com.bigdata.btree.raba.codec
Class CanonicalHuffmanRabaCoder.RabaCodingSetup

java.lang.Object
  com.bigdata.btree.raba.codec.CanonicalHuffmanRabaCoder.AbstractCodingSetup
      com.bigdata.btree.raba.codec.CanonicalHuffmanRabaCoder.RabaCodingSetup

Enclosing class:

CanonicalHuffmanRabaCoder

protected static class CanonicalHuffmanRabaCoder.RabaCodingSetup
extends CanonicalHuffmanRabaCoder.AbstractCodingSetup

Sets up for coding an IRaba representing B+Tree values. For this case the code book is generated from only the non-zero frequency counts. This results in a more compact code, but the code can not be searched since it only the byte values with non-zero frequencies have assigned code words.

Version:

$Id: CanonicalHuffmanRabaCoder.java 2547 2010-03-24 20:44:07Z thompsonbry $ FIXME If most byte values are used, then simply code them all. This will be more efficient (smaller data record, no indirection through the symbol table).

Author:

Bryan Thompson

Constructor Summary

CanonicalHuffmanRabaCoder.RabaCodingSetup(IRaba raba)

Method Summary

int	byte2symbol(byte b)
it.unimi.dsi.compression.HuffmanCodec	codec() The codec used to encode and decode the logical byte[][].
it.unimi.dsi.compression.HuffmanCodec.DecoderInputs	decoderInputs() The data required to reconstruct the decoder.
int	getSymbolCount() Return the #of distinct symbols used to generate the code.
byte	symbol2byte(int symbol)

Methods inherited from class com.bigdata.btree.raba.codec.CanonicalHuffmanRabaCoder.AbstractCodingSetup

buildSymbolTable, getFrequencyCount, getPackedFrequencyCount, getSymbolCount, printCodeBook

Methods inherited from class java.lang.Object

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

Constructor Detail

CanonicalHuffmanRabaCoder.RabaCodingSetup

public CanonicalHuffmanRabaCoder.RabaCodingSetup(IRaba raba)

Method Detail

decoderInputs

public it.unimi.dsi.compression.HuffmanCodec.DecoderInputs decoderInputs()

Description copied from class: CanonicalHuffmanRabaCoder.AbstractCodingSetup

The data required to reconstruct the decoder.

Specified by:

decoderInputs in class CanonicalHuffmanRabaCoder.AbstractCodingSetup

codec

public it.unimi.dsi.compression.HuffmanCodec codec()

Description copied from class: CanonicalHuffmanRabaCoder.AbstractCodingSetup

The codec used to encode and decode the logical byte[][].

Specified by:

codec in class CanonicalHuffmanRabaCoder.AbstractCodingSetup

getSymbolCount

public final int getSymbolCount()

Description copied from class: CanonicalHuffmanRabaCoder.AbstractCodingSetup

Return the #of distinct symbols used to generate the code.

Specified by:

getSymbolCount in class CanonicalHuffmanRabaCoder.AbstractCodingSetup

byte2symbol

public final int byte2symbol(byte b)

symbol2byte

public final byte symbol2byte(int symbol)