mirror of
https://github.com/DarkflameUniverse/DarkflameServer.git
synced 2024-09-20 01:21:32 +00:00
72 lines
2.5 KiB
C++
72 lines
2.5 KiB
C++
/// \file
|
|
/// \brief \b [Internal] Generates a huffman encoding tree, used for string and global compression.
|
|
///
|
|
/// This file is part of RakNet Copyright 2003 Kevin Jenkins.
|
|
///
|
|
/// Usage of RakNet is subject to the appropriate license agreement.
|
|
/// Creative Commons Licensees are subject to the
|
|
/// license found at
|
|
/// http://creativecommons.org/licenses/by-nc/2.5/
|
|
/// Single application licensees are subject to the license found at
|
|
/// http://www.jenkinssoftware.com/SingleApplicationLicense.html
|
|
/// Custom license users are subject to the terms therein.
|
|
/// GPL license users are subject to the GNU General Public
|
|
/// License as published by the Free
|
|
/// Software Foundation; either version 2 of the License, or (at your
|
|
/// option) any later version.
|
|
|
|
#ifndef __HUFFMAN_ENCODING_TREE
|
|
#define __HUFFMAN_ENCODING_TREE
|
|
|
|
#include "RakMemoryOverride.h"
|
|
#include "DS_HuffmanEncodingTreeNode.h"
|
|
#include "BitStream.h"
|
|
#include "Export.h"
|
|
#include "DS_LinkedList.h"
|
|
|
|
/// This generates special cases of the huffman encoding tree using 8 bit keys with the additional condition that unused combinations of 8 bits are treated as a frequency of 1
|
|
class RAK_DLL_EXPORT HuffmanEncodingTree : public RakNet::RakMemoryOverride
|
|
{
|
|
|
|
public:
|
|
HuffmanEncodingTree();
|
|
~HuffmanEncodingTree();
|
|
|
|
/// Pass an array of bytes to array and a preallocated BitStream to receive the output
|
|
/// \param [in] input Array of bytes to encode
|
|
/// \param [in] sizeInBytes size of \a input
|
|
/// \param [out] output The bitstream to write to
|
|
void EncodeArray( unsigned char *input, size_t sizeInBytes, RakNet::BitStream * output );
|
|
|
|
// Decodes an array encoded by EncodeArray()
|
|
unsigned DecodeArray( RakNet::BitStream * input, BitSize_t sizeInBits, size_t maxCharsToWrite, unsigned char *output );
|
|
void DecodeArray( unsigned char *input, BitSize_t sizeInBits, RakNet::BitStream * output );
|
|
|
|
/// Given a frequency table of 256 elements, all with a frequency of 1 or more, generate the tree
|
|
void GenerateFromFrequencyTable( unsigned int frequencyTable[ 256 ] );
|
|
|
|
/// Free the memory used by the tree
|
|
void FreeMemory( void );
|
|
|
|
private:
|
|
|
|
/// The root node of the tree
|
|
|
|
HuffmanEncodingTreeNode *root;
|
|
|
|
/// Used to hold bit encoding for one character
|
|
|
|
|
|
struct CharacterEncoding
|
|
{
|
|
unsigned char* encoding;
|
|
unsigned short bitLength;
|
|
};
|
|
|
|
CharacterEncoding encodingTable[ 256 ];
|
|
|
|
void InsertNodeIntoSortedList( HuffmanEncodingTreeNode * node, DataStructures::LinkedList<HuffmanEncodingTreeNode *> *huffmanEncodingTreeNodeList ) const;
|
|
};
|
|
|
|
#endif
|