 0 3 12 5 65-96 22 10 2049-3072 3 0 4 13 5 97-128 23 10 3073-4096 4 1 5,6 14 6 129-192 24 11 4097-6144 5 1 7,8 15 6 193-256 25 11 6145-8192 6 2 9-12 16 7 257-384 26 12 8193-12288 7 2 13-16 17 7 385-512 27 12 12289-16384 8 3 17-24 18 8 513-768 28 13 16385-24576 9 3 25-32 19 8 769-1024 29 13 24577-32768 30 14 32769-49152 31 14 49153-65536 --------------------------------------------------------------------
private boolean	finalBlock
private static int[]	FIXED_DISTANCE
private static int[]	FIXED_LITERALS	Huffman Fixed Literal / Distance tables for mode 1
private java.io.InputStream	in
private HuffmanDecoder.DecodingMemory	memory
private BitInputStream	reader
private static short[]	RUN_LENGTH_TABLE	-------------------------------------------------------------------- idx xtra base idx xtra base idx xtra base -------------------------------------------------------------------- 257 0 3 267 1 15,16 277 4 67-82 258 0 4 268 1 17,18 278 4 83-98 259 0 5 269 2 19-22 279 4 99-114 260 0 6 270 2 23-26 280 4 115-130 261 0 7 271 2 27-30 281 5 131-162 262 0 8 272 2 31-34 282 5 163-194 263 0 9 273 3 35-42 283 5 195-226 264 0 10 274 3 43-50 284 5 227-257 265 1 11,12 275 3 51-58 285 16 3 266 1 13,14 276 3 59-66 --------------------------------------------------------------------
private HuffmanDecoder.DecoderState	state

Constructor Summary

Constructors

Constructor	Description
HuffmanDecoder(java.io.InputStream in)

Method Summary

Modifier and Type	Method	Description
(package private) int	available()
private static HuffmanDecoder.BinaryTreeNode	buildTree(int[] litTable)
void	close()
int	decode(byte[] b)
int	decode(byte[] b, int off, int len)
(package private) long	getBytesRead()
private static int[]	getCodes(int[] litTable)
private static int	nextSymbol(BitInputStream reader, HuffmanDecoder.BinaryTreeNode tree)
private static void	populateDynamicTables(BitInputStream reader, int[] literals, int[] distances)
private long	readBits(int numBits)
private static long	readBits(BitInputStream reader, int numBits)
private int[][]	readDynamicTables()
private void	switchToUncompressedState()

Methods inherited from class java.lang.Object

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

Field Detail

RUN_LENGTH_TABLE

private static final short[] RUN_LENGTH_TABLE

 --------------------------------------------------------------------
 idx  xtra  base     idx  xtra  base     idx  xtra  base
 --------------------------------------------------------------------
 257   0     3       267   1   15,16     277   4   67-82
 258   0     4       268   1   17,18     278   4   83-98
 259   0     5       269   2   19-22     279   4   99-114
 260   0     6       270   2   23-26     280   4   115-130
 261   0     7       271   2   27-30     281   5   131-162
 262   0     8       272   2   31-34     282   5   163-194
 263   0     9       273   3   35-42     283   5   195-226
 264   0     10      274   3   43-50     284   5   227-257
 265   1     11,12   275   3   51-58     285   16  3
 266   1     13,14   276   3   59-66
 --------------------------------------------------------------------
 

value = (base of run length) << 5 | (number of extra bits to read)

DISTANCE_TABLE

private static final int[] DISTANCE_TABLE

 --------------------------------------------------------------------
 idx  xtra  dist     idx  xtra  dist       idx  xtra  dist
 --------------------------------------------------------------------
 0    0     1        10   4     33-48      20    9   1025-1536
 1    0     2        11   4     49-64      21    9   1537-2048
 2    0     3        12   5     65-96      22   10   2049-3072
 3    0     4        13   5     97-128     23   10   3073-4096
 4    1     5,6      14   6     129-192    24   11   4097-6144
 5    1     7,8      15   6     193-256    25   11   6145-8192
 6    2     9-12     16   7     257-384    26   12   8193-12288
 7    2     13-16    17   7     385-512    27   12   12289-16384
 8    3     17-24    18   8     513-768    28   13   16385-24576
 9    3     25-32    19   8     769-1024   29   13   24577-32768
 30   14   32769-49152
 31   14   49153-65536
 --------------------------------------------------------------------
 

value = (base of distance) << 4 | (number of extra bits to read)

CODE_LENGTHS_ORDER

private static final int[] CODE_LENGTHS_ORDER

When using dynamic huffman codes the order in which the values are stored follows the positioning below

FIXED_LITERALS

private static final int[] FIXED_LITERALS

Huffman Fixed Literal / Distance tables for mode 1

FIXED_DISTANCE

private static final int[] FIXED_DISTANCE

finalBlock

private boolean finalBlock

state

private HuffmanDecoder.DecoderState state

reader

private BitInputStream reader

in

private final java.io.InputStream in

memory

private final HuffmanDecoder.DecodingMemory memory

Constructor Detail

HuffmanDecoder

HuffmanDecoder(java.io.InputStream in)

Method Detail

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

decode

public int decode(byte[] b)
           throws java.io.IOException

Throws:

java.io.IOException

decode

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

Throws:

java.io.IOException

getBytesRead

long getBytesRead()

Since:

1.17

switchToUncompressedState

private void switchToUncompressedState()
                                throws java.io.IOException

Throws:

java.io.IOException

readDynamicTables

private int[][] readDynamicTables()
                           throws java.io.IOException

Throws:

java.io.IOException

available

int available()
       throws java.io.IOException

Throws:

java.io.IOException

nextSymbol

private static int nextSymbol(BitInputStream reader,
                              HuffmanDecoder.BinaryTreeNode tree)
                       throws java.io.IOException

Throws:

java.io.IOException

populateDynamicTables

private static void populateDynamicTables(BitInputStream reader,
                                          int[] literals,
                                          int[] distances)
                                   throws java.io.IOException

Throws:

java.io.IOException

buildTree

private static HuffmanDecoder.BinaryTreeNode buildTree(int[] litTable)

getCodes

private static int[] getCodes(int[] litTable)

readBits

private long readBits(int numBits)
               throws java.io.IOException

Throws:

java.io.IOException

readBits

private static long readBits(BitInputStream reader,
                             int numBits)
                      throws java.io.IOException

Throws:

java.io.IOException