Top Description Fields Constructors Methods

io.netty.handler.codec.compression

pack-priv final Class Bzip2HuffmanStageDecoder

Class Inheritance

extends Object

java.lang.Object
io.netty.handler.codec.compression.Bzip2HuffmanStageDecoder

Static Imports

io.netty.handler.codec.compression.Bzip2Constants.HUFFMAN_DECODE_MAX_CODE_LENGTH, .Bzip2Constants.HUFFMAN_GROUP_RUN_LENGTH, .Bzip2Constants.HUFFMAN_MAX_ALPHABET_SIZE

A decoder for the Bzip2 Huffman coding stage.

Field Summary

Modifier and Type	Field and Description
pack-priv final int	alphabetSize The total number of codes (uniform for each table).
private final int[][]	codeBases An array of values for each Huffman table that must be subtracted from the numerical value of a Huffman code of a given bit length to give its canonical code index.
private final int[][]	codeLimits An array of values for each Huffman table that gives the highest numerical value of a Huffman code of a given bit length.
private final int[][]	codeSymbols A mapping for each Huffman table from canonical code index to output symbol.
pack-priv int	currentAlpha
pack-priv int	currentGroup
pack-priv int	currentLength
pack-priv int	currentSelector
private int	currentTable The Huffman table for the current group.
private int	groupIndex The index of the current group within the selectors array.
private int	groupPosition The byte position within the current group.
private final int[]	minimumLengths The minimum code length for each Huffman table.
pack-priv boolean	modifyLength
private final Bzip2BitReader	reader A reader that provides bit-level reads.
pack-priv byte[]	selectors The Huffman table number to use for each group of 50 symbols.
pack-priv final byte[][]	tableCodeLengths The Canonical Huffman code lengths for each table.
pack-priv final Bzip2MoveToFrontTable	tableMTF Table for Move To Front transformations.
pack-priv final int	totalTables Total number of used Huffman tables in range 2..6.

Constructor Summary

Access	Constructor and Description
pack-priv	Bzip2HuffmanStageDecoder(final Bzip2BitReader reader, final int totalTables, final int alphabetSize)

Method Summary

Modifier and Type	Method and Description
pack-priv void	createHuffmanDecodingTables() Constructs Huffman decoding tables from lists of Canonical Huffman code lengths.
pack-priv int	Returns: The decoded symbol nextSymbol() Decodes and returns the next symbol.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

alphabetSize	back to summary
pack-priv final int alphabetSize The total number of codes (uniform for each table).

codeBases	back to summary
private final int[][] codeBases An array of values for each Huffman table that must be subtracted from the numerical value of a Huffman code of a given bit length to give its canonical code index.

codeLimits	back to summary
private final int[][] codeLimits An array of values for each Huffman table that gives the highest numerical value of a Huffman code of a given bit length.

codeSymbols	back to summary
private final int[][] codeSymbols A mapping for each Huffman table from canonical code index to output symbol.

currentAlpha	back to summary
pack-priv int currentAlpha

currentGroup	back to summary
pack-priv int currentGroup

currentLength	back to summary
pack-priv int currentLength

currentSelector	back to summary
pack-priv int currentSelector

currentTable	back to summary
private int currentTable The Huffman table for the current group.

groupIndex	back to summary
private int groupIndex The index of the current group within the selectors array.

groupPosition	back to summary
private int groupPosition The byte position within the current group. A new group is selected every 50 decoded bytes.

minimumLengths	back to summary
private final int[] minimumLengths The minimum code length for each Huffman table.

modifyLength	back to summary
pack-priv boolean modifyLength

reader	back to summary
private final Bzip2BitReader reader A reader that provides bit-level reads.

selectors	back to summary
pack-priv byte[] selectors The Huffman table number to use for each group of 50 symbols.

tableCodeLengths	back to summary
pack-priv final byte[][] tableCodeLengths The Canonical Huffman code lengths for each table.

tableMTF	back to summary
pack-priv final Bzip2MoveToFrontTable tableMTF Table for Move To Front transformations.

totalTables	back to summary
pack-priv final int totalTables Total number of used Huffman tables in range 2..6.

Constructor Detail

Bzip2HuffmanStageDecoder	back to summary
pack-priv Bzip2HuffmanStageDecoder(final Bzip2BitReader reader, final int totalTables, final int alphabetSize)

Method Detail

createHuffmanDecodingTables	back to summary
pack-priv void createHuffmanDecodingTables() Constructs Huffman decoding tables from lists of Canonical Huffman code lengths.

nextSymbol

back to summary

pack-priv int nextSymbol()

Decodes and returns the next symbol.

Returns:int: The decoded symbol