You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
69 lines
1.9 KiB
69 lines
1.9 KiB
//========= Copyright Valve Corporation, All rights reserved. ============// |
|
// |
|
// LZSS Codec. Designed for fast cheap gametime encoding/decoding. Compression results |
|
// are not aggresive as other alogrithms, but gets 2:1 on most arbitrary uncompressed data. |
|
// |
|
//=====================================================================================// |
|
|
|
#ifndef _LZSS_H |
|
#define _LZSS_H |
|
#pragma once |
|
|
|
#define LZSS_ID uint32( BigLong( ('L'<<24)|('Z'<<16)|('S'<<8)|('S') ) ) |
|
#define SNAPPY_ID uint32( BigLong( ('S'<<24)|('N'<<16)|('A'<<8)|('P') ) ) |
|
|
|
// bind the buffer for correct identification |
|
struct lzss_header_t |
|
{ |
|
unsigned int id; |
|
unsigned int actualSize; // always little endian |
|
}; |
|
|
|
class CUtlBuffer; |
|
|
|
#define DEFAULT_LZSS_WINDOW_SIZE 4096 |
|
|
|
class CLZSS |
|
{ |
|
public: |
|
unsigned char* Compress( const unsigned char *pInput, int inputlen, unsigned int *pOutputSize ); |
|
unsigned char* CompressNoAlloc( const unsigned char *pInput, int inputlen, unsigned char *pOutput, unsigned int *pOutputSize ); |
|
unsigned int Uncompress( const unsigned char *pInput, unsigned char *pOutput ); |
|
//unsigned int Uncompress( unsigned char *pInput, CUtlBuffer &buf ); |
|
unsigned int SafeUncompress( const unsigned char *pInput, unsigned char *pOutput, unsigned int unBufSize ); |
|
|
|
static bool IsCompressed( const unsigned char *pInput ); |
|
static unsigned int GetActualSize( const unsigned char *pInput ); |
|
|
|
// windowsize must be a power of two. |
|
FORCEINLINE CLZSS( int nWindowSize = DEFAULT_LZSS_WINDOW_SIZE ); |
|
|
|
private: |
|
// expected to be sixteen bytes |
|
struct lzss_node_t |
|
{ |
|
const unsigned char *pData; |
|
lzss_node_t *pPrev; |
|
lzss_node_t *pNext; |
|
char empty[4]; |
|
}; |
|
|
|
struct lzss_list_t |
|
{ |
|
lzss_node_t *pStart; |
|
lzss_node_t *pEnd; |
|
}; |
|
|
|
void BuildHash( const unsigned char *pData ); |
|
lzss_list_t *m_pHashTable; |
|
lzss_node_t *m_pHashTarget; |
|
int m_nWindowSize; |
|
|
|
}; |
|
|
|
FORCEINLINE CLZSS::CLZSS( int nWindowSize ) |
|
{ |
|
m_nWindowSize = nWindowSize; |
|
} |
|
#endif |
|
|
|
|