Top Description Fields Constructors Methods
org.brotli.dec

pack-priv final Class Huffman

extends Object
Class Inheritance
Utilities for building Huffman decoding tables.

Field Summary

Modifier and TypeField and Description
pack-priv static final int
HUFFMAN_MAX_TABLE_SIZE

Maximum possible Huffman table size for an alphabet size of 704, max code length 15 and root table bits 8.

private static final int
MAX_LENGTH

Constructor Summary

AccessConstructor and Description
pack-priv
Huffman()

Method Summary

Modifier and TypeMethod and Description
pack-priv static void
buildHuffmanTable(int[] rootTable, int tableOffset, int rootBits, int[] codeLengths, int codeLengthsSize)

Builds Huffman lookup table assuming code lengths are in symbol order.

private static int
getNextKey(int key, int len)

Returns reverse(reverse(key, len) + 1, len).

private static int

Returns:

table width of the next 2nd level table.
nextTableBitSize(int[]
histogram of bit lengths for the remaining symbols,
count, int
code length of the next processed symbol.
len, int rootBits)

private static void
replicateValue(int[] table, int offset, int step, int end, int item)

Stores item in table[0], table[step], table[2 * step] .., table[end].

Inherited from java.lang.Object:
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Field Detail

HUFFMAN_MAX_TABLE_SIZEback to summary
pack-priv static final int HUFFMAN_MAX_TABLE_SIZE

Maximum possible Huffman table size for an alphabet size of 704, max code length 15 and root table bits 8.

MAX_LENGTHback to summary
private static final int MAX_LENGTH

Constructor Detail

Huffmanback to summary
pack-priv Huffman()

Method Detail

buildHuffmanTableback to summary
pack-priv static void buildHuffmanTable(int[] rootTable, int tableOffset, int rootBits, int[] codeLengths, int codeLengthsSize)

Builds Huffman lookup table assuming code lengths are in symbol order.

getNextKeyback to summary
private static int getNextKey(int key, int len)

Returns reverse(reverse(key, len) + 1, len).

reverse(key, len) is the bit-wise reversal of the len least significant bits of key.

nextTableBitSizeback to summary
private static int nextTableBitSize(int[] count, int len, int rootBits)
Parameters
count:int[]

histogram of bit lengths for the remaining symbols,

len:int

code length of the next processed symbol.

Returns:int

table width of the next 2nd level table.

replicateValueback to summary
private static void replicateValue(int[] table, int offset, int step, int end, int item)

Stores item in table[0], table[step], table[2 * step] .., table[end].

Assumes that end is an integer multiple of step.